Wildlife Monographs

Translocations have been widely used to restore and conserve bighorn sheep (Ovis canadensis) populations in North America. Some translocations have been successful, but many populations remain small and genetically isolated. Population structure can influence the viability and long-term success of reintroductions. Social ungulates often function as interconnected subpopulations (metapopulations); however, few studies evaluate subpopulation sizes, connectivity, and genetic diversity within metapopulations. To address this gap, we conducted a comprehensive study of a reintroduced Rocky Mountain bighorn sheep (Ovis canadensis canadensis) population in Dinosaur National Monument in Colorado and Utah, USA, between 2006-2020. We analyzed global positioning system (GPS) radio-collar data, genetic samples, and results of health testing to evaluate abundance, distribution, genetic structure and diversity, habitat use, movement and connectivity, and presence of or exposure to respiratory pathogens. We integrated these analyses to evaluate the outcomes of a reintroduction effort that began in 1952, over 70 years ago, and to inform management decisions in Dinosaur National Monument. We also provide a framework for evaluating metapopulation processes, including a non-invasive approach that links genetic structure with Bayesian spatial capture-recapture analyses to estimate subpopulation sizes. Despite models indicating continuous suitable habitat, we found a spatially structured population with at least 4 subpopulations with constrained connectivity. Evidence from step selection and density analyses suggested that movement among subpopulations may be limited by semi-permeable barriers including rivers and human disturbance, which could contribute to maintenance of spatial structure over time. In 2006, antibody to Mycoplasma ovipneumoniae was detected in all geographically and genetically distinct subpopulations. Widespread clinical signs of disease and a confirmed exposure to M. ovipneumoniae in 2019 indicate a long-term disease challenge. Proximity to domestic sheep creates repeated opportunities for introduction of new M. ovipneumoniae strains. We estimated abundance in 2019 at 109 (95% CrI = 87-133), composed of subpopulations ranging from 18-39 animals (95% CrIs from 11-50). Genetic diversity was relatively high compared to other reintroduced and native Rocky Mountain bighorn sheep populations, which is likely a consequence of multiple translocations from different sources. Three of 4 subpopulation centers generally aligned with the locations of original translocation release sites. Persistence in the presence of pathogens may be facilitated by metapopulation structure and moderately high genetic diversity. Conversely, metapopulation structure can also facilitate pathogen persistence. Our approach offers a path to advance understanding of the population ecology of reintroduced bighorn sheep and can inform effective conservation and management of their populations.

There has been global concern regarding the effects of selective harvest on the size of horns and antlers. Many government agencies have imposed regulations on hunters based on the size of antlers or horns to protect young males. This has caused phenotypic and genetic decline in the horn size of one bighorn sheep (Ovis canadensis) population and concern about the decline of antler size in white-tailed deer (Odocoileus virginianus). In Texas, USA, there has been interest in selective harvesting to increase genetic potential for antler size of white-tailed deer based on the results of several studies of penned deer. Designed studies on effects of selective harvest on horn or antler size in ungulates are rare, especially studies with a control area. We conducted 20 years of experiments on the effects of selective harvest on antler size of white-tailed deer using 2 research sites in South Texas, USA, each with a control area. Our first experiment was on the King Ranch in southeastern South Texas, where our objective was to see if we could change the phenotypic size of antlers in a population as one of the prerequisites for evolution. We picked a selective harvest area and a nearby area with only incidental recreational harvest as a control, each of about 3,800 ha. There were no barriers to deer movement on or off the study areas. We harvested the treatment area for 6 years (1999-2004) and monitored 1 year post-harvest (2005). For the selective harvest treatment, we used Texas legal methods for hunters and harvested yearling males (1.5 years of age) with <6 antler points and older males with <= 8 antler points. We monitored antler size by age class each year with pre-harvest captures in both areas using a helicopter and net gun. We harvested 135 males in the treatment area and an additional 33 were harvested by recreational hunters. Eight of the recreational harvests met our criteria. During the study, we caught and aged deer, measured antlers, implanted a microchip for recognition of recaptures, and released 436 and 303 males in the treatment and control areas, respectively. Selectively harvested males had smaller antlers than captured males for 1.5- and 3.5-4.5-year-olds but not other ages. Despite an average 8.6% annual harvest rate, antlers of all ages did not differ from the beginning to the end of the study. We concluded that insufficient harvest rate, immigration and emigration of yearling males, and rainfall variation affecting recruitment contributed to our results. We used results of the King Ranch experiment to guide design of follow-up experiments on the Comanche Ranch in southwest South Texas. We used 3 existing game-fenced areas to prevent or restrict deer exchange. A control area of 20 km(2) was completely high-fenced, as was an intensively harvested area of 14 km(2). A third area with a moderate selective harvest treatment encompassed 73 km(2) and was 85% enclosed by high fence. Deer on all study sites were provided with a pelleted nutritional supplement, which a concurrent study on Comanche Ranch showed prevented density-dependent population dynamics. The intensive treatment had harvest criteria similar to the King Ranch experiment, targeting 1.5-year-olds with <6 antler points and 3.5-4.5-year-olds with <= 8 antler points. Males 2.5 years old were harvested if <8 points, as were >= 5.5-year-olds with a gross Boone and Crockett score (GBC) <145. For the moderate harvest treatment, we released all 1.5- and 2. 5-year-olds and harvested older males with the same criteria as for the intensive treatment. To increase harvest rate, instead of using hunters, we harvested males at capture if they met selective harvest criteria. Males with antlers larger than the selective harvest criteria were released. We monitored antler size through yearly captures by helicopter and net gun in each area. In addition to measuring antler size, we aged and weighed captured males and inserted a microchip at the base of an ear of those that were released. We applied selective harvest treatments for 7 years (2006-2012) and continued capturing for 6 years post-harvest (2013-2018) to monitor for any lag effects of treatments. We estimated adult sex ratios using annual surveys by helicopter. Our initial objective, like the King Ranch study, was to see if harvest treatments increased the population antler size as one of the prerequisites for evolution. We captured 6,675 males over the 13 years of the study, including 3,346 recaptures. During the treatment period, we selectively harvested 365 males in the intensive treatment and 878 males in the moderate treatment. Harvested males of all age classes averaged smaller antlers than released males. We estimated a 19% yearly harvest rate in the moderate treatment (no harvest of 1.5- and 2.5-year-olds) and 48% of all ages in the intensive treatment. During the treatment period, adult sex ratio increased from 2:1 to 5:1 (female:male) in the intensive treatment but did not change in the moderate treatment, despite a male population size decrease of 65%. There was a large female harvest by Comanche Ranch during the harvest period that influenced sex ratio results in the moderate treatment. The male population decreased 88% during the harvest period in the intensive area. At the end of the harvest period (2013), antler size was larger compared to control in the 3.5-4.5-year (+10.67 GBC) and >= 5.5-year (+8.87 GBC) age classes in the intensive treatment and the >= 5.5-year (+3.70 GBC) age class in the moderate treatment. However, there was little evidence of phenotypic change and thus no detectable trait evolution by the end of the post-harvest period (2018), as all ages averaged smaller antlers or did not differ compared to the control. Additionally, only the 3.5-4.5 age class in the moderate treatment had larger antlers in 2018, versus the study beginning in 2006. Males changed state across years from eligible for harvest to the do-not-harvest category according to our criteria, and vice versa, likely as a result of stochastic rainfall. We used the experimental design, capture data, and ear tissue from the Comanche Ranch experiment to conduct 3 genetic studies. First, we analyzed male breeding success using 15 microsatellite loci. Our objective was to determine if male breeding success by age class changed in the treatment areas versus the control site during the treatment period (2006-2012). We genotyped 162, 432, and 1,504 captured males in the control, intensive, and moderate areas, respectively. Mature males (>= 5.5 years of age) comprised most of the sires in the control (62%) and intensive areas (42%). However, young males (1.5-2.5 years old) outnumbered mature males in the moderate treatment by 40% versus 28%, respectively. We assigned sires for 650 of 938 (69%) sampled offspring (1.5 years of age). Successful males sired 1-6 male offspring/year. During the post-harvest period (2013-2018), mature males comprised most of the candidate sires in the control (81%) and moderate (40%) areas. In contrast, young males slightly outnumbered mature males, 39% versus 34% in the intensive treatment. During post-harvest, successful males sired 1-4 male offspring that were recruited and averaged 1.1, 1.8, and 1.5 offspring/year for the control, intensive, and moderate areas, respectively. The objectives of our second genetic study were to 1) estimate heritability for antler traits, the proportion of variation in a trait within a population that is attributable to genetic differences rather than environmental factors, by age class, and 2) whether Comanche Ranch selection differentials were sufficient to cause evolution in antler size. We constructed pedigrees based on paternity assignments and then used an animal model procedure to estimate variance components and heritability of antler traits. Estimated heritability (h(2)) for antler points and GBC was low (0.06-0.16) for males 1.5-2.5 years of age. For males >= 3.5 years of age, heritability for antler points ranged from 0.25-0.32, and for GBC ranged from 0.31-0.68. Repeatability for antler points and GBC score ranged from 54-58%. Our annual estimates for generation time across treatments and the control area ranged from 3.8-7.3 years. Estimated response to selection was <= 0.2 for antler points for all ages and 0.8-5.8 GBC units for males >= 3.5 years of age. Given the long generation times and modest predicted responses, if there were genetic changes due to our selective harvest treatments, they appeared to be minor in these high-fenced populations. Our third genetic study was to estimate if selective harvest for antler size at Comanche Ranch was correlated with the distribution of major histocompatibility complex (MHC) DRB II genotypes in sires and offspring. The MHC DRB complex is associated with the immune system in animals. Previous research in Oklahoma, USA, has shown a relationship between MHC DRB and antler size in white-tailed deer. For this study, we used tissue from captured males of known age that were born in 2011 and 2012. No association between MHC DRB II alleles and antler development was detected. We speculated that the semi-arid climate of South Texas may result in fewer pathogens than the more mesic climate of previous research. We concluded that selective harvest to alter gene frequencies at the population scale to increase antler size in white-tailed deer, if possible, would require decades and would be unlikely in open populations with dispersal and no supplemental feed. Our results also showed that antler size restrictions on harvest by governmental agencies would be unlikely to cause evolution in white-tailed deer.

Wildfire has been a fundamental component of ecosystem dynamics for millennia. However, climate change, fire suppression, and land use practices have produced larger, more severe, and more frequent fires that threaten a range of wildlife species. Land managers in some fire-prone forest systems use fuels reduction treatments, including prescribed burning and mechanical thinning, to reduce vegetation density and the risk of large, high-severity fires. The strategy is to create forest landscapes that are more resilient to wildfire, which in turn will lessen the negative impact of uncharacteristically severe wildfire on wildlife. Yet there is uncertainty regarding the extent to which fire-adapted species are threatened by novel wildfire characteristics. The spotted owl (Strix occidentalis) has become a focal point for this controversy owing to its use of fire-suppressed forests that have been and will be vulnerable to changing fire regimes in the future. In this study, we attempted to address the question of how spotted owls respond to high-severity fire in California, USA, by leveraging 1) over 3 decades of detection-non-detection surveys in 1,514 historical spotted owl territories and 2) global positioning system (GPS) movement data from 171 individual spotted owls. Our study area included 7 national forests, 3 national parks, and extensive privately owned forests in California. Dynamic occupancy analysis indicated that spotted owl territories were more likely to become vacant and less likely to be colonized if they experienced recent and extensive high-severity fire. Consistent with the occupancy analysis, our movement analysis indicated that individual spotted owls avoided using severely burned forest. Although spotted owl territory persistence was higher in pyrodiverse territories (i.e., those with a mixture of low, moderate, and high severity burned areas), foraging owls showed mixed responses to local pyrodiversity, with some evidence that use of severely burned forest increased when pyrodiversity was high. We conclude that large and severe wildfires threaten the persistence of spotted owls in California. That said, forest restoration and fuels reduction treatments that reduce the risk of large and uncharacteristically severe fires while promoting multi-scale heterogeneity and pyrodiversity will likely benefit spotted owls and other species that occupy mixed conifer forests in California.

Highly pathogenic avian influenza viruses (HPAIV) have had disastrous, worldwide effects on wild birds and domestic poultry since the emergence of the A/goose/Guangdong/1/1996 (Gs/GD/96) lineage. The currently circulating H5N1 clade 2.3.4.4b has an expanded set of susceptible hosts, including many migratory wild birds, and is associated with higher transmission rates, increased susceptibility among wild bird hosts, and a greater number of wildlife reservoirs. Certain wild bird life-history strategies and behaviors have been suggested to explain avian hosts' susceptibility and exposure to HPAIV. These biological traits include gregariousness, such as colonial nesting and mixed flock foraging, predation or scavenging on wild birds, and association with aquatic habitats. Variation in host infection responses (e.g., infectability, shedding rates and duration, mortality rate, antibody development) informs the overall infection risk across avian species, yet the specific role of biological traits is often inconsistent and unclear across taxa. Moreover, the interactions and potential compounding effects among these biological traits remain largely unknown. To develop a more holistic understanding of cumulative risk across bird species, we integrate existing information on infection risk factors (i.e., susceptibility, immunological response, and behavioral traits) into a qualitative multivariate analysis. This approach enabled us to examine how infection risk factors relate to biological traits (e.g., phylogeny, physiology, behavior, species range) and to begin disentangling their complex interactions. We quantified and summarized these risk factors across host species and qualitatively ranked species by their viral responses along a proposed HPAIV response continuum, guided by expectations of traits and metrics associated with competence or vulnerability to HPAIV. In doing so, we aimed to better understand how viral responses and biological traits synergistically interact to influence cumulative risk across wild bird species. This work broadly expands on the previous avian influenza literature, which has focused on Anseriformes and Charadriiformes as primary viral reservoirs. We tie our findings to effective disease management responses with links to risk components, including descriptions of potential surveillance strategies applied to research and One Health goals, as well as a fuller understanding of how resources may be better deployed for rapid response when spillovers do inevitably occur. Additionally, we identified numerous areas where vital epidemiological information is lacking to best characterize the spread of these viruses. Ultimately, this improved understanding will help identify and inform disease management needs and decision making.

Effective wildlife management relies upon understanding a hierarchy of demographic characteristics of wildlife populations, including population growth rate, age structure, component vital rates, and factors influencing those vital rates. Moose (Alces alces) occupy a circumboreal range spanning North America and Eurasia, across which their ecology and demography vary substantially. Given uncertainties regarding the status of moose in Montana, USA, and factors limiting their population growth, we studied moose population dynamics during 2013-2023 and focused on 3 study areas. We estimated population growth rates as a function of population age structure and several key vital rates, including adult female survival, adult female fecundity (the product of pregnancy and litter size rates), and calf survival. We also evaluated relationships amongst a suite of environmental conditions (weather metrics of temperature and snow conditions, seasonal forage quality, parasite effects including winter ticks (Dermacentor albipictus) and arterial worms (Elaeophora schneideri), and relative predator abundances) and vital rates, with the ultimate goals of determining the status of moose populations in Montana and the relative importance among factors affecting them. We studied adult female survival for 615 moose-years of monitoring across 186 individual moose, fecundity with pregnancy testing across 779 moose-years and litter size for 491 observed litters post-parturition, and calf survival using calf-at-heel monitoring of 619 pregnancies and 541 calves throughout their first year of life. We used previously reported results to monitor ambient temperature, snow, arterial worms, and winter ticks in these study areas and present new results concerning diet, forage quality, and relative predator abundance in these study areas. All vital rates (adult female survival, fecundity, and calf survival) showed significant effects of maternal age, which, in combination with differences in age distribution among study areas, had important effects on population growth rates. Adult female survival was 0.88-0.92 across study areas, and causes of mortality for adult females were predominantly health-related (annual cumulative incidence function [CIF] = 0.075) but also included effects of predation (CIF = 0.017) and humans (CIF = 0.014). Arterial worm infection intensities were associated with roughly 1-3% of annual mortality due to health-related causes. Health-related mortality was also higher for animals in poor nutritional condition, those who failed to recruit a calf the previous year, and in animal-years with more snow. Wolves (Canis lupus) were responsible for the highest proportion of predation-caused adult mortality, followed by grizzly bears (Ursus arctos) and mountain lions (Puma concolor). In addition, relative predator densities within seasonal spatial polygons were predictive of predation-caused mortality across individual moose. At the population-level, moose summer diet reflected selection of forage species that offered higher digestible energy (DE), whereas such selectivity in diet was less evident according to variation among plants in DE during winter or in digestible protein during either season. Furthermore, summer DE was the forage quality metric most related (R 2 = 0.876) to differences in fecundity (calves/female; range = 0.74-0.96) among populations. Calf survival was negatively related to predator densities during the fetal-neonatal period, to predator densities and prior reproductive effort during the summer, and to snow during the winter. Population growth rates were stable to increasing (1.00, 1.06, 1.10 in Big Hole, Cabinet-Salish, and Rocky Mountain Front, respectively) among populations, and adult female survival was the vital rate with the highest elasticity (e = 0.83-0.88) in all populations. Perturbation analyses indicated, in order of importance, effects of nutrition, predation by wolves, parasitism by arterial worms, and predation by other predators each playing roles in driving variation in population dynamics of moose in Montana. Simulated predator reduction management at levels recently prescribed in parts of Montana had negligible predicted effects on moose population dynamics, with a maximum projected increase in population growth rate of 1.1% in the study area with the strongest effects of predation. Our results also suggest a potentially important role of arterial worm parasitism in driving adult mortality and population growth rates in some parts of Montana, but more research is needed to fully understand the mechanisms behind infection-caused mortality and the dynamics of sublethal impacts on other moose vital rates. Ultimately, our results uphold the importance of nutrition as a driver of moose population dynamics even in the midst of other top-down forces such as predation and parasitism. R & eacute;sum & eacute;El manejo eficaz de la fauna silvestre est & aacute; basado en el entendimiento de una jerarqu & iacute;a de caracter & iacute;sticas demogr & aacute;ficas de sus poblaciones, incluyendo la tasa de crecimiento poblacional, estructura etaria, tasas vitales y factores que determinan estas tasas vitales. El alce (Alces alces) ocupa una distribuci & oacute;n circumboreal que abarca Norteam & eacute;rica y Eurasia, a lo largo de la cual su ecolog & iacute;a y demograf & iacute;a var & iacute;an considerablemente. Ante las incertidumbres respecto al estado de las poblaciones de alce en Montana (Estados Unidos) y los factores que limitan su crecimiento, analizamos la din & aacute;mica poblacional de esta especie durante el per & iacute;odo 2013-2023, enfoc & aacute;ndonos en tres & aacute;reas de estudio. Estimamos las tasas de crecimiento poblacional en funci & oacute;n de la estructura etaria de las poblaciones y de diversas tasas vitales, incluyendo la supervivencia de hembras adultas, su fecundidad (como producto de las tasas de pre & ntilde;ez y el tama & ntilde;o de camada), y la supervivencia de cr & iacute;as. Tambi & eacute;n evaluamos las relaciones entre un conjunto de condiciones ambientales -incluyendo variables clim & aacute;ticas de temperatura y nieve, variaci & oacute;n estacional de la calidad del forraje, efectos parasitarios de la garrapata de invierno (Dermacentor albipictus) y el nematodo (Elaeophora schneideri) y la abundancia relativa de depredadores- y las tasas vitales, con el objetivo de determinar el estado de las poblaciones de alce en Montana y la importancia relativa de los factores que las afectan. Estudiamos la supervivencia de hembras adultas a lo largo de 615 a & ntilde;os-alce de monitoreo, correspondientes a 186 individuos, y evaluamos la fecundidad mediante pruebas de pre & ntilde;ez en 779 a & ntilde;os-alce y el tama & ntilde;o de camada en 491 camadas observadas tras el parto. Adicionalmente estimamos la supervivencia de cr & iacute;as mediante el seguimiento de 619 pre & ntilde;eces y 541 cr & iacute;as durante su primer a & ntilde;o de vida. Utilizamos resultados previamente reportados para monitorear temperatura ambiental, nieve, nematodos y garrapatas en las & aacute;reas de estudio, y presentamos nuevos resultados sobre dieta, calidad del forraje y abundancia relativa de depredadores en dichas & aacute;reas. La edad materna tuvo efectos significativos sobre todas las tasas vitales evaluadas (supervivencia y fecundidad de hembras adultas y supervivencia de cr & iacute;as), los cuales, combinados con las diferencias en la estructura etaria entre las & aacute;reas de estudio, influyeron notablemente en las tasas de crecimiento poblacional. La supervivencia de hembras adultas se encontr & oacute; en un rango de 0.88 a 0.92 en las & aacute;reas de estudio. Las causas de mortalidad se analizaron mediante la funci & oacute;n de incidencia acumulada (CIF, por sus siglas en ingl & eacute;s), la cual indic & oacute; que las mortalidades fueron principalmente relacionadas con el estado de salud (CIF anual = 0.075), aunque tambi & eacute;n se registraron muertes asociadas a depredaci & oacute;n (CIF = 0.017) y a causas humanas (CIF = 0.014). Las intensidades de infecci & oacute;n por el nematodo E. schneideri estuvieron asociadas con un 1-3% de la mortalidad anual atribuible a causas de salud. La mortalidad por causas de salud tambi & eacute;n fue mayor en individuos con mala condici & oacute;n corporal, en individuos que no reclutaron cr& Lobos (Canis lupus) fueron responsables de la mayor proporci & oacute;n de mortalidad en adultos causada por depredaci & oacute;n, seguidos por osos grizzly (Ursus arctos) y pumas (Puma concolor). Las densidades relativas de depredadores en pol & iacute;gonos estacionales fueron predictoras de mortalidad causada por depredaci & oacute;n a nivel individual en alces. A nivel poblacional, su dieta estival reflej & oacute; una selecci & oacute;n de especies forrajeras con mayor energ & iacute;a digestible (ED), mientras dicha selectividad fue menos evidente de acuerdo con la variaci & oacute;n entre plantas en ED en el invierno o en prote & iacute;na digestible durante ambas estaciones. Adicionalmente, la energ & iacute;a digestible (ED) en verano fue el indicador de calidad del forraje m & aacute;s relacionado (R-2 = 0.876) con las diferencias en fecundidad (cr & iacute;as/hembra; rango = 0.74-0.96) entre poblaciones. La supervivencia de cr & iacute;as se relacion & oacute; negativamente con las densidades de depredadores durante el periodo fetal-neonatal, con las densidades de depredadores y el previo esfuerzo reproductivo durante el verano, y con la nieve durante el invierno. Las tasas de crecimiento poblacional se observaron de estables a crecientes entre poblaciones (1.00, 1.06 y 1.10 en Big Hole, Cabinet-Salish y Rocky Mountain Front, respectivamente), y la supervivencia de hembras adultas fue la tasa vital con mayor elasticidad (e = 0.83-0.88) en todas las poblaciones. Los an & aacute;lisis de perturbaci & oacute;n indicaron que, en orden de importancia, los efectos de la nutrici & oacute;n, la depredaci & oacute;n por lobos, el parasitismo por nematodos y la depredaci & oacute;n por otros predadores, son todos factores determinantes de la din & aacute;mica poblacional del alce en Montana. Simulaciones de estrategias de reducci & oacute;n de depredadores, en niveles comparables a los implementados recientemente en algunas regiones de Montana, tuvieron efectos m & iacute;nimos sobre la din & aacute;mica poblacional del alce, con un incremento m & aacute;ximo proyectado del 1.1% en la tasa de crecimiento poblacional en el & aacute;rea de estudio con la mayor intensidad de depredaci & oacute;n. Nuestros resultados tambi & eacute;n sugieren que el parasitismo por el nematodo E. schneideri podr & iacute;a desempe & ntilde;ar un papel importante en la mortalidad de adultos y en las tasas de crecimiento poblacional en algunas regiones de Montana. Sin embargo, se requieren m & aacute;s investigaciones para entender los mecanismos detr & aacute;s de las mortalidades en alces causadas por infecci & oacute;n y las din & aacute;micas de sus efectos subletales en otras tasas vitales. En conjunto, nuestros resultados recalcan la importancia de la nutrici & oacute;n como un factor determinante en la din & aacute;mica poblacional del alce, a pesar de la presencia de otras fuerzas de control tr & oacute;fico como la depredaci & oacute;n y el parasitismo.

When resources are limited, iteroparous species often favor their own survival over reproductive investment. Even under the umbrella of iteroparity, however, resource allocation strategies vary markedly among species. One key axis of variation is the capital–income breeding continuum, which is defined by the degree of reliance on stored energy to finance reproduction. In theory, the influence of local environmental conditions on optimal reproductive strategies should lead to both inter‐ and intraspecific variation in allocation of resources to reproduction. Yet little is known about the mechanisms that underpin life‐history variation within species or about the consequences of that variation. Bighorn sheep ( Ovis canadensis ) are generally considered to be capital breeders, relying on energy and protein reserves to finance reproduction. Nevertheless, bighorn sheep occupy a diversity of landscapes, and the potential for life‐history strategies to vary across environmental gradients remains largely unexplored. We linked spatiotemporal variation in forage quality and biomass to behavior, survival, and reproduction of female bighorn sheep across 3 populations that spanned a range of environmental conditions: a grassland environment with low seasonality and abundant, predictable forage, and 2 populations in highly seasonal alpine environments where resources were spatially and temporally unpredictable. During spring and summer, 2019–2022, we sampled digestible energy, protein, and biomass of vegetation at all 3 sites, and monitored behavior and performance metrics (i.e., autumn body fat, adult survival, pregnancy rates, and juvenile survival) of bighorn sheep in each population. Bighorn sheep in the grassland environment exhibited a more income‐based life‐history strategy: use of the foodscape positively influenced neonate survival, and probability of pregnancy and overwinter survival of adults were insensitive to changes in autumn body fat. In contrast, alpine bighorn sheep exhibited a more capital‐based strategy wherein probability of pregnancy and overwinter survival of adults were positively influenced by autumn body fat, but relationships between juvenile survival and maternal behavior (e.g., foodscape selection) were more variable. Our work demonstrates that life‐history strategies can vary markedly within a species as a function of local adaptation to environmental conditions that determine the strength of tradeoffs between survival and reproduction. This variation should be considered when developing approaches for conservation and management.

Effective wildlife management relies upon understanding a hierarchy of demographic characteristics of wildlife populations, including population growth rate, age structure, component vital rates, and factors influencing those vital rates. Moose ( Alces alces ) occupy a circumboreal range spanning North America and Eurasia, across which their ecology and demography vary substantially. Given uncertainties regarding the status of moose in Montana, USA, and factors limiting their population growth, we studied moose population dynamics during 2013–2023 and focused on 3 study areas. We estimated population growth rates as a function of population age structure and several key vital rates, including adult female survival, adult female fecundity (the product of pregnancy and litter size rates), and calf survival. We also evaluated relationships amongst a suite of environmental conditions (weather metrics of temperature and snow conditions, seasonal forage quality, parasite effects including winter ticks ( Dermacentor albipictus ) and arterial worms ( Elaeophora schneideri ), and relative predator abundances) and vital rates, with the ultimate goals of determining the status of moose populations in Montana and the relative importance among factors affecting them. We studied adult female survival for 615 moose‐years of monitoring across 186 individual moose, fecundity with pregnancy testing across 779 moose‐years and litter size for 491 observed litters post‐parturition, and calf survival using calf‐at‐heel monitoring of 619 pregnancies and 541 calves throughout their first year of life. We used previously reported results to monitor ambient temperature, snow, arterial worms, and winter ticks in these study areas and present new results concerning diet, forage quality, and relative predator abundance in these study areas. All vital rates (adult female survival, fecundity, and calf survival) showed significant effects of maternal age, which, in combination with differences in age distribution among study areas, had important effects on population growth rates. Adult female survival was 0.88–0.92 across study areas, and causes of mortality for adult females were predominantly health‐related (annual cumulative incidence function [CIF] = 0.075) but also included effects of predation (CIF = 0.017) and humans (CIF = 0.014). Arterial worm infection intensities were associated with roughly 1–3% of annual mortality due to health‐related causes. Health‐related mortality was also higher for animals in poor nutritional condition, those who failed to recruit a calf the previous year, and in animal‐years with more snow. Wolves ( Canis lupus ) were responsible for the highest proportion of predation‐caused adult mortality, followed by grizzly bears ( Ursus arctos ) and mountain lions ( Puma concolor ). In addition, relative predator densities within seasonal spatial polygons were predictive of predation‐caused mortality across individual moose. At the population‐level, moose summer diet reflected selection of forage species that offered higher digestible energy (DE), whereas such selectivity in diet was less evident according to variation among plants in DE during winter or in digestible protein during either season. Furthermore, summer DE was the forage quality metric most related ( R 2 = 0.876) to differences in fecundity (calves/female; range = 0.74–0.96) among populations. Calf survival was negatively related to predator densities during the fetal‐neonatal period, to predator densities and prior reproductive effort during the summer, and to snow during the winter. Population growth rates were stable to increasing (1.00, 1.06, 1.10 in Big Hole, Cabinet‐Salish, and Rocky Mountain Front, respectively) among populations, and adult female survival was the vital rate with the highest elasticity ( e = 0.83–0.88) in all populations. Perturbation analyses indicated, in order of importance, effects of nutrition, predation by wolves, parasitism by arterial worms, and predation by other predators each playing roles in driving variation in population dynamics of moose in Montana. Simulated predator reduction management at levels recently prescribed in parts of Montana had negligible predicted effects on moose population dynamics, with a maximum projected increase in population growth rate of 1.1% in the study area with the strongest effects of predation. Our results also suggest a potentially important role of arterial worm parasitism in driving adult mortality and population growth rates in some parts of Montana, but more research is needed to fully understand the mechanisms behind infection‐caused mortality and the dynamics of sublethal impacts on other moose vital rates. Ultimately, our results uphold the importance of nutrition as a driver of moose population dynamics even in the midst of other top‐down forces such as predation and parasitism.

When resources are limited, iteroparous species often favor their own survival over reproductive investment. Even under the umbrella of iteroparity, however, resource allocation strategies vary markedly among species. One key axis of variation is the capital–income breeding continuum, which is defined by the degree of reliance on stored energy to finance reproduction. In theory, the influence of local environmental conditions on optimal reproductive strategies should lead to both inter- and intraspecific variation in allocation of resources to reproduction. Yet little is known about the mechanisms that underpin life-history variation within species or about the consequences of that variation. Bighorn sheep ( Ovis canadensis ) are generally considered to be capital breeders, relying on energy and protein reserves to finance reproduction. Nevertheless, bighorn sheep occupy a diversity of landscapes, and the potential for life-history strategies to vary across environmental gradients remains largely unexplored. We linked spatiotemporal variation in forage quality and biomass to behavior, survival, and reproduction of female bighorn sheep across 3 populations that spanned a range of environmental conditions: a grassland environment with low seasonality and abundant, predictable forage, and 2 populations in highly seasonal alpine environments where resources were spatially and temporally unpredictable. During spring and summer, 2019–2022, we sampled digestible energy, protein, and biomass of vegetation at all 3 sites, and monitored behavior and performance metrics (i.e., autumn body fat, adult survival, pregnancy rates, and juvenile survival) of bighorn sheep in each population. Bighorn sheep in the grassland environment exhibited a more income-based life-history strategy: use of the foodscape positively influenced neonate survival, and probability of pregnancy and overwinter survival of adults were insensitive to changes in autumn body fat. In contrast, alpine bighorn sheep exhibited a more capital-based strategy wherein probability of pregnancy and overwinter survival of adults were positively influenced by autumn body fat, but relationships between juvenile survival and maternal behavior (e.g., foodscape selection) were more variable. Our work demonstrates that life-history strategies can vary markedly within a species as a function of local adaptation to environmental conditions that determine the strength of tradeoffs between survival and reproduction. This variation should be considered when developing approaches for conservation and management.

A variety of metrics based on the remotely sensed normalized difference vegetation index (NDVI) are commonly used as proxies for nutritional conditions of landscapes for ungulates, and these proxies are used to explain variation in animals’ vital rates and movements. One common application of NDVI data is to derive the instantaneous rate of green-up (IRG) to represent the rate of plant phenological progression and evaluate hypotheses regarding animal movements related to the green wave. Although the green wave is generally assumed to occur along elevational gradients in mountain-valley systems, it is unknown how variable patterns of plant phenological progression occur across heterogeneous landscapes. Additionally, the consequences of spatial and temporal variability in these phenological patterns on animal movement behaviors in different ecological systems are unknown. Many ungulates worldwide exhibit migratory behaviors to track the leading edge of plant phenological progression; however, some species, such as pronghorn ( Antilocapra americana ), that occupy mountain-valley and prairie systems may experience variable patterns of plant phenological progression and employ variable movement strategies to exploit these systems. Within 8 pronghorn herd ranges that span broad and heterogeneous landscapes in Montana, USA, our objectives were to 1) calculate and interpret phenology metrics, 2) evaluate spatial and temporal variability in plant phenology patterns, 3) characterize the patterns of plant phenological progression, 4) relate the variability and patterns of plant phenological progression to pronghorn migratory movement behaviors, and 5) evaluate potential nutritional trade-offs between employing a migratory or resident migratory behavior in different landscapes. The study area included the ranges of 3 pronghorn herds in western Montana characterized by an elevational gradient from lower elevation grasslands to higher elevation forests and the ranges of 5 pronghorn herds in eastern Montana characterized by mixed-grass prairie and sagebrush steppe. Across these 8 herds, we collected global positioning system (GPS) collar location data from 586 female pronghorn during 912 animal-years from 2019 to 2021. We processed 12 years of phenology data collected during 2010–2021. Spatial and temporal patterns and predictability of plant phenological progression varied across different pronghorn ranges. In general, the 3 western Montana herd ranges had less annual variation but greater intra-annual spatial variation in values of phenology metrics, as compared to the eastern Montana herd ranges, and greater predictability across years. The estimated green-up order, which represented the strength of the green wave, suggested that a defined and strong wavelike pattern of phenological progression (i.e., a green wave) was not common across pronghorn ranges in Montana. Most ranges in most years experienced a truncated green wave or synchronous greening across the landscape rather than a green wave. Of 817 animal-years of spring migration behavior, we classified 193 as migrant and 624 as resident. The probability of being classified as a migrant increased as landscape productivity increased. We sampled migrants’ and residents’ potential exposure to phenology values along spring movement paths and summer ranges and found that within herds and years, the resident and migrant movement strategies conferred similar exposure to indices of nutrition. Collectively, these results highlight the variability in patterns of plant phenological progression across pronghorn ranges in Montana and indicate that migration behavior is not the dominant movement strategy of the pronghorn sampled or a strategy that resulted in higher exposure to indices of nutrition. Pronghorn employing either resident or migrant movement behaviors may have similar exposure to indices of nutrition, which suggests that factors other than tracking indices of nutrition may influence pronghorn movement behaviors or that remotely sensed nutrition indices may not adequately quantify nutrition-related reasons for migration. Based on these results confirming residency as a behavior employed by the majority of animals, we recommend that habitat conservation strategies should focus efforts to increase landscape permeability not only within movement corridors used by migrants but also within ranges where non-migratory animals are moving.

Effective wildlife management relies upon understanding a hierarchy of demographic characteristics of wildlife populations, including population growth rate, age structure, component vital rates, and factors influencing those vital rates. Moose ( Alces alces ) occupy a circumboreal range spanning North America and Eurasia, across which their ecology and demography vary substantially. Given uncertainties regarding the status of moose in Montana, USA, and factors limiting their population growth, we studied moose population dynamics during 2013–2023 and focused on 3 study areas. We estimated population growth rates as a function of population age structure and several key vital rates, including adult female survival, adult female fecundity (the product of pregnancy and litter size rates), and calf survival. We also evaluated relationships amongst a suite of environmental conditions (weather metrics of temperature and snow conditions, seasonal forage quality, parasite effects including winter ticks ( Dermacentor albipictus ) and arterial worms ( Elaeophora schneideri ), and relative predator abundances) and vital rates, with the ultimate goals of determining the status of moose populations in Montana and the relative importance among factors affecting them. We studied adult female survival for 615 moose-years of monitoring across 186 individual moose, fecundity with pregnancy testing across 779 moose-years and litter size for 491 observed litters post-parturition, and calf survival using calf-at-heel monitoring of 619 pregnancies and 541 calves throughout their first year of life. We used previously reported results to monitor ambient temperature, snow, arterial worms, and winter ticks in these study areas and present new results concerning diet, forage quality, and relative predator abundance in these study areas. All vital rates (adult female survival, fecundity, and calf survival) showed significant effects of maternal age, which, in combination with differences in age distribution among study areas, had important effects on population growth rates. Adult female survival was 0.88–0.92 across study areas, and causes of mortality for adult females were predominantly health-related (annual cumulative incidence function [CIF] = 0.075) but also included effects of predation (CIF = 0.017) and humans (CIF = 0.014). Arterial worm infection intensities were associated with roughly 1–3% of annual mortality due to health-related causes. Health-related mortality was also higher for animals in poor nutritional condition, those who failed to recruit a calf the previous year, and in animal-years with more snow. Wolves ( Canis lupus ) were responsible for the highest proportion of predation-caused adult mortality, followed by grizzly bears ( Ursus arctos ) and mountain lions ( Puma concolor ). In addition, relative predator densities within seasonal spatial polygons were predictive of predation-caused mortality across individual moose. At the population-level, moose summer diet reflected selection of forage species that offered higher digestible energy (DE), whereas such selectivity in diet was less evident according to variation among plants in DE during winter or in digestible protein during either season. Furthermore, summer DE was the forage quality metric most related ( R 2  = 0.876) to differences in fecundity (calves/female; range = 0.74–0.96) among populations. Calf survival was negatively related to predator densities during the fetal-neonatal period, to predator densities and prior reproductive effort during the summer, and to snow during the winter. Population growth rates were stable to increasing (1.00, 1.06, 1.10 in Big Hole, Cabinet-Salish, and Rocky Mountain Front, respectively) among populations, and adult female survival was the vital rate with the highest elasticity ( e  = 0.83–0.88) in all populations. Perturbation analyses indicated, in order of importance, effects of nutrition, predation by wolves, parasitism by arterial worms, and predation by other predators each playing roles in driving variation in population dynamics of moose in Montana. Simulated predator reduction management at levels recently prescribed in parts of Montana had negligible predicted effects on moose population dynamics, with a maximum projected increase in population growth rate of 1.1% in the study area with the strongest effects of predation. Our results also suggest a potentially important role of arterial worm parasitism in driving adult mortality and population growth rates in some parts of Montana, but more research is needed to fully understand the mechanisms behind infection-caused mortality and the dynamics of sublethal impacts on other moose vital rates. Ultimately, our results uphold the importance of nutrition as a driver of moose population dynamics even in the midst of other top-down forces such as predation and parasitism.

Animal space use, activity patterns, and habitat selection—and heterogeneity in these patterns—have important implications for where and when infectious diseases are transmitted. White-tailed deer ( Odocoileus virginianus ) are habitat generalists, with a high degree of heterogeneity in their movement ecology based on sex, age, season, and region. These heterogeneities have important implications for the transmission and management of chronic wasting disease (CWD), which is a deadly prion disease transmitted both directly and indirectly through the environment. As such, favored deer habitats may promote direct interactions between conspecifics or indirect spatial overlap and subsequent environmental transmission. However, little is known about how individual animal space use translates to actual spatial overlap between individuals, leaving uncertainty in how habitat shapes the risk of direct or environmental CWD transmission. In this study, we evaluated seasonal activity patterns, home ranges, and habitat selection for 596 white-tailed deer in southwest Wisconsin, USA, from 2017-2022. We also estimated seasonal encounter distributions—regions where a pair of deer were most likely to encounter each other—for all pairs of deer putatively in different social groups (between-group) in our study, and quantified seasonal variation in the habitat composition of these areas. We found that deer selection for crops, pasture, or grasslands was generally low, relative to forest, but was highest in the post-fawning (summer) and non-breeding (winter) seasons. We observed similar patterns for the habitat composition of encounter distributions, suggesting that crops, pasture, and grasslands may be attractive resources that facilitate between-group transmission. Site fidelity between years was generally high; combined with small female home ranges in the fawning season, this implies that females likely re-use the same small, high-quality fawning habitats from year to year. We found that attraction toward between-group individuals was low during the post-fawning season but high during the breeding (fall) and non-breeding seasons. These results suggest that space use and habitat selection could shape the risk of environmental transmission in the fawning and post-fawning seasons, social selection could favor direct transmission risk in the breeding season, and combined social and habitat selection may shape risk of both direct and environmental transmission during the non-breeding season. We provide a detailed picture of the physiological and social drivers of deer movement through the year, with implications for CWD transmission and management.

The ongoing biodiversity crisis requires policy tools to establish baselines and assess biodiversity status. Reindeer and caribou ( Rangifer tarandus ) are iconic ungulates in the Arctic and subarctic, but populations are declining. Although the species is considered vulnerable globally in the International Union for Conservation of Nature [IUCN] Red List, more detailed policy tools at the population level would allow for targeted conservation efforts nationally. We developed an environmental quality standard (or norm) for reindeer populations to evaluate their overall status and put complex variation and change into simple status categories (poor, medium, and good) based on sets of quantitative indicators for 1) population performance, genetic diversity, and health status; 2) available lichen resources; and 3) loss of seasonal habitat and connectivity. We implemented the environmental quality standard for 10 national and 14 smaller wild reindeer areas (populations) in Norway. Except for 1 area with good status, all others ranged from medium ( n  = 11) to poor quality ( n  = 12). More than half of the populations had medium ( n  = 7) or poor ( n  = 6) status for 1 or more population performance indicators, with negative trends in calf body mass and recruitment in several populations. High loss of genetic diversity gave poor status in 4 small and isolated populations, and 2 populations with chronic wasting disease scored poor on health status. The status of lichen resources was medium ( n  = 20) or good ( n  = 3), with 1 exception. However, lichen time series data were not available to evaluate temporal trends to assess overgrazing. Loss of connectivity (poor; n  = 7) was more problematic than loss of seasonal habitat ( n  = 3). The poor availability of high-quality empirical data, particularly on population performance, has limited the ability to fully assess the conservation status of several small populations. The environmental quality standard provides an important step towards operationalizing management and aiding in securing the long-term conservation of wild reindeer. We discuss further improvements and the potential usefulness of this approach for other large mammals.

In forested landscapes of the Central Appalachians, wildlife openings are often created and maintained by land managers to provide early-successional habitat and food resources for game species, such as wild turkey ( Meleagris gallopavo ), ruffed grouse ( Bonasa umbellus ), and American woodcock ( Scolopax minor ). Although management may focus on these regionally important game birds, wildlife openings can also benefit a myriad of avian species and guilds, depending on local habitat features and landscape-level factors. Yet little effort has been made to investigate how to optimally manage wildlife openings to attract a full spectrum of avifauna throughout spring and summer and to maximize richness across habitat guilds. Therefore, the purpose of this study was to identify the characteristics of wildlife openings that support target game birds and a diversity of breeding and post-breeding songbirds. Specifically, we investigated the effects of local habitat attributes, opening size, management decisions, and landscape context on multi-species occupancy of 3 game birds (wild turkey, ruffed grouse, and American woodcock) during the game bird courtship season and songbird guild richness during the breeding and post-breeding seasons. During April–August 2019–2021, we used species-specific and community-wide point count surveys, game cameras, acoustic recording units, and transect surveys to sample avian communities in 335 wildlife openings within the Monongahela National Forest in West Virginia, USA. We incorporated multiple data sources for game bird occurrence into multi-species occupancy models, which were constructed within a Bayesian framework, and we used Bayesian hierarchical community models to calculate breeding and post-breeding songbird guild richness, followed by generalized linear mixed effects models to assess relationships with wildlife opening characteristics. Results from our game bird analyses indicated that wild turkey, ruffed grouse, and American woodcock occupancy probabilities were best explained by predictor variables relating primarily to management actions, such as mowing frequency, and secondarily to size and local habitat attributes of the wildlife openings, such as area, percent sapling cover, and elevation. Songbird guild richness also responded to area and elevation, with additional influence from predictor variables relating to landscape context. The songbird model results further indicated that it is feasible to manage wildlife openings for the mutual benefit of different species groups across seasons. Ultimately, these findings can be integrated into the design and management of wildlife openings to support target game bird populations and promote avian diversity in forest ecosystems.

When resources are limited, iteroparous species often favor their own survival over reproductive investment. Even under the umbrella of iteroparity, however, resource allocation strategies vary markedly among species. One key axis of variation is the capital-income breeding continuum, which is defined by the degree of reliance on stored energy to finance reproduction. In theory, the influence of local environmental conditions on optimal reproductive strategies should lead to both inter- and intraspecific variation in allocation of resources to reproduction. Yet little is known about the mechanisms that underpin life-history variation within species or about the consequences of that variation. Bighorn sheep (Ovis canadensis) are generally considered to be capital breeders, relying on energy and protein reserves to finance reproduction. Nevertheless, bighorn sheep occupy a diversity of landscapes, and the potential for life-history strategies to vary across environmental gradients remains largely unexplored. We linked spatiotemporal variation in forage quality and biomass to behavior, survival, and reproduction of female bighorn sheep across 3 populations that spanned a range of environmental conditions: a grassland environment with low seasonality and abundant, predictable forage, and 2 populations in highly seasonal alpine environments where resources were spatially and temporally unpredictable. During spring and summer, 2019-2022, we sampled digestible energy, protein, and biomass of vegetation at all 3 sites, and monitored behavior and performance metrics (i.e., autumn body fat, adult survival, pregnancy rates, and juvenile survival) of bighorn sheep in each population. Bighorn sheep in the grassland environment exhibited a more income-based life-history strategy: use of the foodscape positively influenced neonate survival, and probability of pregnancy and overwinter survival of adults were insensitive to changes in autumn body fat. In contrast, alpine bighorn sheep exhibited a more capital-based strategy wherein probability of pregnancy and overwinter survival of adults were positively influenced by autumn body fat, but relationships between juvenile survival and maternal behavior (e.g., foodscape selection) were more variable. Our work demonstrates that life-history strategies can vary markedly within a species as a function of local adaptation to environmental conditions that determine the strength of tradeoffs between survival and reproduction. This variation should be considered when developing approaches for conservation and management. RESUMEN Muchas especies iter & oacute;paras juegan a largo plazo favoreciendo su propia supervivencia frente a la inversi & oacute;n reproductiva actual. Sin embargo, incluso bajo el paraguas de la iteroparidad, las estrategias de asignaci & oacute;n de recursos var & iacute;an notablemente entre las especies. Un eje principal de variaci & oacute;n es el continuo de reproducci & oacute;n entre el capital y los ingresos, que se define por el grado de dependencia de la energ & iacute;a almacenada para financiar la reproducci & oacute;n. En teor & iacute;a, la influencia de las condiciones ambientales locales en las estrategias reproductivas & oacute;ptimas deber & iacute;a conducir a variaciones tanto interespec & iacute;ficas como intraespec & iacute;ficas en la asignaci & oacute;n de recursos a la reproducci & oacute;n. Sin embargo, se sabe poco sobre los mecanismos que sustentan la variaci & oacute;n de la historia de vida dentro de las especies o sobre las consecuencias de esa variaci & oacute;n. El borrego cimarr & oacute;n (Ovis canadensis) se considera generalmente como un reproductor de capital, que depende de las reservas de energ & iacute;a y prote & iacute;nas para financiar la reproducci & oacute;n. Sin embargo, el borrego cimarr & oacute;n ocupa una diversidad de paisajes, y el potencial de las estrategias de historia de vida para variar a trav & eacute;s de los gradientes ambientales sigue sin explorarse. Vinculamos la variaci & oacute;n espacio-temporal en la calidad del forraje y la biomasa con el comportamiento, la supervivencia y la reproducci & oacute;n del borrego cimarr & oacute;n en tres poblaciones que abarcaban una variedad de condiciones ambientales: un entorno de pastizales con baja estacionalidad y forraje abundante y predecible, y dos poblaciones en ambientes alpinos altamente estacionales donde los recursos eran espacial y temporalmente impredecibles. Durante la primavera y el verano de 2019-2022, tomamos muestras de la energ & iacute;a digerible, las prote & iacute;nas y la biomasa de la vegetaci & oacute;n en los tres sitios, y monitoreamos el comportamiento y las m & eacute;tricas de rendimiento (es decir, la grasa corporal de oto & ntilde;o, la supervivencia de los adultos, las tasas de embarazo y la supervivencia de los juveniles) del borrego cimarr & oacute;n en cada poblaci & oacute;n. El borrego cimarr & oacute;n en el entorno de los pastizales exhibi & oacute; una estrategia de historia de vida m & aacute;s basada en los ingresos: el uso del paisaje alimentario influy & oacute; positivamente en la supervivencia de los neonatos, y la probabilidad de embarazo y supervivencia durante el invierno de los adultos fue insensible a los cambios en la grasa corporal de oto & ntilde;o. Por el contrario, el borrego cimarr & oacute;n alpino exhibi & oacute; una estrategia m & aacute;s basada en el capital, en la que la probabilidad de embarazo y la supervivencia durante el invierno de los adultos estaban influenciadas positivamente por la grasa corporal del oto & ntilde;o, pero las relaciones entre la supervivencia juvenil y el comportamiento materno (por ejemplo, la selecci & oacute;n del paisaje alimentario) eran m & aacute;s variables. Nuestro estudio es uno de los primeros en demostrar que las estrategias de historia de vida pueden variar marcadamente incluso dentro de una especie en funci & oacute;n de la adaptaci & oacute;n local a las condiciones ambientales que determinan la fuerza de las compensaciones entre la supervivencia y la reproducci & oacute;n.

The ongoing biodiversity crisis requires policy tools to establish baselines and assess biodiversity status. Reindeer and caribou (Rangifer tarandus) are iconic ungulates in the Arctic and subarctic, but populations are declining. Although the species is considered vulnerable globally in the International Union for Conservation of Nature [IUCN] Red List, more detailed policy tools at the population level would allow for targeted conservation efforts nationally. We developed an environmental quality standard (or norm) for reindeer populations to evaluate their overall status and put complex variation and change into simple status categories (poor, medium, and good) based on sets of quantitative indicators for 1) population performance, genetic diversity, and health status; 2) available lichen resources; and 3) loss of seasonal habitat and connectivity. We implemented the environmental quality standard for 10 national and 14 smaller wild reindeer areas (populations) in Norway. Except for 1 area with good status, all others ranged from medium (n = 11) to poor quality (n = 12). More than half of the populations had medium (n = 7) or poor (n = 6) status for 1 or more population performance indicators, with negative trends in calf body mass and recruitment in several populations. High loss of genetic diversity gave poor status in 4 small and isolated populations, and 2 populations with chronic wasting disease scored poor on health status. The status of lichen resources was medium (n = 20) or good (n = 3), with 1 exception. However, lichen time series data were not available to evaluate temporal trends to assess overgrazing. Loss of connectivity (poor; n = 7) was more problematic than loss of seasonal habitat (n = 3). The poor availability of high-quality empirical data, particularly on population performance, has limited the ability to fully assess the conservation status of several small populations. The environmental quality standard provides an important step towards operationalizing management and aiding in securing the long-term conservation of wild reindeer. We discuss further improvements and the potential usefulness of this approach for other large mammals. La crise actuelle de la biodiversit & eacute; n & eacute;cessite des outils politiques permettant d'& eacute;tablir des donn & eacute;es de r & eacute;f & eacute;rence et d'& eacute;valuer l'& eacute;tat de la biodiversit & eacute;. Les rennes et les caribous (Rangifer tarandus) sont des ongul & eacute;s embl & eacute;matiques de l'Arctique et du subarctique, mais leurs populations sont en d & eacute;clin. Bien que l'esp & egrave;ce soit consid & eacute;r & eacute;e comme vuln & eacute;rable & agrave; l'& eacute;chelle mondiale dans la liste rouge de l'Union internationale pour la conservation de la nature [UICN], des outils politiques plus d & eacute;taill & eacute;s au niveau des populations permettraient de mener des efforts de conservation cibl & eacute;s & agrave; l'& eacute;chelle nationale. Nous avons & eacute;labor & eacute; une norme de qualit & eacute; environnementale pour les populations de rennes afin d'& eacute;valuer leur & eacute;tat g & eacute;n & eacute;ral et de classer les variations et les changements complexes en cat & eacute;gories simples (mauvais, moyen ou bon) sur la base d'un ensemble d'indicateurs quantitatifs portant sur 1) les performances de la population, la diversit & eacute; g & eacute;n & eacute;tique et l'& eacute;tat de sant & eacute;; 2) les ressources en lichens disponibles; et 3) la perte d'habitat saisonnier et de connectivit & eacute;. Nous avons appliqu & eacute; la norme de qualit & eacute; environnementale & agrave; 10 zones nationales et & agrave; 14 zones plus petites abritant des populations de rennes sauvages en Norv & egrave;ge. & Agrave; l'exception d'une zone pr & eacute;sentant un bon & eacute;tat, toutes les autres pr & eacute;sentaient une qualit & eacute; moyenne (n = 11) ou mauvaise (n = 12). Plus de la moiti & eacute; des populations pr & eacute;sentaient un statut moyen (n = 7) ou mauvais (n = 6) pour au moins un indicateur de performance d & eacute;mographique, avec des tendances n & eacute;gatives concernant la masse corporelle des veaux et le recrutement dans plusieurs populations. La perte de diversit & eacute; g & eacute;n & eacute;tique a entra & icirc;n & eacute; un mauvais & eacute;tat dans 4 populations petites et isol & eacute;es, et deux populations atteintes de la maladie du d & eacute;p & eacute;rissement chronique ont obtenu de mauvais r & eacute;sultats pour leur & eacute;tat de sant & eacute;. L'& eacute;tat des ressources en lichens & eacute;tait moyen (n = 20) ou bon (n = 3), & agrave; une exception pr & egrave;s. Toutefois, l'absence de s & eacute;ries temporelles sur l'abondance en lichens n'a pas permis d'& eacute;valuer les tendances temporelles afin d'& eacute;valuer le surp & acirc;turage. La perte de connectivit & eacute; (faible; n = 7) & eacute;tait plus probl & eacute;matique que la perte d'habitat saisonnier (n = 3). La faible disponibilit & eacute; de donn & eacute;es empiriques de haute qualit & eacute;, en particulier sur les performances d & eacute;mographiques, a limit & eacute; la capacit & eacute; & agrave; & eacute;valuer enti & egrave;rement l'& eacute;tat de conservation de plusieurs petites populations. La norme de qualit & eacute; environnementale constitue une avanc & eacute;e importante vers l'op & eacute;rationnalisation de la gestion et la mise en oe uvre de mesures visant & agrave; assurer la conservation & agrave; long terme du renne sauvage. Nous discutons des am & eacut Biodiversitetskrisen krever forvaltningsverkt & oslash;y som etablerer referanseverdier og vurderer status for biologisk mangfold. Villrein (Rangifer tarandus) er et ikonisk hjortedyr i Arktis og subarktiske omr & aring;der, men mange bestander er i tilbakegang. Selv om arten globalt er vurdert som s & aring;rbar p & aring; den internasjonale r & oslash;dlista, vil mer detaljerte forvaltningsverkt & oslash;y p & aring; bestandsniv & aring; gj & oslash;re det mulig med m & aring;lrettede bevaringstiltak nasjonalt. Vi har utviklet en kvalitetsnorm for villrein for & aring; evaluere bestandenes samlede status og forenkle komplekse variasjoner og endringer til enkle statuskategorier (d & aring;rlig, middels og god) basert p & aring; et sett av kvantitative indikatorer for 1) bestandskondisjon, genetisk mangfold og helsetilstand, 2) mengden lavressurser, og 3) tap av sesonghabitat og konnektivitet. Vi implementerte kvalitetsnormen for 10 nasjonale og 14 mindre villreinomr & aring;der (bestander) i Norge. Med unntak av ett omr & aring;de med god status, hadde de & oslash;vrige status som middels (n = 11) eller d & aring;rlig (n = 12). Over halvparten av bestandene hadde middels (n = 7) eller d & aring;rlig (n = 6) status for & eacute;n eller flere indikatorer for bestandskondisjon, med negative trender i kalvevekter og rekruttering i flere bestander. Betydelig tap av genetisk mangfold ga d & aring;rlig status i fire sm & aring; og isolerte bestander, og to bestander med skrantesjuke fikk d & aring;rlig status for helsetilstand. Status for lavressurser var middels (n = 20) eller god (n = 3), med ett unntak. Tidsseriedata for lavressurser manglet, og det var derfor ikke mulig & aring; evaluere utviklingen over flere & aring;r for & aring; vurdere eventuell overbeiting. Tap av konnektivitet (d & aring;rlig; n = 7) var et st & oslash;rre problem enn tap av sesonghabitat (n = 3). Begrenset tilgang p & aring; empiriske data, s ae rlig for bestandskondisjon, reduserte muligheten til & aring; vurdere bevaringsstatus for flere sm & aring; bestander. Kvalitetsnormen for villrein representerer et viktig skritt mot operasjonalisering av forvaltningstiltak, og den bidrar til & aring; sikre langsiktig bevaring av villrein. Vi diskuterer videre forbedringer og mulig nytte av denne tiln ae rmingen for andre store pattedyr.

A variety of metrics based on the remotely sensed normalized difference vegetation index (NDVI) are commonly used as proxies for nutritional conditions of landscapes for ungulates, and these proxies are used to explain variation in animals’ vital rates and movements. One common application of NDVI data is to derive the instantaneous rate of green‐up (IRG) to represent the rate of plant phenological progression and evaluate hypotheses regarding animal movements related to the green wave. Although the green wave is generally assumed to occur along elevational gradients in mountain‐valley systems, it is unknown how variable patterns of plant phenological progression occur across heterogeneous landscapes. Additionally, the consequences of spatial and temporal variability in these phenological patterns on animal movement behaviors in different ecological systems are unknown. Many ungulates worldwide exhibit migratory behaviors to track the leading edge of plant phenological progression; however, some species, such as pronghorn ( Antilocapra americana ), that occupy mountain‐valley and prairie systems may experience variable patterns of plant phenological progression and employ variable movement strategies to exploit these systems. Within 8 pronghorn herd ranges that span broad and heterogeneous landscapes in Montana, USA, our objectives were to 1) calculate and interpret phenology metrics, 2) evaluate spatial and temporal variability in plant phenology patterns, 3) characterize the patterns of plant phenological progression, 4) relate the variability and patterns of plant phenological progression to pronghorn migratory movement behaviors, and 5) evaluate potential nutritional trade‐offs between employing a migratory or resident migratory behavior in different landscapes. The study area included the ranges of 3 pronghorn herds in western Montana characterized by an elevational gradient from lower elevation grasslands to higher elevation forests and the ranges of 5 pronghorn herds in eastern Montana characterized by mixed‐grass prairie and sagebrush steppe. Across these 8 herds, we collected global positioning system (GPS) collar location data from 586 female pronghorn during 912 animal‐years from 2019 to 2021. We processed 12 years of phenology data collected during 2010–2021. Spatial and temporal patterns and predictability of plant phenological progression varied across different pronghorn ranges. In general, the 3 western Montana herd ranges had less annual variation but greater intra‐annual spatial variation in values of phenology metrics, as compared to the eastern Montana herd ranges, and greater predictability across years. The estimated green‐up order, which represented the strength of the green wave, suggested that a defined and strong wavelike pattern of phenological progression (i.e., a green wave) was not common across pronghorn ranges in Montana. Most ranges in most years experienced a truncated green wave or synchronous greening across the landscape rather than a green wave. Of 817 animal‐years of spring migration behavior, we classified 193 as migrant and 624 as resident. The probability of being classified as a migrant increased as landscape productivity increased. We sampled migrants’ and residents’ potential exposure to phenology values along spring movement paths and summer ranges and found that within herds and years, the resident and migrant movement strategies conferred similar exposure to indices of nutrition. Collectively, these results highlight the variability in patterns of plant phenological progression across pronghorn ranges in Montana and indicate that migration behavior is not the dominant movement strategy of the pronghorn sampled or a strategy that resulted in higher exposure to indices of nutrition. Pronghorn employing either resident or migrant movement behaviors may have similar exposure to indices of nutrition, which suggests that factors other than tracking indices of nutrition may influence pronghorn movement behaviors or that remotely sensed nutrition indices may not adequately quantify nutrition‐related reasons for migration. Based on these results confirming residency as a behavior employed by the majority of animals, we recommend that habitat conservation strategies should focus efforts to increase landscape permeability not only within movement corridors used by migrants but also within ranges where non‐migratory animals are moving.

Animal space use, activity patterns, and habitat selection—and heterogeneity in these patterns—have important implications for where and when infectious diseases are transmitted. White‐tailed deer ( Odocoileus virginianus ) are habitat generalists, with a high degree of heterogeneity in their movement ecology based on sex, age, season, and region. These heterogeneities have important implications for the transmission and management of chronic wasting disease (CWD), which is a deadly prion disease transmitted both directly and indirectly through the environment. As such, favored deer habitats may promote direct interactions between conspecifics or indirect spatial overlap and subsequent environmental transmission. However, little is known about how individual animal space use translates to actual spatial overlap between individuals, leaving uncertainty in how habitat shapes the risk of direct or environmental CWD transmission. In this study, we evaluated seasonal activity patterns, home ranges, and habitat selection for 596 white‐tailed deer in southwest Wisconsin, USA, from 2017‐2022. We also estimated seasonal encounter distributions—regions where a pair of deer were most likely to encounter each other—for all pairs of deer putatively in different social groups (between‐group) in our study, and quantified seasonal variation in the habitat composition of these areas. We found that deer selection for crops, pasture, or grasslands was generally low, relative to forest, but was highest in the post‐fawning (summer) and non‐breeding (winter) seasons. We observed similar patterns for the habitat composition of encounter distributions, suggesting that crops, pasture, and grasslands may be attractive resources that facilitate between‐group transmission. Site fidelity between years was generally high; combined with small female home ranges in the fawning season, this implies that females likely re‐use the same small, high‐quality fawning habitats from year to year. We found that attraction toward between‐group individuals was low during the post‐fawning season but high during the breeding (fall) and non‐breeding seasons. These results suggest that space use and habitat selection could shape the risk of environmental transmission in the fawning and post‐fawning seasons, social selection could favor direct transmission risk in the breeding season, and combined social and habitat selection may shape risk of both direct and environmental transmission during the non‐breeding season. We provide a detailed picture of the physiological and social drivers of deer movement through the year, with implications for CWD transmission and management.

In forested landscapes of the Central Appalachians, wildlife openings are often created and maintained by land managers to provide early‐successional habitat and food resources for game species, such as wild turkey ( Meleagris gallopavo ), ruffed grouse ( Bonasa umbellus ), and American woodcock ( Scolopax minor ). Although management may focus on these regionally important game birds, wildlife openings can also benefit a myriad of avian species and guilds, depending on local habitat features and landscape‐level factors. Yet little effort has been made to investigate how to optimally manage wildlife openings to attract a full spectrum of avifauna throughout spring and summer and to maximize richness across habitat guilds. Therefore, the purpose of this study was to identify the characteristics of wildlife openings that support target game birds and a diversity of breeding and post‐breeding songbirds. Specifically, we investigated the effects of local habitat attributes, opening size, management decisions, and landscape context on multi‐species occupancy of 3 game birds (wild turkey, ruffed grouse, and American woodcock) during the game bird courtship season and songbird guild richness during the breeding and post‐breeding seasons. During April–August 2019–2021, we used species‐specific and community‐wide point count surveys, game cameras, acoustic recording units, and transect surveys to sample avian communities in 335 wildlife openings within the Monongahela National Forest in West Virginia, USA. We incorporated multiple data sources for game bird occurrence into multi‐species occupancy models, which were constructed within a Bayesian framework, and we used Bayesian hierarchical community models to calculate breeding and post‐breeding songbird guild richness, followed by generalized linear mixed effects models to assess relationships with wildlife opening characteristics. Results from our game bird analyses indicated that wild turkey, ruffed grouse, and American woodcock occupancy probabilities were best explained by predictor variables relating primarily to management actions, such as mowing frequency, and secondarily to size and local habitat attributes of the wildlife openings, such as area, percent sapling cover, and elevation. Songbird guild richness also responded to area and elevation, with additional influence from predictor variables relating to landscape context. The songbird model results further indicated that it is feasible to manage wildlife openings for the mutual benefit of different species groups across seasons. Ultimately, these findings can be integrated into the design and management of wildlife openings to support target game bird populations and promote avian diversity in forest ecosystems.

Although ecological impacts of overabundant white-tailed deer ( Odocoileus virginianus ) are well documented in eastern North America, few studies have evaluated the long-term effects of adaptive deer population suppression after a period of overabundance. We examined vegetation community changes over a period of 30 years (1992–2021) on the Long Point Peninsula, Ontario, Canada following a >85% reduction of a previously overabundant white-tailed deer population. We documented a significant increase in species diversity and shifts in the species composition of understory plants and woody vegetation. We then evaluated several hypotheses to explain these patterns. Our results provide support for the all-you-can-browse hypothesis, in which the abundance of woody stems above the browse layer did not increase within the first 3 years of sampling but, consistent within an expected period of recruitment, increased by >1,500% from 1995–2021. We also found support for both the lawn maintenance hypothesis, with a significant decline in the proportional abundance of non-preferred species relative to preferred species, and for the seed bank hypothesis, with native species accounting for nearly 80% of new species observed over the sampling period. We conclude that the effective, long-term management and continued suppression of an previously overabundant white-tailed deer population can lead to increased vegetation community heterogeneity and diversity, which is likely one of the most important steps for the regeneration of woody stems and native vegetation communities.

The effect of non-native herbivores on ecosystems and diversity has become a global concern in conservation. Management challenges associated with non-native free-roaming equids have existed for decades in a wide range of ecosystems yet have been difficult to resolve. Although much of the challenge is associated with non-biological considerations, empirical ecological research is crucial for guiding sound management decisions. We conducted a field study on the associations between feral burros (Equus asinus) and elements of the Sonoran Desert ecosystem in Arizona, USA, during 2017-2019. We identified areas with and without established burro herds, and collected data on vegetation, ungulate sign, small mammals, birds, and herpetofauna at multiple, randomly selected grids within these areas, while accounting for vegetation community and distance to water. We predicted that burros would be associated with differences in vegetation metrics such as lower ground cover, smaller perennial plant size, and lower plant density, foliage density, recruitment, and species richness among perennial native plants susceptible to burro foraging or trampling. We further predicted that these differences would be accompanied by lower density or relative abundance and lower species richness of small mammals, birds, and herpetofauna. Finally, because burro distribution has been documented to be associated with water in this arid landscape, we predicted that effects would be most pronounced near water. The results of our study did not consistently support our predictions, perhaps because of small sample sizes or, in several cases, inherent complexities associated with seasonal burro habitat use and plant phenology patterns. However, our study documented that the presence of this feral equid is associated with a number of key differences that may be ecologically important and have the potential to alter community structure in this sensitive arid ecosystem. In areas with established burro herds, we documented lower ground cover, plant density, foliage density, or smaller plant size in several species, and changes were often influenced by distance from water. For example, density of Engelmann's prickly pear cactus (Opuntia engelmannii) was 94% lower and Anderson wolfberry (Lycium andersonii) plants were 49% smaller in areas with established burro herds. In areas with burros, we also recorded lower density of white bursage (Ambrosia dumosa) in areas distant from water. Of notable concern was that our metric of recruitment indicated 63% lower recruitment in saguaro cactus (Carnegiea gigantea) and that foliage densities of yellow paloverde (Parkinsonia microphylla) and desert ironwood (Olneya tesota) were lower in areas with established burro herds. Data on some plant species did not support our predictions. For example, white bursage and Anderson wolfberry plants were found at similar densities in areas with and without established burros near water, but they occurred at lower densities far from water in areas with established burros. Our data revealed that in 4 of 7 small mammal species evaluated (Bailey's pocket mouse [Chaetodipus baileyi], desert pocket mouse [C. penicillatus], deer mice [Peromyscus spp.], and Merriam's kangaroo rat [Dipodomys merriami]), density was associated with an interaction between burros and distance to water, with lower densities close to water in burro areas. Contrary to predictions, 3 of these species (Bailey's pocket mouse, desert pocket mouse, and deer mice) exhibited higher densities in burro areas than in non-burro areas at grids farther from water. Density of a fifth species (Arizona woodrat [Neotoma devia]) was 68% lower in burro areas than in non-burro areas, and the densities of 2 species were not associated with burros. Across species, we did not find consistent patterns in our analysis of bird group density, with some species exhibiting a negative effect associated with burros and others exhibiting a positive effect. When we categorized birds by hypothesized nesting and foraging vulnerabilities (low, medium, high), vulnerability levels did not predict the effect of burros. However, all categories exhibited a negative burro effect distant from water but not close to water, contrary to our expectations. Relative abundance of common side-blotched lizards (Uta stansburiana) was 26% lower in areas with established burros, but data on other herpetofauna species did not support our predictions, with some species exhibiting higher relative abundance in areas with established burros. Our data did not reveal an association between burros and bird, small mammal, or herpetofauna species richness, but species richness of native perennial plants was higher in burro areas close to water. We recommend that future bird studies focus on riparian birds and nest success, and possibly evaluate potential effects in relation to other aspects of bird ecology such as feeding guilds or nesting ecology, and that future herpetofauna studies use survey methods that can better account for detection. Although some results did not support our predictions, our study documented negative associations between burros and a number of native plant species, and density in some small mammal species. These associations are important and of concern in and of themselves because changes in long-lived keystone plant species and in small mammal densities indicate that the long-term sustainability of portions of this ecosystem may be affected, and it is likely that these changes can have additional indirect effects on plants and wildlife in this ecosystem. Field data on ungulate sign (fecal groups and tracks) suggested that the associations detected in our study were related to burros and not cattle (Bos taurus) or native ungulates such as mule deer (Odocoileus hemionus) or bighorn sheep (Ovis canadensis). Our results indicate that the presence of established burro herds was associated with changes, primarily in the plant community that is critical for ecosystem function, and we suggest that current management of this feral equid may not be adequate for maintaining the long-term viability of this arid and fragile ecosystem.