Pronghorn Antilocapra americana occupy only a portion of their historical range and in Oklahoma occur at the eastern edge of the species' contemporary distribution. Monitoring has suggested pronghorn populations in Oklahoma have declined in recent years. We captured and collared 125 adult females across two winters, monitored them for signs of parturition during each subsequent spring, and then captured and radio-collared 70 fawns <= 4 days old. We assessed cause-specific mortality, estimated proportional survival, and visualized survival of fawns through 60 days of life with Kaplan-Meier curves. Nearly 87% of fawn mortalities were attributed to predation, with > 77% of predations attributed to coyotes Canis latrans. Our results indicated that fawn survival was lowest during the first 15 days of life, with 33% of fawns surviving to 15 days and 12% surviving to 60 days. We used known-fate models to evaluate the influence of biological factors (i.e. sex, mass, birth timing), environmental factors (i.e. ambient temperature, precipitation, vegetation), and temporal variation on the probability of early life (i.e. the first 15 days) survival. For each adult female with a collared fawn, we used female space-use patterns for 30 days before and 15 days after parturition to collect environmental covariates. Early life probability of survival was lower for larger fawns, those born earlier in the parturition period (i.e. earlier in the year relative to the range of parturition days), and those with higher pre-parturition temperatures; daily probability of survival decreased with time-since-parturition within the first 15 days of life. Our results indicate poor fawn survival, highlight a potential limitation of population growth, and can inform population management by identifying factors influencing early life fawn survival.
Many mesocarnivores have low detection rates that hinder practitioners' abilities to implement effective monitoring strategies. Using olfactory attractants (i.e. lures) may increase detection rates, but variation in effects among species is not well understood. Thus, investigating factors influencing detection of mesocarnivores, can inform and improve monitoring efforts. We evaluated the effects of lures and environmental covariates on the detection of plains spotted skunks Spilogale interrupta, striped skunks Mephitis mephitis, northern raccoons Procyon lotor, gray foxes Urocyon cinereoargenteus, coyotes Canis latrans, bobcats Lynx rufus and Virginia opossums Didelphis virginiana. We conducted surveys during January-May 2023 in southeast Oklahoma using motion-triggered cameras at randomly selected sites. We surveyed sites using a 4-camera cluster and leave-one-out lure design, where 3 cameras were randomly assigned 1 of 4 lures (i.e. skunk-based lure, fatty acid tablets, sweet lure or sardines) and 1 camera was a control (i.e. no lure). We analyzed species-specific detection data within an occupancy framework to determine the influence of lure combinations and environmental covariates (i.e. temperature, precipitation and moon illumination) on site-level detection patterns for each species. When lures influenced detection, we assessed species-specific preference among lures (and the control) within sites by comparing camera-level independent detections with Kruskal-Wallis and Dunn's tests at sites where the species was detected. The effect of lures varied among species; lure combinations influenced site-specific daily detection of plains spotted skunks, striped skunks, gray foxes, raccoons and bobcats, but did not affect detection of coyotes or opossums. One environmental covariate influenced detection of striped skunks (i.e. moon illumination), bobcats (i.e. temperature), and gray foxes (i.e. precipitation). Within sites, lure preference varied among species. Spotted skunks, gray foxes and raccoons preferred sardines whereas striped skunks preferred the skunk-based lure. Identifying lure preferences and effects of environmental factors can help optimize sampling and improve mesocarnivore monitoring efforts.
Motivation: SNAPSHOT USA is an annual, multi-contributor camera trap survey of mammals across the United States. The growing SNAPSHOT USA dataset is intended for tracking the spatial and temporal responses of mammal populations to changes in land use, land cover and climate. These data will be useful for exploring the drivers of spatial and temporal changes in relative abundance and distribution, as well as the impacts of species interactions on daily activity patterns. Main Types of Variables Contained: SNAPSHOT USA 2024 contains 377,427 records of camera trap image sequence data and 3127 records of camera trap deployment metadata. Spatial Location and Grain: Data were collected across the United States of America in 49 states, 12 ecoregions and many ecosystems. Time Period and Grain: Data were collected between 1 August and 19 December in 2024. Major Taxa and Level of Measurement: The dataset includes a wide range of taxa but is primarily focused on medium to large mammals. Software Format: SNAPSHOT USA 2024 comprises two.csv files. The original data can be found within the SNAPSHOT USA 2024 project on the Wildlife Insights platform.
Ringtails (Bassariscus astutus) are widely distributed in the western United States and across much of Mexico, yet due to their relatively low densities and cryptic nature, little is known about their basic ecology even where they are common. Recent public sightings suggest ringtails may have expanded their distribution north into southern Idaho, USA. Currently, ringtails remain unclassified in Idaho thus limiting resources and time available for population monitoring. We attempted to detect these small carnivores in southern Idaho during winter 2023. We deployed 49 camera traps with a combination of lures (i.e., trapping lure, fruit, and orange drink mix) in canyon habitats in southern Idaho near recent ringtail sightings. We detected ringtails nine times on six different camera traps. Although incidental ringtail observations increased in southern Idaho since the early 2000s, our detections were the first to result from a targeted survey effort. Given more than 20 years of incidental sightings and multiple detections during our survey, it appears that ringtails have expanded their range northward into southern Idaho and could be considered a resident species in the state. Further efforts to document reproduction, annual persistence, and an assessment of threats could be next steps if the state wildlife management agency deems it a priority and an appropriate use of resources.
Sampling conducted from May to August of 2024 yielded new distributional records for the federally threatened Theliderma cylindrica (Rabbitsfoot) in the Caney River, OK. We found 4 live individuals, representing at least 2 age classes, similar to 7 km upstream of the confluence with the Verdigris River. This report is the first documentation of live Rabbitsfoot in the Caney River, where the species was previously known only from weathered shells. This finding extends the known distribution of Rabbitsfoot into a system previously unrecognized as part of its range.
Context Interspecific interactions shape ecological communities, influence community dynamics, and drive co-evolution. Despite their ecological significance, predation and competition remain understudied in plains spotted skunks (Spilogale interrupta), a species of conservation concern. Clarifying how predator management influences their occurrence is crucial for effective conservation.Aims We investigated how coyote (Canis latrans) management affects the occupancy of plains spotted skunks and whether interspecific interactions with domestic cats (Felis catus) and striped skunks (Mephitis mephitis) influence plains spotted skunk occurrence.Methods We analysed live-trap data from east-central South Dakota collected in spring of 2021 and 2022. The study area encompassed portions of counties that implemented disparate predator management regimes, including one with systematic annual coyote removal and another without. We used single-species occupancy models to estimate detection and occupancy probabilities for plains spotted skunks, domestic cats, and striped skunks, incorporating environmental factors, including the site-specific predator control regime. We then applied conditional two-species occupancy models to test whether cats and striped skunks influenced plains spotted skunk occurrence.Key results Plains spotted skunks had the lowest occupancy, followed by domestic cats, and striped skunks. Our findings showed significant associations between coyote removal and occupancy probabilities for each mesocarnivore species. Plains spotted skunks had higher occupancy in areas where coyotes were annually removed. Spotted skunk occurrence was not conditional on either domestic cat or striped skunk occurrence.Conclusions In our study system, cats appear to pose less predation risk to spotted skunks than do other predators, reducing the likelihood that cats significantly influence spotted skunk occupancy. Defensive behaviours and use of spatial refugia by plains spotted skunks may further mitigate predation risk. In addition, co-evolutionary pressures may have led to trait adaptations that facilitate the independent co-occurrence of plains spotted skunks and striped skunks.Implications Our findings highlighted the ecological consequences of predator management and the importance of considering predator-prey dynamics in conservation and management planning. Strategies aimed at conserving plains spotted skunks should integrate predator control measures while considering broader mesocarnivore community interactions.
Lanius ludovicianus (Loggerhead Shrike) is a predatory songbird that has experienced a severe population decline throughout its range since the 1940s, likely driven by a combination of factors, including habitat loss and fragmentation. Occupying larger territories compared to many other passerines, L. ludovicianus requires open habitat with interspersed trees and shrubs for nesting and perching and heterogeneous ground cover that provides hunting opportunities. Despite the general knowledge of L. ludovicianus habitat during breeding and nonbreeding seasons in many parts of its range, factors influencing long-term occupancy dynamics remain poorly understood. We addressed these knowledge gaps by analyzing 10 yr of L. ludovicianus detection data collected from breeding bird point-count surveys at a grassland-sagebrush ecotone in northeastern Wyoming, USA. We quantified L. ludovicianus detection and occupancy probabilities using a dynamic (multi-season) occupancy modeling framework and evaluated how initial occupancy and dynamic parameters (i.e., colonization and local extinction) were influenced by land-cover composition and change using remotely sensed land-cover data. Additionally, we used observer survey data to assess the influence of survey date and cloud cover on detection probability. We found that detection probability was influenced by survey date, while initial occupancy probability was positively associated with fences and presence of trees. Colonization probability increased with increased litter cover, whereas extinction probability was not influenced by land-cover and remained low throughout our study period. These findings highlight the importance of habitat features, such as fences and tree presence in shaping L. ludovicianus occupancy patterns. Further research is needed to understand the relationships between L. ludovicianus occupancy dynamics and demographic processes such as reproduction and survival. Identifying factors that influence occupancy dynamics and associated demographic processes can guide efforts to conserve and sustain L. ludovicianus populations. Lanius ludovicianus is a predatory songbird that has experienced a steep population decline across its range, likely due to a combination of factors, such as habitat loss and fragmentation. L.anius ludovicianus occupy open habitat with trees and shrubs for nesting and hunting; however, the factors driving their occupancy patterns remain poorly understood. Our 10-year study revealed that L. ludovicianus was more likely to occupy areas with longer lengths of fence and where at least one tree was present, whereas areas with more litter cover were more likely to become occupied. L.anius ludovicianus occupancy in our study remained stable across years. This highlights the importance of maintaining key habitat features, such as fences and trees, which provide important nesting and hunting opportunities. Lanius ludovicianus es un ave canora depredadora que ha experimentado un severo declive poblacional en toda su distribuci & oacute;n desde la d & eacute;cada de 1940, probablemente debido a una combinaci & oacute;n de factores, incluyendo la p & eacute;rdida y fragmentaci & oacute;n del h & aacute;bitat. Lanius ludovicianus ocupa territorios m & aacute;s grandes en comparaci & oacute;n con muchos otros paseriformes, y requiere h & aacute;bitats abiertos con & aacute;rboles y arbustos intercalados para anidar y posarse, adem & aacute;s de una cobertura de suelo heterog & eacute;nea que brinde oportunidades de caza. A pesar del conocimiento general sobre el h & aacute;bitat de L. ludovicianus durante las temporadas reproductivas y no reproductivas en muchas partes de su distribuci & oacute;n, los factores que influyen en la din & aacute;mica de ocupaci & oacute;n a largo plazo siguen estando poco comprendidos. Abordamos estas lagunas de conocimiento analizando 10 a & ntilde;os de datos de detecci & oacute;n de L. ludovicianus colectados en relevamientos de aves reproductivas mediante conteo por puntos en un ecotono de pastizal-artemisa en el noreste de Wyoming, EE. UU. Cuantificamos las probabilidades de detecci & oacute;n y ocupaci & oacute;n de L. ludovicianus utilizando un marco de modelado din & aacute;mico de ocupaci & oacute;n (multi-estacional) y evaluamos c & oacute;mo la ocupaci & oacute;n inicial y los par & aacute;metros din & aacute;micos (i.e., colonizaci & oacute;n y extinci & oacute;n local) estuvieron influenciados por la composici & oacute;n y el cambio de la cobertura del suelo utilizando datos de teledetecci & oacute;n. Adem & aacute;s, utilizamos datos de los observadores para evaluar la influencia de la fecha del relevamiento y la cobertura de nubes sobre la probabilidad de detecci & oacute;n. Encontramos que la probabilidad de detecci & oacute;n estuvo influenciada por la fecha del relevamiento, mientras que la probabilidad de ocupaci & oacute;n inicial se asoci & oacute; positivamente con las cercas y la presencia de & aacute;rboles. La probabilidad de colonizaci & oacute;n aument & oacute; con una mayor cobertura de mantillo, mientras que la probabilidad de extinci & oacute;n no estuvo influenciada por la cobertura del suelo y se mantuvo baja durante todo nuestro per & iacute;odo de estudio. Estos hallazgos destacan la importancia de las caracter & iacute;sticas del h & aacute;bitat, como las cercas y la presencia de & aacute;rboles, en la configuraci & oacute;n de los patrones de ocupaci & oacute;n de L. ludovicianus. Se necesita m & aacute;s investigaci & oacute;n para comprender las relaciones entre la din & aacute;mica de ocupaci & oacute;n de L. ludovicianus y los procesos demogr & aacute;ficos como la reproducci & oacute;n y la supervivencia. Identificar los factores que influyen en la din & aacute;mica de ocupaci & oacute;n y en los procesos demogr & aacute;ficos asociados puede guiar los esfuerzos para conservar y sostener las poblaciones de L. ludovicianus.
Mesopredator suppression has implications for community structure, biodiversity, and ecosystem function, but mesopredators with physical defenses may not avoid apex predators. We investigated nine-banded armadillos (Dasypus novemcinctus) in southwestern Oklahoma (USA) to evaluate if a species with physical defenses was influenced by a dominant predator, the coyote (Canis latrans). We sampled nine-banded armadillos and coyotes with motion-activated cameras. We used single-species and conditional two-species occupancy models to assess the influences of environmental factors and coyotes on nine-banded armadillo occurrence and site-use intensity (i.e., detection). We used camera-based detections to characterize the diel activity of each species and their overlap. Nine-banded armadillo occupancy was greater at sites closer to cover, with lower slopes, and further from water, whereas coyote space use was greater at higher elevations; both species were positively associated with recent burns. Nine-banded armadillo occurrence was not influenced by coyotes, but site-use intensity was suppressed by the presence of coyotes. Nine-banded armadillos (strictly nocturnal) and coyotes (predominantly nocturnal) had a high overlap in summer diel activity. Nine-banded armadillos are ecosystem engineers but are often considered a threat to species of concern and/or a nuisance. Thus, understanding the role of interspecific interactions on nine-banded armadillos has important implications for conservation and management.
Anthropogenic factors are accelerating species extinction, with small mammalian carnivores among the most affected. These species play vital ecological roles, yet their conservation needs are often overlooked. Our study focused on the plains spotted skunk ( Spilogale interrupta (Rafinesque, 1820)), a small carnivore that has experienced population declines. We hypothesized that their resource selection was influenced by factors expected to influence prey availability, protection from predators, and human activity. We tracked 14 plains spotted skunks in east-central South Dakota, USA, over 2 years during spring and summer. Using mixed-effects logistic regression, we identified seasonal habitat associations. In spring, plains spotted skunks selected areas near farming structures and human development, avoiding high wetland density and crop cover. In summer, they continued to select areas near farming structures and low human development, but also high wetland density and pasture, while avoiding hay bales and crop cover. Our first analysis of the species’ resource use in the Great Plains indicates that plains spotted skunks select habitats with permanent small-scale agricultural features and varying levels of human development across seasons. Our findings suggest that species’ persistence in the region may depend on conservation strategies that account for seasonal planning, habitat heterogeneity, and key agricultural structures.
Biological invasions pose significant risks to ecosystems and native species. Wild pigs (Sus scrofa) are a highly detrimental invasive species in North America, directly and indirectly affecting native species. Co-occurrence of wild pigs and native species may lead to interspecific interactions that alter ecological communities. Accordingly, we investigated spatial and temporal factors influencing detection and occupancy of Eurasian Wild Pig and Nine-banded Armadillo (Dasypus novemcinctus) before examining interspecific effects. We analyzed camera-trap data collected from August to September 2021 using a hierarchical modeling framework to estimate detection and occupancy of both species individually (single-species analyses) and concurrently (conditional co-occurrence analyses). We observed higher Wild Pig detection rates and space use in late summer and in areas with greater riparian cover, respectively. Armadillo detection increased linearly throughout our sampling season and in response to precipitation. Moreover, armadillo detection was 3.5 to 5.1× higher at sites used by wild pigs, regardless of whether wild pigs were detected during a survey period. Occupancy of armadillo was best explained by a quadratic trend in site elevation but did not depend on the presence of wild pigs. Our results indicate that wild pigs may influence armadillo detection (or site-use intensity), but not occupancy, therefore revealing nuanced interspecific interactions. Between species, we observed high overlap in diel activity but significantly different activity peaks, with armadillos being strictly nocturnal and wild pigs being crepuscular but with more cathemeral activity, suggesting that fine-scale temporal partitioning may have occurred. Our results provide insights into the influence of a large-bodied and destructive invasive species (Wild Pig) on a smaller, ecologically important native species (Nine-banded Armadillo).
ABSTRACTMotivationSNAPSHOT USA is an annual, multicontributor camera trap survey of mammals across the United States. The growing SNAPSHOT USA dataset is intended for tracking the spatial and temporal responses of mammal populations to changes in land use, land cover and climate. These data will be useful for exploring the drivers of spatial and temporal changes in relative abundance and distribution, as well as the impacts of species interactions on daily activity patterns.Main Types of Variables ContainedSNAPSHOT USA 2019–2023 contains 987,979 records of camera trap image sequence data and 9694 records of camera trap deployment metadata.Spatial Location and GrainData were collected across the United States of America in all 50 states, 12 ecoregions and many ecosystems.Time Period and GrainData were collected between 1st August and 29th December each year from 2019 to 2023.Major Taxa and Level of MeasurementThe dataset includes a wide range of taxa but is primarily focused on medium to large mammals.Software FormatSNAPSHOT USA 2019–2023 comprises two .csv files. The original data can be found within the SNAPSHOT USA Initiative in the Wildlife Insights platform.
The white-backed hog-nosed skunk (Conepatus leuconotus) is an understudied mesocarnivore thought to be declining throughout its range in the southwestern United States. With the exception of a single skull of unknown age, hog-nosed skunks have not been documented in Oklahoma since 1930. We conducted a camera trapping survey in Cimarron County, Oklahoma during summer 2022 and confirmed the presence of a hog-nosed skunk in Oklahoma. This finding provides the first evidence of a hog-nosed skunk in Oklahoma in over 90 years and is within the range of a poorly documented subspecies (C. l. figginsi) believed to be in decline.
Understanding habitat selection is critical in habitat prioritization for species of conservation and management concern. Information on habitat selection is particularly important for grassland bird species whose populations have suffered steep declines over the last few decades. We assessed ring-necked pheasants' (Phasianus colchicus) habitat selection in a dynamic agricultural landscape. The population dynamics of pheasants are partially related to nest survival, which may be influenced by the quality of nesting habitat. Consequently, knowledge of vegetation composition and structural characteristics associated with the selection and survival of nests would help inform management decisions to improve nest success. We monitored nests from 103 radio-collared pheasants inhabiting an agricultural landscape in South Dakota, USA, from 2017-2019 to determine the effect of landscape composition and configuration on nest-site selection and nest survival. We explored nesting behavior at 2 orders of selection: resource selection within the home range (third order) and selection of specific resource items from a resource patch (fourth order). Proportion of row crop and connectivity of row crop was negatively associated with nest-site selection at the third order. At the fourth order, pheasants tended to select for taller vegetation and greater percent grass cover than at paired random sites. Pheasants also selected areas with more grasslands. A 1% increase in grass cover and proportion of grassland increased the odds of nest-site selection by 1% and 2%, respectively. Connectivity of row crop patches was negatively associated with daily nest survival. We also evaluated factors affecting pheasant brood-site selection. A 1-unit increase in grass cover and Hemiptera biomass increased the odds of brood-site selection by 4%. The probability of brood-site selection also increased with fewer row crop patches. Weather played a crucial role in driving nest survival. The consideration of local weather trends and regional variation in habitat can inform habitat management for pheasants. Pheasant populations may benefit from research that identifies thermal landscapes and land management techniques that promote cooler microclimates for nesting and brood-rearing activities.
Abstract Close‐kin mark–recapture (CKMR) methods use information on genetic relatedness among individuals to estimate demographic parameters. An individual's genotype can be considered a ‘recapture’ of each of its parent's genotype, and the frequency of kin‐pair matches detected in a population sample can directly inform estimates of abundance. CKMR inference procedures require analysts to define kinship probabilities in functional forms, which inevitably involve simplifying assumptions. Among others, population structure can have a strong influence on how kinship probabilities are formulated. Many terrestrial species are philopatric or face barriers to dispersal, and not accounting for dispersal limitation in kinship probabilities, can create substantial bias if sampling is also spatially structured (e.g. via harvest). We present a spatially explicit formulation of CKMR that corrects for incomplete mixing by incorporating natal dispersal distances and spatial distribution of individuals into the kinship probabilities. We used individual‐based simulations to evaluate the accuracy of abundance estimates obtained with one spatially naïve and two spatially explicit CKMR models across six scenarios with distinct spatial patterns of relative abundance and sampling probability. Estimates of abundance obtained with a CKMR model naïve to spatial structure were negatively biased when sampling was spatially biased. Incorporating patterns of natal dispersal in the kinship probabilities helped address this bias, but estimates were not always accurate depending on the model used and the scenario considered. Incorporating natal dispersal into spatially structured CKMR models can address the bias created by population structure and heterogeneous sampling but will often require additional assumptions and auxiliary data (e.g. relative abundance indices). The models shown here were designed for terrestrial species with continuous patterns of natal dispersal and high year‐to‐year site fidelity but could be extended to other species.
Studies involving individually marked animals provide insights predicated on the assumption marked individuals are accurate models of their unmarked counterparts. Taxa-specific and marker-specific examinations are needed to determine if marked animals are suitable models for the parameter(s) being measured. Our objective was to determine if brightly colored ear tags influenced the probability of predation for neonatal ungulates. We captured 94 neonatal pronghorn (Antilocapra americana (Ord, 1815)), fitted each neonate with a tracking collar, and attached a yellow ear tag to 49 (52.1%) of the captured neonates. We monitored the survival of each neonate during 2023–2024 in Oklahoma, USA. Predation was the leading cause of mortality during our monitoring period and accounted for 29 (82.9%) of the 35 mortalities with a known cause. Coyotes (Canis latrans Say, 1823) were the predominant predator of neonatal pronghorn in our study area. Presence of a yellow ear tag seemingly did not influence the probability of predation, even though coyotes can distinguish yellow objects from most natural backgrounds. A larger sample size may be needed to validate our results, but neonatal ungulates with an ear tag appear to be accurate models of neonatal ungulates without an ear tag when examining predation risk.
American black bear ( Ursus americanus ) sightings have increased in the Oklahoma Panhandle, an area outside of the species’ historical range, prompting an assessment of bears in the region. We used camera traps and an occupancy modeling framework to identify factors influencing bear detection and space-use patterns. We used noninvasive genetic sampling techniques to evaluate genetic diversity, population structure, and bear abundance in the region. During the summers of 2022–2023, we deployed cameras at 160 sites across western Oklahoma (USA) and detected ≥1 bear at 20 sites. The most-supported model from our single-season single-species analysis indicated that bear detection was positively associated with temperature and precipitation, negatively associated with day of year, and differed between years. The most-supported model indicated that bear space use was negatively associated with elevation (β = −0.013, 85% CI = −0.025, 0.000), and positively associated with slope (β = 0.645, 85% CI = 0.305, 0.984) and coarse woody debris counts (β = 1.539, 85% CI = 0.314, 2.765). We deployed 41 hair snares in Oklahoma resulting in the collection of 153 hair samples and received 69 tissue samples from black bears harvested in northeastern New Mexico. Using 11 microsatellite markers, we identified 21 (12M:9F) bears in western Oklahoma, and 69 (40M:29F) in New Mexico. We found evidence that bears occurring in Oklahoma were an extension of a previously documented population that occurred in northcentral New Mexico. We detected significant population-level heterozygote deficiency ( P = 0.013) compared to expectations under Hardy-Weinberg equilibrium. Using capture with replacement models, we estimated 26 (95% CI = 19–43) bears in western Oklahoma during 2022–2023. Our results provide baseline data on population distribution, abundance, and genetic health of bears in the region and identify factors that may drive human-bear conflicts as the bear population increases in western Oklahoma.
Reliable estimates of prairie dog (Cynomys spp.) population size and distribution are critical for assessing the status of prairie dogs and for selecting sites to reintroduce black-footed ferrets (Mustela nigripes). The density of active prairie dog burrows has commonly been used as an index of prairie dog abundance. Indices derived from active burrow counts were developed for black-tailed (C. ludovicianus) and white-tailed (C. leucurus) prairie dogs, but their efficacy has not been evaluated for all prairie dog species and studies affirming their validity with robust abundance estimators are few. We indexed or estimated the abundance of Gunnison's prairie dogs (C. gunnisoni) in the Aubrey Valley, Arizona, USA, in 2006 at 2 different time periods using 4 different methods-maximum above ground counts (MAGC), minimum number known alive (MNKA), capture-mark-recapture (CMR), and mark-resight-and compared these estimates to active burrow counts in 2005 and 2006. We found no positive relationship between active burrow counts and any abundance estimators. Mark-resight estimates of abundance were greater than the MNKA and were positively correlated with both the MNKA (r2 = 0.30) and CMR estimates (r2 = 0.49). Both CMR estimates and MAGC were typically below the MNKA and therefore biased low. Our results indicated that more rigorous estimation methods may be necessary to accurately estimate prairie dog abundance and assess habitat quality for ferret conservation. We investigated the relationship between estimates of abundance and active burrow counts for Gunnison's prairie dogs (Cynomys gunnisoni) in the Aubrey Valley, AZ. We found no relationship between any index or esimate of abundance and active burrow counts. Active burrows poorly indexed abundance or density of prairie dogs. image
Parturition timing has long been a topic of interest in ungulate research. However, few studies have examined parturition timing at fine scale (e.g., <1 day). Predator activity and environmental conditions can vary considerably with diel timing, which may result in selective pressure for parturition to occur during diel times that maximize the likelihood of neonate survival. We monitored parturition events and early‐life survival of elk (Cervus canadensis) and mule deer (Odocoileus hemionus) in Utah, USA to better understand diel timing of parturition in temperate ungulates. Diel timing of parturition was moderately synchronous among conspecifics and influenced by environmental variables on the date of parturition. For elk, parturition events were most common during the morning crepuscular period and generally occurred later (i.e., closer to 12:00) when a relatively large proportion of the moon was illuminated. For mule deer, parturition events were most common during the diurnal period and generally occurred later (i.e., closer to 15:00) on cold, wet dates. Diel timing of parturition did not influence neonate survival, but larger datasets may be required to verify the apparent lack of influence. Although additional work could evaluate alternative variables that might affect parturition timing, our data provide an improved and finer scale understanding of reproductive ecology and phenology in ungulates.
Wildlife must adapt to human presence to survive in the Anthropocene, so it is critical to understand species responses to humans in different contexts. We used camera trapping as a lens to view mammal responses to changes in human activity during the COVID-19 pandemic. Across 163 species sampled in 102 projects around the world, changes in the amount and timing of animal activity varied widely. Under higher human activity, mammals were less active in undeveloped areas but unexpectedly more active in developed areas while exhibiting greater nocturnality. Carnivores were most sensitive, showing the strongest decreases in activity and greatest increases in nocturnality. Wildlife managers must consider how habituation and uneven sensitivity across species may cause fundamental differences in human–wildlife interactions along gradients of human influence.