We simulated the reintroduction of Mediterranean monk seal Monachus monachus individuals to create new populations using the Cabo Blanco colony (Western Sahara/Mauritania) as the source population. We evaluated potential negative impacts of removing weaned pups on population growth in the Cabo Blanco population and projected a range of plausible outcomes for reintroduced populations under 4 vital rate scenarios. Lifetables of simulated reintroduced populations were parameterized with published survival and reproductive rate estimates from the 2 extant monk seal populations in the eastern Atlantic: Cabo Blanco and Madeira. Two scenarios simulated enhanced neonatal survival to represent potentially higher survival of pups born on open beaches at reintroduction sites compared to the relatively low observed survival of pups born in caves at Cabo Blanco and Madeira. Reintroduction scenarios simulated the translocation of 6 weaned pups per year (4 females and 2 males) for 5 yr from Cabo Blanco to a reintroduction site, and both populations were subsequently projected an additional 5 yr. Simulations indicated that this level of removal would have relatively minor effects on the Cabo Blanco population, which could theoretically sustain considerably more removals and continue increasing in abundance. All simulated reintroduced populations were extant after the 10 yr projections, and the median of an aggregate distribution of final abundance from all scenarios was 27 seals (5 and 95 percentiles 15 and 52 seals, respectively). Our results support the viability of establishing new monk seal populations without causing undue harm to the Cabo Blanco colony.
Abandoned, lost, or otherwise discarded fishing gear causes harm to marine species and ecosystems. To mitigate the destruction wrought by this ocean plastic debris, various cleanup programs have been established, though to our knowledge the benefits of such efforts to marine species and ecosystems have not yet been empirically demonstrated. We examined more than 40 years of Hawaiian monk seal marine debris entanglement records before and after large-scale marine debris removal efforts were initiated in the Northwestern Hawaiian Islands, demonstrating a substantial reduction in entanglement rates where debris removal effort was most concentrated. Large-scale and sustained removal of abandoned, lost, or otherwise discarded fishing gear meaningfully benefits marine ecosystems and has the potential to be transformational in restoration efforts.
We describe a hierarchical N-mixture model for estimating northern fur seal pup production from batch mark-resight data. Our goal was to improve upon a traditional design-based estimation method used for over 50 years. To this end, we propose a hierarchical N-mixture model to account for differences in animal availability for resighting and observer detection probabilities. A Bayesian approach is used for inference with three separate methods proposed for necessary computations. First a straightforward posterior sample is drawn using MCMC. This was considered the gold standard for this analysis. However, we also consider an approximate model-based on Gaussian approximation of the Poisson and binomial distributions used in the exact hierarchical model. By using the Gaussian approximations, analytic integration can be used to marginalize over latent components. Inference can then be made by maximizing the posterior to find the mode. Following this we investigate both delta-method and parametric bootstrap approaches for calculating abundance and the associated standard errors with batch sampling data collected on northern fur seals in 2016. Each of the three newly proposed methods produced virtually identical estimates and standard errors. In addition, the parametric bootstrap approximation to a posterior sample was also virtually the same as the MCMC derived sample. There were a handful of small differences in the point estimates of abundance but these were not large enough to be especially notable. There were some noticeable differences in uncertainty estimates. The production estimate coefficients of variation ranged from 2.5–9.5% for the model-based estimates, but 0.0–12.5% for the design-based estimates. The design-based estimates of uncertainty were more volatile using the design-based method with some standard error estimates unreasonably small. Through a case study we have provided support for using Gaussian approximation in N -mixture type models when abundance is relatively large. These situations are typically challenging for fitting models using any sort of marginalization because there is no analytic solution for the exact models. However, when abundances are large using a Gaussian approximated model allows for analytic integration over latent abundance states which can greatly facilitate methodology such as maximum likelihood or posterior inference. ### Competing Interest Statement The authors have declared no competing interest.
We provide the first comprehensive demographic assessment of the Endangered Mediterranean monk seal Monachus monachus population residing in the Madeira Archipelago to identify factors that may impede population growth. Encounter data was obtained for this small, elusive population from 2012 to 2021 using a variety of non-invasive methods. From birth to age 2 mo, when pups molt, survival averaged 0.57. From birth to 1 yr and from 1-2 yr, estimated survival rates were 0.47 and 0.85, respectively. Beyond 2 yr, survival estimates differed by sex: 0.98 for females and 0.90 for males. These survival rates are similar to published estimates from the Cabo Blanco (Western Sahara/Mauritania) population. This is remarkable given that Cabo Blanco is situated adjacent to the extremely productive Canary Current system, whereas the marine environment of Madeira is far less productive. Instead of reducing survival, low marine productivity in Madeira appears to manifest in strikingly depressed reproductive rates. We estimated a mean gross reproductive rate of just 0.31; less than half the value (0.71) reported for Cabo Blanco. The youngest parturient females in Madeira were 6 yr old, whereas 3 yr olds give birth at Cabo Blanco. Despite low fecundity, the monk seal population in Madeira has been recovering, aided by a series of conservation measures implemented since 1988. Our results document that abundance increased from 19 seals in 2013 to 27 in 2021. Despite this undeniable success, the monk seals of Madeira remain vulnerable and require continued monitoring and protection in order to persist.
•We review evidence for climate change effects on marine mammal species that occur in U.S. waters relative to past predictions.•Compelling cases of climate change effects on marine mammals have been documented, though few studies have confirmed population-level impacts on abundance or vital rates.•While many of the observed effects had been predicted, unforeseen and relatively acute consequences have also been documented.•These often occur when climate-induced alterations are superimposed upon marine mammals’ ecological (e.g., predator-prey) relationships or coincident human activities.•As they were unanticipated, some of these unpredicted effects have strained the ability of existing conservation and management systems to respond effectively.•The literature is replete with cases suggestive of climate change impacts on marine mammals, but which remain unconfirmed.•This uncertainty is partially explained by insufficient research and monitoring designed to reveal the connections.•Detecting and mitigating the threats of climate change to marine mammals will require some realignment of research and monitoring priorities, coupled with rapid and flexible management that includes both conventional and novel conservation interventions.
In the Southern Great Plains, wheat cultivars have been selected for a combination of outstanding yield and drought tolerance as a long-term breeding goal. To understand the underlying genetic mechanisms, this study aimed to dissect the quantitative trait loci (QTL) associated with yield components and kernel traits in two wheat cultivars `TAM 112' and `Duster' under both irrigated and dryland environments. A set of 182 recombined inbred lines (RIL) derived from the cross of TAM 112/Duster were planted in 13 diverse environments for evaluation of 18 yield and kernel related traits. High-density genetic linkage map was constructed using 5,081 single nucleotide polymorphisms (SNPs) from genotyping-by-sequencing (GBS). QTL mapping analysis detected 134 QTL regions on all 21 wheat chromosomes, including 30 pleiotropic QTL regions and 21 consistent QTL regions, with 10 QTL regions in common. Three major pleiotropic QTL on the short arms of chromosomes 2B (57.5 - 61.6 Mbps), 2D (37.1 - 38.7 Mbps), and 7D (66.0 - 69.2 Mbps) colocalized with genes Ppd-B1, Ppd-D1, and FT-D1, respectively. And four consistent QTL associated with kernel length (KLEN), thousand kernel weight (TKW), plot grain yield (YLD), and kernel spike-1 (KPS) (Qklen.tamu.1A.325, Qtkw.tamu.2B.137, Qyld.tamu.2D.3, and Qkps.tamu.6A.113) explained more than 5% of the phenotypic variation. QTL Qklen.tamu.1A.325 is a novel QTL with consistent effects under all tested environments. Marker haplotype analysis indicated the QTL combinations significantly increased yield and kernel traits. QTL and the linked markers identified in this study will facilitate future marker-assisted selection (MAS) for pyramiding the favorable alleles and QTL map-based cloning.
To assess the efficacy of conservation translocations, survival of released individuals is typically compared to that of control groups. Such comparisons assume that treatment groups consist of otherwise equivalent individuals. When that assumption is unmet, incorporating physiological parameters may improve assessment of translocation programs. During 2012-2014, 19 weaned female Hawaiian monk seal pups were translocated to sites where survival prospects were expected to be more favorable than at their natal locations. We compared survival from weaning to age two years of translocated pups to two control groups; pups remaining at source sites and pups native to destination sites. To account for the known relationship between weaning girth and survival, we generated probability distributions of the number of survivors at source and destination sites given the weaning girths of translocated seals. Data were available to calculate girth-adjusted survival probabilities for 13 of the translocated pups. Of these, we estimated that only one pup would have been expected to have survived had the translocated pups remained at their natal site. Seven of the 13 translocated seals survived, a value just below the median (eight) expected to have survived at the destination site. Thus, translocation substantially improved survival. Had we not accounted for weaning girth effects on survival, we would have erroneously concluded that the translocation program had yielded no survival benefit. Identifying and integrating correlates of survival into quantitative analyses associated with conservation translocations can reduce bias and lead to greater success.
Identifying, assessing, and ranking the impact of individual threats is fundamental to the conservation and recovery of rare and endangered species. In this analysis, we quantify not only the frequency of specific causes-of-death (CODs) among Main Hawaiian Island (MHI) monk seals, but also assess the impact of individual CODs on the intrinsic growth rate, lambda, of the MHI population. We used gross necropsy results, histopathology, and other evidence to assign probabilities of 11 COD types to each mortality and then used Monte Carlo sampling to evaluate the influence of each COD on lambda. By right censoring realizations involving specific CODs, we were able to estimate lambda (and its associated uncertainty) when CODs were selectively removed from influencing survival. Applying the analysis to all known and inferred deaths believed to have occurred 2004-2019, the CODs with the largest influence on lambda were anthropogenic trauma, anthropogenic drowning, and protozoal disease. In aggregate, anthropogenic CODs had a larger effect on the growth rate than either natural or disease CODs. Possible bias associated with differential carcass detection, recovery, and COD classification are discussed.
We provide the first complete set of survival rate estimates for the Endangered Mediterranean monk seal Monachus monachus from birth into adulthood, as well as the first age-specific reproductive rates for the species. From 2002 to 2016, we obtained individual seal live encounter data through non-invasive monitoring techniques that were analyzed to estimate vital rates of Mediterranean monk seals of the Cabo Blanco (Western Sahara/Mauritania) population. From birth to age 2 mo, when pups molt, survival averaged 0.59, ranging from 0.41 to 0.74 among cohorts. From birth to 1 yr and from 1 to 2 yr, median estimated survival rates were 0.46 and 0.75, respectively. Beyond 2 yr, survival estimates differed by sex: 0.94 for males and 0.97 for females. From 2005 to 2016, we estimated a mean gross reproductive rate of 0.71. The youngest parturient females were 3 yr old. Fitted age-specific reproductive rates increased beginning at age 3 yr and exceeded 0.80 from age 6 to 17 yr. Despite low survival during the first 2 mo of life, the aggregate vital rates of the population are favorable for growth; a Leslie matrix containing our survival and fecundity estimates yielded an intrinsic growth rate of 1.058. Increasing abundance and favorable vital rates are a testament to the efficacy of the many measures taken to promote the conservation of this population.
Abstract Thermal imaging has been used to determine canopy temperature and study plant water relationships. The objective of this study was to investigate the potential use of infrared thermal imaging to determine crop canopy temperature (Tc) and evaluate wheat (Triticum aestivum L.) genotypes under drought conditions. Thermal images were acquired at anthesis and grain‐filling stages from 17 genotypes grown under dryland conditions in 2015 and 2016 winter wheat growing season at Bushland, TX. A handheld thermal camera was used to acquire thermal images and the images were processed using customized image processing software. The customized software filters out the background soil from the thermal images and calculates the mean Tc. A significant difference (p < .05) in Tc among genotypes was found during grain filling in 2015 and at anthesis in 2016. Genotypes TAM 111, TAM 114, PlainsGold Byrd, and Jagalene had cooler canopies, and Billings, TAM 304, and TAM 105 had warmer canopies in both years. There was a significant negative correlation between grain yield and Tc measured at anthesis (r =–.48, p < .05) and grain‐filling (r = –.33, p < .05). Infrared thermal imaging showed a promising method to obtain Tc, which can be used to evaluate genotypes for drought tolerance.
We used sighting reports, including decades of citizen-reported Hawaiian monk seal (Neomonachus schauinslandi) sightings, to describe female breeding biology and reproductive success in the main Hawaiian Islands. We first used this data set to describe the timing of events in the female reproductive cycle. We then conducted an expert review of patterns in sighting histories to detect unobserved pupping events. Finally, we estimated the age-specific reproductive curve for female monk seals in the main Hawaiian Islands. Charting reproductive cycles showed indications of the robust condition of female monk seals in the main Hawaiian Islands; they nursed pups 12% longer than their counterparts in the Northwestern Hawaiian Islands and regained condition to molt more quickly after weaning a pup. By examining sighting histories, we were able to infer 25 unobserved pupping events that had previously gone uncounted. We accounted for additional uncertainty with a randomization procedure. After accounting for unobserved pupping events, the age-specific reproductive rate of main Hawaiian Islands monk seals exceeded 0.70 for prime aged females (8-18 years). This is the highest reproductive rate reported for any of the Hawaiian monk seal breeding sites, illustrating the important role of the main Hawaiian Islands population in Hawaiian monk seal recovery.
Whaling has decimated North Atlantic right whales Eubalaena glacialis (NARW) since the 11 th century and southern right whales E. australis (SRW) since the 19 th century. Today, NARWs are Critically Endangered and decreasing, whereas SRWs are recovering. We review NARW health assessment literature, NARW Consortium databases, and efforts and limitations to monitor individual and species health, survival, and fecundity. Photographs are used to track individual movement and external signs of health such as evidence of vessel and entanglement trauma. Post-mortem examinations establish cause of death and determine organ pathology. Photogrammetry is used to assess growth rates and body condition. Samples of blow, skin, blubber, baleen and feces quantify hormones that provide information on stress, reproduction, and nutrition, identify microbiome changes, and assess evidence of infection. We also discuss models of the population consequences of multiple stressors, including the connection between human activities (e.g. entanglement) and health. Lethal and sublethal vessel and entanglement trauma have been identified as major threats to the species. There is a clear and immediate need for expanding trauma reduction measures. Beyond these major concerns, further study is needed to evaluate the impact of other stressors, such as pathogens, microbiome changes, and algal and industrial toxins, on NARW reproductive success and health. Current and new health assessment tools should be developed and used to monitor the effectiveness of management measures and will help determine whether they are sufficient for a substantive species recovery.
Two drought-tolerant wheat cultivars, 'TAM 111' and 'TAM 112', have been widely grown in the Southern Great Plains of the U.S. and used as parents in many wheat breeding programs worldwide. This study aimed to reveal genetic control of yield and yield components in the two cultivars under both dryland and irrigated conditions. A mapping population containing 124 F5:7 recombinant inbred lines (RILs) was developed from the cross of TAM 112/TAM 111. A set of 5,948 SNPs from the wheat 90K iSelect array and double digest restriction-site associated DNA sequencing was used to construct high-density genetic maps. Data for yield and yield components were obtained from 11 environments. QTL analyses were performed based on 11 individual environments, across all environments, within and across mega-environments. Thirty-six unique consistent QTL regions were distributed on 13 chromosomes including 1A, 1B, 1D, 2A, 2D, 3D, 4B, 4D, 6A, 6B, 6D, 7B, and 7D. Ten unique QTL with pleiotropic effects were identified on four chromosomes and eight were in common with the consistent QTL. These QTL increased dry biomass grain yield by 16.3 g m-2, plot yield by 28.1 g m-2, kernels spike-1 by 0.7, spikes m-2 by 14.8, thousand kernel weight by 0.9 g with favorable alleles from either parent. TAM 112 alleles mainly increased spikes m-2 and thousand kernel weight while TMA 111 alleles increased kernels spike-1, harvest index and grain yield. The saturated genetic map and markers linked to significant QTL from this study will be very useful in developing high throughput genotyping markers for tracking the desirable haplotypes of these important yield-related traits in popular parental cultivars.
The normalized difference vegetation index (NDVI) has been widely used to quantify vegetation by measuring the difference between near-infrared (NIR) and red light. Measuring NDVI throughout a growing season helps to evaluate the effect of continuous phenological and morphological changes on grain yield. A 2-year field study was conducted to characterize plant response to water stress in 20 winter wheat (Triticum aestium L.) genotypes during the season based on their NDVI values under the dryland and irrigated conditions. In addition, final biomass and yield were measured at maturity. The 2018 season was extremely dry with only 23 mm of precipitation, whereas 2016 was more favorable for wheat production with 315 mm seasonal precipitation. Except in a severe drought condition (2018, dryland), NDVI values increased from early spring to mid-season (anthesis) and decreased from mid-season to physiological maturity, indicating gradual leaf senescence. There was a significant (P = 0.05) positive correlation between NDVI and grain yield, especially for NDVI values after jointing. However, under the severe drought condition of 2018 (dryland), NDVI often did not show a strong relationship with grain yield. Even genotypes with higher NDVI at early growth stages ended up with lower yield because of the severe water stress at later growth stages. Hence, the use of NDVI is not suggested in screening genotypes for yield under extreme weather conditions.
Where disease threatens endangered wildlife populations, substantial resources are required for management actions such as vaccination. While network models provide a promising tool for identifying key spreaders and prioritizing efforts to maximize efficiency, population-scale vaccination remains rare, providing few opportunities to evaluate performance of model-informed strategies under realistic scenarios. Because the endangered Hawaiian monk seal could be heavily impacted by disease threats such as morbillivirus, we implemented a prophylactic vaccination programme. We used contact networks to prioritize vaccinating animals with high contact rates. We used dynamic network models to simulate morbillivirus outbreaks under real and idealized vaccination scenarios. We then evaluated the efficacy of model recommendations in this real-world vaccination project. We found that deviating from the model recommendations decreased the efficiency; requiring 44% more vaccinations to achieve a given decrease in outbreak size. However, we gained protection more quickly by vaccinating available animals rather than waiting to encounter priority seals. This work demonstrates the value of network models, but also makes trade-offs clear. If vaccines were limited but time was ample, vaccinating only priority animals would maximize herd protection. However, where time is the limiting factor, vaccinating additional lower-priority animals could more quickly protect the population.
Environmental microplastics are widely documented in marine life and bioaccumulation may present risks to marine predators. Investigations of microplastics in marine mammals are increasing, though none have examined animals routinely consumed by humans. Here, we investigate microplastic exposure in the northern fur seal (Callorhinus ursinus), a species consumed by humans, using fecal material. We examined 44 feces (scat) at sites encompassing the seals' eastern Pacific range. Multiple contamination control measures were implemented, including field and laboratory controls. Fragments were the most common microplastic recovered, in 55% (24/44) of scat and no controls (range 1 to 86 fragments/scat, mean 16.6, sd 19.1). Microplastic fibers were recovered from 41% of scats (18/44), though some controls contained fibers confounding fiber results. Fecal analysis documented northern fur seal exposure to microplastics throughout their eastern Pacific range.
‘TAMO 411’ (Reg. No. CV‐384, PI 675450) winter oat (Avena sativa L.) was developed and released by Texas A&M AgriLife Research in 2012 based on the merits of its excellent grain yield, volume weight, forage potential, winter survival, and straw strength as compared to all recent Texas A&M AgriLife Research oat releases. It was also highly resistant to crown rust and moderately resistant to stem rust races prevalent in Texas during the time of its release. Authorized seed classes of TAMO 411 in the United States are breeder, foundation, registered, and certified. TAMO 411 was submitted for US Plant Variety Protection (PVP) under Public Law 91‐577 with the Certification Only option and a PVP certificate has been issued (Certificate No. 201500356).
Core Ideas We investigated the depth and amount of soil‐water extraction in TAM wheat cultivars. Yield was largely related to soil‐water extraction under dryland conditions. Relatively newer cultivars were able to extract more water from deeper soil profile. Drought is the most important factor limiting wheat (Triticum aestivum L.) yield in the U.S. southern High Plains (SHP). Adoption of suitable cultivars and crop management practices are crucial to reducing yield loss from drought in the area. We conducted a 5‐yr study to investigate the depth and amount of net soil water extraction (SWE) in four wheat cultivars at different growth stages. Plants were grown under dryland conditions and volumetric soil water content (SWC) was measured in 0.2‐m increments to the depth of 2.4 m at planting, jointing, anthesis, and maturity. There were large variations in grain yields (474–3685 kg ha−1) in dryland wheat across years and cultivars. Yield was largely determined by plant available soil water (PASW) at planting and seasonal precipitation. In a season with high yield (3548 kg ha−1 in 2016), net SWE occurred in the whole 0.0‐ to 2.4‐m profile. In contrast, in a season with very low yield (650 kg ha−1 in 2011), net SWE was limited to the upper 1.2 m. More recent cultivars (TAM 110, TAM 111, and TAM 112) were able to extract more water from deeper in the soil profile (particularly between jointing and maturity), and had higher evapotranspiration (ET), biomass, and yield than the legacy wheat cultivar (TAM 105), especially during the dry seasons of 2011 and 2012. This study demonstrated that effective use of soil water from greater soil depths is important for greater ET and yield under dryland conditions in a semiarid environment.