Understudied Species Research Articles

Formerly considered rare, the ant species Cryptoponeochracea (Mayr, 1855) can be commonly detected using citizen-science tools.

Citizen science is a valuable tool for monitoring different species, especially in cases concerning truly rare and difficult-to-detect species where time-consuming field studies are limited and long-term research projects are uncertain. To better understand the distribution of the rarely collected Cryptoponeochracea (Mayr, 1855) (Hymenoptera, Formicidae) in Hungary, we obtained the occurrence data with photos uploaded by non-professionals to the page of the largest Hungarian Facebook group dealing with ants and a citizen-science website dealing with biological data collection. In this article, we expand the known distribution of C.ochracea to include 46 new records from Hungary and one from Serbia. With two historical records, this previously undersampled species has now been found 48 times in Hungary. Our results prove that social media platforms and other websites for citizen science projects offer new and useful opportunities for researchers to involve non-professionals in scientific work and, thus, obtain large amounts of valuable data, even for understudied arthropod species.

Reducing uncertainty in climate change responses of inland fishes: A decision‐path approach

AbstractClimate change will continue to be an important consideration for conservation practitioners. However, uncertainty in identifying appropriate management strategies, particularly for understudied species and regions, constrains the implementation of science‐based solutions and adaptation strategies. Here, we share a decision‐path approach to reduce uncertainty in climate change responses of inland fishes to inform conservation and adaptation planning. With the Fish and Climate Change database (FiCli), a comprehensive, online, public database of peer‐reviewed literature on documented and projected climate impacts to inland fishes, users can identify relevant studies and associated management recommendations via geographic regions, response types (i.e., fish assemblage dynamics, demographic, distributional, evolutionary, phenological), fish taxa, and traits (e.g., thermal guilds, feeding type, parental care, habitat type) and use a suite of summary tools to make more informed decisions. For both data‐rich and data‐poor scenarios, we demonstrate that this approach can reduce uncertainty in understanding climate change responses. Using thermal sensitivity as an example, we also establish the utility of FiCli database to address other user‐defined, management‐relevant questions via supplementary analyses. This decision‐path approach can be applied to rapid assessments, management decisions, and policy development and may serve as a model for other conservation decision‐making processes.

Influence of check dams on the activity pattern and morphometric traits of overwintering tadpoles in the Western Himalaya

Delaying metamorphosis in low-temperature conditions by anuran larvae known as ‘overwintering’ have been poorly studied, especially in terms of habitat ecology and behavioural aspects. The present study investigates some of the ecological aspects of overwintering tadpoles of the genus Nanorana in the Western Himalaya in an anthropogenically modified stream where check dams have altered the natural habitat, which can potentially influence the amphibian ecology. We present insights on the influence of check dams on the tadpole activity pattern and morphometric traits useful in the conservation planning of the narrowly distributed and understudied species, which are most sensitive to habitat modification.We monitored natural and modified pool habitats in the stream during winter and post-winter seasons based on the visual density of tadpoles to assess the diurnal and seasonal emergence pattern with associated habitat variables. Generalized Linear Mixed Modeling (GLMM) was used to understand the influence of various habitat variables on the visible density of tadpoles. Fine-scale temporal scan sampling of tadpoles was carried out to complement the understanding of the visible density variation and analyzed using circular plots and activity overlap estimation. Variation in morphometric traits was assessed using field morphometry and photogrammetry.Mean tadpole visible density at nighttime was higher in modified pools than natural pools during winter, but there was no statistically significant difference during daytime; the nocturnal pattern changed in the post-winter, where visible density was higher in natural pools. Tadpole visible density was influenced by the interaction of mean canopy cover with water temperature, instream cover items richness, mean canopy cover percentage, water temperature, leaf litter depth, water velocity and interaction of time of the day with pool modification. Tadpole activity patterns varied significantly between pool types during post-winter, where modified pool population increased daytime activity and thus the activity overlap reduced from winter (90.8%) to post-winter (64.5%). During both seasons, the mean body size of the natural pool population was significantly lower than the modified pool population; mean relative tail length was significantly lower in natural pools during post-winter; mean tail depth was significantly lower in natural pools during winter.The study presents evidence of the influence of anthropogenic habitat alterations on behaviour and morphometric traits of overwintering tadpoles, which needs to be further investigated. We also discuss the variation in nocturnal emergence, habitat selection and morphometric trait patterns in the modified habitat, potential reasons and similar behaviour in other aquatic organisms, which need to be considered while developing conservation strategies for the overwintering tadpoles in the region.

Primatology in zoos: Studying behavior, cognition, and welfare

Primatological research in zoos is increasing globally. Such research allows scientists to study primate biology, behavior, and cognition while helping to advance the welfare of captive primates. Moreover, zoos welcome millions of visitors annually, which creates unique opportunities for public engagement with this research. Reflecting the importance of zoos in the field of primatology, the articles in this special issue showcase the range of primatological research currently being conducted in zoos around the world. With this special issue, I have chosen to focus on research examining primate behavior and cognition, addressing both basic and applied questions. The articles included in this special issue also highlight the array of technologies and methods being used to study zoo-housed primates. While zoos house a variety of primate species, potentially enabling the testing of under-studied species or widescale comparative research, great apes are disproportionately represented in current zoo-based research. Thus, while an interest in conducting research with primates in zoos continues to grow, there are still opportunities to increase the breadth and diversity of this study.

A large-scale citizen science approach to assess the distribution and ecology of the declining Garden Dormouse in Germany

The Garden Dormouse has shown an ongoing decline over the last decades across large parts of its range. As the reasons for the species’ shrinking range are poorly understood, effective conservation actions have been lacking so far. The Germany- wide project “In Search of the Garden Dormouse” aims to investigate the causes, and develop concepts and measures to mitigate the decline. The current distribution has been assessed using a large-scale citizen science approach. More than 6,000 dormouse observations were gathered via an online reporting tool, of which >4,000 reports could be verified by photos, videos, or call recordings. Our aim was to obtain important information about the ecology of the species in different habitat types. For this, volunteers systematically collected approximately 1,000 Garden Dormouse droppings for food analysis, installed footprint tunnels and camera traps, helped to obtain several hundred DNA samples, collected > 500 carcasses, and recorded Garden Dormouse calls from various sampling sites. Volunteers also used a novel device for automated Garden Dormouse monitoring in the field that was developed and successfully applied in support of the project. The gathered data displays the current Garden Dormouse distribution in Germany and provides insights into the biology and ecology of this endangered, understudied species. The multidisciplinary approach of the project combined several disciplines, from field ecology to population genomics, in a fruitful cooperation of scientists, citizen scientists, and a conservation NGO. It can serve as a template for future projects aiming to produce large-scale scientific data in animal research and conservation.

Life in the slow lane: field metabolic rate and prey consumption rate of the Greenland shark (Somniosus microcephalus) modelled using archival biologgers.

Field metabolic rate (FMR) is a holistic measure of metabolism representing the routine energy utilization of a species living within a specific ecological context, thus providing insight into its ecology, fitness and resilience to environmental stressors. For animals that cannot be easily observed in the wild, FMR can also be used in concert with dietary data to quantitatively assess their role as consumers, improving understanding of the trophic linkages that structure food webs and allowing for informed management decisions. Here, we modelled the FMR of Greenland sharks (Somniosus microcephalus) equipped with biologger packages or pop-up archival satellite tags (PSATs) in two coastal inlets of Baffin Island (Nunavut) using metabolic scaling relationships for mass, temperature and activity. We estimated that Greenland sharks had an overall mean (±s.d.) FMR of 21.67±2.30 mg O2 h-1 kg-0.84 (n=30; 1-4 day accelerometer package deployments) while residing inside these cold-water fjord systems in the late summer, and 25.48±0.47 mg O2 h-1 kg-0.84 (n=6; PSATs) over an entire year. When considering prey consumption rate, an average shark in these systems (224 kg) requires a maintenance ration of 61-193 g of fish or marine mammal prey daily. As Greenland sharks are a lethargic polar species, these low FMR estimates, and corresponding prey consumption estimates, suggest they require very little energy to sustain themselves under natural conditions. These data provide the first characterization of the energetics and consumer role of this vulnerable and understudied species in the wild, which is essential given growing pressures from climate change and expanding commercial fisheries in the Arctic.

Two new food items in the diet of the Aztec Thrush (Ridgwayia pinicola) and first evidence of florivory

The Aztec Thrush (Ridgwayia pinicola) is an understudied species. Many aspects of its basic biology are unknown, including its food and foraging preferences. Here, we describe observations of Aztec Thrush consuming fruits of the tree Ilex brandegeeana and flowers of the bromeliad Tillandsia bourgaei in the pine-oak forest of the highlands of Jalisco in western Mexico. These observations provide information about the diet of this species and its possible ecological role in regenerating and structuring processes of this forest.

Population characteristics of benthopelagic Gymnoscopelus nicholsi (Pisces: Myctophidae) on the continental shelf of South Georgia (Southern Ocean) during austral summer

Southern Ocean myctophid fish (Family Myctophidae) are an important conduit of energy through foodwebs and between the surface layers and mesopelagic depths. Species that reside in both pelagic and near-bottom environments of continental shelves, such as Gymnoscopelus nicholsi and Gymnoscopelus bolini, may also be important in benthopelagic coupling, although their ecology and role in such processes remain unresolved. Here, we examined inter-annual variation in the depth of occurrence, biomass and population dynamics of benthopelagic G. nicholsi on the South Georgia shelf (100–350 m) using bottom trawl data collected between 1987 and 2019. Gymnoscopelus nicholsi was a regular component of the local benthopelagic community, particularly northwest of South Georgia, but was patchily distributed. It appeared to enter a benthopelagic phase at ~ 3 years, with annual growth and recruitment of year classes between ~ 3 and 5 years. However, transition of cohorts into the benthopelagic zone was not annual. There was clear inter-annual variation in G. nicholsi biomass and depth of occurrence. Shallower depth of occurrence was significantly (P < 0.05) correlated with years of warmer summer sea surface temperatures, suggesting that inter-annual variation in local environmental conditions has an important influence on its migration behaviour and ecology. Our data also suggest that Antarctic krill is an important dietary component of the older G. nicholsi cohorts (~ 5 years) in the benthopelagic zone. We note that Gymnoscopelus bolini is rare in bottom trawl catches between 100 and 350 m, although Antarctic krill appears to dominate its diet from the available data. Our study provides important information on understudied myctophid species in a poorly investigated region of the water column that is relevant for Southern Ocean ecosystem studies, particularly in relation to understanding trophic connectivity between the pelagic and near-bottom realms.

A Review of Camera-Trapping Methodology for Eastern Spotted Skunks

Abstract Eastern spotted skunks Spilogale putorius are an understudied species that has experienced range-wide declines. Over the past 16 y, camera traps have become an increasingly common tool to monitor and understand their current distribution. To inform best surveying practices, we reviewed 16 camera-trap studies specifically targeting this species. We focused on reported latency to initial detection and three main aspects of study design: seasonality of detections, baits and lures, and camera-trap brands. Latency to initial detection ranged from 1 to 82 d with a mean of 17.1 d (SD = 9.1). Attractants varied among projects, but most (75%) used sardines as bait. The percentage of skunk detections tended to vary across the year, with the highest percentage of skunk detections occurring in March (92%). We conclude by suggesting best practices and directions for future research techniques that will aid in developing more efficient methods to address key knowledge gaps for this elusive species. Given the long timeframes for latency to initial detection, monitoring individual sites for at least 4 wk, with the use of bait, is likely the best strategy to detect eastern spotted skunks. We encourage further experimental approaches on the effectiveness of different baits and lures, and methods to increase latency to initial detection. Collectively, we hope this leads to the development of a standardized monitoring approach that researchers can implement across studies and states within the eastern spotted skunk's range.

The genome trilogy of Anopheles stephensi, an urban malaria vector, reveals structure of a locus associated with adaptation to environmental heterogeneity

Anopheles stephensi is the most menacing malaria vector to watch for in newly urbanising parts of the world. Its fitness is reported to be a direct consequence of the vector adapting to laying eggs in over-head water tanks with street-side water puddles polluted by oil and sewage. Large frequent inversions in the genome of malaria vectors are implicated in adaptation. We report the genome assembly of a strain of An. stephensi of the type-form, collected from a construction site from Chennai (IndCh) in 2016. The genome reported here with a L50 of 4, completes the trilogy of high-resolution genomes of strains with respect to a 16.5 Mbp 2Rb genotype in An. stephensi known to be associated with adaptation to environmental heterogeneity. Unlike the reported genomes of two other strains, STE2 (2R+b/2Rb) and UCI (2Rb/2Rb), IndCh is found to be homozygous for the standard form (2R+b/2R+b). Comparative genome analysis revealed base-level details of the breakpoints and allowed extraction of 22,650 segregating SNPs for typing this inversion in populations. Whole genome sequencing of 82 individual mosquitoes from diverse geographical locations reveal that one third of both wild and laboratory populations maintain the heterozygous genotype of 2Rb. The large number of SNPs can be tailored to 1740 exonic SNPs enabling genotyping directly from transcriptome sequencing. The genome trilogy approach accelerated the study of fine structure and typing of an important inversion in An. stephensi, putting the genome resources for this understudied species on par with the extensively studied malaria vector, Anopheles gambiae. We argue that the IndCh genome is relevant for field translation work compared to those reported earlier by showing that individuals from diverse geographical locations cluster with IndCh, pointing to significant convergence resulting from travel and commerce between cities, perhaps, contributing to the survival of the fittest strain.

Modelling the distribution and intraguild associations of an understudied mesocarnivore across the contiguous United States

AbstractAimUnderstanding the range‐wide distribution and abundance of species is critical for their conservation and management. Grey foxes (Urocyon cinereoargenteus) are an understudied, low‐density mesocarnivore with a broad geographic range. However, the factors that underlie this broad distribution are poorly understood and large‐scale analyses of this species’ range and ecological niche are lacking.LocationWe modelled the probability and intensity of site use for grey foxes at two spatial scales using a coordinated survey of 1485 camera traps across the contiguous United States in 2019.MethodsWe used Bayesian occupancy modelling and post hoc species interaction comparisons to evaluate factors hypothesized to affect grey fox site use, including habitat, anthropogenic effects, and intraguild interactions.ResultsOur results showed that the presence of bobcats (Lynx rufus) and striped skunks (Mephitis mephitis), as well as forest variables, had positive associations with grey fox site use. Surprisingly, we found no support for negative effects on grey fox space use from dominant competitors (coyotes, Canis latrans, or pumas, Puma concolor), and a complete lack of effects from urbanization metrics and gross primary productivity. We did, however, find a consistent negative association with red foxes (Vulpes vulpes), which is the most ecologically and morphologically similar competitor of grey foxes.Main conclusionsTaken together, these results imply that grey fox distribution is not limited by dominant carnivores or anthropogenic pressure. Rather, this species seems to occupy a unique niche across its broad range by exploiting diverse forest habitats shared with less ecologically similar competitors (striped skunks and raccoons, Procyon lotor), while being somewhat limited by a competitor occupying a similar ecological niche (red foxes). Our study highlights the value of broad‐scale approaches for evaluating factors influencing the distribution and abundance of understudied species, as local dynamics might fail to manifest across geographic ranges.

A trait‐based framework for predicting foodborne pathogen risk from wild birds

Recent foodborne illness outbreaks have heightened pressures on growers to deter wildlife from farms, jeopardizing conservation efforts. However, it remains unclear which species, particularly birds, pose the greatest risk to food safety. Using >11,000 pathogen tests and 1565 bird surveys covering 139 bird species from across the western United States, we examined the importance of 11 traits in mediating wild bird risk to food safety. We tested whether traits associated with pathogen exposure (e.g., habitat associations, movement, and foraging strategy) and pace-of-life (clutch size and generation length) mediated foodborne pathogen prevalence and proclivities to enter farm fields and defecate on crops. Campylobacter spp. were the most prevalent enteric pathogen (8.0%), while Salmonella and Shiga-toxin producing Escherichia coli (STEC) were rare (0.46% and 0.22% prevalence, respectively). We found that several traits related to pathogen exposure predicted pathogen prevalence. Specifically, Campylobacter and STEC-associated virulence genes were more often detected in species associated with cattle feedlots and bird feeders, respectively. Campylobacter was also more prevalent in species that consumed plants and had longer generation lengths. We found that species associated with feedlots were more likely to enter fields and defecate on crops. Our results indicated that canopy-foraging insectivores were less likely to deposit foodborne pathogens on crops, suggesting growers may be able to promote pest-eating birds and birds of conservation concern (e.g., via nest boxes) without necessarily compromising food safety. As such, promoting insectivorous birds may represent a win-win-win for bird conservation, crop production, and food safety. Collectively, our results suggest that separating crop production from livestock farming may be the best way to lower food safety risks from birds. More broadly, our trait-based framework suggests a path forward for co-managing wildlife conservation and food safety risks in farmlands by providing a strategy for holistically evaluating the food safety risks of wild animals, including under-studied species.

The pikas of China: a review of current research priorities and challenges for conservation.

Of the approximately 30 extant species of pika (Ochotona; Ochotonidae; Lagomorpha), at least 23 occur in China. Of these, 8 are endemic, and 3 are classified as Endangered by the IUCN. Research into most Chinese species is scarce, and there is much to learn about basic aspects of their ecology. We reviewed the literature on the 23 Chinese Ochotona species, with the aim of highlighting knowledge gaps and biases in research allocation. Specifically, we identify (1) which pika species receive the most attention from researchers, (2) which topics are the most frequently studied, and (3) how well research satisfies conservation priorities. We covered a total of 879 articles, most of which were written in English or Chinese. Around 75% of all publications focused on the plateau pika Ochotona curzoniae. Seven species were represented by 10 or fewer publications each. Endangered and endemic species were particularly poorly represented. 204 papers treated pikas as a pest, while 13 studied conservation issues. Nine species were considered possible targets for pest control, including some poorly known endemics. We make some recommendations on how research into Chinese Ochotona could be improved, including: (1) recognizing that the current species-level taxonomy may be an ineffective way to prioritize conservation research in Ochotona, (2) directing more research toward threatened and endemic species, subspecies, and populations, (3) researching the ecosystem engineering effects of pikas, (4) collecting basic data on natural history of the many understudied species, and (5) researching threats, including climate change and pest control campaigns.

Stability and change in gartersnake social networks across ontogeny

AbstractDevelopmental studies of sociality in non‐human animals can offer important insights into the evolution, function, and plasticity of social behavior, especially in understudied species. We examined the development of social behavior in gartersnakes. We hypothesized that social interactions change as snakes age, but are relatively stable in the short term. To assess developmental changes in social patterns, we examined the social tendencies of a group of 6 eastern gartersnakes over the first year and a half of their lives. We placed the snakes in an arena for 8 days and recorded the time that they spent in physical proximity to each other. We repeated this 8‐day process 7 times across the snakes’ development. We looked at changes in association patterns and individual differences in sociality (i.e., network position), and examined the effect of group size reduction on social behavior. We found that individuals tended to show repeatable network position across time, but there was a behavioral divide between younger snakes and mature snakes. When male snakes reached sexual maturity, they began initiating most social interactions. Additionally, group member attrition caused the networks to tighten, and the population reduction in combination with sexual maturity created stable social networks. This research shows that social context can have important effects on sociability, and that even a species without permanent social groups will be influenced by its social environment.

A Global Review of Causes of Morbidity and Mortality in Free-Living Vultures.

Vulture species worldwide play a key role in ecosystems as obligate scavengers, and several populations have had precipitous declines. Research on vulture health is critical to conservation efforts including free-living vultures and captive breeding programs, but is limited to date. In this systematic review, we determined the reported causes of free-living vulture species morbidity and mortality worldwide. The most commonly reported cause of mortality was from toxins (60%), especially lead and pesticides, followed by traumatic injury (49%), including collisions with urban infrastructure and gunshot. Neglected areas of research in free-living vulture health include infectious diseases (16%), endocrine and nutritional disorders (6%), and neoplasia (< 1%). Almost half of the studies included in the review were conducted in either Spain or the USA, with a paucity of studies conducted in South America and sub-Saharan Africa. The highest number of studies was on Griffon (Gyps fulvus) (24%) and Egyptian vultures (Neophron percnopterus) (19%), while half of all vulture species had five or fewer studies. Future investigations on free-living vulture health should focus on neglected areas of research, such as infectious diseases, and areas with gaps in the current literature, such as South America, sub-Saharan Africa, and under-studied vulture species.

Emerging models: The "development" of the ctenophore Mnemiopsis leidyi and the cnidarian Nematostella vectensis as useful experimental models.

The goal of this chapter is to explain the reasoning for developing two understudied invertebrate animal species for asking specific biological questions. The first is the ctenophore (comb jelly) Mnemiopsis leidyi and the second is the anthozoan cnidarian (starlet sea anemone) Nematostella vectensis. Although these two taxa belong to some of the earliest branching extant metazoan clades, their developmental features could hardly be more different from one another. This should serve as a general warning to be careful when extrapolating comparisons of one species to another. Two-taxon comparisons are especially flawed; and to interpret features in a phylogenetic context one must sample carefully within a given taxon to determine how representative certain features are before comparing with other clades. The other benefit of this comparison is to identify key practical factors when attempting to develop new species for experimental investigation.

Evaluating Environmental Enrichment Methods in Three Zoo-Housed Varanidae Lizard Species

Environmental enrichment has been shown to enhance the behavioural repertoire and reduce the occurrence of abnormal behaviours, particularly in zoo-housed mammals. However, evidence of its effectiveness in reptiles is lacking. Previously, it was believed that reptiles lacked the cognitive sophistication to benefit from enrichment provision, but studies have demonstrated instances of improved longevity, physical condition and problem-solving behaviour as a result of enhancing husbandry routines. In this study, we evaluate the effectiveness of food- and scent-based enrichment for three varanid species (Komodo dragon, emerald tree monitor lizard and crocodile monitor). Scent piles, scent trails and hanging feeders resulted in a significant increase in exploratory behaviour, with engagement diminishing ≤330 min post provision. The provision of food- versus scent-based enrichment did not result in differences in enrichment engagement across the three species, suggesting that scent is just as effective in increasing natural behaviours. Enhancing the environment in which zoo animals reside is important for their health and wellbeing and also provides visitors with the opportunity to observe naturalistic behaviours. For little known and understudied species such as varanids, evidence of successful (and even unsuccessful) husbandry and management practice is vital for advancing best practice in the zoo industry.

The influence of social context on pinyon mouse (Peromyscus truei) vocalizations

Abstract Mice in the diverse genus Peromyscus are emerging as important models in the study of acoustic communication. However, reports on vocal repertoires exist for only 8 of the 56 currently recognized species. Descriptions of acoustic content and context are necessary to facilitate comparative studies. In this study, we present the first recordings of wild-captured pinyon mice (Peromyscus truei) in the laboratory in different social contexts. Similar to other Peromyscus species, pinyon mice produced four general types of vocalizations, including sustained vocalizations (SVs), barks, simple sweeps, and complex sweeps. SVs were produced primarily by females in social isolation, highlighting the potential significance of SVs in female advertisement behavior. While agonistic barks were rare, simple and complex sweeps were reliably produced in response to olfactory cues from same- and opposite-sex mice, and in paired contexts. Opposite-sex pairs produced significantly more complex sweeps than same-sex pairs, consistent with the well-supported function of sweeps in coordinating close-distance interactions. In addition, females produced sweeps with lower peak frequencies following separation from their social partner, indicative of a sex-specific mechanism to facilitate advertisement to potential mates and competitors. Together, our findings highlight the importance of social context in rodent vocal production, the significance of female vocal behavior, and the continued need to sample understudied species to better understand similarities and differences in rodent communication systems.

Assessing the extinction risk of insular, understudied marine species.

Hydrothermal vents are rare deep‐sea oases that house faunal assemblages with a similar density of life as coral reefs. Only approximately 600 of these hotspots are known worldwide, most only one‐third of a football field in size. With advancing development of the deep‐sea mining industry, there is an urgent need to protect these unique, insular ecosystems and their specialist endemic faunas. We applied the IUCN (International Union for the Conservation of Nature) Red List criteria to assess the extinction risk of vent‐endemic molluscs with varying exposure to potential deep‐sea mining. We assessed 31 species from three key areas under different regulatory frameworks in the Indian, West Pacific, and Southern Oceans. Three vent mollusc species were also examined as case studies of different threat contexts (protected or not from potential mining) to explore the interaction of local regulatory frameworks and IUCN Red List category assignment. We found that these assessments were robust even when there was some uncertainty in the total range of individual species, allowing assessment of species that have only recently been named and described. For vent‐endemic species, regulatory changes to area‐based management can have a greater impact on IUCN Red List assessment outcomes than incorporating additional data about species distributions. Our approach revealed the most useful IUCN Red List criteria for vent‐endemic species: criteria B and D2. This approach, combining regulatory framework and distribution, has the potential to rapidly gauge assessment outcomes for species in insular systems worldwide.

The Current Status of the World\u2019s Primates: Mapping Threats to Understand Priorities for Primate Conservation

Over the past decades, primate populations have been declining. Four years ago, >60% of species were listed as threatened. As the rate of loss accelerates and new IUCN assessments are being published, we used IUCN Red List assessments and peer-reviewed literature published within the last 5 yr to evaluate the status of primates globally, by region and by taxonomic group. We also examined the main factors affecting a species’ conservation status to determine if we could predict the status of understudied species. We found that 65% of species are in the top three IUCN Red List categories (Vulnerable, Endangered, Critically Endangered). Globally, the main threats to primates are Biological Resource Use, including Hunting & Logging, and Agriculture. The impact of these threats varied by region and taxon. Our model showed that Malagasy and Asian primates, and those affected by Agriculture, Human Disturbance, and Climate Change were more likely to be considered at risk of extinction. The model’s predictive probability, however, was low. Our literature analysis showed that some threats, especially climate change and disease, affected more species than indicated by the IUCN Red List. As we move into the next decade, we must continue tackling hunting and agricultural expansion but also be vigilant about emerging threats. We must also aim to regularly test the effectiveness of mitigation strategies, evaluating their long-term adoption and their impact on primates; as well as to increase communication between researchers and applied conservationists to ensure IUCN assessments include current and emerging threats.