Camera Trap Photos Research Articles

First Photographic Evidence of the Central African Oyan in Uganda

ABSTRACTArboreal camera trap photographs were captured of the Central African Oyan Poiana richardsonii in Bwindi Impenetrable National Park, Uganda. In total, 10 photographs were obtained from three sites in the park in 2019. This is likely the furthest east record of this species.

External and internal driving forces of community and functional group stability in the forest mammal community

Conserving mammal community stability in forest ecosystems is an urgent challenge in the face of global biodiversity threats and complex trophic interaction. However, understanding of the stability of mammal communities and targeted functional groups is still limited, hindering adaptive strategy development. We collected 210 120 camera trap photos across 5897 km 2 within the Amur tiger ( Panthera tigris altaica ) range in China’s natural forests. We decomposed stability into compensatory effects, statistical-averaging effects and population stability. Using structural equation modelling, we explored the impact of external factors, species diversity and vertical effects on the stability of the community and of four functional groups. As external factors, primary productivity increased the stability of top predators, while precipitation had inconsistent effects. Horizontal diversity (richness and evenness) positively impacted community stability. However, the vertical structure of the community, including trophic-level richness and functional groups’ compensatory dynamics, were the largest drivers for maintaining community stability. Horizontal diversity within functional groups and the diversity or biomass of their food resources/consumers both influenced the stability of functional groups. Our results recognize the importance of conserving and even re-establishing vertical trophic structures in forest communities. Acknowledging multiple levels of stability, from functional groups to communities, is an indispensable step for effective conservation strategies.

Estimating body condition of Apennine brown bears using subjective scoring based on camera trap photographs

The assessment of animal body condition has important practical and management implications for endangered wildlife populations. The nutritional condition of a population can be evaluated in a non-invasive way using photogrammetry techniques, avoiding direct manipulation. This study evaluates the utility of using body condition scoring (BCS) based on the visual assessment of subcutaneous fat and muscle from the body contour as a non-invasive method to quantify body condition in free ranging bears from camera trap photographs. Photographs of Apennine brown bears (Ursus arctos marsicanus), taken between 2007 and 2009 in the Abruzzo, Lazio and Molise National Park (PNALM, Italy), were used to evaluate the potential of this technique. BCS assessment was performed on 754 photographs representing 71 independent observations. Forty-eight of these photographs were selected to also score quantitative body ratios using a standardised measure of torso height. BCS varied seasonally, as expected by food availability and brown bear nutritional physiology, and it was also positively correlated to all three body ratios. Our findings indicate that BCS assessment is a good proxy for body condition, and that camera trap data can be effectively used to assess and monitor the nutritional condition of bear populations, such as the critically endangered one in central Italy.

FSC-certified forest management benefits large mammals compared to non-FSC

More than a quarter of the world’s tropical forests are exploited for timber1. Logging impacts biodiversity in these ecosystems, primarily through the creation of forest roads that facilitate hunting for wildlife over extensive areas. Forest management certification schemes such as the Forest Stewardship Council (FSC) are expected to mitigate impacts on biodiversity, but so far very little is known about the effectiveness of FSC certification because of research design challenges, predominantly limited sample sizes2,3. Here we provide this evidence by using 1.3 million camera-trap photos of 55 mammal species in 14 logging concessions in western equatorial Africa. We observed higher mammal encounter rates in FSC-certified than in non-FSC logging concessions. The effect was most pronounced for species weighing more than 10 kg and for species of high conservation priority such as the critically endangered forest elephant and western lowland gorilla. Across the whole mammal community, non-FSC concessions contained proportionally more rodents and other small species than did FSC-certified concessions. The first priority for species protection should be to maintain unlogged forests with effective law enforcement, but for logged forests our findings provide convincing data that FSC-certified forest management is less damaging to the mammal community than is non-FSC forest management. This study provides strong evidence that FSC-certified forest management or equivalently stringent requirements and controlling mechanisms should become the norm for timber extraction to avoid half-empty forests dominated by rodents and other small species.

Spatiotemporal Niche Separation among Passeriformes in the Halla Mountain Wetland of Jeju, Republic of Korea: Insights from Camera Trap Data.

This study analyzed 5322 camera trap photographs from Halla Mountain Wetland, documenting 1427 independent bird sightings of 26 families and 49 species of Passeriformes. Key observations include morning activities in Cyanoptila cyanomelana and Horornis canturians and afternoon activity in Muscicapa dauurica and Phoenicurus auroreus. Wetlands were significantly preferred (P_i = 0.398) despite their smaller area, contrasting with underutilized grasslands (P_i = 0.181). Seasonal activity variations were notable, with overlap coefficients ranging from 0.08 to 0.81 across species, indicating diverse strategies in resource utilization and thermoregulation. Population density was found to be a critical factor in habitat usage, with high-density species showing more consistent activity patterns. The study's results demonstrate the ecological adaptability of Passeriformes in the Halla Mountain Wetland while highlighting the limitations of camera trapping methods. These limitations include their fixed field of view and intermittent recording capability, which may not fully capture the spectrum of complex avian behaviors. This research underlines the need for future studies integrating various methodologies, such as direct observation and acoustic monitoring, to gain a more comprehensive understanding of avian ecology.

A review of using deep learning from an ecology perspective to address climate change and air pollution

<p>Artificial intelligence techniques that can shatter pattern recognition accuracy records, has recently attracted a lot of attention. With its flexibility and capacity to handle massive and complicated datasets, deep learning has transformed numerous academic domains, including bioinformatics and medicine, in a few of years. We think ecologists can also benefit from these methods, since ecological datasets are getting bigger and more complicated. This review examined current implementations and demonstrates how deep learning has been effectively applied to classify animal activity, identify species, and estimate biodiversity in big datasets such as audio recordings, videos, and camera-trap photos. This review paper show that most ecological disciplines, including applied contexts like management and conservation, can benefit from deep learning. This review also identify frequent problems concerning the application of deep learning, like what is the process for building a deep learning network, what resources are available, and what kind of data and processing power are needed. To assist ecologists in utilising deep learning, it offer guidelines, suggestions, and helpful materials, such as a reference flowchart. This contend that deep learning has the potential to become an extremely useful reference tool for ecologists at a time when automated population and ecological monitoring creates massive amounts of data that humans are no longer able to interpret efficiently.</p>

The prey of the Harpy Eagle in its last reproductive refuges in the Atlantic Forest

The Harpy Eagle (Harpia harpyja) is threatened with extinction throughout its distribution in the neotropical forests. In the Atlantic Forest, deforestation has reduced the number of suitable habitats, with only a few remnant forest fragments hosting active nests; currently, the only known nests in this region are in the Central Atlantic Forest Ecological Corridor (CAFEC), in Brazil. Little is known about Harpy Eagle diets in this region, despite this information being essential for developing effective conservation strategies. We classified the composition, frequency, richness, ecological attributes, and conservation status of the species that make up the Harpy Eagle’s diet in its last refuges in the CAFEC. Between 2017 and 2021, we collected and analyzed 152 prey remains and 285 camera trap photographs from seven active nests. We identified at least 16 mammal species (96.7%), one parrot and other bird remains (3.3%). The Harpy Eagle’s diet consisted mainly of medium-sized arboreal, folivorous, frugivorous, and diurnal mammals. Five prey species are currently threatened with extinction at global, six at national and seven at regional levels. The majority of the diet consists of Sapajus robustus, which is threatened, and Bradypus variegatus, which is not threatened. In addition to the effects of habitat loss and hunting, the Harpy Eagle may also suffer from the decline in the populations of their prey in the Atlantic Forest.

Sexual Dimorphism Affects Herd Composition in African Antelopes

Herd behaviour is a crucial aspect of antelope development and survival. Understanding determinants of differences in herd composition is necessary to predict patterns of habitation, social interaction, and life history; thus, the possibility of sexual dimorphism acting as a dictator of herd size and composition in African antelope was explored. Sexual dimorphism is a key factor in determining intersexual and intrasexual interactions, which can create selection pressures driving divergence in behavioural and social traits. Consequently, it was predicted that sexually dimorphic species would exhibit increased social behaviour and be found in larger groups when compared to sexually monomorphic species. Two closely related species, sexually dimorphic impalas and non-sexually dimorphic hartebeests were compared using 60 camera trap photos obtained through the WildCam Gorongosa project to determine if there was a difference in herd size and the number of young observed. It was discovered that impalas were found in larger groups than hartebeests and that there was no difference in the proportion of offspring. This discrepancy can be attributed to sexually dimorphic females needing to group together for protection against predation as they lack horns for self-protection. Group size differences can imply tendencies to inhabit different habitats and exhibit unique social interactions within the herd while foraging. These findings are key in understanding herd behaviour in African antelopes and can be applied to accurately track and monitor antelope species’ success in relation to conservation.

Acoustic recording complements camera traps for monitoring sensitive penguin populations

In the face of global biodiversity loss that threatens social–ecological sustainability, we must improve our knowledge of species' behaviours, life histories and populations. Enhanced understanding is especially critical for taxa like seabirds that live in remote habitats where monitoring is logistically challenging, and technology‐based approaches could lead to major advances. Considering conservation threats and breeding behaviours, penguins represent a promising taxon for further exploration of monitoring methods. Only five of 18 penguin species are currently considered species of Least Concern by the IUCN, and the sensitivity of penguins to ecological disturbances makes them important indicators of ecosystem dynamics. Penguins regularly congregate in dense breeding colonies and are visually and aurally conspicuous animals, making them relatively easy to monitor in some respects. In situ observations and visual remote sensing monitoring methods (i.e. camera traps, uncrewed aerial vehicles and satellite imagery) currently provide highly valuable information on penguin behaviour and population dynamics, but these methods have a number of shortcomings. Several rely on human presence in remote areas, some require clean lines of sight with no visual obstructions, and some offer limited spatial and temporal resolution. In this study we explore the use of passive acoustic monitoring (PAM) as a complementary remote sensing method to monitor penguin behaviour and populations at high spatial and temporal resolution without visual constraints or the need for continuous human presence. We conducted observations of vocalization rates and placed automated acoustic recorders in colonies of Magellanic Penguins Spheniscus magellanicus and Southern Rockhopper Penguins Eudyptes chrysocome in conjunction with camera traps. We found positive relationships between acoustic activity and counts of Magellanic Penguins in camera trap photos. We also identified clear diel patterns of acoustic activity that differed between breeding stages, and we found positive correlations between acoustic activity and estimates of colony density for various times of day and radii around recorders. While much work remains to improve this method and refine interpretation, PAM holds great promise as a complementary tool for monitoring the relative abundance and behavioural dynamics of penguins and other colonial animals, particularly those that burrow or nest in dense vegetation that impairs visual monitoring techniques.

Setting large- and medium-sized mammal restoration goals in a last mountain Chaco remnant from central Argentina

BackgroundSetting large- and medium-sized wild mammal (≥ 2 kg) restoration goals is important due to their role as ecosystem engineers and generalized numeric reductions. However, determining wild mammal restoration goals is very challenging due to difficulties in obtaining data on current mammal density and due to unclear information on what mammal density values should be used as a reference. Here we chose a 154 ha conservation area within one of the last remnants of the mountainous Chaco from central Argentina. We suspected that extensive and unreported defaunation had occurred due to past human pressure and the introduction of non-native mammals. To conduct the analyses, we used a simplified technique that integrates methods used in rangeland and ecological sciences.ResultsEight native mammal species including only one herbivore species, and four non-native mammal species including three herbivore species were detected during 6113 camera trap days. We used known cattle densities as estimated by droppings and direct counts, together with the relative abundance indexes obtained from camera trap photos to calculate the densities of the other species, correcting for mammal size. Densities for the least and most abundant native species were 0.2 and 1.33 individuals km−2, respectively; and for non-native species, 0.03 and 5.00 individuals km−2, respectively. Native and non-native species represented 0.8% and 99.2%, respectively, of the biomass estimates. Reference values for native herbivore biomass, as estimated from net primary productivity, were 68 times higher than values estimated for the study area (3179 vs. 46.5 kg km−2).ConclusionsThere is an urgent need to increase native mammals, with special emphasis on herbivore biomass and richness, while non-native mammal numbers must be reduced. As cattle are widespread in large portions of the globe and there is a lot of experience estimating their abundances, the ratio method we used extrapolating from cattle to other large- and medium-sized mammals could facilitate estimating mammal restoration goals in other small and defaunated areas, where traditional methods are not feasible when target mammal densities get very low.

New records of the Anatolian leopard (Panthera pardus tulliana Valenciennes 1856) in Türkiye

In this study, new records of the Anatolian leopard obtained in Türkiye after 2004 were presented. Many field studies were carried out in 37 provinces in Türkiye, from Kars in the far east to Edirne in the west, from Antalya in the south to Kastamonu in the north. Until 2013, footprints of the leopard were primarily used to indicate leopard presence, and in later studies, camera traps and thermal cameras were also used in addition to the footprints. As a result of the study, a total of 84 new records from 54 different localities were obtained from all regions except the Marmara region in Northwestern Türkiye. Most of the records were obtained from Northeastern (NE) Türkiye, where most field studies were carried out. A total of 84 new records are listed as follows; 66 footprints, 4 camera trap photos, 1 camera trap video, 3 thermal camera videos, 2 cell phone videos, 1 cell phone photo, 4 locals seen, 1 full skin, 1 death, and 1 fatal attack.

Behavioral "bycatch" from camera trap surveys yields insights on prey responses to human-mediated predation risk.

Human disturbance directly affects animal populations and communities, but indirect effects of disturbance on species behaviors are less well understood. For instance, disturbance may alter predator activity and cause knock‐on effects to predator‐sensitive foraging in prey. Camera traps provide an emerging opportunity to investigate such disturbance‐mediated impacts to animal behaviors across multiple scales. We used camera trap data to test predictions about predator‐sensitive behavior in three ungulate species (caribou Rangifer tarandus; white‐tailed deer, Odocoileus virginianus; moose, Alces alces) across two western boreal forest landscapes varying in disturbance. We quantified behavior as the number of camera trap photos per detection event and tested its relationship to inferred human‐mediated predation risk between a landscape with greater industrial disturbance and predator activity and a “control” landscape with lower human and predator activity. We also assessed the finer‐scale influence on behavior of variation in predation risk (relative to habitat variation) across camera sites within the more disturbed landscape. We predicted that animals in areas with greater predation risk (e.g., more wolf activity, less cover) would travel faster past cameras and generate fewer photos per detection event, while animals in areas with less predation risk would linger (rest, forage, investigate), generating more photos per event. Our predictions were supported at the landscape‐level, as caribou and moose had more photos per event in the control landscape where disturbance‐mediated predation risk was lower. At a finer‐scale within the disturbed landscape, no prey species showed a significant behavioral response to wolf activity, but the number of photos per event decreased for white‐tailed deer with increasing line of sight (m) along seismic lines (i.e., decreasing visual cover), consistent with a predator‐sensitive response. The presence of juveniles was associated with shorter behavioral events for caribou and moose, suggesting greater predator sensitivity for females with calves. Only moose demonstrated a positive behavioral association (i.e., longer events) with vegetation productivity (16‐day NDVI), suggesting that for other species bottom‐up influences of forage availability were generally weaker than top‐down influences from predation risk. Behavioral insights can be gleaned from camera trap surveys and provide complementary information about animal responses to predation risk, and thus about the indirect impacts of human disturbances on predator–prey interactions.

Camera Trap Evidence of Polymorphic Asiatic Golden Cat (Catopuma temminckii) in Trashigang Forest Division, Eastern Bhutan

The Asiatic golden cat, Catopuma temminckii, is a medium-sized felinae distributed throughout South Asia. It is currently categorized as Near Threatened on the IUCN Red List and listed in Appendix I by CITES and Schedule I of the Forest and Nature Conservation Act of Bhutan, 1995. The six colour morphs of Asiatic golden cats have been recognized from their geographic range. The present study (2014-2015) was conducted as a part of the third nationwide tiger survey and wildlife monitoring assessments (2017-2021) in the Trashigang Forest Division. We used camera traps as a tool for the survey. The camera trap photographs confirmed the occurrence of five morphs of Asiatic golden cat from the present locality. All five morphs were photographed at altitudes ranging from 2200-3800 m. The results highlight the importance of conserving eastern Himalayan landscapes to ensure the safe refuse to globally threatened felids, including Asiatic golden cat.

The European Mink (Mustela lutreola) on Kunashir Island: Confirmed Survival 40 years After Introduction

In the early 1980s, the European mink (Mustela lutreola) was introduced on Kunashir [Kunashiri] Island in the Kuril [Chishima] Islands in order to preserve it in a region where its main competitor, the American mink (Neovison vison), is absent. We present records of the European mink on Kunashir in 2014–2021. In 23 cases, mink footprints were recorded on the snow or on sandbanks; in other nine cases, the animals were recorded visually or using camera traps. Camera trap photos reliably confirm the existence of a European mink population far from its severely contracted native range. The data were used to compose the dataset “Database of the European mink [Mustela lutreola (Linnaeus, 1761)] occurrence on Kunashir Island” that was transferred to the open international repository GBIF.

Rasprostranjenost i najmanja veličina populacije euroazijskog risa (Lynx lynx) u Hrvatskoj u razdoblju 2018.–2020.

Scientific data on distribution and abundance of endangered species are the foundation for their effective conservation and management. In this paper, we present results of the first scientifically – based estimation of lynx population size in Croatia. The goal of the study was to determine the area of lynx distribution and to estimate the minimum size of lynx population in Croatia in the period 2018 - 2020. To determine lynx distribution, 902 signs of lynx presence were collected in the period from the beginning of May 2018 until the end of April 2020. Out of those, 92.8% of lynx observations were categorized as C1, 2.8% as C2 and 4.4% as C3. Permanent lynx presence was confirmed in Primorsko – Goranska and Ličko – Senjska county, in southern part of Karlovac county and north-eastern part of Zadar county on the total surface of 7200 km2. For the minimum population size estimation, 804 camera trap photographs led to identification of 89 – 108 adult lynxes. Among 108 identified individuals there were 29 females, 22 males, while for 7 animals the sex was not determined. During the two reproductive seasons, we photographed 44 cubs in 25 litters. Future important steps in lynx population monitoring are correcting the deficiencies identified in this study and implementation of methodology that will allow us to use spatial capture recapture models for estimation of lynx abundance in Croatia.

SpaceNtime: an R package for estimating abundance of unmarked animals using camera-trap photographs

The space to event (STE), time to event (TTE), and instantaneous sampling (IS) methods were developed to estimate abundance of unmarked animals from camera trap images (Moeller et al. in Ecosphere 9(8):e02331, 2018). The space and time to event models use camera data in a different way than other abundance estimation methods do. Instead of using counts of animals over independent events, STE uses a measure of sampled space before the first detection of the target species, and TTE uses the time until the first detection. We introduce spaceNtime, a free and open-source R package designed to assist in the implementation of the STE and TTE models, along with the IS estimator. This package takes the user through the steps of transforming data, defining sampling effort, selecting sampling occasions, building encounter histories, and estimating abundance from camera data using these three methods. The package is designed for users with a baseline level of knowledge of R and statistics, without requiring expertise in either.

Resighting African wildcats (Felis lybica): Camera trap photographs in Nyungwe National Park, Rwanda

Resighting African wildcats (<i>Felis lybica</i>): Camera trap photographs in Nyungwe National Park, Rwanda

Photographic evidence of Red Panda Ailurus fulgens Cuvier, 1825 from West Kameng and Shi-Yomi districts of Arunachal Pradesh, India

Camera-trap photos of Red Panda Ailurus fulgens were obtained from three locations in the state of Arunachal Pradesh in northeastern India during a survey conducted from March to July 2019. Two of the locations are in West Kameng district and one location is in Shi-Yomi district (formerly West Siang). These records are important additions to the currently limited information available for species distribution in the state, and was gathered as part of a tri-country study on the status of tiger habitats in high altitude ecosystems of Bhutan, India, and Nepal.

First camera trap photographs of Indian Pangolin Manis crassicaudata (Mammalia: Pholidota: Manidae) from Pakistan

In the current study, we have camera trapped Indian pangolin in the country providing very 1st camera trap photographs of the species from Pakistan. The species has been camera trapped from two sampling sites; one from Pothwar Plateau (Kallar Syedan site 33.465N 73.409E district Rawalpindi) and from other sites named Rolli Hills (33.486N 73.902E), surrounding the University of Kotli, Azad Jammu &amp; Kashmir. For this purpose, we installed camera traps eight camera trap stations from January 2021 till June 2021. We collected a total of 131 pictures of Indian pangolin from Kallar Syedan site and 25 pictures of the species from Rolli Hills site surrounding University of Kotli AJ&amp;K. At Kallar Syedan site we confirmed two pangolins (one male and one female) while the female being pregnant and gave birth to baby pangolin (direct field observation) in the month of April.

Estimating survival of unmarked neonates with camera traps

AbstractSurvival and recruitment of offspring are important drivers of population dynamics. Yet, studying wildlife shortly after parturition is logistically challenging and oftentimes cost‐prohibitive. As a result, our ecological understanding of neonate survival is limited for many species and management decisions are often made without an adequate understanding of their implications. We developed a model to estimate the overall survival rate of neonates and the timing of mortality (i.e., shape of the survival curve) based on changes in the ratio of neonates to adult females observed in camera trap photographs. We evaluated the model with simulations and provided an example application using North American elk (Cervus canadensis) in Idaho. Our simulations suggested that estimates of the overall neonate survival rate and the shape of the survival curve are accurate when researchers provide unbiased estimates of adult female survival, birth rate (offspring per adult female), and the distribution of birth dates. When researchers can provide a priori values for just adult female survival and birth rate, estimates of the overall survival rate were accurate, but early neonate mortality was underestimated. Our estimate of neonate elk survival in Idaho was consistent with values generated by capture‐based studies. Our ratio‐based model provides an alternative to traditional methods for estimating neonate survival and does not rely on invasive or expensive capture and monitoring techniques. We believe this method could apply to a wide variety of species due to the ease of data collection and the relatively small number of critical model assumptions. A major benefit of our model is the ability to simultaneously monitor other species in the community, which will facilitate a better understanding of drivers of variation in neonate survival.