Monitoring wild animal communities with arrays of motion sensitive camera traps

Studying animal movement and distribution is of critical importance to addressing environmental challenges including invasive species, infectious diseases, climate and land-use change. Motion sensitive camera traps offer a visual sensor to record the presence of a broad range of species providing location -specific information on movement and behavior. Modern digital camera traps that record video present new analytical opportunities, but also new data management challenges. This paper describes our experience with a terrestrial animal monitoring system at Barro Colorado Island, Panama. Our camera network captured the spatio-temporal dynamics of terrestrial bird and mammal activity at the site - data relevant to immediate science questions, and long-term conservation issues. We believe that the experience gained and lessons learned during our year long deployment and testing of the camera traps as well as the developed solutions are applicable to broader sensor network applications and are valuable for the advancement of the sensor network research. We suggest that the continued development of these hardware, software, and analytical tools, in concert, offer an exciting sensor-network solution to monitoring of animal populations which could realistically scale over larger areas and time spans

A large-scale automated radio telemetry network for monitoring movements of terrestrial wildlife in Australia

Technologies for remotely observing animal movements have advanced rapidly in the past decade. In recent years, Australia has invested in an Integrated Marine Ocean Tracking (IMOS) system, a land ecosystem observatory (TERN), and an Australian Acoustic Observatory (A2O), but has not established movement tracking systems for individual terrestrial animals across land and along coastlines. Here, we make the case that the Motus Wildlife Tracking System, an open-source, rapidly expanding cooperative automated radio-tracking global network (Motus, https://motus.org) provides an unprecedented opportunity to build an affordable and proven infrastructure that will boost wildlife biology research and connect Australian researchers domestically and with international wildlife research. We briefly describe the system conceptually and technologically, then present the unique strengths of Motus, how Motus can complement and expand existing and emerging animal tracking systems, and how the Motus framework provides a much-needed central repository and impetus for archiving and sharing animal telemetry data. We propose ways to overcome the unique challenges posed by Australia’s ecological attributes and the size of its scientific community. Open source, inherently cooperative and flexible, Motus provides a unique opportunity to leverage individual research effort into a larger collaborative achievement, thereby expanding the scale and scope of individual projects, while maximising the outcomes of scant research and conservation funding

Primates

Over the past 20 years, GPS collars have emerged as powerful tools for the study of nonhuman primate (hereafter, "primate") movement ecology. As the size and cost of GPS collars have decreased and performance has improved, it is timely to review the use and success of GPS collar deployments on primates to date. Here we compile data on deployments and performance of GPS collars by brand and examine how these relate to characteristics of the primate species and field contexts in which they were deployed. The compiled results of 179 GPS collar deployments across 17 species by 16 research teams show these technologies can provide advantages, particularly in adding to the quality, quantity, and temporal span of data collection. However, aspects of this technology still require substantial improvement in order to make deployment on many primate species pragmatic economically. In particular, current limitations regarding battery lifespan relative to collar weight, the efficacy of remote drop-off mechanisms, and the ability to remotely retrieve data need to be addressed before the technology is likely to be widely adopted. Moreover, despite the increasing utility of GPS collars in the field, they remain substantially more expensive than VHF collars and tracking via handheld GPS units, and cost considerations of GPS collars may limit sample sizes and thereby the strength of inferences. Still, the overall high quality and quantity of data obtained, combined with the reduced need for on-the-ground tracking by field personnel, may help defray the high equipment cost. We argue that primatologists armed with the information in this review have much to gain from the recent, substantial improvements in GPS collar technology.PEC 13-249/HX/HSRD VA/United States#31622053/National Natural Science Foundation of China (CN)/0504495/National Science Foundation IGERT GLOBES program/5189-00135B/Innovationsfonden/R01 AG034513/AG/NIA NIH HHS/United StatesW267-13/National Geographic Society's Waitt Program/PR12-012/Margot Marsh Biodiversity Foundation/2018TD-017/Department of Science and Technology of Shaanxi Prov. China/BCS 1638822/National Science Foundation/P51 OD010425/CD/ODCDC CDC HHS/United StatesPR14-36/Margot Marsh Biodiversity Foundation/9234-12/National Geographic Young Explorer's Grant/P51 OD010425/OD/NIH HHS/United StatesP2C HD042828/HD/NICHD NIH HHS/United StatesBCS 1062540/National Science Foundation/#31730104/National Natural Science Foundation of China (CN)/2021-05-13T00:00:00Z31965380PMC8118416972

Evaluation of tree frog tracking methods using Phyllomedusa trinitatis (Anura: Phyllomedusidae)

Evaluation of tree frog tracking methods using Phyllomedusa trinitatis (Anura: Phyllomedusidae). Investigating the behaviors of small, inconspicuous and cryptic animals can be helped by tracking their movements. The effectiveness of different tracking methods can be very dependent on behavior and ecology; radio-telemetry and thread bobbins have been widely used over a range of environments and taxa, but each presents problems. Phyllomedusa trinitatis is a tree frog found in Trinidad and Venezuela and has mostly been studied for its nest building and breeding behavior, but little is known about its behavior away from breeding ponds. This study aimed to identify the strengths and weaknesses, including impacts on the welfare of these frogs, of different tracking methods, thread bobbins and radio-telemetry, when used to track them in a dense rainforest environment. A pilot study found that fuorescent dyes were unsuitable for this species. Individuals were tested in laboratory conditions to determine the application time for each tracker and to test on this species the tracker 10% weight rule. The rule was found to be too restrictive for this frog; trackers up to 15% of body weight were used with no signifcant impacts on distances travelled. Frogs became lethargic when bearing trackers longer than two days, so we limited tracking in the feld to one overnight period. Of the 26 frogs tracked in the feld (nine radio-tags, 17 bobbins), 16 were successful (six radio-tags, 10 bobbins) and six untracked frogs were found in the feld during the day as controls. Bobbins were cheaper and allowed visualization of the detailed path taken, including substrates used, but caused more bruising due to entanglement, and individuals tracked with this method were less likely to return on following nights to the breeding ponds. Radio-tags had no threat of entanglement but were much more expensive and the signal was interrupted by the dense vegetation preventing some individuals from being found. There were no signifcant differences in the distances travelled by tracked or control frogs, from which we infer that these tracking methods did not impact signifcantly on movement. It appears that neither of these tracking methods work perfectly for Phyllomedusa in a densely vegetated environment, and that both incur welfare problems. Our study emphasizes the need to test out tracking methods on each species in each habitat.Avaliação de métodos de rastreamento de pererecas usando Phyllomedusa trinitatis (Anura: Phyllomedusidae). A investigação do comportamento de animais pequenos, inconspícuos e crípticos pode ser auxiliada pelo rastreamento de seus movimentos. A efciência de diferentes métodos de rastreamento pode ser muito dependente de seu comportamento e ecologia; rádiotelemetria e bobinas de rastreamento têm sido largamente utilizadas com uma variedade de ambientes e táxons, mas cada uma dessas técnicas apresenta problemas. Phyllomedusa trinitatis é uma perereca encontrada em Trinidad e na Venezuela e tem sido estudada principalmente no que se refere a seu comportamento reprodutivo e de construção de ninhos, mas pouco se sabe sobre seu comportamento longe das lagoas reprodutivas. Este estudo teve como objetivo identifcar vantagens e desvantagens de diferentes métodos de rastreamento (bobinas de rastreamento e rádio-telemetria), incluindo impactos no bem-estar desses anuros, quando usados para rastreá-los em um ambiente de foresta pluvial densa. Um estudo-piloto mostrou de tintas fuorescentes foram inadequadas para essa espécie. Indivíduos werforam testados em condições laboratoriais para determinar o tempo de aplicação de cada rastreador e para testar nessa espécie a regra dos 10% do peso. A regra mostrou-se muito restritiva para essa perereca; rastreadores com até 15% do peso corpóreo foram usados sem impactos signifcativos sobre a distância percorrida. Os animais tornaram-se letárgicos quando portavam rastreadores por mais de dois dias, de forma que limitamos o rastreamento no campo a um período de uma noite. Dos 26 indivíduos rastreados no campo (nove com radiotransmissores, 17 com bobinas), 16 foram bem-sucedidos (seis com radiotransmissores, 10 com bobinas) e seis indivíduos não-rastreados foram encontrados no campo durante o dia como controles. As bobinas são mais baratas e permitem a visualização detalhada do caminho percorrido, incluindo os substratos utilizados, mas causam mais injúrias devido ao entrelaçamento, e os indivíduos rastreados com este método eram menos propensos a retornar nas noites seguintes para as lagoas de reprodução. Os radiotransmissores não ofereciam a ameaça de emaranhamento, mas são muito mais caros, e o sinal era interrompido pela densa vegetação, impedindo que alguns indivíduos fossem encontrados. Não houve diferenças signifcativas nas distâncias percorridas por indivíduos rastreados e animaiscontrole, do que inferimos que esses métodos de rastreamento não tiveram impacto signifcativo sobre o movimento. Parece que nenhum desses métodos de rastreamento funciona perfeitamente para Phyllomedusa em um ambiente com vegetação densa e que ambos geram problemas de bem-estar. Nosso estudo enfatiza a necessidade de testar métodos de rastreamento para cada espécie em cada habitat

A first test of the thread bobbin tracking technique as a method for studying the ecology of herpetofauna in a tropical rainforest

The lack of information about amphibians and reptiles in highly threatened tropical rainforest habitats has led to a need for innovative methods that can rapidly generate data on ecological behavior. The thread bobbin technique has proven successful for gathering ecological information in a range of habitats, but has not yet been used in tropical rainforests. Here we test the method for the first time in a humid tropical forest habitat on 14 herpetofaunal species. We found thread bobbins to be effective for large anurans (one leptodactylid and one bufonid), medium-large terrestrial snakes (one boid, three colubrids and one viperid), and testudines (one chelid), but largely unsuccessful for arboreal snakes (one boid and one colubrid), small and slender snakes (two colubrids), and small anurans (one strabomantid). We tracked 18 individuals for 1.2-15 d (mean 4.6 d) for distances of 5.5-469.3 m (mean 159.2 m). The thread trail revealed the exact movements of the tracked animal, providing detailed information on activity and microhabitat use that many alternative tracking methods cannot provide. Conservation projects rely heavily upon understanding the life history of species and without this prior knowledge, conservation efforts can fail, wasting funds and resources. We show that the thread bobbin method is a cost-effective technique that can be used to rapidly gather detailed ecological information on the life history of relatively unknown rainforest reptiles and amphibians

INVESTIGATING THE SPATIAL BEHAVIOR AND HABITAT USE OF THE MATSCHIE’S TREE-KANGAROO (DENDROLAGUS MATSCHIEI) USING GPS COLLARS AND UNMANNED AIRCRAFT SYSTEMS (UAS)

Understanding the movement patterns and habitat needs of the endangered Matschie’s tree-kangaroo (Dendrolagus matschiei) is important for their conservation and management. Endemic to the montane cloud forests of the Huon Peninsula in northeastern Papua New Guinea, these elusive arboreal marsupials are tremendously challenging to study using traditional observational methods. This study is an assessment of novel techniques to overcome the significant challenges to in-situ data collection in remote and rugged tropical cloud forests. Animal locations are remotely tracked using purpose built altitude and motion logging GPS collars and habitat structure data is measured using photogrammetry from small Unmanned Aircraft Systems (UAS) aerial imagery. Leveraging the autocorrelation of regular GPS location sampling, this study applied a Time-Local Convex Hull (T-LoCoH) analysis to investigate particular locations that may be important to D. matschiei as well as potential barriers to movement that would be inside of the home range as identified in previous studies. A novel technique of ground surface interpolation from canopy gaps is presented to overcome the challenges of photogrammetric reconstruction of terrain surfaces under closed canopy forests. From this a variety of forest structure variables were calculated to understand the 3D complexity of these heterogeneous cloud forests. This investigation found that custom GPS collars can provide high fix success rates in dense multilayer forests found at the research site. The regular sampling intervals resulted in areas of utilization that were notably smaller than with traditional home range analyses, and provided insight into landscape features that the animals do not use. D. matschiei were found to preferentially use trees that were taller than average and were found in closer than average proximity to canopy emergent trees. The reconstruction of 3D habitat data from UAS aerial photogrammetry resulted in forest structure maps that have significant potential to overcome the necessity of manual habitat data collection that hinders large scale habitat research, for this and many other species

Review of GPS Collar Deployments and Performance on Nonhuman Primates

Over the past twenty years, GPS collars have emerged as powerful tools for the study of nonhuman primate (hereafter, "primate") movement ecology. As the size and cost of GPS collars have decreased and performance has improved, it is timely to review the use and success of GPS collar deployments on primates to date. Here we compile data on deployments and performance of GPS collars by brand and examine how these relate to characteristics of the primate species and field contexts in which they were deployed. The compiled results of 179 GPS collar deployments across 17 species by 16 research teams show these technologies can provide advantages, particularly in adding to the quality, quantity, and temporal span of data collection. However, aspects of this technology still require substantial improvement in order to make deployment on many primate species pragmatic economically. In particular, current limitations regarding battery lifespan relative to collar weight, the efficacy of remote drop-off mechanisms, and the ability to remotely retrieve data need to be addressed before the technology is likely to be widely adopted. Moreover, despite the increasing utility of GPS collars in the field, they remain substantially more expensive than VHF collars and tracking via handheld GPS units, and cost considerations of GPS collars may limit sample sizes and thereby the strength of inferences. Still, the overall high quality and quantity of data obtained, combined with the reduced need for on-the-ground tracking by field personnel, may help defray the high equipment cost. We argue that primatologists armed with the information in this review have much to gain from the recent, substantial improvements in GPS collar technology