Camera Trap Feasibility for Ecological Studies of Elusive Forest Deer

Abstract

The difficulty in observing and capturing elusive species in the wild is one of the main reasons for the limited number of studies on such species. This knowledge gap affects the development of conservation and management plans. Hence, testing the feasibility of research tools is essential for the future use and reliability of such tools. Camera traps increasingly are used as an alternative to capturing animals for wildlife research, and to generate important data for the management and conservation of many species. We identified individual free-ranging gray brocket deer (Mazama gouazoubira) from the Brazilian Pantanal by their natural markings. From October 2011 through September 2012, we investigated the feasibility of using camera traps for home range, habitat use, and activity period studies based on individuals with natural marks compared with the concurrent data collected from Global Positioning System (GPS) collars. Home range studies based on camera traps have limitations related to the quantity of individuals with natural marks and need for population premonitoring to detect them. The irregular performance of camera traps and lower detection probability in open habitats restricted its application in the habitat use study, especially among highly heterogeneous habitats. However, the positive correlation (r = 0.98, P < 0.001) between the frequency of photographic records and distances travelled by deer with GPS locations indicated reliable use of camera traps for research into activity periods. Camera traps can be used as an alternative to telemetry, potentially expanding the perspective and scope of noninvasive ecological studies for elusive and cryptic species.

Comparing GPS collar and fecal sampling using detection dogs for habitat selection analysis in brocket deer (Mazama)

“…Habitat selection through fecal sampling.— Habitat utilization estimates may present biases that compromise data analyses if detectability is too low, and Gray Brocket Deer detection in Pantanal exemplifies the problem as both camera trap and transect visualization methods failed to account for open grassland utilization in previous studies at the same site analyzed here (Desbiez et al 2009; Grotta-Neto et al 2020). The species visualization in open grassland accounted for 5.9% of the records in a transect sampling design composed by 57% of this habitat (Desbiez et al 2009).…”

“…Gray Brocket Deer ecology.— This study represents the most intense and systematic sampling effort to date to monitor forest deer spatial use in the Neotropical region. The same GPS-monitored animals had their activity and movement data explored in a separate study focused on fine-scale GPS monitoring (each location minutes apart) that recovered trajectory information (Grotta-Neto et al 2019), and a methodological study that compared daily activity budget measured by camera traps and GPS collars (Grotta-Neto et al 2020). Here, we add to this body of knowledge the first results on habitat selection of a brocket deer using both GPS data and proposed a noninvasive fecal sampling framework.…”

Affordable RFID loggers for monitoring animal movement, activity, and behaviour

“…Our RFID loggers performed equally, or better than camera traps in identifying individuals: we were able to successfully identify individuals at 80% of visits compared to camera trap picture detection rates which vary depending on species (e.g. 5.3% of photos of an indistinct deer [ 42 ]; 59–80% probability of matching photos of cheetahs [ 43 ]; identifications from 73% of detection events of perentie [ 44 ]). Further, the RFID loggers described here are cheaper per unit ($130 AUD), compared to camera traps which cost between $300-$1050 AUD (Outdoor Cameras, Australia: Swift Enduro and Reconyx XR6 Ultrafire models respectively).…”

Comparison of Minimally Invasive Monitoring Methods and Live Trapping in Mammals

“…Since their development in the early 1980s, camera traps have been used to study population sizes especially for large carnivores with distinctive natural marks (e.g., Panthera tigris , Panthera onca , and Lynx rufus ) [ 6 ]. Camera traps are noninvasive methods useful for species inventories, estimating population density, calculating home range, and monitoring population dynamics [ 7 ]. The advantages of using camera traps, compared to other methods, is that they have a relatively low cost and do not require physical or chemical animal restraint, avoiding capture stress [ 6 , 7 ].…”

“…Camera traps are noninvasive methods useful for species inventories, estimating population density, calculating home range, and monitoring population dynamics [ 7 ]. The advantages of using camera traps, compared to other methods, is that they have a relatively low cost and do not require physical or chemical animal restraint, avoiding capture stress [ 6 , 7 ]. Natural marks and fur patterns help identify individuals and establish capture history [ 8 ].…”