Determining the efficacy of camera traps, live capture traps, and detection dogs for locating cryptic small mammal species

Metal box (e.g., Elliott, Sherman) traps and remote cameras are two of the
most commonly employed methods presently used to survey terrestrial
mammals. However, their relative efficacy at accurately detecting cryptic
small mammals has not been adequately assessed. The present study
therefore compared the effectiveness of metal box (Elliott) traps and
vertically oriented, close range, white flash camera traps in detecting
small mammals occurring in the Scenic Rim of eastern Australia. We also
conducted a preliminary survey to determine effectiveness of a
conservation detection dog (CDD) for identifying presence of a
threatened carnivorous marsupial, Antechinus arktos, in
present-day and historical locations, using camera traps to corroborate
detections. 200 Elliott traps and 20 white flash camera traps were set for
four deployments per method, across a site where the target small mammals,
including A. arktos, are known to occur. Camera traps produced
higher detection probabilities than Elliott traps for all four species.
Thus, vertically mounted white flash cameras were preferable for detecting
the presence of cryptic small mammals in our survey. The CDD, which had
been trained to detect A. arktos scat, indicated in total 31 times when
deployed in the field survey area, with subsequent camera trap deployments
specifically corroborating A. arktos presence at 100%
(3) indication locations. Importantly, the dog indicated twice within
Border Ranges National Park, where historical (1980s-1990s) specimen-based
records indicate the species was present, but extensive Elliott and camera
trapping over the last 5-10 years have resulted in zero A.
arktos captures. Camera traps subsequently
corroborated A. arktos presence at these sites. This
demonstrates that detection dogs can be a highly effective means of
locating threatened, cryptic species, especially when traditional methods
are unable to detect low-density mammal populations.