SiMPL Wildlife Magnets: A camera trap tool for detecting all creatures great and small

Small mammals compose a substantial portion of the seed predators and
dispersers, as well as the prey, in many ecosystems. Nevertheless,
information on distribution and habitat use is limited, partly because
inexpensive, minimally -invasive surveying of small mammals has remained
challenging. We created the SiMPL wildlife magnet – a baited camera trap
design that allows passive monitoring of wildlife, especially small- to
medium-sized mammals. The SiMPL magnet is inexpensive and easy to
construct. To evaluate its effectiveness, we conducted a case study using
10 sites operating for two years along an elevation gradient in the White
Mountains of the northeastern U.S. We found that the SiMPL wildlife magnet
can be used to detect rodents, mesocarnivores, and, to a lesser extent,
ungulates. We examined how the detection probability of mammal species
changed with the inclusion of a SiMPL wildlife magnet using data from pre-
and post-establishment. We found a significant increase in community-level
detection probability with the use of SiMPL magnets and for some species,
including red squirrels (Tamiasciurus hudsonicus), American marten (Martes
americana), and fisher (Pekania pennanti). Moreover, we were able to
capture more species with SiMPL magnets than without, including flying
squirrels (Glaucomys spp.), various Cricetidae spp., black bears (Ursus
americanus), moose (Alces alces), owls and other birds. The SiMPL wildlife
magnet is an effective, low-cost method for surveying wildlife
communities, especially rodents and mesocarnivores. It addresses the
limited range view presented by other techniques for capturing small
mammals on camera traps and enables efficient collection of phenology
data, including vegetation and snowpack. This tool has several
applications, including monitoring species’ responses to silvicultural
practices and global change.