Oral Presentation- Symposium 12th International Mammalogical Congress

Camera trapping as an alternative to pitfall trapping to sample prey availability of insectivorous mammals (#327)

Rachael A Collett 1 , Diana O Fisher 1
  1. School of Biological Sciences, The University of Queensland, St Lucia, Queensland, Australia

Pitfall trapping is the standard technique to estimate activity and relative abundance of leaf litter arthropods in ecological studies of prey availability. Pitfall trapping is not ideal for long-term sampling because it is a lethal method that can deplete arthropods over time, it is labour intensive, and it may have taxonomic sampling biases. We test an alternative sampling method that can be left in place for several months: horizontally placed, time-lapse camera traps that have a short focal distance, enabling identification of small arthropods in pictures. Time lapse is necessary to capture small arthropods, but the cameras concurrently use a standard infra red trigger, so small mammals are also captured whenever they move into the field of view. We tested the effectiveness of these time-lapse cameras, and quantified escape and avoidance behaviour of arthropod orders encountering pitfall traps. We also recorded small mammals captured on camera traps. Cameras recorded around twice as many arthropod taxa and a third more individuals per day than pitfall traps. Ants, webspinners and cockroaches frequently escaped from pitfalls so were particularly under-sampled by them. The same cameras recorded as many species of small mammals as concurrent live-trapping in our rainforest sites, and also recorded cryptic species that were not live-trapped. The new close-focus time-lapse camera method effectively samples litter arthropods to collect long-term data on prey availability suitable for ecological studies. We are currently using the cameras to sample arthropods and small mammals to assess prey availability of dasyurids.