Pit B or not Pit B? The pitfall array is the question

Pitfall trapping is a long established method for trapping terrestrial vertebrates globally. Many variations in bucket and drift fence arrays are used. Recent survey guidelines have been published for Queensland and the Northern Territory. In Queensland a “T” pattern is recommended, and we used data collected over five years to assess whether the use of this array, with the addition of a central bucket (Pit B), results in more captures, particularly in the central bucket. A total of 263 sites representing 1052 bucket samples were examined and the differences in capture abundance in bucket location was tested using analysis of variance. Pitfall bucket location significantly affected the captures of Dasyuridae, Muridae, Agamidae, Pygopodidae, Scincidae (P<0.1), and mean abundance was highest in the central Pit B except for Agamidae. There was also significant variation in abundance across habitat type for these families, excluding Dasyuridae, but including Gekkonidae. We conclude that having a central bucket where drift fences join can increase trap success, and this is a function of effective trapping area (i.e. catchment of animal activity and length of drift fence per bucket). Increased captures may have some relationship to habitat type (i.e. small mammals more abundant in grassland habitat). Though this particular array has some benefits in increasing trap success, the use of multiple survey techniques is recommended for any thorough fauna inventory.