Comparison of pitfall traps and belt transects to examine lizard populations in different vegetative communities
AuthorBounds, Dixie Louise, 1961-
AdvisorSchwalbe, Cecil R.
MetadataShow full item record
PublisherThe University of Arizona.
RightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
AbstractI used two sampling techniques, visual line transects and pitfall traps, to compare the numbers and species richness of lizards in four vegetative communities representative of the Sonoran Desert region: exotic grasslands, native grasslands, oak woodlands and desertscrub. I found similar numbers of lizards and species richness in three of the four communities, but I detected more lizards using transects than pitfall traps in the oak woodland community. On a per area basis, I detected significantly more lizards with transects than with pitfall traps in all four communities (P = 0.018). I compared capture success using three different pitfall traps. Overall, I found no differences between capture success in black and white plastic 19-1 buckets (Chi square = 0.58, df = 1, P > 0.05) or between white buckets and number 10 cans stacked three deep (Chi square = 0.60, df = 1, P > 0.05). I did find that one species (Sceloporus magister) was captured more often in black buckets than in white buckets (Chi square = 5.33, df = 1, P < 0.05). Pitfall traps were significantly more expensive (P = 0.02) than transects in terms of materials, installation and data collection. I did not obtain sufficient recaptures of any species in the pitfall traps to generate population or survivorship estimates using the programs RELEASE, SURGE, or JOLLY. I calculated the effort necessary to obtain sufficient recaptures to make those estimates using pitfall traps. I also calculated the effort needed to obtain similar estimates using transects in each vegetative community. Recommendations for sampling days for the two methods varied considerably depending on the species and the vegetative community. If managers need mark-recapture data or detailed information on individual lizards, pitfall traps should be used. However, if managers do not need detailed information, I recommend using transects to sample lizard populations because they are less expensive, less time-consuming, and provide similar information on the relative abundance and species richness of lizard populations.
Degree ProgramGraduate College
Renewable Natural Resources