A comparison of linear transect and capture recapture methods results in Iranian Jerboa population density and abundance estimation in Mirabad plains, Shahreza

Abstract

During a period from spring 2008 till fall 2010, Iranian Jerboa population abundance was estimated using distance (linear transect) and capture-recapture methods in the Mirabad plains near Shahreza city in Isfahan Province. In the study period, during the active time of the species except reproduction time, we tried to live-trap, mark, release and recapture individuals based on Schnabel method on different sampling occasions. Simultaneously, we also traversed line transects using motorcycle and spot-light by two observers in different habitat types. We tried to get uniform trapping nights in different lunar nights and different habitat types. The population abundance, using Schnabel and distance methods was estimated to be 226 and 402 individuals, respectively. With regard to the obtained results and species behavior, it seems that distance method yields more precise confidence limits of the estimation compared with capture-recapture method. However, capture-recapture method yields more precise estimates for closed populations because of its more limiting assumptions, but the confidence reliability of abundance estimation of a species depends on the species and its habitat selection behavior completely.

Keywords

• confidence limits
• distance methods
• estimation precision
• marking
• plain habitats