Post-fire abundance and age composition dynamics of Lacerta agilis (Reptilia, Lacertidae) in the Orenburg State Nature Reserve (Russia)

Abstract

In different months during 2015–2017, the abundance and sex-age structure of the Sand lizard (Lacerta agilis) were studied on two transects. Parallel transects were established in the southeastern part of the cluster area «Burtinskaya steppe» of the Orenburg State Nature Reserve (Russia). The length of each transect was 3 km. The width of the mineralised plowed strip between the transects was 9–11 m. Transect 2 was located in the area burnt in August 2014, while transect 1 was situated in the area burnt in August 2016. In terms of size and external morphological traits, the captured Sand lizards were divided into three groups: juvenile individuals, adult males, and adult females. After measurements, the marked animals were put back to the places of capture. The number and sex-age structure were restored on transects in May – June, after the first winter following the fire impact. We found that on transect 1, the species abundance at late April – early May 2015 was almost three times higher (18.67 individuals / km) than on transect 2 (6.67 individuals / km). However, at late May 2015, the species abundance on both transects became almost the same (12.67 individuals / km in transect 1 against 11.33 individuals / km in transect 2). The juvenile individuals suffered from the fire influence more than adults. After the 2016 fire (i.e., in mid-May 2017), the proportion of one-year-old individuals was 21.2% of the total number of Sand lizards recorded in transect 1, while it counted 67.3% of the total number of Sand lizards recorded in transect 2, burnt in 2014. We believe that the rapid recovery of the abundance and sex-age structure in the Burtinskaya steppe was associated with the migration of Sand lizards through the mineralised strip separating the burnt and non-burnt transects.

Keywords

• cluster area «Burtinskaya steppe»
• fire
• Orenburg region
• Sand lizard