SEXUAL SIZE DIMORPHISM IN THE BALKAN SUBSPECIES OF THE SAND LIZARD LACERTA AGILIS BOSNICA SCHREIBER, 1912 (REPTILIA: LACERTIDAE) IN BULGARIA
STELIYANA POPOVA1*, EMILIYA VACHEVA2, (NIKOLAY TZANKOV2 in memoriam)
1- Faculty of Biology, Sofia University “St. Kliment Ohridski”, 8 Dragan Tsankov blvd., 1164 Sofia, Bulgaria
2 -National Museum of Natural History, Bulgarian Academy of Sciences, 1 Tsar Osvoboditel blvd., 1000 Sofia, Bulgaria
*Corresponding author: steliyanski@gmail.com
Keywords: lacertids, body proportions, morphometrics
Abstract: Sexual size dimorphism (SSD) among species from the Lacertidae family is expressed mainly in body and head size, with males being larger than females, having larger heads but shorter trunks in relation to body size. Most lacertid species display male-biased SSD, but in few species, such as Lacerta agilis, females display larger size. The sand lizard Lacerta agilis is one of the most widespread lizard species in Eurasia and inhabits an area from central Greece and south Armenia to south Sweden in the North, and from Great Britain to the lake Baikal in the East. At least nine subspecies are currently recognized and two of them occur in Bulgaria. In the present study we analysed SSD in the poorly known subspecies Lacerta agilis bosnica, which inhabits the mountain areas on the Balkan Peninsula. We examined 9 somatometric traits, which were transformed into 10 indices, describing body proportions. All of the measurements were taken in live animals captured in mountains in Western Bulgaria (the mountains of Vitosha, Osogovo, Stara Planina, and Plana). We established statistically significant differences between the sexes in 9 of the indices. The differences could be described as follows: males have longer tails, longer legs (fore and hind legs), and larger heads (both in length and width). The similarities and differences in regards to SSD in other taxa from the genus Lacerta (for which similar research was done in Bulgaria) are further discussed.