Quantifying the intersexual and interspecific morphometric variation in two resembling sympatric lacertids: Iberolacerta horvathi and Podarcis muralis

Abstract

th . Abstract. Podarcis muralis and Iberolacerta horvathi are sympatric, frequently syntop- ic, lacertids through the entire range of I. horvathi and very similar in their general body size and shape, as well as in most ecological traits. We morphologically com- pared adults from the area of sympatry using biometric measurements and performed analyses to investigate their sexual size and shape dimorphism. A total of 34 males and 24 females of I. horvathi, and 25 males and 23 females of P. muralis , all adult indi- viduals, were measured. Both species showed sexual size dimorphism with females being longer (snout-vent length, SVL) than males. After SVL correction (ANCOVA), head width, length and height and mass showed to be sexually dimorphic in both spe- cies. Males carry relatively wider, longer and higher heads and were heavier than con- specific females. I. horvathi heads were more flattened than those of P. muralis and P. muralis were heavier than I. horvathi. Both species displayed the same pattern of sexu- al dimorphism regarding body size, head size and shape not only in direction but also in magnitude. All results confirm that both species are very similar in studied biomet- ric characters and, together with their ecological similarities, these suggest in absence of other factors they are likely to interact when living together.