The co-occurrence of the lizards Podarcis muralis and P. siculus is frequent but anecdotally reported in the literature, mostly as side notes of their complex ecology and life history. There are a few studies on the interactions between these two species, but these are old or focalized only on individual populations. This research aims to fill and enlighten the possible competitive interactions between P. muralis and P. siculus when they share a microhabitat. Being a base research, which is not founded on previous works, every result will be an important contribution to the study of these two lizards. We have observed a clear trend in P. muralis associated with the elongation of the jaw in the syntopic population of Calci, while their body size remains unchanged between syntopic and allopatric populations. This differentiation causes an overlap in jaw length between the two species and the sharing of the same range of variation for this character. Hence, in syntopy, they are not distinguishable at all if we base our discrimination only on the length of the jaw, contrary to the common situation where P. siculus head-length outmeasures P. muralis. Syntopic P. muralis are instead well discriminable from their allopatric populations. For the first time, we provide comparative data from different populations, both in allopatry and in syntopy. Our preliminary results suggest a diversification only in head morphology (convergent character displacement) in the area of co-occurrence, hence a proxy of a history of co-evolution that shape the relationship of these two species.
First observation of convergent character displacement in a syntopic community of two italian lizards: Podarcis muralis and P.siculus
Sacchi R.;Coladonato A. J.
2019-01-01
Abstract
The co-occurrence of the lizards Podarcis muralis and P. siculus is frequent but anecdotally reported in the literature, mostly as side notes of their complex ecology and life history. There are a few studies on the interactions between these two species, but these are old or focalized only on individual populations. This research aims to fill and enlighten the possible competitive interactions between P. muralis and P. siculus when they share a microhabitat. Being a base research, which is not founded on previous works, every result will be an important contribution to the study of these two lizards. We have observed a clear trend in P. muralis associated with the elongation of the jaw in the syntopic population of Calci, while their body size remains unchanged between syntopic and allopatric populations. This differentiation causes an overlap in jaw length between the two species and the sharing of the same range of variation for this character. Hence, in syntopy, they are not distinguishable at all if we base our discrimination only on the length of the jaw, contrary to the common situation where P. siculus head-length outmeasures P. muralis. Syntopic P. muralis are instead well discriminable from their allopatric populations. For the first time, we provide comparative data from different populations, both in allopatry and in syntopy. Our preliminary results suggest a diversification only in head morphology (convergent character displacement) in the area of co-occurrence, hence a proxy of a history of co-evolution that shape the relationship of these two species.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
