Niche segregation of sand lizard (Lacerta agilis) and green lizard (Lacerta viridis) in an urban semi-natural habitat

Abstract

Different types of semi natural habitats has important role in long-term survival and maintenance of reptile species in urban environments. Heterogeneous urban green islands can provide conditions that enable competing species to live together in relatively small areas. However, the key mechanism of coexistence could vary from types of habitats and taxa. We investigated the population structure, the fine scale habitat segregation and diel activity pattern of two lizard species (Lacerta viridis and L. agilis) coexisting populations in a town cemetery. We hypothesized, that fine scale habitat segregation is a more important factor in coexistence than differences in diel activity pattern, because of the environmental dependent thermoregulation constrain. During the study, 178 L. agilis and 79 L. viridis occurrences were recorded. The daily activity patterns of both species were very similar, with peaks found in the forenoon and afternoon. Lizards were found to be the most active at 31-32°C. The probability of occurrence of the species was influenced more by the differences in the random selection of parcels rather than the random differences in the survey days. Around the proximate observation point the bush covered areas was significantly higher than average in the parcels. Our results showed that niche segregation based on fine scale habitat patches had a fundamental role in the coexistence of the two lizard species. L. agilis preferred the more open spaces, whereas L. viridis preferred areas with more bushes, but there was no difference in the daily activity pattern of the two species.

Reptile responses to vegetation structure in a grassland restored for an endangered snake

“…Contrary to these studies, our results show that L. viridis was more abundant in cells characterised by less tussocky vegetation and low burrow numbers. Previous works on the habitat selection of L. agilis suggested the importance of soil type and wetness (Covaciu-Marcov et al 2006), burrow availability (Török 2002), and a preference to open, bush-and treeless habitats (Nemes et al 2006;Heltai et al 2015). In our study, we found no evidence of the effect of burrow numbers on abundance on L. agilis, but we detected a preference to open and wet vegetation, characterised by high cover and vertical diversity.…”

“…Many studies showed that the studied Lacerta species are present in a wide range of habitats; however, there is surprisingly limited information about the fine-scale (microhabitatlevel) requirements and preference of the studied species. The general view on the habitat of L. viridis is that it consists of grasslands interspersed with bushes, trees, particularly containing edges and ecotones between grassland and forest (Heltai et al 2015). The thermal quality of the microhabitat is also known to influence habitat selection (Korsós 1982).…”

Realized niche and microhabitat selection of the eastern green lizard (Lacerta viridis) at the core and periphery of its distribution range

“…Nevertheless, an influence of the interaction of both species on the niche of L. viridis can be expected in southern regions, where the habitat of both species overlaps (Korsós, ), due to the trend of L. viridis to inhabit more covered areas toward lower latitudinal regions. However, even in this region, analyses at a finer scale have demonstrated significant niche segregation (Babocsay, ; Heltai et al, ) that allows the coexistence of both species in the same habitat.…”

“…Hence, niche would still be smaller compared to the core but probably less differentiated. On the other hand, in low latitudinal regions, interactions with other lizards’ species might have a more important role in restricting the niche than it does in northern peripheries (Cahill et al, ).However, the study of the niche and microhabitat selection of several species must be carefully addressed at the proper spatial scales in order to correctly quantify possible overlaps or segregation among species (Heltai et al, ), and its effects in the intraspecific comparison of the niche of populations at peripheries with the core.…”

“…Lacerta viridis, for example, is a common species in the Balkan Peninsula in Eastern Europe and Asia Minor (Elbing, 2001) and has its northern distribution range located in Germany and in the Bohemian region of the Czech Republic. In core regions, the species is found in habitats ranging from slopes with rock covering, bushlands, and road edges to mixed forest and pine plantations, including several seminatural and urban habitats (Heltai, Sály, Kovács, & Kiss, ;Covaciu-Marcov et al, 2009;Popgeorgiev & Mollov, 2005). In Germany and Czech Republic, where thermal conditions and other limiting factors like daily hours of sunshine (Frör, 1986;Laube & Leppelsack, 2007) do not provide many suitable habitats for the species, it is scarce and mostly found in open areas and river valleys (Böhme & Moravec, 2011;Böhme, Schneeweiß, Fritz, Schlegel, & Berendonk, 2007).…”