Because the effect of competition on distributional patterns is more easily detected at a smaller rather than at larger spatial scales (Wiens, 1989; Prinzing et al., 2002; Soberón & Nakamura, 2009), we here study local co-occurrence of the two salamander species

within contact zones. If interspecific competition affects the distribution of the two species, then they should have spatial ranges that do not strongly overlap at local scale (Hofer, Bersier & Borcard, 2004). To further study whether interspecific interactions restrict the species’ ranges and to better understand patterns of local co-occurrence of these parapatric salamanders within their contact zones, we use site-occupancy models (MacKenzie et al., 2002; MacKenzie, Bailey & Nichols, 2004; Yackulic et al., in press) to study species–habitat relationships by comparing syntopic LDK378 nmr and allotopic occurrences at a local scale in Switzerland. Specifically, we aim (1) to identify the habitat predictors for the species’ distributions within the contact zones and

(2) to test whether the presence of one species affects the occupancy probability of the other species. Based on previous research on parapatric salamanders where both abiotic and biotic factors were important, we expect (1) that the alpine and fire salamanders show dissimilar species–habitat relationships and (2) that the presence of one species negatively affects the presence of the other. Salamandra salamandra is widely distributed throughout western and central Europe, while S. atra NVP-AUY922 purchase is restricted to sub-montane and montane areas of the central and eastern European and the Dinaric Alps (Guex & Grossenbacher, 2004; Thiesmeier & Grossenbacher, 2004). click here In the European Alps,

the geographic range of S. atra coincides with a distribution gap of S. salamandra but small contact zones with few localities of local syntopic co-occurrence are known (Klewen, 1986; Guex & Grossenbacher, 2004; Thiesmeier & Grossenbacher, 2004). Across its large distribution in geographic space, S. salamandra occurs in a wide range of different habitats. However, within the contact zones of the parapatric range margins, it (S. s. terrestris and S. s. salamandra) often inhabits deciduous forests with small streams, a habitat also used by alpine salamanders (S. a. atra) (Klewen, 1986; Thiesmeier & Grossenbacher, 2004). Streams are used by female S. salamandra for the deposition of larvae, which here remain until metamorphosis. In contrast, S. atra is viviparous and does not require water bodies for reproduction (Guex & Grossenbacher, 2004). While reproductive modes are different, the two species both are primarily nocturnal and remain most of the time under shelter, while their foraging and reproductive activity is highly dependent on rainy weather conditions (Guex & Grossenbacher, 2004; Thiesmeier & Grossenbacher, 2004).