Modelling terrestrial interactions and shelter use in great crested newts (Triturus cristatus)

Abstract

The great crested newt (Triturus cristatus) is a pond-breeding salamander with a prolonged aquatic phase and a period of activity in the terrestrial environment prior to hibernation. Individuals use ground-covering objects and burrows as shelters from predators and unfavourable conditions. We investigated how interactions and spacing patterns were formed in staged experiments where paired newts were exposed to an arena with two shelters. Shelter use was predominant in all sets of great crested newts, irrespective of sex and size. Males and females differed in their shelter-use response. Females were more prone to reside in shelters when meeting other females than when meeting males, whereas males appeared indifferent to the sex of another individual. The social interaction was uniform for all combinations, with a 2:1 relation between the numbers of pairs sharing shelters vs. positioned in different shelters, instead of a random 1:1 distribution. Thus, the differences in shelter sharing could be attributed to the predominance of shelter use for females when meeting other females. We suggest that this behaviour, when females respond to the presence of another female, is a form of resource protection. Although sex effects were clearly noted, we could not demonstrate that size-related characteristics affected the outcome of any social interactions.

Cohabitation patterns of the San Marcos salamander (Eurycea nana)

“…Females preferred to cohabit with conspecifics in both intersexual and intrasexual pairings and these patterns did not differ between pair treatments. Female preference for cohabitation with other females and males has been seen in other salamanders (Gautier et al, 2006;Malmgren, Andersson and Simon, 2007). The intersexual cohabitation patterns we observed might reflect these aggregative tendencies of females or mate seeking behavior by males, although these should not be considered mutually exclusive.…”

Landscape genetics reveals contrasting patterns of connectivity in two newt species (Lissotriton montandoniandL. vulgaris)

“…Genetic connectivity was compromised in both species when forest-cover was absent (categorical models, Figure 5b), or lower than ~25% (continuous models, Figure 5a). These results are expected considering that even the widespread L. vulgaris shows higher abundance in ponds closer to forest edges as opposed to open terrain (Denoël et al, 2013;Skei et al, 2006) and preferential emigration from ponds towards forests (Malmgren, 2002). Interestingly, the exact response to forestcover varied between species, with L. montandoni showing highest connectivity across the heavily forested areas (Figure 5a), while L.…”