Emergence and dispersal of snakes after syntopic hibernation

Abstract

A communal hibernaculum situated in Southwestern Bulgaria and its adjacent area (4 km in diameter) was studied. Seven snake species used this hibernating den, Malpoloninsignitus, Dolichophiscaspius, Platycepsnajadum, Elaphequatuorlineata, Telescopusfallax, Viperaammodytes and Xerotyphlopsvermicularis. The emergence of the snakes was related to the rise of daily temperatures. Malpoloninsignitus emerged from hibernation earlier in the spring than the other species, and most individuals were the first to leave the hibernaculum. There was a temporal segregation among the basking area in early spring, between the latter species and D.caspius, which were the two most abundant species. These two species also used the same area of the hibernaculum, in contrast to P.najadum and E.quatuorlineata, which used a different area. After spring dispersal, M.insignitus and D.caspius used the same microhabitats during the rest of the active period. The earlier emergence of M.insignitus (and earlier departure from the site) probably reduces the competition for basking sites. The early departure of the species may give advantage in the competition for optimal microhabitats with D.caspius.

Evolutionary trade-offs in dormancy phenology

“…The authors posited that, as younger individuals had a greater chance of reproducing in subsequent years, they delayed their emergence for survival benefit at the expense of their immediate reproductive success (Bieber et al 2018). In ectotherms, several studies suggest that the benefits for reproduction (Diamond et al 2011, Navarro-Cano et al 2015) and the benefits for survival such as avoiding predators (Slusarczyk 1995, Kroon et al 2008, Ji 2011) or intra-(Tougeron et al 2018) and interspecific competition (Dyugmedzhiev et al 2019), influence dormancy phenology at the species level. Thus, the life history hypothesis finds important support to explain the phenology of dormancy at different scales (e.g.…”

“…Diamond et al 2011, Navarro-Cano et al 2015 and the benefits for survival such as avoiding predators(Slusarczyk 1995, Kroon et al 2008, Ji 2011 or intra-(Tougeron et al 2018) and interspecific competition(Dyugmedzhiev et al 2019), influence dormancy phenology at the species level. Thus, the life history hypothesis finds important support to explain the phenology of dormancy at different scales (e.g.…”

Trade-offs in dormancy phenology in endotherms and ectotherms

“…Although this has already been contested for some species (Gregory, 1982;Mayhew, 1965), only few evolutionary perspectives have been presented. The following observations of a temperature-independent dormancy phenology may be explained by other benefits for survival such as avoiding predators (Ji, 2011;Kroon et al, 2008;Slusarczyk, 1995) or intra- (Tougeron et al, 2018) and interspecific competition (Dyugmedzhiev et al, 2019).…”

Crepuscular and nocturnal activity of the Nose-horned viper, Vipera ammodytes (Linnaeus, 1758) is more common than previously reported

“…When possible, immediately after hand-capturing an active viper, we used a quick-reading digital thermometer (precision: 0.1 °С) to measure the snake's body temperature at the cloaca (T body ), temperature of the substrate (T substrate ) and air temperature (T air ) at 15 cm above the ground. We estimated temperature of the microhabitat (T microhabitat ) as the average of T substrate and T air (Dyugmedzhiev et al 2019;Dyugmedzhiev 2020). When possible, we measured an individual's snout to venth length (SVL) and tail length using a flexible ruler (precision: 0.5 cm).…”