Repeated use of high risk nesting areas in the European whip snake, Hierophis viridiflavus

Oviparous snakes deposit their egg clutches in sites sheltered from predation and from strong thermal and hydric fluctuations. Appropriate laying sites with optimum thermal and hydric conditions are generally scarce and are not necessarily localised in the home range. Thus, many gravid females undertake extensive trips for oviposition, and many may converge at the best egg laying sites. Dispersal mortality of neonates post-hatchling is also a critical factor. Assessing the parameters involved in this intergenerational trade-off is difficult however, and no study has succeeded in embracing all of them. Here we report data indicating that gravid females of the highly mobile European whip snake, Hierophis viridiflavus exhibit nest site fidelity whereby they repeatedly deposit their eggs in cavities under sealed roads over many decades. These anthropogenic structures provide benefits of relative safety and suitable incubation conditions (due to the protective asphalted layer?), but they expose both females and neonates to high risk of road mortality. Artificial laying sites constructed at appropriate distances from busy roads, along with artificial continuous well protected pathways (e.g. dense hedges) that connect risky laying sites to safer areas, should be constructed.

The anurans and squamates assemblage from Final Natufian Eynan (Ain Mallaha, Israel) with an emphasis on snake-human interactions

During the Natufian period, more than 12,000 years ago, Eynan (Ain Mallaha) was an important human settlement in the Hula Valley, Israel. This study concentrates on the anuran and squamate assemblage from the ultimate stage of the Natufian period at the site, the Final Natufian. Over five thousand bones assigned to at least sixteen taxa were studied from a sampled segment of the excavated open-air site. Relative species abundance, spatial distribution, taphonomic observations and ecological considerations all pointed to the conclusion that the inhabitants of Eynan intensively exploited three large “colubrine” snakes species: the Large Whip Snake (Dolichophis jugularis), the Eastern Montpellier Snake (Malpolon insignitus) and an Eastern Four-lined Ratsnake (Elaphe cf. sauromates). These snakes were the most desired and were intensively gathered, while other snakes and lizards could have been opportunistically collected when encountered. We raise questions about whether the large “colubrines” exploitation should be interpreted as additional evidence of increasing diet breadth. We suggest challenging this line of reasoning and offer possible alternative motives.

The Horseshoe whip snake (Hemorrhois hippocrepis) on Ibiza: predator release in an invasive population

The key to fighting a biological invasion may lie in understanding every variable that can explain its success. The Enemy Release Hypothesis (ERH) states that when an invader arrives to a new environment, the absence of its common enemies (predators, parasites and competitors) facilitates the invasion success. The Horseshoe whip snake (Hemorrhois hippocrepis) has been recently introduced from the Iberian Peninsula to the island of Ibiza, and it is currently threatening the only endemic vertebrate, the Ibiza wall lizard (Podarcis pityusensis). We hypothesized that the snake invasion success is caused by the absence of natural predators, and we checked the ERH by relating the tail breakage rate to predation pressure. The invasive population showed a much lower incidence of tail breakage than the source population, which is in agreement with the almost absence of snake predators among the Ibizan reduced and naïve native vertebrate community. These results confirm the ERH, and support the prolongation of invasive snake trapping campaigns.

Observations of an aggregation between two species of Australian elapid snakes: the threatened Little Whip Snake Parasuta flagellum and Common Eastern Brown Snake Pseudonaja textilis

This short note presents field observations of a pair of adult threatened Little Whip Snakes Parasuta flagellum and a pair of juvenile Common Eastern Brown Snakes Pseudonaja textilis in an aggregation beneath artificially placed Masonite board used in the Turallo Nature Reserve long-term Little Whip Snake monitoring program. The observation represents the first documented record of an interspecific aggregation between these two species. Presumably, there may be thermal or anti-predatory advantages for the Little Whip Snake by aggregating with other snakes, particularly when both species are of a similar size. However, similar behaviours may also have fitness disadvantages including food competition, and potentially predation as the Common Eastern Brown Snake neonates grow and surpass the substantially smaller Little Whip Snake and warrants further experimental research.

Asynchrony of actuarial and reproductive senescence: a lesson from an indeterminate grower

Evolutionary theories relating to aging predict that patterns of actuarial and reproductive senescence should be aligned, with a common onset of senescence set at the age of first reproduction. However, a few empirical studies reported asynchrony between actuarial and reproductive senescence. This asynchrony is expected to be particularly pronounced in organisms with indeterminate growth. Yet, this process is still poorly documented due to the lack of long-term demographic data on known-aged individuals. We investigated the asynchrony of actuarial and reproductive senescence in the European whip snake, Hierophis viridiflavus, an oviparous colubrid with indeterminate growth. Using demographic data collected over a 29-year period, we showed that females did not experience any fecundity loss late in life. In contrast, they suffered from an early, severe actuarial senescence. Our findings thus revealed a pronounced asynchrony in actuarial and reproductive senescence processes, a phenomenon that could be widespread across the tree of life.