Herpetology in FranceHerpetology in France

Marbled newt, Triturus marmoratus (above left). A common species found over much of the surveyed area. It is terrestrial from late May/June until around December when it enters ponds where it is usually active for most of the winter. Marbled newts frequently hybridise with crested newts (Triturus cristatus) producing the form shown above right. The hybrid apparently grows larger and lives longer than either parent species. Populations appear to fluctuate substantially. For instance, during early 2009 increased numbers were present in ponds and was reflected in a corresponding four-fold upsurge in road-kill during 2009/2010 compared to that recorded previously. The photographs below (left) show a female depositing eggs on the leaves of Elodea sp at around midnight during late December and a female (bottom right) entering the same pond during late November.      

Marbled Newt in FranceMarbled Newt in France

Herpetology in France

The common toad (Bufo bufo) lives in all types of habitat, including gardens. The migration period in Vendée begins in October until around December, which differs from many other areas of Europe - the UK for example.  It is sometimes active diurnally when it may bask and maintain relatively high body temperatures, but this could also involve sit-and-wait predation. However, it is mostly active at night when body temperatures are similar to environmental temperatures.

Herpetology in France

Palmate newt, Lissotriton helveticus.
A common species, mostly found in wetlands. It has similar movement patterns to the marbled newt but arrives in ponds around 3-4 weeks earlier and becomes terrestrial again from late May – June. The photograph shows a group of 8 individuals feeding at the bottom of a pond on a tubifex cube. They are active all winter except during extreme cold. Photographs below show a male L. helveticus out of water during the breeding period illustrating the enlarged sexual organs at the tail base (left) and two males courting a female on a pond bottom (right).       

Palmate Newt in FrancePalmate Newt in France

The Agile frog, in franceHerpetology in France

The agile frog, Rana dalmatina is mainly a woodland species but occasionally found in grassy fields and gardens. It is one of the earliest breeders arriving at ponds in February and quickly colonises new ponds for breeding. It spawns in virtually any water body including shallow ditches. The spawn clusters are usually laid around twigs and water plants (see above right). In dry springs shallow ditches may desiccate by May but they have water temperatures that are around 4˚C higher than deeper ponds. This may enable quicker larvae development thus avoiding mortalities.

From late May adults and subadults forage (diurnally and nocturnally) in woodland, even during the hottest weather. The species suffers road-kill in significant numbers from June until September, mostly due to entering roads in late evenings and at night to forage.

Agile Frog in France

Early spawning (February) in Western France by agile frogs presents a high risk of spawn freezing. Extensive freezing occurred during the early springs of 2012 (see photograph left) and 2018, which resulted in spawn being encased in ice (middle photograph). However some larvae survived (photograph bottom left) mainly due to the eggs being situated in the centre and bottom of the egg masses. A short paper (publication 68) on egg mass freezing and long term population changes in agile frogs (publication 76)  can be found in the publications list in the Academic Employment page.

frozen Agile Frog spawn
Agile Frof tadpoles Agile Frog in France

Tree FrogTree Frog

The tree frog Hyla arborea is found mostly in woodlands but also in gardens. The populations fluctuate widely, for example from 2003 until 2008 they were relatively scarce but in 2009, 2010 and 2011 were abundant and heard calling over many areas. Thermoregulation is mostly by microhabitat selection, by selecting leaves in shaded or partially shaded areas as resting spots but sometimes they bask on leaves that are in the sun. Summer home ranges may be at a distance from water but some individuals remain in the vicinity of ponds throughout the summer. A paper on tree frog thermal ecology (publication 64) can be found in the publications list in the Academic Employment page.

Water frogs in France

Water Frogs in France

The water frogs Pelophylax lessonae are the ubiquitous frogs, being found around most major ponds and ditches. This is an intriguing amphibian with an unusual genetic structure and forms a complex of species and hybrids . Water frogs are heliothermic with a sedentary lifestyle around ponds; the latter probably contributes to their low road-kill frequency since extensive movement, and hence road-crossings, are limited. Additionally many individuals appear to aestivate in drainage systems when ponds dry out rather than migrate to new water bodies. In Vendée it was previously possible to hear large numbers calling over extensive distances and indeed the calls are a way of identifying the various species and hybrids. This indicates most populations in Vendée are the full species P. lessonae, here shown basking in hot sun around a garden pond (5 individuals) and a pair in amplexus.



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