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This is my blog about amphibians. If you would like to add a comment please use the contact us form
28.5.10 Do the Thessaloniki frogs mean an earthquake is imminent? thousands of tiny frogs were seen swarming on a highway in Thessaloniki, Greece over the last two days, and some reports say that this could be an early warning of an imminent large earthquake. I notice in the reports of the Thessaloniki frogs that they were
"tiny". This means it is likely that they are newly metamorphosed
juveniles. Many species of frog synchronise the laying of spawn, and
metamorphosis is similarly synchronised, which is probably a "predator
swamping" strategy (ie more frogs than predators can possibly eat in
one go). Also the time of year is right for early breeding frogs to
have metamorphosed and be starting to disperse. This is completely
normal. If they were adult frogs moving in such large numbers I would
be more concerned. However the media have already picked up on the
possibility of an earthquake...of course it is possible but then I
would expect adult frogs to also be moving...and it does not seem that
this is the case.
11.3.10 Paper just released in the Journal animal behaviour shows that visual cues are important for reproductive success in the frog Rana temporaria. Sztatecsny et al. (2010). Chin up: are the bright throats of male common frogs a condition-independent visual cue? Considering the high densities during breeding, our results suggest
that bright male throats can act as a visual signal among males to
facilitate gender recognition and avoid attacks by other males. In press Animal Behaviour  doi:10.1016/j.anbehav.2010.01.003
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