Friday, June 04, 2010

The Green Frog/ Pelophylax esculentus

The frog lake in late May 2010.

Green Frog, Mid Jutland, May 2010.
photo: stig bachmann nielsen,
Naturplan foto

The Green Frog/Edible Frog (Pelophylax kl. esculentus) is a name for a common European Frog, also known as the common water frog or green frog (however, this latter term is also used for the North American species Lithobates clamitans. It is used for food, particularly in France for the delicacy frog's legs. It is a large green frog with black spots and often with a light stripe along the back. It jumps out into the water with a big splash when you come near. It's about 11 cm long and found in the eastern part of Denmark and a few places in Jutland. It stays all summer by water holes close to a forest.

The frog lake lies close to the forest

The green frog has declined since its waterholes have been destroyed or reduced. It is listed and must not be gathered or killed. Eggs and tadpoles may be gathered in limited numbers and the grown frog may be gathered in limited numbers for education and research. Its waterholes are listed according to the Nature Protection Law if they are over 100m2. The green frog quickly finds new-digged waterholes, since it is moving much about.

The green frog has various sounds, both males and females croak, but only the males have "croak-bags". The grown frog takes everything which moves and which it is able to swallow. Small insects, hornets, small birds like swallows, wagtails and young birds of grebes. The green frog eats all sorts of frogs - also green frogs.

The green frog started as a cross between the shortlegged green frog and marsh frog, but has turned into an independent species via some special conditions of its heredity. The green frog lays eggs latest of all other frogs in spring and demands the warmest water. Therefore the sun has to shine on each corner of its water hole. The water has to be clean with many water plants.

It lays its eggs in the end of May in lumps of 20 up to 1000 eggs - in all about two thousand eggs. They vary much in size, which indicates that the eggs come from a green frog. The tadpoles are very shy - and this might be the reason, why the green frog can survive in water holes with fish.

When the eggs have been laid, the frogs stay at the places where they have been breeding. Some frogs walk out to larger bogs and lakes. They begin their hibernation in September, both on land and in water. Their enemies are grass snake, grey heron, otter, badger and polecat.

The green frog was earlier a common frog in many places in Denmark, but has declined much and has become rare in large parts of Funen and Zealand. This is a result of that the water holes have been filled up or been overgrown or polluted. The green frog is listed as opmærksomhedskrævende (demanding attention) on the Danish gulliste 1997 (yellow list) - and it is covered by Habitatsdirectives, Listed and Natura 2000.

Superstition: It is wellknown that to kill a frog is bad, as you are killing the soul of a little boy or girl, who died in childhood. A frog that croaks in the middle of the day means that rain is due. A frog that jumps into your home is a sign of good luck to all in the household. It is also wellknown in fairy tales that frogs have been used for love spells. And if you rub the frog over your warts then they will disappear.

Or the famous fairy tale of the Brother's Grimm about the Frog Prince. The princess has to kiss a frog which then transforms into a handsome prince.

photo May 2010 Mid Jutland: grethe bachmann


MyMaracas said...

There's something a little scary about a frog that eats birds. I'm amazed at your photos. Our ponds are full of frogs, but I never get a good shot of one.

Thyra said...

Hej! This day we were very lucky, for the frogs were so many and so active - and they hardly noticed us. We might as well have come there on another day without seeing anything at all.

This frog is the edible frog. Maybe it tastes of duck since it eats ducklings??? `:)
Well, I would never expose myself to eat frog legs. Bvadr!