By Denis O’Connor

Wharfedale Naturalists Society

AT the beginning of March, a few days after the end of a very cold spell and with the ice having just left our garden ponds, I was surprised to find dozens of newts already in residence in all four ponds.

Trawling with a net brought up both adults (pictured is a male palmate newt showing partially webbed hind toes and tail filament) and newt tadpoles, the latter like tiny versions of the adults with both fore and hind legs but proportionately longer tails. These tadpoles were ones that had not completed their metamorphosis by the end of last summer so had passed the winter in the ponds.

Overwintering of amphibian tadpoles has been found to occur in frogs, toads and all our newt species although these palmate newts are the only ones where I have seen it. Often, while clearing out excess vegetation from the ponds in the autumn, I have had to restore numbers of these tadpoles to the water.

Almost all our newts are palmates, with a total population well into the hundreds, although last year for the first time I discovered a few male smooth newts, slightly larger and darker with a prominent wavy crest along the back and lobed back toes.

Going back nine years we used to get 100 to 150 frogs spawning in one of the ponds but their numbers fell catastrophically after the very cold spring of 2013 when our ponds stayed iced over until well into March and many did not survive hibernation. Since then numbers have been much lower with about 30 spawning this year on 22nd and 23rd March.

Going out with a torch on the evening of 22nd I found newts clustered around the frog spawn nibbling at the jelly. A week later some clusters of spawn were empty, stripped bare of eggs leaving just the jelly, while others still contained eggs or developing tadpoles.

Newts and frogs tend to have a boom bust relationship with the newts eating both frog eggs and tadpoles, so ponds with lots of newts tend to have fewer frogs. However, if the number of frogs decreases the supply of food for the newts goes down leading to fewer newts and the chance for the frog population to recover.

Given that frogs and newts have been living in balance for millions of years I am sure they will sort it out!