Tuesday, 16 June 2009

Bye bye newts!

Male and female palmate newts (left) and male and female smooth newts

Yesterday I decided I wanted to release the four newts I've been keeping for a few months back to their original pond in Epping Forest. I first went there in mid-March for a Field Studies Council course on British amphibian identification and conservation, and was so taken with the dozens of smooth and palmate newts we collectively caught that I took a pair of each home with me for study and hopefully for breeding.

Male palmate (above) and male smooth newts. Note enlarged black hindfeet of palmate and enlarged black-tipped hindfeet of smooth.

The night I got them home, two of them (Mr. Palmate and Mrs. Smooth, if I remember correctly) escaped and hid underneath the radiator. Needless to say, they were a bit worse for wear; I'm just glad the cats didn't get to them! Once they were cleaned up, cooled down and rehydrated, both recovered and regained their appetites. All four of them gobbled up live bloodworms.

I noticed the first eggs after a couple of weeks, and began to harvest them by removing the leaves to which the eggs were attached and keeping them in a separate container. A week or so later, they hatched into tiny larvae. That brood didn't survive, but there were more eggs to come. They hatched, and all died. The third brood did a little better, but as they lived for more than a week, the problem arose of what to feed them. Their yolk store was enough to keep them going for their first seven days of life, but they are still far too small to eat bloodworms; even adult Daphnia dwarf them!

I was on the lookout for something suitable to feed tadpoles or fish fry, and found various plankton, including Cyclops (a copepod) and Artemia nauplii. The latter turned out to be the most successful. They are known in the aquarist trade as 'baby brine shrimp', and that's exactly what they are. They are the newly hatched eggs of what are commonly known as 'sea monkeys', and are the perfect size for my new babies to eat. So far, so good.

I left for Cyprus in late April, by which time the newest batch of young are a couple of weeks old. There were 27 larvae when I left, but I came home to 4. Despite being well cared for by their foster-foster parent, my sister Sheree, very few survived. I put it down to the fact that they were sharing a small container and were killing each other. A few were even eaten. A few days later, and I was left with one.

This single larva has survived to this day, and I am still looking after it. The picture above was taken under a low-powered microscope in Cambridge this past weekend, whilst exhibiting it and its parents/parents' friends at the Conversazione exhibition. I'm truly amazed at how large its eyes are!

Male (foreground) and female smooth newts

The adults meanwhile were getting bored of their environs, a small tank filled with water and decorated with stones and plants. I could tell they wanted to leave. The day after the exhibition finished I decided to take them back to their place of origin. They were reluctant to leave the ice-cream tub, so I placed them by the margin of the pond. It took a few minutes before any of them responded. The female smooth newt slowly approached the water, then plopped in, swimming at the surface until it reached a mat of floating vegetation. Her mate soon followed, but went down instead of across.

Male (rear) and female palmate newts

The palmate pair were reluctant to head towards the water. I even put the male in, and he climbed back out again! Clearly, they were past their aquatic phase and wanted to be on land. I released them a few metres from the pond in the undergrowth. That was where I left them, and I felt like a mother bird watching their young leave the nest. I felt sad, but also happy. The newts had provided a stimulating exhibit for the show, and had helped people learn about newts and other amphibians. I'm thinking of getting fire-bellied toads (Bombina orientalis) next, or maybe an Argentine horned frog (Ceratophrys ornatus), I still haven't decided.

Male palmate newt retreating from pond

Taxonomic information:

Smooth newt
Lissotriton vulgaris (Linnaeus, 1758)
Salamandridae; Caudata; Amphibia; Chordata

Palmate newt
Lissotriton helveticus Razoumowsky, 1789
Salamandridae; Caudata; Amphibia; Chordata

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