A collection of wildlife photographs

Sunday, 15 March 2015

Amphibians in Epping Forest

On the 14th and 15th March 2015, I went on an Amphibian course with the Field Studies Council in Epping Forest. It was a lot of fun and we saw all three newts native to the UK, along with Common Frog Rana temporaria and Common Toad Bufo bufo. Below are some photos of these species.

Great Crested Newt Triturus cristatus

This is the largest newt native to the UK, growing to 15cm in length. 

The skin of a Great Crested Newt is rough and warty, unlike the smooth skin of a Smooth Newt and Palmate Newt. The Great Crested Newt is also black, darker in colour than Smooth and Palmate Newts. The flanks are speckled white, with some orange 'finger nails'.

The underside of this species is orange with black blotches. The pattern of these blotches is unique to different individuals (see lower photo)

During the breeding season, the male has conspicuous silver stripes along both sides of its tail and a crest which is even more pronounced than usual. The females lack a crest and have an orange stripe on the underside of the tail. Females are slightly bigger than males. The disturbance on these newts caused by handling them was done under a Great Crested Newt class licence.

Great Crested Newt
Great Crested Newt
The distinctive, white eggs of Great Crested Newt are larger than Smooth Newt and Palmate Newt. The slightly smaller eggs of Smooth Newt and Palmate Newt are similar in size to each other and dirty grey-brown colour; they cannot easily be told apart from each other. Newts use their back legs to individually wrap eggs in aquatic vegetation. On a good night females can wrap ~20 eggs.

Great Crested Newt prefer larger, deeper ponds to the other two native newts and they are more discerning with the ponds they inhabit. Smooth Newts can breed in a wider variety of ponds. Habitat fragmentation across the UK has caused recent population declines.

Smooth Newt Lissotriton vulgaris

Noticeably smaller than Great Crested Newt, but a similar size to the Palmate Newt (both growing to ~10cm). Smooth Newt is the most common Newt in the UK and relatively widely distributed. The male Smooth Newt also has a crest during the breeding season, however the crest of the Smooth Newt does not dip between the body and tail like that of Great Crested Newt. This species is speckled with black spots on its belly and its throat, unlike Palmate Newts which lacks a speckled throat.

Smooth Newt
Smooth Newt

Palmate Newt Lissotriton helveticus

Palmate Newts are also much smaller than Great Crested Newts. The neck of Palmate Newts are pale pink (or yellow) as shown below, but the neck is rarely speckled as that of the Smooth Newt is. The belly of this species is orange with a few black spots. The male Palmate Newt does not have a crest during the breeding season, instead just develops a tail filament.

This species can tolerate more acidic waters than Smooth Newt and is thus present on heathlands and coniferous woodland. The acidic soils of Epping Forest make this the most common newt in the local area.
Palmate Newt
Palmate Newt
Common Toad 

The Common Toad has rough skin, opposed to the smoother skin of Common Frog. Swollen parotid glands in this species (see lower photo below) behind the eyes release toxins to repel predators, which allow them to crawl relatively slowly, rather than have to jump away from predators quickly like the Common Frog has evolved to do.
Common Toad
Common Toad

Common Frog

This species can inhabit smaller ponds than Common Toad because juveniles develop lungs at an earlier stage of metamorphosis. Common Toad do not develop their lungs until near the end of their metamorphosis and therefore require to remain submerged for longer in ponds which do not dry up.

These are not the only amphibian species native to the UK. In addition to these there are the rare Natterjack Toad Epidalea calamita which is limited to ephemeral ponds, and the Pool Frog Pelophylax lessonae which was originally considered to be introduced, but two relic populations are known about (one of which went extinct in mid 1800s).

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