All Things Amphibian……
Diane Wood, Wildlife Correspondent
Following on from my last article, spring migration is gaining momentum. In the amphibian world, these cold-blooded vertebrates have made their way from their overwintering underground refuges to their breeding waterbodies where many have already mated.
The mating process in amphibians takes place in water and is called amplexus, which is the Latin word for embrace.
This is when the male clasps the female and they deposit eggs and sperm externally together.
The fertilised eggs (in newts) or spawn (in frogs and toads) hatch and larvae or tadpoles emerge.
These have gills enabling them to breathe underwater where they stay for about 4-5 months until they have grown legs, absorbed their gills, developed lungs and resemble small adults.
Once they have undergone this metamorphosis, they then leave the water and live on land for the rest of the year where they feed on invertebrates such as insects, slugs and worms.
Amphibians that are native to the UK are common frog (Rana temporaria), common toad (Bufo bufo), smooth newt (Lissotriton vulgaris), palmate newt (Lissotriton helveticus), great crested newt (Triturus cristatus), native pool frog (Pelophylax lessonae) and natterjack toad (Epidalea calamita).
The latter two species are not known in Yorkshire.
Great crested newt
This species which has been around for approximately 40 million years, has suffered a large decline due to habitat loss and changes in farming practices.
As such great crested newts and their eggs, breeding and resting places are fully protected by European and UK law.
In my consultancy work the season for surveying for our rarest and largest newt, the great crested newt, runs between mid-March to mid-June as they are easier to find when they are gathered together at ponds to breed.
The newest method of surveying is by collecting water samples from suitable ponds, which are then sent off to a laboratory to be tested for great crested newt DNA presence.
|Also by Diane Wood...|
|Nathusius' Pipistrelle Bat - A Long Distance Migrant In Yorkshire|
|April Bat Update|
|Preparing For The Water Voles|
These surveys must be undertaken under a licence and the most common methods include torchlight surveys of the ponds at night when newts are most active; searching for eggs and overnight trapping for newts in ponds, where they are released, unharmed first thing the next morning.
This newt can be identified from other newts by its larger size, of up to 16cm long. It has a rough black skin with a white warty effect and an orange belly with irregular black spots.
In the breeding season, the male has a jagged crest from its head to its tail, with a gap at the base of the tail and a white flash along the bottom of the tail.
I am going to be out and about the UK doing great crested newt surveys for the next few weeks, but in the past I have surveyed many sites in Yorkshire where they are still present.
You could help the conservation effort for our more common amphibian species by creating refuges in your garden.
This could include placing log piles in shady areas; having a compost heap and allowing an area of grass to grow long and dense.
Any amphibian sightings could be reported to Amphibian and Reptile Conservation Trust at:
or the Yorkshire Amphibian & Reptile Group at:
https://groups.arguk.org/NEWYorksARG where further details about helping the conservation effort can be found.
All Things Amphibian……, 31st March 2019, 20:12 PM