Toad migration

It’s the time of year when our resident amphibians are mating and heading for the nearest stretch of water to spawn. I find it a particularly stressful phenomenon due to the number of frogs and toads that need to cross roads and don’t make it. In my vicinity the completion of the guided busway running into the north of Cambridge has imposed an impassable barrier to thousands of common toads, Bufo bufo, which hibernate in the woods and hedgerows along the northern edge of the busway.


Pair of toads, the lady is the larger one underneath doing the legwork

It’s clear from the picture that the toads stand little or no chance of negotiating the sheer walls at the side of the busway – and even if they did they would have a further three to climb on the way to the lake and all four again on the way back. All this whilst numerous pedestrians and cyclists are making their way to school in Histon and work on Cambridge Science Park. It’s an extremely hazardous operation.


A pair that made it on their way to the water

When they make it to the water toads lay strings of eggs, as opposed to the gelatinous mass of eggs laid by frogs, and their tadpoles are slightly shorter and fatter than frogs. They feed on vegetable matter and absorb oxygen through their skin. As they grow they develop lungs and come to the surface to breathe. Eventually the tadpoles metamorphose into adult toads and the tail shrinks away at which point they leave the water as immature adults and will only return to the water to breed.

Adult toads differ from frogs in that they don’t hop, they walk. The colour of toads is also rather different, they have light ot dark brown warty skin with darker spots and frogs have more homogeneous green and smooth skin. And the eye colours of the toad is gorgeous – a lovely deep reddish gold. I like toads, they eat garden pests including slugs and are consequently good things to have around.

As with alot of creatures with the word ‘common‘ in their name, this is something of a misnomer, because of habitat destruction and the best attempts of predators including domestic cats they are no longer common. They secrete a toxic irritant through the skin but some predators are immune to this so they still get eaten.

It’s a real struggle being an amphibian in modern Britain so if you see one heading for the water – or on the return trip – please rescue it and help it on its way by placing it out of the way of humans, cars, cats etc.

Advertisements

Please share your thoughts:

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s