Wild Harris

Common Frog

Until recently Frogs did not live on Harris. They were probably brought here less than 50 years ago, but they love wet places and they are rapidly expanding on Lewis and Harris!

common frog 19bLCampbell.jpgCommon Frog    (Photo: Laurie Campbell)

Special features

Frogs can breathe through their skin.  To do this they have thin, soft skin that water and air can move through.   If frogs spent time in the sun they would dry to a crisp, so frogs like to live in shady, boggy areas.

Young frogs are called tadpoles; they live in water and look like fish. As they grow they get legs and their tail disappears so that they can hop out of the water and onto land.

commonfrog5b L.Campbell.jpgCommon Frog Tadpole    (Photo:Laurie Campbell)

Frogs can hibernate (sleep) though the winter and you might find them hiding safely under stones or in compost heaps.

They are green, - but frogs are not vegetarians! They catch worms and slugs and even spiders with their long sticky tongues.

Life cycle and habitat

Frogs can live for eight years. From the age of about three years they gather every Spring near ponds, lochs and ditches. Males choose a female and embrace her for days or even a week. Eventually the female lays the eggs and these are immediately fertilised by the attentive males. The eggs float to the top of the water and form the familiar slimy clumps of frog spawn.

common frog 22dLCampbell.jpgCommon Frog Spawn Close-up  (Photo: Laurie Campbell)

To see frogs spawning look around ditches or ponds in the evening with a torch. In the day frogs stay hidden so that they are not eaten by birds and cats.

Good frog parents lay their eggs in ponds that will stay wet but some parents accidentally choose a puddle that dries out. This spells death for their eggs. Other eggs are eaten by birds and fish but some lucky ones survive and turn into tadpoles.

commonfrog5486 L.Campbell.jpgCommon Frog Tadpoles    (Photo: Laurie Campbell)

Like fish, tadpoles breathe through gills on the side of their head. They like to eat small plants and rotting scraps. As they grow their bodies change so that they can live on the land. Their tail shrinks and they grow four legs, the back ones are big for hopping. They grow lungs instead of gills so they can breathe air, they can also breathe through their skin.

In the early summer you suddenly see lots of little froglets leaving their ponds and ditches for the first time. Frogs spend the rest of their life on land but they must stay in damp places or they will quickly dry out and die.

Adult frogs are carnivores and gardeners like them because they hunt garden pests like slugs, snails and caterpillars.

In Harris frogs are eaten by birds and otters. To stop this frogs change colour to match their hiding place. Sometimes we find mutant frogs; there have been yellow frogs with red eyes and frogs that turn blue!

Links

http://www.bbc.co.uk/nature/wildfacts/factfiles/483.shtml

http://www.snh.gov.uk/about-scotlands-nature/species/amphibians-and-reptiles/amphibians/

by Katherine Ross