Common Frogs in Your Garden
One of the great things about water gardening and having a garden pond is the diversity of wildlife that it will attract. We have only a few amphibians in the UK, one of our most treasured being the common frog, (Latin name Rana Temporaria). Even the smallest garden pond will make a welcome breeding ground for Common Frogs.
Common frogs have different variations of skin colour, and can have colouration tones of brown, green, pink, red and yellow in appearance. Some have mild or more distinct markings of black and brown blotches on their bodies, and stripes on their legs. They hop rather than taking small tiny hops and crawling as do Common Toads, and they have quite a repetitive croak, also very different to our Common Toads. Adult males grow to about 9 cm in length; the females are slightly larger up to 13 cm in length.
Invite them in!
Frogs favour garden ponds that are not too deep. Variations of shelf levels and a shallow gradient beach area are ideal. Plant these with a mixture of low creeping, and compact marginal plants, a waterlily or two, and some good oxygenating plants to make a perfect breeding habitat. Filling moist borders, and bog gardens with plant life will also encourage frogs, for two reasons:
- they will have places to hide from predators such as Herons, mammals and grass snakes
- surrounding undergrowth will also make a good habitat for the invertebrates which frogs feed on.
Life Cycle: Hibernation and Spawning
Common frogs semi-hibernate in winter; they are more dormant than in full hibernation, and will still feed in very mild winter weather. They spend most of the winter under stones, leaves and decaying foliage, or buried at the bottom of the pond under silty sludge or mud.
On the first warm rainy spring nights they become fully active and make their way to spawning grounds, quite often returning to the same spawning ground they were born in. The time of this spawning migration can vary around the country: down in the West Country it can be as early as January, while up in parts of Scotland it can be as late as May. If you get the opportunity, take a stroll in the rain with a torch. It’s quite a sight to see the vast number of eyes appearing above the water, and to hear the low rumbling noise of spawning communication.
Newly-laid frog spawn is very small in appearance, tiny clumps that appear more black eggs than the jelly that surrounds them. These freshly laid clumps can be as little as 1-2 inches in diameter. Over the next 48 hours the jelly will expand and the clumps can then be 6-10 inches in diameter. Very occasionally Albino frogspawn is laid. Over the next 2-3 weeks the black eggs will start to grow, firstly elongating and then starting to twist in their individual jelly cells, on which they feed. When they are ready they will break free, consuming the rest of the clump before taking their first swim. They have a multitude of underwater predators which is why a single clump of frogspawn can contain up to 2000 eggs.
Life Cycle: Tadpoles and Adulthood
Newly hatched tadpoles are black in appearance and feed on algae and decaying submerged pond plants. Over the next 16 weeks they will feed and grow, changing in appearance to a colour of speckled brown and gold. As they mature they become carnivorous, eating dead insects and other decaying pond life. During their late development they sprout small buds at the base of their tails that slowly develop into back legs.
At about 15 weeks their front legs have developed inside their bodies. When these front legs break out they start to lose their gills; their tails start to shrink; and they come to the surface to breath oxygen. This whole transformation is known as metamorphosis. In the last few days they will be half aquatic and half land creatures, before leaving the pond as miniature frogs, sometimes called froglets.
Over the next 2-3 years they will grow into full sized adults, avoiding predators as best they can. Adult common frogs live 5-10 years in the wild, but have been known to live twice as long in captivity.
Please visit my website www.lilieswatergardens.co.uk to read over 160 informative articles on all aspects of water gardening and all the wildlife that fresh water and ponds can attract to your garden.