Common frog

These are a couple of the frogs that come back each year into my pond for breeding. During the rest of the year frogs can be found in meadows, gardens and woodland. They breed in puddles, ponds, lakes and canals, preferring areas of shallow water. In my pond they lay their spawn on my primrose willow stalks and watercress. In the wild, the common frog can live for up to 8 years. It would be lovely to think that they could survive in my pond for that long and only die of old age.

Common frogs do not feed at all throughout the breeding season, but when they are active they will feed on any moving invertebrates of a suitable size, such as insects, snails, slugs and worms, which they catch with their long, sticky tongues. The back garden where my pond is situated seems to be devoid of slugs and snails due to the frogs which is wonderful. It is just a shame that they haven’t realised yet that the front garden holds a stupendous feast for them.

Adult frogs feed entirely on land, whereas the younger frogs will also feed in the water. Tadpoles are herbivorous and feed on algae but become carnivores when they mature into adult frogs I know that some people feed them with catfood. Well after all they do ‘purr’ when croaking.
Although common frogs are active both day and night, they tend to be more active at night. I know that I have to keep my feet carefully placed when I go out into the garden at night as I often find them coming home as I take out my rubbish to the bin.

During the winter they hibernate in compost heaps, under stones and logs, or underwater beneath piles of mud and decaying leaves.The common frog can breathe through its skin. This enables it to hibernate for several months beneath piles of mud and decaying leaves underwater. I think that the male frogs tend to stay in the pond during the winter whereas the females and juveniles stay in the rocks around the pond. The best thing about having a liner in the pond is that sometimes the creases are good hibernating areas.

Common frogs become sexually mature at around three years of age. During February and March they begin to emerge from hibernation and make their way to the breeding grounds. Ours come back usually toward the end of March. It always amazes me that they can find their way back to the pond that they emerged from. The males arrive first and attempt to attract a mate by producing a low purring croak. A successful male will wrap his forelimbs around the female in a mating embrace known as ‘amplexus’. When I first saw this I was shocked at how long they could hold on for. Each female lays 1000-4000 eggs at a time, which are fertilised by the male as they are released. Frogs can spawn as early as December and as late as April, depending on how warm the weather is.

Frogspawn is surrounded with a clear jelly-like substance, which swells up in the water to protect the fragile embryos. The spawn floats to the surface in large round clumps so that the sun can warm the eggs. After 30 to 40 days, tadpoles begin to emerge from the jelly-like spawn. The tadpoles feed on the spawn for the first few days until they begin to eat algae. Tadpoles change into frogs through a process called ‘metamorphosis’, which takes between 12 and 14 weeks. Both spawn and tadpoles are extremely vulnerable, and many get eaten by predators such as fish, birds and grass snakes. This year my fish have had a few tasty dinners, but that is the problem when you have them both in the same pond. I am thinking of putting a smaller wildlife pond in before next spring to keep the spawn safe especially when on average, only 5 out of every 2000 eggs will survive to become adult frogs. That does not sound very good odds.

When tadpoles hatch they have gills that allow them to breathe underwater. After 9 weeks they have lost their gills and developed lungs, and therefore must swim to the surface to breathe. As they grow, tadpoles begin to feed on insects as well as plants. Hind legs develop between 6 and 9 weeks, and front legs are fully developed after about 11 weeks. The tail begins to be absorbed by the developing tadpole, and by 12 weeks it has practically disappeared, leaving a tiny froglet. At this stage the tadpoles are less dependent on water and will hide in long grass in and around the pond. We just love to see the froglets. Such tiny forms of the adult frog. They have to shed their skins many times before becoming a full sized frog.

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