Frogs and Toads
Frogs and toads have come under a number of threats in recent years. Many of their usual breeding places are disappearing, as ponds become filled in or polluted because of housing development or intensive agriculture. Large numbers are dying on the roads, especially toads on the way to their breeding sites. Over-collecting of spawn may be another factor on the decline of frog and toad populations.
Frog spawn is laid in clumps in shallow water, while toad spawn forms long strands winding around aquatic vegetation in deeper water. It takes about three weeks for tadpoles to emerge, and a further 12 weeks before they become mature froglets (6 - 8 weeks for toadlets).
Spawn should only be collected from garden ponds that are really overcrowded with it - and it is important to take only a very small amount.
Keeping Spawn in Captivity
One clump of spawn might produce 200 tadpoles, and in a confined space most would die of starvation or an oxygen shortage. Tadpoles kept in overcrowded conditions eventually begin to eat one another.
Spawn should never be taken from the wild.
The spawn or tadpoles should be put into a small aquarium tank filled with rain or pond water. Tap water should be avoided if possible, as it can kill tadpoles. If it has to be used, it should be allowed to stand for several days beforehand. The water should be changed whenever it becomes cloudy or dirty.
Tadpoles will eat canned spinach (washed to remove the brine), bits of boiled lettuce, or food pellets sold in pet shops for rabbits or hamsters. For 100 tadpoles about 5 large pellets should be given every 3-4 days. As soon as the hind legs begin to appear, the tadpoles must be given small pieces of raw red meat - but be sure to remove any pieces of uneaten food before it begins to rot. The best time to release the froglets is when the hind legs are large, but before the front legs start to appear. If kept any longer, the froglets might escape from the container or drown. Newly metamorphosed frogs are fragile, and drown very easily.
Froglets should be released in shallow water at the site from which the spawn was taken.
An ideal pond for amphibians should have shallow areas for spawning, and some plant life, and it should not contain a high density of predators such as fish, newts, ducks or moorhens - although common newts will usually leave toad tadpoles alone.
Frogs hibernate at the bottom of ponds, under old logs, in stone walls or in compost heaps. Toads hibernate on land under stones or logs, or in a hole in the ground. They rarely hibernate in water. In a severe winter frogs may die if the pond remains frozen for a long time: toxic gases such as methane build up from decaying vegetation and cannot escape because of the ice. To prevent this, melt the ice from time to time by standing a saucepan of hot water on it.
Garden ponds are becoming an increasingly important refuge for frogs forced out of their old habitats. It has been estimated that nearly 50% of frogs in Britain live in garden ponds. This can be good news for the gardener, as they eat a number of insect pests.
Frog colonies tend to be fairly small, so they can exist quite easily in gardens, but toads in field ponds frequently form colonies of over a thousand. Frogs and toads usually return to the same pond every year.
Five Point Action Plan
1) Don’t Panic!
Sometimes people fear that too many frogs have come to their pond to spawn and that they will be over run with frogs. Remember that only a tiny percentage (between 1% and 5%) of the eggs laid will ever make it to adulthood. Frog spawn, tadpoles, froglets and adult frogs are all predated upon by other creatures so only a very small number ever reach maturity. Don’t move frogs or frog spawn from garden ponds into the countryside.
2) Avoid the use of chemicals
Try to create a natural balance in your garden by employing the services of wildlife to help control pest species. Frogs are wonderful for keeping slug numbers down and insects such as ladybirds will help control aphids in the summer. By voiding excessive use
of chemicals it is easier to create the conditions in which a range of helpful wildlife species can thrive. Try using wildlife friendly forms of slug control such as sprinkling grit or crushed egg shells around tender plants or wrapping copper wire around the top of pots and tubs to discourage slugs.
3) Be creative.
Why not create a range of habitats in your garden where frogs can thrive. Log piles, rockeries, bog gardens and even compost heaps all help to provide food and shelter for frogs and other wildlife. If you do build a pond, make sure it is safe for children by building a fence around it or by installing strong wire mesh just beneath the surface of the water. It is also important to make sure that frogs and other wildlife have an easy way out of the water. This can be achieved by using gently sloping pond sides or by placing planters at the edge of the pond which animals can use to climb out.
4) Be Aware
Keep a look out for any signs of frog disease. If you find frogs with open sores or damaged limbs, which don’t seem to have been caused by an attack by other wildlife please contact Froglife on 01986 873733
Learn to appreciate the role that all creatures play in the natural cycle of life. Encourage children to learn more about wildlife by studying the fascinating development of frogs from spawn through to adulthood.
You can also download and print this Frogs and Toads fact sheet