Spawn & tadpoles FAQs I have too much spawn / too many tadpoles, what shall I do with the excess?Answer During spring amphibians return to ponds to breed. In garden ponds, common frogs can be particularly numerous at this time of year. Sometimes upwards of fifty frogs can return to the pond, leading to the popular concern that ponds may be 'overcrowded' or that there may be 'too much spawn'. This is a completely natural phenomenon, typical of amphibian populations around the world. While some years may be particularly good for breeding amphibians, many people report that in subsequent years the numbers are not sustained and they then drop down. Large numbers of breeding frogs can result in enormous 'rafts' or 'mats' of frogspawn being deposited, sometimes covering the whole surface of the pond. This is natural and will not result in your pond being 'over-run with tadpoles' or your garden being 'over-run with frogs' later in the year. Amphibians lay large numbers of eggs as a natural way to counter the range of predators that eat spawn and tadpoles. A popular statistic says that around one in fifty of the eggs laid in the pond will actually make it out of the pond as a froglet. The rest will be eaten by pond predators that might include fish (if present), dragonfly larvae or newts. Having large numbers of tadpoles can also lead to intense competition between individuals for food, meaning again that numbers of tadpoles will naturally thin out. Of the froglets that leave the pond, only a handful will make it to adulthood - the rest will get eaten by other predators including grass snakes, blackbirds, crows, magpies, hedgehogs, foxes and badgers. We advise that you refrain from interfering with the natural events that occur in your pond. Instead, enjoy it - frog numbers may not be as high in future years. Moving frogs or spawn?We do not advise that you attempt to move amphibians or their spawn away from your pond at this time of year: by taking them to a different pond you may unwittingly transfer various diseases and invasive plants. Also, many amphibians may try to return and they will suffer if placed in an unsuitable area. Do not release spawn, tadpoles or adult amphibians into the wild or into public water bodies such as rivers, canals reservoirs or country park/nature reserve ponds. I haven't got any spawn in my pond this year, what might be wrong?Answer Depending on the weather, it may still be too early for amphibians to be returning to ponds to breed. Amphibians breed in the spring when they migrate to their breeding ponds/ditches/etc. Migration is weather dependent (they prefer mild, wet evenings) and so is determined by location - it tends to occur later in the north and east of the country and earlier in the south. Follow the link to the Nature's Calendar website to view how spawning dates differ around the country. Newts may arrive in ponds after other amphibians have left, as they tend to breed a little later than frogs and toads. Newts also migrate, but it tends to be more drawn out than frogs and toads, with animals arriving at the pond over a longer period of time. In general, newts will start to migrate in early spring (February/March) but this could be earlier or later in different parts of the country or if the spring is particularly mild or cold. In some cases, lack of breeding amphibians in your pond could be the result of a population decline locally. This might be an indicator of pond loss: ponds form 'stepping stones' for amphibians across a landscape. If ponds disappear, so can local populations of amphibians. Similarly, their terrestrial habitats are just as important - amphibians disperse on land, to forage, hibernate and colonise new areas and if these areas or 'corridors' have been blocked (by a new road or even a fence) or destroyed (through development), the route to your garden may have been lost. Amphibian populations can fluctuate dramatically year on year so having years with low numbers of amphibians can be a natural phenomenon and nothing to worry about. If no breeding adults appear in your pond, there may be other juvenile amphibians in the areas that will turn up next year as breeding adults (frogs take two or three years to reach breeding age). You may be tempted to introduce some spawn from elsewhere to try and help your local population but we advise against this. By moving spawn you can accidentally introduce diseases and invasive pond plants. If you have seen frogs but no spawn it's important to remember that all amphibian life-stages form a natural part of the food chain. Spawn is probably the lifecycle stage that is the safest from the attack of predators, despite the numerous predators in and out of the pond. Spawn will also sink below the surface in deep water so it may not be visible. Occasionally spawn can sink below the surface and die; it is particularly susceptible to late frosts. Where can I get spawn to put in my pond?Answer We do not recommend moving animals or their spawn around because of the threat of unwittingly transferring various diseases and invasive plants. In most parts of the UK, amphibians (particularly common frogs and smooth newts) should find their own way to good quality ponds. It can take two years or more for a pond to colonise so do not be concerned if your pond is not immediately inundated with amphibians. See our FAQ: 'How can I encourage frogs / toads into my garden?' and our Dragons in your Garden section for tips on attracting amphibians. What the law saysAll wild, native amphibians (adults and spawn) are protected against sale/trade. Please inform us if you see amphibians being sold (including on internet auction sites); it is legal to buy/sell exotic or captive bred individuals/spawn though this should be stated in the advert. The spawn in my pond never develops properly, what's wrong?Answer The two common reasons for 'spawn-failure' are: Late frosts: spawn can be extremely sensitive to frosts, particularly during long spells of icy weather. Lack of light: to develop, spawn requires lots of light. If your pond is too shaded you might notice that spawn fails to develop. Occasionally pond-owners notice a white filamentous fungi covering dead spawn. This is a natural decomposer of dead pond matter. Amphibian and Reptile Conservation also receives reports of ponds where spawn continues to fail year after year - the jelly coating breaks down before the tadpoles are fully developed and ready to hatch. Moving the spawn to hatch in a bucket of rainwater can sometimes combat this but even this does not always help. Unfortunately, it's unclear what the cause might be and how best to help. All my spawn / tadpoles have disappeared, what's gone wrong?Answer There can be several causes behind disappearing spawn / tadpoles: Predators: spawn and tadpoles have numerous predators, in and out of the pond, including: fish, dragonfly larvae, water boatmen, newts, grass snakes and birds. This is the most common cause of disappearing spawn / tadpoles. Late frosts: spawn can be extremely sensitive to late frosts, particularly long spells of icy weather - the spawn may have died and sunk to the bottom / broken down without you noticing. Lack of light: to develop, spawn requires lots of light. If your pond is too shaded the spawn might die and break down. My spawn / tadpoles are being preyed upon, what can be done?Answer Amphibian eggs and their tadpoles make up a vital part of the food chain. To ensure that some eggs survive to develop into adults, amphibians produce lots of eggs. You should expect that 95% of the eggs, tadpoles or young amphibians in your pond will be eaten throughout spring by numerous predators, including: fish, dragonfly larvae, water boatmen, grass snakes, birds and even hedgehogs. Larger tadpoles may also sometimes prey on smaller, weaker tadpoles. Frogs, particularly, are part of the food chain; tadpoles are an important food source for wildlife, including other amphibians - newts are a predator of tadpoles, especially in the weeks after frog spawning when adult newts are in the pond laying their eggs on pond plants. Garden ponds are often home to more than one species of amphibian. This is a healthy situation and indicates that the pond is functioning well. There is no need to remove newts or other predators though we would advise against deliberately introducing fish to a wildlife pond. Adding places within the pond for tadpoles to hide could help increase their chances of survival. Potential hiding places include rocks/pebbles and aquatic planters. We would advise that pond-owners avoid using pond-netting. Sometimes the animals you're trying to attract (like grass snakes or hedgehogs) can become caught and die. I've found dead tadpoles in the pond, what's happened to them?Answer The most common cause of tadpoles suddenly dying is an algal bloom. If there has been some warm weather and the water has turned green, this indicates that there is a lot of algae growing in the water. Algae removes oxygen leaving the water 'anoxic' and the tadpoles suffocate. To avoid this happening again, make sure the pond is not completely in full sunlight and that there are plenty of aquatic plants present to use up excess nutrients and stop too much algae growing. If the water is not green then it could be that some sort of chemical/product has been washed off surrounding land by rain and run into the pond. If you suspect this to be the case contact the Environment Agency. There is spawn in the pond but icy weather is due, should I protect it from frost?Answer Spawn can be affected by cold weather. If a layer of ice forms over the surface of the spawn it may die, though the eggs at the bottom of the clump may survive. Sometimes icy weather can interrupt spawning, in which case a second batch of frogspawn may turn up in your pond once the cold weather subsides. Newt eggs and toad spawn tend to be more protected from frosts as they are laid slightly later in the year and deeper underwater. Some people choose to take measures to protect spawn from icy weather, by using a pond cover or by removing some of the spawn and keeping it somewhere slightly more protected (in a bucket of pond water in the shed, for instance) until the cold weather has passed. I still have tadpoles late in the the year (into autumn), is this normal?Answer Tadpoles / larvae usually develop into young amphibians and leave the pond during the summer months, but occasionally you might still see them in the pond throughout autumn and winter. These 'overwintering' tadpoles complete their development the following spring. There could be several reasons for this slow development: The pond may be so crowded that the tadpoles are short of food. The pond may be too cold, due to a shaded location or steep-sided construction. Crowding is likely to resolve itself over time. If the pond is shaded, consider cutting back some of the overhanging vegetation to increase the amount of light and warmth reaching the surface of the water. At this stage, do not attempt to help these 'slow-growers' by providing extra food or taking them out of the pond - you could end up with them completing their development in the middle of winter when there is no food around to support them. They will be fine in the pond until next spring. Should I feed the tadpoles in my pond?Answer Ponds normally provide enough food for tadpoles without any need to supplement their diet. Newly hatched tadpoles are herbivorous and feed on the algae that grows on pond plants or on rocks in the pond, particularly those exposed to the sun. In the latter stages of their development they become omnivorous, feeding on decaying matter in the pond and tiny creatures such as water fleas (daphnia). Some people choose to supplement tadpole diets with lettuce/spinach (to start) or fish flakes (for cold water fish). This approach is undoubtedly beneficial, especially if numbers are high or if the pond is relatively new, though adding too much food will pollute the water and may lead to unwanted algal blooms. I am working on my pond, what shall I do with the spawn / tadpoles in it?Answer If possible, delay pond maintenance until late autumn (September/October), so that tadpoles have been given time to metamorphose and leave the water (and before adult frogs return to the pond to hibernate). If you need to carry out the work more urgently remove the spawn/tadpoles with a net and place in a tank or suitable container filled with pond water while you do the work; carefully return them to the pond when you've finished. Occasionally tadpoles/newt larvae remain in the pond over the winter and develop the following spring, so be sure to be check the pond carefully before starting work at any time of year. If you are considering filling in your pond because of safety concerns we advise you to consider installing some simple safety precautions for the pond instead, see: 'How can I make my pond safer for children?'. Removing a pond can be very detrimental to local wildlife, particularly as adult amphibians will have nowhere to spawn when they return the following spring. Unfortunately there is no organisation that will pick up animals disturbed as a result of you filling in your pond. How do I tell the difference between frog, toad and newt spawn / tadpoles?Answer Key features to look out for: Frogs Spawn is laid in clumps in shallower water. On hatching, tadpoles are black and will stick together in a writhing mass. As they develop, tadpoles become mottled/brown and do not shoal. Tadpoles grow back legs first. Toads Spawn is laid in strings, usually wrapped around vegetation in slightly deeper water. On hatching, tadpoles are jet black and remain so. Tadpoles often form shoals. Tadpoles grow back legs first . Newts Eggs are laid individually on submerged plant leaves. Larvae (sometimes called efts or tadpoles) have a frill of gills behind the head. Larvae develop front legs first (when newly hatched they can be mistaken for fish fry). See our amphibian identification guide for more information... I've seen white spawn / tadpoles, what's going on?Answer There can be a couple of explanations behind white spawn or tadpoles. If you have seen seen white spawn then it could be because it has not been fertilised. This spawn will naturally break down in the water. If the white dots in the centre of the spawn start to become 'comma' shapes, like ordinary spawn, then this will hatch into white or 'transparent' tadpoles. These tadpoles are either albino (missing skin colour pigments, they will have pink eyes) or are just missing certain skin pigments. White tadpoles do not always survive well in the wild as they are so conspicuous to predators. Those that do survive don't necessarily turn into white frogs, often they become darker in colour as they grow. It may not be an albino frog that has laid these eggs, it could just be that there is a high proportion of the local frog population that carries the gene for albinism. If this is the case then you may see this occurring in future years. I've found spawn in an unsuitable place, should I move it to a pond?Answer Frogs often choose to lay spawn in small water bodies including puddles, buckets and even watering cans. This strategy can be beneficial for frogs - such 'ponds' often lack predators meaning the chances of tadpole survival could be higher. The strategy can be successful if the tadpoles can develop and leave the 'pond' before it dries up. Often, however, the strategy fails and tadpoles are left without enough water to survive. To a degree this is a natural phenomenon, typical of amphibians around the world. However, you may want to 'rescue' such tadpole populations. If you choose to do this we advise introducing tadpoles to a pond as near as possible, ideally to a garden pond within one mile. Moving tadpoles or spawn around can accidently transfer wildlife diseases or invasive plants, so for this reason we do not recommend that you release tadpoles into the wild or in public water bodies (such as rivers, canals, parks or streams). You may decide to raise these tadpoles in a tank - if this is the case please see the FAQ question below. The froglets that the tadpoles develop into should be released into a suitable habitat near to where they were found. I would like to raise tadpoles in captivity, is it illegal and what do I need to know?Answer It is not illegal to raise common frog or common toad tadpoles in captivity. We do recommend, however, that tadpoles (or froglets) are released back into the same pond from which they were taken. This reduces the threat of moving amphibian diseases or invasive pond plants to new ponds. Key points are to have around 3-5 tadpoles per litre of water, and ideally they should be kept in pond water. If tap water is used it should be left to stand for a day or so to let the chemicals settle out. Feed newly hatched tadpoles on boiled (and cooled) lettuce or spinach, and fish food (for cold water fish) when they get bigger. Make sure there are rocks and plants for the developing froglets to climb on, if they cannot easily exit the water at this stage they can drown. If you keep the tadpoles until they have metamorphosed into froglets please do not release them back into the pond, instead release them into some damp vegetation close to the pond. An amphibian habitat is threatened, what can be done?Answer Of the widespread species of amphibian, the great crested newt, Pool frog and Natterjack toad are protected by law from intentional killing and injury; their habitats (including ponds and key foraging areas) are also protected. If you suspect incidents where this law might be being flouted, please inform us. In 2007, the UK Biodiversity Action Partnership (UKBAP) listed the common toad as a species of conservation concern. In England and Wales this means that (under Section 41 of the Natural Environment and Rural Communities (NERC) Act 2006) all public bodies must have regard for common toads, and great crested newts, (specifically under 'biodiversity conservation') when carrying our their functions. In addition, Planning Policy Statement 9 (PPS9) states that planning authorities should ensure that species of principal importance, including the common toad and great crested newt, are protected from the adverse effects of development. It's important you submit records of your sightings to your local Biological Records Centre and local Amphibian and Reptile Group (ARG) so if/when consultants are researching an area they pick up these species at the earliest opportunities.