How to help frogs spawn survive in a pond

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Frogs return to the pond in Spring and leave frogs spawn:

  • They travel and try to return to the pond of their birth.
  • Frogs come out of hibernation when night temperatures in an area warm to over 5'C.
  • Males return to the pond first.
  • Male frogs attract the females to them by croaking.

Frog Mating:

  • They mate in shallow, still areas of the pond among rafting plant growth.
  • The male attracts a female & will grip her from above with his forelimbs in an embrace called 'amplexus'.
  • They may stay in this position for days before you see frogspawn.
  • Cold weather can 'stall' the process.
  • When she is ready the female lays her eggs into the water and the male releases his sperm to fertilize them.
  • The female can be suffocated or drowned during mating.
  • To help her add plenty of shallow shelves & <p>Suitable for shelf depth 13-15cm(5-6”) or waterlogged mud </p> shelf pond plants in baskets for her to sit on for support.
  • Add plants that make rafts of stems across the water surface for support like Myosotis scorpioides, Veronica beccabunga, Mentha aquatica Myriophyllum Red Stem or Rorippa nasturtium aquaticum.
  • If you have no baskets in an area where mating is happening add a basket filled with gravel as a platform for her to sit on.
  • The mating can last for days and more than one male can mount one female while she is laying frogs spawn.

Frogs spawn:

  • Each female usually produces one clump of frogs spawn in a season, usually in warm days in Spring in UK.
  • Over the weeks of spawning many frogs will appear in the water with a mass of movement and frog spawn as a result.
  • Frog spawn is laid on shallow shelf areas as lumps about the size of a tennis ball.
  • Each lump will swell to grapefruit size as it matures and will float to the water surface.
  • They will merge to look like one jelly mat.
  • Frogs need to lay spawn in water so the tadpoles can swim when they hatch.
  • Don't move spawn from the wild or buy spawn. This can spread frog diseases and viruses or invasive plants.
  • The sale of wild-caught spawns or tadpoles is an offence under The Wildlife and Countryside Act 1981.
  • Follow the Froglife campaign #StopSpawnSales.

Freshwater Habitats Trust (formerly Pond conservation) ask pond owners to take part in the Pondnet Big Spawn Count every year to see how many clumps of spawn appear in your pond so they can see how many breeding females are reported.

Please enter any results on dates and volume of frog and toad spawn arrival this year in their survey.

Big Spawn Count results in the past show:

  1. Frogs Spawn laying depends on the outside temperature and can vary by 2-3 weeks.
  2. Up to 5mx5m appears to be the optimum size for the pond water area.
  3. Construct the pond with shelves to produce shelf areas of shallow water.
  4. A pond should be in the sun in Spring.
  5. The average number of clumps of spawn in a 5mx5m pond was 14.
  6. A smaller pond of 1mx1m had, on average, 7 clumps of spawn (or 7 visiting female frogs).
  7. Plant the area around the pond densely to give a habitat for protection and hiding places to get the best numbers of frog visitors and survivors.

Juvenile frogs not yet capable of mating (3 years old) may appear in the pond too.

Watch our video 'Frogs in your pond in Spring' to see them spawn.

How does Frogs spawn survive?

Froglife (the wildlife charity for conservation of amphibians and reptiles) advises that frog spawn is not taken from one pond to another to help control the spread of invasive pond plants and amphibian diseases like ranavirus.

  • The adult female lays several thousand eggs to allow for huge losses.
  • Each egg looks like dark brown-black centres in a circle of jelly.
  • Eggs are laid as a mass of jelly with the black eggs in one tennis ball size clump.
  • A clump of frog spawn often sits half submerged under the water and half exposed to the air. It is vulnerable to overnight frosts.
  • Frost can kill the spawn closest to the outside of the clump.
  • Do not remove the mass from the pond as the centre of the clump may survive as it is protected by the outside jelly.
  • Leave any frogspawn that dies in the pond to get eaten by other creatures.
  • Dead eggs will have grey or white centres.
  • Very cold weather can interrupt spawning - a second batch of frogspawn may appear in your pond after the cold spell from females that haven't spawned earlier.

Frog tadpoles hatch around three weeks after spawning:

  • Each tadpole is about 12mm long and brown in colour.
  • They will feed on the old jelly mass and any algae which is growing on it.
  • You can supplement their early food requirements with a vegetable based food - particularly important in a new pond.
  • At first use Early Stage - Tadpole Food.
  • Frogs are a protected species so their spawn or tadpoles should not be removed from their pond.

How do Frog tadpoles grow in Summer:

  • Once they start to develop legs the tadpoles change from being vegetarians to carnivores.
  • Most established ponds will have enough food for the tadpoles to develop to maturity but not in a new pond. With a large number of tadpoles in your pond you can supplement as they grow with Late Stage (high protein) Tadpole Food.
  • Up to 90% of the eggs, tadpoles or froglets in a pond are lost to predators in the warm shallow waters at the edge of a pond. These predators include dragonfly larvae, water boatmen, snakes or birds.
  • They need as much cover from plant leaf as possible so they have somewhere to hide from these predators.
  • Grow Myosotis species, Veronica beccabunga and in a larger pond area - Mentha aquatica and Rorippa nasturtium-aquaticum from the shelf area as cover.
  • Also grow Aponogeton distachyos to cover & protect the tadpoles in deeper water
  • Garden ponds are often home to more than one species of amphibian - see newt and toad pages - this is a healthy situation and shows that the pond is doing well.
  • Numbers of one species will control another until they balance each other out.
  • Adult newts can eat frog spawn. Late stage frog tadpoles can eat young newts when the frog tadpoles are in the carnivore stage.
  • Froglets leave the pond in late Summer.
  • They will not come back to the water for 2-3 years.  Then they are ready to breed.

 What do adult frogs in Summer:

  • They will leave the pond and keep cooling damp, shady parts of the garden under foliage or logs.
  • They are a good biological control for slugs on your plants.

Frog death caused by Ranavirus:

  • Adult frogs can be affected by Frog 'red leg' disease and die. 
  • On hot days between June and August at temperatures above 25°C  you can find a number of dead frogs in the pond.
  • The frogs are often thin and lethargic.

Symptoms of ranavirus:
Abnormal wasting.
Redness of the skin.
Skin ulcers or sores.
Bleeding from mouth/anus.
Breakdown of limbs.
Eye problems.

  • There is no known cure or treatment for this disease.
  • To dispose of the bodies please either burn or bury them.
  • Do not place them in the rubbish as this could help to spread the disease.
  • Do not move your frogs, spawn or pond plants to other ponds as this could potentially spread the disease.

 What do Frogs do in Autumn?

  • Frogs will be feeding well on insects, slugs and spiders ready for Winter.
  • Most will find safety under logs or sheds, in compost heaps or any other damp hiding place they can find.
  • Create wild areas in your garden with log piles.
  • Build an Amphibian House (or Hibernaculum) - use a pile of old pallets and fill the gaps with twigs, wood, leaves, soil, earth, old tiles and anything else that amphibians can bury into or crawl between.

What happens to Frogs in Winter?

  • Frogs may live in the pond over winter as they can breathe through their skin.
  • They bury themselves in the silt at the bottom.
  • In Winter they will come out of hiding and forage for food. Don't worry if you see them sometimes in milder weather.
  • If you disturb an animal in hiding in Winter put it back where it was and cover it up. Or put it somewhere frost free and safe from predators like cats and large birds.
  • After Winter hibernation frogs return to mate in the pond.
  • They often return to the same pond they were laid in as frogs spawn.

Frog Winterkill:

  • Frogs can die of 'Winterkill'
  • Winterkill occurs when toxic gases are released into the pond water through decomposition of dead foliage.
  • This process needs oxygen and the toxic gases are produced if there is not sufficient oxygen to complete the process.
  • Water becomes deoxygenated if decomposition continues but the oxygenating plants are not functioning well enough.
  • Oxygenating plants can not photosynthesize in darkness ie under a blanket of snow over the pond surface. Try and brush some snow off the pond where you can safely reach from the side with a broom.
  • Or if there is excess rotting vegetation in the bottom of the pond. Good maintenance in Autumn will reduce the risk of this.
  • Seeing the frogs float on the water surface in the thaw will be upsetting to wildlife pond owners.
  • There is no known cure or treatment for this disease.
  • To dispose of the bodies please either burn or bury them.
  • Do not place them in the rubbish as this could help to spread the disease.
  • Do not move your frogs, spawn or pond plants to other ponds as this could potentially spread the disease.

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