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How to build a wildlife pond
Ponds are one of the most important features to include in a wildlife-friendly garden because a huge variety of species depend on them. And they can be great places to sit and watch anything from bats to birds.
- A few common (smooth) newts will overwinter in a pond, as will frogs and any tadpoles that did not emerge the previous summer.
- Great pond snails are less active in the winter and are generally found in the deeper parts of a pond. In the summer, they are often seen at the surface, gulping in air.
- Dragonfly nymphs spend three or four years in a pond before emerging as adults; they do not pupate. They feed on other invertebrates and larger nymphs hunt tadpoles.
- Water hog-lice (Asellus spp) are extremely abundant in the detritus at the bottom of ponds, and eat rotting vegetation. They resemble, and are close relatives of, wood lice.
- Ponds attract flocks of birds, such as starlings, to bathe, foxes to drink, and sparrows and pipistrelle bats to feed on their abundant insects.
- Damselflies/dragonflies will lay their eggs on aquatic plants or drop them onto the surface of a pond throughout the summer.
- Common pondskaters are bugs that live on the surface of a pond, where they grab and eat the insects that fall into the water.
- Common backswimmers fly at night and are one of the first species to colonise a pond. They are voracious predators of other aquatic life.
- Daphnia waterfleas are eaten by adult and larval newts, as well as other aquatic insects. They filter algae from the water and thereby help to keep a pond clear.
- It’s best to dig a pond in the autumn when the ground is soft, then let it fill up with rainwater and leave it to settle over winter. Clean it out in late autumn/early winter, but search through the removed vegetation to release trapped animals, or spread it around the pond’s edges so they can creep back into the water.
- Preformed ponds are easier to install than those with butyl rubber liners, but a liner will enable you to design a more varied pond, with shallow sloping sides and a variety of depths. A maximum depth of at least 75cm will ensure that your pond does not completely freeze over during a hard winter.
- Blanketweed and green algae tend to be a problem in new ponds and those with a large amount of water in direct sunlight. Remove blanketweed by hand and position plants at the pond margins to provide shade and so reduce water temperature.
- Let the water level drop in the summer; damp mud is a good habitat for invertebrates. Even if the pond needs topping up, never do it with tap water.
- If you have small children, either surround your pond with a fence or install a metal mesh or plastic grid just above the water surface that will support the weight of a child. Plants will grow through, and the mesh will also help to reduce the amount of debris that blows into the pond in the autumn.
- Most insects and amphibians will colonise your pond naturally, but you will need to add water snails (both ramshorn and great pond snails), and species such as freshwater shrimp, waterlouse and freshwater (swan) mussels.
If you enjoyed this, read the previous part here.