- What fish live in lakes?
- Where do frogs spawn?
- What birds can be found on the shores of lakes?
Fish
Among vertebrates, the most characteristic inhabitants of water bodies are fish. Based on their diet, fish are categorised as both non-predatory and predatory fish. Non-predatory fish do not eat other fish, but they are not entirely herbivorous either. Most of their food is made up of zooplankton, tiny benthic animals, and insect larvae. Examples of non-predatory fish are the crucian carp, common roach, and common bream. Typical predatory fish that feed mainly on other fish are common perch and northern pike.
The body of the perch is greenish and striped, darker in dark water and lighter in light water. Despite this camouflaging colour, the perch catches the eye with its red pectoral fins, and yellow eyes that monitor the surroundings from under a leaf or a branch. Young perch feed mainly on zooplankton, and as they grow larger, they increasingly eat benthic animals and fish.
The pike is a large-headed predatory fish with a long and slim body. Pike eat smaller fish, they may even eat a smaller counterpart of their own species. That's why these fish do not live in a school of fish, but keep away from each other.
- Crucian carp
- Perch
- Bream
- Roach
- Pike
Amphibians
You can see several species of frogs swimming in the lake. The moor frog and the common frog breed there in spring; the common frogs also spend the winter there. In April, frogs congregate to spawn on the shallow shore of the lake, where the water warms fast. When the tadpoles have developed lungs and four legs, and the tail is gone, they settle on dry land. You can also meet a green frog in some smaller lakes, whose life is spent mainly in water. This is the common water frog. For the winter, most of the frogs hide deep in the mud at the bottom of water bodies, because the temperature there usually does not fall below +4 degrees.
- Frogs spawn in the shallow water of the lake.
- Tadpoles live in the water.
- Frogs feed on fish.
- Most frogs spend the winter in the lake mud.
Birds and mammals
There are many different species of birds living by the lake. Some live in the shoreline's vegetation, some feed on benthic vegetation and invertebrates in the body of water, and others feed on fish.
Several species of reed warblers catch insects in the coastal vegetation. The great grey heron catches fish in the shallow shore water. Mallards who prefer to stay near the shores of the lake feed mainly on benthic plants and invertebrates. Mallards search for food in the shallow water by reaching the bottom from the water's surface; they are not good divers. Ducks that get food this way are called dabbling ducks.
Farther from the shore, there are the great crested grebes and diving ducks, which dive for food and can be underwater for a long time. Diving ducks mainly feed on invertebrates living at the bottom of the lake, especially snails and shellfish. On the lakes, you can most often meet the tufted duck.
Gulls are also fish-eating birds. The black-headed gull is most often found European lakes. It catches smaller fish in the water directly from the flight. It also eats invertebrates, and often looks for food in the fields, or even in trash bins.
Some mammals also search for food in water bodies. Water voles and beavers that feed on plants, and otters that feed on fish, can live along lakes and rivers.
Recommended Listening Resource
- Listen to the sound of the sedge warbler, grey heron and black-headed gull on the internet.
- Grey warbler
- Reed warbler
- Black-headed gull
- Grey heron
- Mallard
- Great crested grebe
- Taft duck
- Tufted duck
- Swimming duck
- Floating duck
I now know that…
Among the vertebrates, fish are the most characteristic in water bodies. Among the non-predatory fish, the crucian carp, roach, and bream are common in European lakes, and perch and pike among predatory fish. Moor frogs and common frogs breed in the lake. There are also many different species of birds on the shores of the lakes.
