Great Crested and Little Grebes are common, though the former took a terrible hammering from plume collectors, egg collectors and fish farmers until the 1860s, with the result that only around 40 breeding pairs survived in England.
Legislation from 1869 to 1880 put a stop to this abuse and the Great Crested Grebe (Podiceps cristatus, wingspan 90cm) has flourished since, helped in recent decades by the creation of reservoirs and of lakes in disused gravel pits. There are now at least 4,000 breeding pairs, most of which depart to the coast for the winter owing to the danger of being frozen in on ponds.
Courtship in most birds is not studied so closely as that of Great Crested Grebes, whose ritualised antics during the breeding season, including head shaking, the weed ceremony and virtually dancing on the water, are an aesthetic joy as well as scientifically informative.
To give one example, in a poorly-managed pond with no aquatic vegetation a pair of the birds was forced to use decaying deciduous leaves for the weed ceremony – proof of their adaptability, and of the sorry effects of lack of management leading to lack of life for flora and invertebrates.
Great Crested Grebes are very much water birds, with legs set well back in the way that those of Divers are, making them clumsy on rare visits to the land. Almost any kind of fish, from Minnows (Phoxinus phoxinus) to small Pike (Esox lucius), is caught by diving for less than 30 seconds, but the strike-rate is indifferent, something like one in four. Nests are constructed of almost any available material and are set low above the water, resulting in loss of eggs and chicks when levels rise through heavy rain. As with various waterfowl, youngsters travel on the parent's back for protection for up to two weeks.
Little Grebes or Dabchicks (Tachybaptus ruficollis, wingspan 42cm) are much commoner on rivers than Great Crested Grebes and they, too, are exciting to watch in courtship as they career across the water as if joined.
There is something in the region of 8,000 breeding pairs in the UK, though they are not always easy to see, tending to scuttle for cover at the slightest hint of danger along rivers in particular.
Little Grebes do not go to the coast in winter, so harsh conditions are bad news, as are too many medium- to large-sized fish in unmanaged ponds, which can eat the food normally taken by the birds. This includes small molluscs, crustaceans, amphibians and insect larvae as well as such fish as Minnows. The dive is a very rapid affair, coming after little or no warning, but the success rate is often better than that of the Great Crested Grebe because of the more varied diet.
Most eggs are laid from the end of March, with clutches of around six hatching on a nest consisting of a floating platform of aquatic weeds attached to other vegetation below.
Images © Jeremy Early. All rights reserved.