Strange as it may seem, winter is a good time to catch up with the five
species of grebe that either breed or winter within the county. When people
think of grebes, they often have an image of the Great Crested Grebe,
resplendent in its breeding finery and indulged in an elaborate courtship
dance, or the Little Grebe – the dabchick of smaller waterbodies. Both species
are less showy in their winter plumage and both may leave their breeding waters
to winter elsewhere, where they may swim alongside Red-necked, Black-necked and
Slavonian Grebes, all winter visitors to Norfolk.
A trip to the coast can provide views of all five species in a single
day and, sometimes, at a single site. The Little Grebe makes use of brackish
pools and saline lagoons, with Titchwell and the ditches at Cley both favoured
sites. Great Crested Grebes may join them at Titchwell but are more often
encountered just off the beach, making use of our inshore coastal waters. Here
they mingle with much smaller numbers of the other three species, providing
birdwatchers with an opportunity to practice their identification skills.
The Great Crested Grebes leave their breeding sites in the autumn,
seeking out larger waterbodies and coastal waters on which to moult, a process
which leaves them flightless for several weeks. While several dozen individuals
may gather at favoured sites, our wintering population is dwarfed by the 30,000
that moult and winter on the Ijsselmeer in The Netherlands.
Both Black-necked and Slavonian Grebes have small breeding populations
in northern Britain (roughly 40-50 pairs each), which are part of a much larger
breeding range. While some of our breeders may be among the birds wintering
around the Norfolk coast, other wintering birds will have arrived from
elsewhere. The size of the arrival is influenced by weather conditions across
more northerly waters. All of the species that make use of coastal waters
prefer shallow, sheltered bays, which is why Holkham, Holme and Titchwell seem
to hold birds to a greater degree than other sites around the county. Here they
feed on crustaceans and small fish, often feeding alongside Red-throated Divers
and Cormorants.
During the hardest of the winter weather, when bitter winds deliver
ferocious storms to our shores, the birds may be forced inland, affording
birdwatchers easier viewing than is typically the case when watching these
birds at sea. The winter plumages of these birds are dull in comparison with
their breeding finery and separation of the different species requires an
understanding of the physical structure of each species as well as the plumage
pattern. It is worth the effort, however, when you can see all five in a single
morning.
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