The Complete Guide to British Birds: Divers and Grebes
Red Throated Diver in Breeding Plumage
Red Throated Diver in Winter Plumage
Red Throated Diver
The red throated diver is an exceptional swimmer both on and below the water’s surface and is one of only four species of diver or loon, as they are known in North America, in the world. It’s a superbly streamlined bird, with an outstretched neck and its legs tucked neatly back, it also possesses a graceful quality when in flight. However, like its diver brethren it doesn’t cope with landing all that well; its legs are so well adapted for swimming that they are set far back on its body, giving the bird a rather awkward gait whenever they venture onto land, which they do very rarely. But it's in the water, where this bird excels, it is so aquatically efficient that it can chase fish or scoop up shellfish as far down as 30 feet. It's even capable of ‘running’ across the water, beating up spray with its wings as part of its courtship display.
Like other divers, the red throated species loses its flight feathers during its late summer moult, and is effectively grounded until the new ones grow, though it is still capable of diving for its food. During the winter, the bird takes to coastal areas and is virtually unrecognisable having lost its striking red throat during the moult. The pale grey feathers of its head and back merge with the white feathers of its neck and breast.
The red-throated diver returns to the Highland lochs from the coasts in spring to breed, building a nest which is basically a heap of moss or water plants. They prefer nesting in shallow water or close to the shoreline, and usually lay two dark olive eggs, with blackish-brown blotches. Both birds incubate the eggs for about a month, once hatched the chicks take to the water virtually straight away and take just six weeks to mature enough to take to the air.
The bird’s most common call is a sort of reedy cooing, which is definitely the most musical of its vocalisations. English country folk used to think that the mewing wail of a bird in courtship heralded rain, and termed the red-throated diver, the ‘rain goose’.
The Call of the Red Throated Diver
Summer and Winter
Raising the Next Generation
Black Throated Diver
Whenever you decide to go birdwatching at one of Scotland’s famous lochs, you may encounter a big dark bird swimming confidently across the vast expanse of water; it’s likely that this bird is a black throated diver. This particular species has more of a preference for the bigger stretches of water than its slightly smaller cousin, the red throated diver. One of the most haunting sounds to be heard anywhere in the north western highlands of Scotland is the wailing cry of the black-throated diver, the call echoes eerily against the mountains as it seeks to assert its territory. In flight it delivers a sharp ‘kwuk-kwuk-kwuk’ call.
Like the red throated diver, the black throated species possesses a striking breeding plumage with outstanding black and white patterns. The head is more rounded than the red throated diver, but is just as ungainly on land as all other divers.
The bird feeds on fish of various sizes from cod to sprats; they also enjoy feasting on shellfish. Like its red throated cousin, they construct nests in shallow water primarily using heaps of moss or water plants. They normally lay two slightly glossy, olive green eggs with black speckles or blotches. The chicks hatch after a month’s worth of incubation carried out by both parents.
Like most aquatic birds, the chicks are proficient in water right from birth, although they will return to the nest for their first few nights, subsequently sleeping under the adults wing and occasionally hitching a ‘ride’ on the backs of swimming adults. The chicks grow up fast, becoming confident enough to catch their own food in as little as eight weeks, by which time they are already at least embarking on the first tentative steps towards being able to fly. They don’t reach full independence until they have left the loch that birthed them.
The Great Northern Diver
Great Northern Diver
The wailing call of the great northern diver may be familiar to those who regularly watch films that contain moments of suspense or else elements of the supernatural, as directors often dub recordings of its plaintive moans and howls on to such scenes in order to heighten tension. In reality, the bird’s eerie calls, echoing across the lonely waters of its Arctic breeding grounds are simply its proclamations of territory.
Virtually all of the great northern divers seen in British waters are visitors who head to our shores in the winter. Thus, even the most dedicated British bird watcher rarely sees the diver in its glossy, spotty breeding plumage; instead we have to be content in observing this bird in its dowdy winter plumage. There are a few that sometimes their summer in the far north and west of Scotland; for years though it was uncertain whether the birds were actually breeding there. But in 1970, a pair was spotted with two chicks swimming in a loch in Wester Ross. However, the great northern diver’s usual breeding sights are in North America, where it’s commonly known as the common loon. It also breeds in Iceland and Greenland.
The bird is larger than both the red and black throated diver, but is slightly smaller than the white billed diver, which is a very rare visitor to Britain, normally electing to remain within its Arctic homeland. In common with all other divers, it’s superbly adapted to a life in and on the water, while looking ungainly and awkward on land. Despite only possessing small wings, it’s quite a strong flyer but cannot take off without a considerable amount of effort.
The Cry of the Great Northern Diver
The Distribution of the Little Grebe
From the grand lake at Buckingham Palace to the smallest and humblest farm pond, there’s a good chance that you'll see a little grebe, sometimes known as the dabchick- it’s the most widespread of its family in Britain as well as the smallest. It’s as home in any still or slow moving that has a lush growth of vegetation. On larger lakes it spends much of its time in sheltered, shallow bays with a thick growth of aquatic plants that provide both food and protection from predators.
During the day, this bird which can often look at a distance like a small ball of feathers is often busily searching for small fish or aquatic insects. It dives frequently, bobbing up again after a few seconds. Sometimes to make a deeper dive, it jumps up first and the water with a splash. The little grebe is more often identified by sound than sight; it has a trilling call, somewhat reminiscent of the whinny of a horse that rises and falls in volume and pitch over the space of a few seconds.
During the breeding season, the bird sports an impressive breeding plumage, with a red neck and a pale patch at the inner end of the bill. The females are slightly duller than the male. In the winter, the plumage becomes paler, with the birds having dull brown upper parts and white lower parts.
When breeding, the pairs mostly prefer to keep themselves to themselves, but on their favourite stretches of water, the population may be so dense that they virtually breed in colonies. The nest is basically a heap of aquatic plants built up from the surface or supported by a fallen branch in shallow water. The female lays two, or sometimes three clutches of four to six eggs in what is comparatively long breeding season. The eggs are white but soon become stained by water weed. The chicks hatch after about a month and leave the nest almost immediately, often carried on their parents back.
The Great Crested Grebe
The Grebe That Dances
Great Crested Grebe
There are few British birds that have a more elaborate and fascinating courtship display than the great crested grebe. Prior to the breeding season both sexes acquire conspicuous and beautiful dark head plumes which are raised during the height of the courtship display. The display mainly involves head shaking, diving, fluffing out its plumage in the so called ‘cat’ display, and presenting each other with water plants while rising from the water breast to breast. Just over a century ago, the fashion for ladies’ grebe feather hats meant that they were almost lost to Britain forever, but conservationists saved the species and the birds have since produced a large, healthy population.
The nest, similar to other grebes is a simple heap of aquatic plants built up from the bottom of shallows, or else supported by a fallen branch or submerged stems. The shallow cup of the nest is surrounded by fine vegetable material which is used to cover the eggs when they are unattended.
The eggs are whitish and rather elongated in comparison with other grebes. The female normally lays four, and they take around four weeks to hatch into distinctively striped chicks. Within no time at all, they squeak shrilly to the adults as they swim towards them begging for food, which comes in the form of insects or fish. The chicks are dependent of the parents to an extent for around ten weeks before becoming independent.
Another Grebe That Dances
Red Necked Grebe
If you happen to travel to the lakes of Denmark, Finland or Germany, you might catch a glimpse of the red necked grebe in its handsome breeding plumage; it’s a treat that is sadly absent from Britain. On its annual migrations to British shores it is usually seen in drab winter garb and from a distance is virtually indistinguishable from the native great crested grebe.
The red necked grebe however, favours smaller and shallower stretches of water, with more vegetation growing above the surface. Although it nests and breeds on fresh water, when it visits Britain, the red necked grebe tends to favour estuaries or coastal marshes. Aquatic insects and their larvae are its favourite food, plucked from the water or from plants. It also catches fish, which they do either by shallow diving or by swimming with only the head submerged. Small fish are swallowed live, while larger fish are killed before consumption usually by crushing or violently shaking them.
Red necked grebes are seldom seen in flight because they are mostly active at night. They have a slow and awkward take off, so whenever they come under attack they are more likely to dive out of the way. Back in their European breeding grounds, they are the most vocal of all grebes, but are normally silent whenever they visit Britain.
The Slavonian Grebe
The Slavonian Grebe's Nest and Eggs
This eyecatching bird was first observed breeding in Scotland back in 1908. They presumably crossed the North Sea from their nearest foreign breeding grounds in Iceland or Scandinavia. Since then, any progress in terms of population has been slow and uncertain, with fewer than 60 pairs concentrated on shallow freshwater lochs in the remoter and less disturbed parts of Scotland. They are more vulnerable than other grebes to human exploitation because of their rarity. Even today, their eggs are still collected, despite the fact that its illegal.
After spending the winter at the coast, the birds’ pair up and return to their breeding grounds and take part in an elaborate ritual of courtship before they actually mate. Their nests of floating vegetation, sometimes positioned just feet apart from each other are hidden among rocks or under drooping tree branches, and are anchored to plants growing from the lake bottom.
Egg clutches vary widely, but the typical number is four or five. After a three week incubation, the chicks hatch and immediately leave the nest. They can dive sufficiently to find their own food after about ten days, but mostly rely on parental support almost until the time they can fly, which is about two months after hatching. The main diet of the Slavonian grebe is water insects, grubs and small fish.
The Black Necked Grebe
The Display of the Black Necked Grebe
Black Necked Grebe
Most of the grebes profiled thus far require extensive areas of open water for successful breeding, but the black necked grebe is an exception. This attractive little bird is roughly the size of a little grebe and requires pools with a rich growth of water plants both fringing the water and submerged and floating in it; often pools like these have very limited open water. Only a few such sites exist in Britain, and is probably the main reason why the species is scarce in Britain. A few remote and secluded Scottish lochs provide the only reliable breeding areas for the black necked grebe, though elsewhere in Europe it may chose a spot for one season before moving on. Occasionally they make take to living on man-made stretches of water, such as reservoirs and sewage farms.
In the springtime, paired up birds engage in a rich courtship display, consisting of a variety of displays, including a water dance similar to that of the great crested grebe, in which the two birds rise up out of the water breast to breast, or side by side. Their nest is a pile of water plants anchored among reeds and sedges in shallow water; occasionally they opt to nest in colonies. The female lays three to four eggs which are incubated for three weeks, before the stripy plumaged young hatch and take to the water straight away.
Outside the breeding season, the black necked grebe makes for more open waters, including estuaries and sea channels. It’s a capable diver and regularly eats small fish, but they mostly prefer insects, grubs and other food taken from the surface or from vegetation.
More to follow...