Sunday 23 December 2012

Gambian Waterbirds

Here are a few more images from The Gambia: starting with the world's largest heron, the Goliath, in the act of taking off, and showing off its 2.2 metre wingspan. That's over 7 ft., an almost sky-darkening sight! We were slowly moving through the Tendaba mangroves in a pirogue (a large canoe hued out of a single tree-trunk) when we came across the heron, resting in a tree-top as it was high tide. The Goliath Heron is well distributed throughout Sub-Saharan Africa. It nests during the rains, usually 3 metres or less up in a tree or bush, on a platform of sticks and reeds. Three eggs are laid, which hatch after 27 days. 

On the same boat-trip, we saw this Hamerkop with nesting material. Hamerkops are aberrant storks, in a family of their own. They build huge domed nests with a circular entrance, usually 1.5 metres across and almost as tall. In most parts of Africa, the Hamerkop is regarded with great respect and rarely suffers any persecution. There are many local myths about the disasters that can follow from harming a Hamerkop. The name is Afrikaans for 'hammer-head.'

Jacanas are a fascinating family of birds, found in all continents except Europe and Antarctica. In 7 of the world's 8 species, the male is the sole carer of nest, eggs and young, (the exception being the uncommon Lesser Jacana of Africa). They all build floating nests, typically on water-lilies, on which the female lays four large and shiny eggs. The male starts incubating when the clutch is complete, so that the chicks hatch (fully feathered and ready to walk and feed) at the same time.  Now his role becomes one of protecting the young by seeing off predators, and leading the brood to suitable feeding grounds. Meanwhile the female, unencumbered by family responsibilities, is free to seek a new mate: a strategy known as polyandry. This African Jacana looks more shaggy and unkempt than usual: it has probably just dried off after a bath, and is about to undergo a long preening session. 

Perhaps the most sought-after species for birders visiting The Gambia is the Egyptian PloverThis exquisite wader, which breeds in Senegal and spends the dry season here, is a must for anyone with a camera. The Greek historian Herodotus first described their habits in the 5th century B.C.: he wrote that on the banks of the Nile one type of bird would enter the open mouths of the crocodiles and pick out flesh from between their teeth. Hence the name: but now their breeding range is from Senegal to Sudan. It only became extinct in Egypt in the first part of the 20th century. 

We saw Collared Pratincole on only one day, and in one place: but at the Kaur Wetlands we came across a flock of over a thousand. Pratincoles are an interesting group of waders, most closely related to coursers - a strange fact in itself, as pratincoles are mostly aerial, and coursers terrestrial. The word comes from the Latin pratum, a meadow, and cola, inhabitant. Pratincoles are elegant aerial feeders, hawking for insects like a small tern or an overgrown swallow. They nest in colonies on the ground. It is unknown whether the Gambian non-breeding flocks nest in Europe or Africa, but there are wet-season colonies in Northern Senegal. 

The Senegal Thick-knee is a very common wader in The Gambia, both along the coast and inland. At Kaur we found  flocks of them with the pratincoles. They are in the same genus as the Stone Curlew which nests in southern Britain in small numbers. The large eye gives a clue to its habits: it is nocturnal and crespuscular (active at dawn and dusk). The world has nine species of thick-knees, ranging from Mexico in the west to Australia in the east. In South Africa they suffer from a bad press: not only thick-knee but 'thick head' too - there they are known by the Afrikaans name dikkop.

 Along the Gambian coast we found impressive flocks of gulls and terns. The fishermen use small boats to unload their catches onto the beaches - a truly sustainable artisan fishery. The beaches and lagoons near these fishing villages attract gulls, terns, and reef herons, all year round.  The photo shows a Caspian Tern in its non-breeding plumage: when nesting, the forehead, crown and nape are all black. Some flocks numbered hundreds, with lesser numbers of Royal Terns, Grey-headed Gulls, and a few Kelp Gulls which have recently spread up the coast from the south. 

Many thanks again to Roger and Yvonne for the photos: in my next post, I will put up my own Gambian shots - people and landscapes for a change, rather than wildlife! 

Wednesday 12 December 2012

The Gambia

The Gambia is Africa's smallest country, a thin strip of land entirely surrounded by Senegal. In November I led an Ornitholidays group of ten keen birders there. We had a week on the coast, then a week inland. On one of our journeys, these three Black Crowned Cranes flew over us. November is just after the rainy season has finished, so the countryside is still green - and most species are still in breeding plumage. 

Three families of brightly coloured birds seem to be everywhere: kingfishers, bee-eaters and rollers. Here is a Blue-breasted Kingfisher, a blackbird-sized bird which can often be found in woodland away from water. Many African kingfishers have a diet of reptiles and insects rather than fish. While most of the Gambian kingfishers are widely distributed throughout Africa, this one is confined to West Africa. We saw eight kingfisher species, from the tiny Pygmy to the great Giant. (Of the world's kingfishers, the Giant is the largest, though the Laughing Kookaburra of Australia is marginally heavier). 

Of the seven bee-eater species we came across, the most spectacular was this Northern Carmine Bee-eater. To see this in The Gambia, you have to travel a long way inland, along the Gambia River. We came across a few of them close to the town of Janjangbureh, which is still often referred to by its old colonial name Georgetown. This individual was very faithful to this dead-tree perch, allowing the photographers many opportunities. In the background to the right of the bee-eater, is an out-of-focus Grey-headed Sparrow. 

Of the four roller species which are common in The Gambia, the one that drew the loudest gasps when first spotted was the Abyssinian Roller. These elegant birds have a chestnut-coloured back to complement the pale blue body and purple shoulders. In fact its plumage is remarkably similar to the European Roller, with the addition of the tail streamers. Rollers feed mostly on large insects such as beetles and grasshoppers, and are usually to be found in open scrubby country: a habitat that is being increasingly turned into farmland. Hence most roller species are declining. The name comes from the rolling display flight performed by many species. Rollers are among the world's worst songsters, uttering harsh cackling, grating, growling and screeching notes!

Widespread in wetlands and gardens, the Yellow-crowned Gonolek is a species of bush-shrike. Much more often heard than seen, it does emerge from thick cover sometimes (as here, in the garden of our coastal hotel). The African bush-shrikes are a diverse and usually brightly coloured family, that includes the Brubru and the boubous, and the South African Bokmakierie (which are all named after their calls). 

The Piapiac is in the crow family, and often known as 'black magpie' by the locals. This photo illustrates adult and young - surprisingly it is the juvenile with the red bill. This is a bird of open country, which can often be seen in gardens, peanut fields or around livestock. This is yet another bird name supposedly derived from its voice. During the trip, I concentrated mostly on binoculars and telescope, leaving the photography to others in the group. Many thanks to Roger Christopher, John Sykes and Roger Ackroyd for the above images. This brief look at some of The Gambia's more eye-catching birds doesn't begin to do justice to the biodiversity of the place: in my next post I'll cover a few of The Gambia's wetland species.