Nightingale’s Journey Provides Valuable Migratory Information

July 20, 2010 by  
Filed under Features

While being fairly nondescript in appearance, the nightingale is legendary for its amazing singing ability, which can often be heard at night, as well as in daylight hours. The name nightingale literally means ‘night songstress’ revealing the misconception early writers had that it is the female that produces the complex range of trills, whistles and gurgles, when in fact it is the male. It has long puzzled researchers as to where exactly in Africa these migratory birds spent the northern hemisphere’s winter months. Now thanks to technological advances, it has been possible for scientists in Norfolk to track a single nightingale’s 3,000 mile migratory journey, thereby providing invaluable information that will hopefully assist in halting the decline in numbers of this fascinating bird.

In April 2009, scientists from the British Trust for Ornithology (BTO) captured a male nightingale near Methwold Hythe in Norfolk and fitted it with a geolocator – a tiny device for tracking the bird’s position. This new technology has proven to be vastly superior in providing accurate information as compared to the method of ringing birds which has been used for decades prior to this. The information gathered helps scientist not only to examine threats to the wellbeing of breeding birds in their home territory, but also to evaluate whether migratory destinations of the birds are impacting negatively on their numbers.

Codenamed OAD, the nightingale left its home territory in Norfolk on July 25, 2009, arriving in southern France in mid-August. By September, OAD had arrived in northern Morocco, where it remained for around three weeks. The nightingale continued on to the Western Sahara, where it appeared to stop for a while before continuing to Senegal in November, and from there to Guinea Bissau where it remained until returning to Norfolk in February 2010. Due to the locator failing, the exact route of the return journey is not known, nevertheless it was captured by researchers about 50 yards from the spot where it was initially found in April 2009.

No doubt, the information gleaned from OAD’s epic journey will be of great value to BTO as they continue their work of understanding the pressures faced by birds migrating to Africa.

African Fish Eagle (Haliaeetus vocifer)

February 9, 2009 by  
Filed under

The African Fish Eagle or as it is scientifically known, Haliaeetus vocifer, can be seen throughout Southern Africa and is known by many varieties of names, in many languages. This includes the River eagle, Aigle pecheur, Pygargue vocifer, Afrikaanse visarend and so on. This fairly large bird is related to the North American Bald Eagle and can be easily identified by the distinct black, brown body and white head and tail. The length of the African Fish Eagle varies between 63 and 75 cm.

The Fish Eagles habitat is limited to mainly lakes, large rivers, pans and dams with surrounding trees for it to perch on. They can also be found near estuaries and coastal lagoons but are rarely spotted in the southwestern parts of Africa and areas on the eastern part of Somalia because the land is so arid. The African Fish Eagle makes its nest out of large piles of sticks, 30 to 60 cm deep and 120 to 180 cm in diameter. The nest is built usually near water at the fork of a tree, sometimes on a cliff ledge or on a steep slope on a low slope.

The beautiful and distinct call of the African Fish Eagle is synonymous with the sound of Africa and is very similar to the American Bald Eagle. There are two specific calls, the one is in flight and the other is when it is perched. When the male fish eagle nears the nest it makes a kind of mellow ‘quock’ sound where as the female has a more of a shriller sound.

The African Fish Eagle pairs up whether it is in or out of mating season, which goes from March to September. The pairs even go as far as sharing any kills that they make between the two of them. The African Fish Eagle is known as a kleptoparasite, which means that it will steal prey from another bird, like the Goliath Heron who loses a lot of its catch to Fish Eagles. They will also take advantage of nesting water birds for their eggs and young.

The main diet of the Fish Eagle is fish that they catch and occasionally when it is dead. They can catch a fish that weighs up to 1 kg in weight and now and again up to 3 kg’s. If the fish weighs more then two and a half kilograms the eagle will not carry it in flight but will plane it along the waters surface to shore. Fish eagles mainly catch lungfish and catfish and in some places will feed off flamingos and other water birds if the occasion presents itself. It has been known to eat dead animals and on very rare occasions they will even feed off monkeys, insects, frogs, dassies and so on. The hunt begins when the eagle leaves its perch to stoop and catch its prey with its feet about 15 cm from the waters surface. It’s not often that the African Fish Eagle will catch prey in the sky or submerge itself in the water.

Cattle Egret (Bubulcus ibis)

February 9, 2009 by  
Filed under

The Cattle Egret (Bubulcus ibis) is approximately 17 inches in length, with both sexes looking similar. They are predominantly white in color, with short, dull orange, pointed bills. In some rare instances, some adult birds might have deep red legs and bills, opposed to the dull yellow or orange that is generally found. Today, these birds are located world wide, but originated from Africa. It is suggested that they moved over the Atlantic ocean, from the African continent, and began a slow advance over areas such as South and North America, until they reached places like Argentina and Canada. Their migration over the world is so great, that they sometimes outnumber the native herons that are resident to a certain area.

Egrets spend their days in the company of cows, cattle herds or any livestock for that matter, relaxing and feeding in the wet pastures. They are constantly on the lookout for any beetles, grasshoppers or edible insects that are disturbed by the cow’s grazing. If the ground does not bring in enough food, they simply hop onto the backs of the cows’ and take a quiet tour around the field while searching for flies and ticks. After a days work, the Cattle Egret will fly up to the roosting accommodations to rest. They are also known to be birds of routine having daily routes which they follow. Egrets are commonly found amongst herons, and they are able to adapt to aquatic vegetation if cattle are not around.

Cattle Egrets nest in trees that are close to rivers or water, or wherever they are able to find vegetation to support their nests. Males will establish a territory, and then start with elaborate dances to attract a suitable female. Once a pair has been established, they head to a second location to build their nest together. Nest building is undertaken in a frenzied manner, with the male usually bringing the materials and the female doing the building. Materials are sometimes stolen from the neighbors, if their nest is left unattended. Nests are built in big colonies that include different species. The light blue eggs are laid with intervals of two days, and number between 3 to 4. Once all the eggs are laid, the male turns his attention to the nest. Both parents assist in the 24 day incubation period, and often need to shelter the eggs from the sun with their wings. Chicks will beg aggressively for food, but for chicks to kill each other is extremely uncommon. Adults will sometimes adopt other chicks if they are less than 14 days old. It takes between 14 to 21 days for the chicks to complete their growth, and although they are now able to leave the nest, they still remain close to their parents. It takes a complete 60 days for the Cattle Egret chicks to be able to fly and forage for themselves.

Common Cuckoo (Cuculus canorus)

February 9, 2009 by  
Filed under

The Common Cuckoo (Cuculus canorus) is a medium-sized bird that averages between 32 to 37 centimeters in length. The males have solid gray coloring over their heads, neck and wings. Their bellies are white with gray to black stripes, dark gray tail feathers and black eyes. Bills are pointed and black of color. The female Cuckoo resembles the males, but with morphed brown coloring. The Common Cuckoo is a migratory bird and is seen across Europe, including Britain, as well as Japan and China, and migrates to Africa during the winter months. It adapts easily to live in cultivated areas, on the edges of dense forests, open country, marshes and coastal areas.

The Cuckoo has a wingspan of approximately 71 to 76 centimeters and has an extremely distinctive low flight. They fly with rapid ing beats and are very swift in flight. Their flight pattern bears a resemblance to that of raptors, with the exception that the Cuckoo has much weaker strokes and does not glide after a series of beats.

The preferred food of the Common Cuckoo includes a diet of hairy caterpillars, larvae and insects. Not being too fussy, they will also eat beetles, crickets and dragonflies, and have in some instances also been seen eating eggs and songbird nestlings. The female Cuckoo is not the best parent, to say the least. They are not interested in parenthood at all. She can lay in the region of eight to twenty five eggs, and the eggs can vary in color. Sometimes the eggs are brown with markings of lilac, gray, black and red-brown. At times eggs can be green, blue or red, with markings. This enables the Cuckoo to secretly lay an egg in another nest. Not all of the Cuckoo species find host parents for their eggs. The Common Cuckoo will find a species with similar eggs to her own and when the host parents are not in sight, she will lay her eggs amongst the eggs already in the nest. The host parents, not realizing anything is amiss, will complete the 11 to 13 day incubation period and rear the chicks until they are ready to fledge the nest. The female Cuckoo will never return or revisit her chick. Most of the time, the Common Cuckoo chick will be bigger in size than host parents, putting strain on the parents to feed the intruder.

Although the Common Cuckoo is a very wide-spread species and difficult to monitor, it is believed to be plentiful and is not threatened by extinction.

Greater Flamingo (Phoenicopterus rubber)

February 9, 2009 by  
Filed under

The Greater Flamingo (Phoenicopterus rubber) can be found in North and South America, Asia, across Europe and in Africa. Standing at approximately five feet, the Flamingo, ranks amongs the tallest birds on the planet. Their distinctive pink plumage, large bodies and long pale pink legs make them unique. The beak of the Greater Flamingo is shaped at 45 degrees, is light of color with a black tip and assists them in filtration and pumping while they feed. Interestingly enough, the Greater Flamingo’s coloring is a result of the crustaceans that they eat. Flamingos that are housed in zoos are given dyes such as flamen oil or a beta-keratin coloring additive to ensure that they do not lose their coloring. Male and female Flamingo’s are similar, with the males being taller.

The Flamingo has webbed feet and an extremely long neck. Having webbed feet allows them to swim, but most importantly it helps them stir up organisms such as algae, diatoms, protozoa and insect larvae on which they feed. Flamingos also eat worms, crustaceans  and mollusks. The feeding process of the Greater Flamingo is very specialized. Flamingos will spend most of their day with their heads bent down, filtering water through their beaks. Their beaks contain a lamellae, which is a sieve-like structure, that is thin and can be described as a comb. Their fleshy tongues are used to suck water in the beak and then force it back out again. The bolus of food that is nearly dry after the water is forced from their beaks, goes to the back of their mouths and is swallowed simultaneously with the next water intake. The Greater Flamingos feed in large groups as this ensures safety by numbers when they have their heads down. Big flocks can also create a lot of noise, and when they are not feeding they flap their wings, preen themselves or stand in beautiful postures. Flight and migration takes place at night, and during flight Flamingos have both their legs and necks outstretched.

Flamingos are filter feeders, and are therefore found by lakes and lagoons, or watery areas that have the right water depth and mud to sustain the flamingos’ feeding process. They will only breed when they are in large numbers, and even though some build new nests, it is known that many use the same nest each year. Breeding takes place during March and July and the birds generally form a pair bond that is long term. Flamingos will built their nests on the waters edge from mud, and it is approximately 35 to 40 centimeters in diameter and 25 centimeters high. The female will lay only one egg that is white in color with a red yolk. Both parents take care of the egg that has a 28 to 32 day incubation period. Chicks are gray in color with a pink bill. The chicks are able to leave the nest after a few days, and parents will only feed their own chick. For 4 to 6 weeks, the chicks will be fed by their parents, and fledge the nest at three months. Fledglings will group together and only reach full size between the ages of 1 to 2 years. Adult plumage is only acquired during the ages of 2 to 4 years, and the long maturing process is suggested to relate to the long life span of the Flamingo. The Greater Flamingo can live to between 25 to 60 years of age.

« Previous PageNext Page »