We were wondering if the good news of our excellent rains spread far and wide across the continent to the Summer Migrants, as many seem to have arrived earlier than usual this year... to feast on the proliferation of food perhaps...?
Each year thousands of millions of African birds undertake seasonal movements, ranging from a few hundred kilometres to fantastic trans-continental journeys of more than 10,000km. Of the 1,800 bird species found in sub-Saharan Africa, nearly 200 species migrate seasonally between Palearctic (Europe/Asia) and Afrotropical (sub-Saharan Africa) regions. More than 580 species are known to make seasonal migrations within Africa.
DIEDERIK'S (Chrysococcyx caprius)) and KLAAS'S CUCKOOS (Chrysococcyx klaas) have been calling for some weeks and more recently, the BLACK CUCKOO (Cuculus clamosus). YELLOWBILLED and BLACK KITES (Milvus migrans) and STEPPE BUZZARDS (Buteo buteo) are scouring the landscape and feeding on the numerous rodents, snakes and insects.
During the early hours of the morning on the 8th of September, the first LESSER STRIPED SWALLOWS (Hirundo Abyssinica) arrived back at SIBUYA, defying the fact that they do not migrate (as many other species), during the night! Each year we wonder exactly where they've come from.....is it Zambia? Sudan? Sierra Leone? or Angola?...Their journey is quite remarkable when one considers their size and of course predators and weather conditions encountered along the way. Being slender streamlined little creatures, they are excellent flyers and have a body suitable for aerodynamics and endurance, reputedly travelling at speeds of up to 65km an hour while migrating!
These monogamous medium sized SWALLOWS have an instinctive internal compass and return to SIBUYA and the same nesting sites year after year. First-time breeders return to where they were born and choose a nesting site close by.
Last year very few LESSER STRIPED SWALLOWS bred as the severe drought conditions meant there were not that many insects around for food and because of the lack of moisture, the nests fell down as quickly as they were repaired!This year however, we're sure they'll easily find enough mud around to build their nests out of pellets and have numerous insects to feed chicks.....it should in fact be a bumper breeding season for everything at SIBUYA!
Very much in evidence lately have been the TRUMPETER HORNBILLS (Bycanistes buchinator) so named as a result of their loud trumpeting, wailing, far-reaching (quite frightening to the uninitiated) cries. They fly for kilometres to eat ripening fruit and have been feasting on that of the NGWENYA TREES (Ekbergia Capensis) dotted about the Reserve....they vary their diet by eat flying termites and large insects like locusts.
HORNBILLS mate for life and have a fascinating and unique breeding ritual whereby courtship feeding is common. Male birds feed their mate continually before actually breeding, thus building up her reserves for laying and replacing her feathers after she's moulted in the nest cavity. The nest site is chosen carefully in a suitable hole in either a tree or crevice in a rock. For security reasons, the entrance is partially sealed with mud from the outside. When the time is right, the female squeezes in and continues to seal the entrance from the inside until only a thin slit remains, through which she's fed by the male. He takes this task very seriously and proceeds to bring her nesting material and food frequently...even apparently sometimes bringing her the shells of snails, thought to be additional calcium for the healthy production of her eggs. During the incubation period (approx 24 days) she keeps the nest sanitary by defecating out of the slit. Now a most remarkable HORNBILL feature takes place- she sheds her tail and wing feathers first and then gradually her body feathers are moulted! What a defenseless and ugly sight she must be! When the eggs hatch, the female breaks out of the nest and lo and behold, her feathers have regrown! Between 39-50 days later (depending on the food supply) the young HORNBILLS, flying strongly, leave the nest and initially remain in a family group. Breeding is usually a great success!