Tourists of a different kind
During the rain season and particularly in a good rain season, the increase in the number of small, medium and large birds that grace our skies is astounding. The bird species that migrate to southern Africa and to Namibia range from tiny 8-gram warblers to large 3-kilogram eagles. One of our visitors, the Arctic Tern Sterna paradisaea holds the record for distance. This bird species weighs only 100 grams and migrates 15 000km, halfway around the world, twice a year.
Most migrant birds arrive from around September. Some species arrive to feed, nest and breed. Others breed in Europe, Asia, some as far north as the Arctic Circle and they only migrate to the southern hemisphere to escape the icy northern winters and to utilize the abundance of food available in our warm and wet summer months. Then in April to early May as the southern hemisphere winter months approach, migrant birds begin flocking for their long return journeys to the northern hemisphere summer.
Driving around much of central, eastern and northern Namibia, or wherever good rains have fallen, the most obvious migrant birds of prey are the Black Kites, Milvus migrans. These 700-gram aerial acrobats are awe-inspiring but can be dangerous to themselves and to vehicles as they swoop and swerve over the roads in chase of aerial insects. In their chase of food the Black Kites are seemingly oblivious to the fast moving traffic. This can be a death trap for the birds as well as for unsuspecting or inexperienced drivers.
Many drivers do not slow down when they have a flock of birds swooping over the road. An experienced driver would know that the length of road along which the birds are foraging would probably be a very short section of a journey. Yet there seems to be a lack of care for both the birds as well as human lives even though the potential danger is obvious. No actual statistics are available but fatal accidents have occurred when fast moving cars have rolled as the driver suddenly swerves to miss a swooping Black Kite.
When migrant kites, kestrels, swifts and swallows arrive in northern Namibia, thousands can be counted and then as the birds spread out across southern Africa flocks of tens or hundreds are seen. On a journey along many of our roads a lot of Black Kite carcasses can be counted. Few drivers stop to check on the condition of the bird that they have collided with. In many cases the drivers cannot stop, they are probably in shock after a high-speed collision with a bird, or have traffic directly behind them and in many cases the birds are probably killed instantly. However some birds may simply have a concussion or a simple fracture that can be repaired.
A common question is why bother to stop and save an individual bird of a species that seems so abundant. A few reasons can be offered; the seeming abundance is because so many of the population have gathered in an area. Some seemingly identical birds are actually subspecies or different races of a species. For example with the kites one subspecies is a short distance intra-African migrant and the other a long-distance inter-African migrant that crosses continents. Black kites are scavengers and insect eaters. Each bird consumes around 70 grams of food per day; this makes them highly useful pest controllers. Just 1000 kites could consume 7 ton of insects in a 3-month period. But as insect eaters and scavengers this species is most susceptible to secondary poisoning from agricultural pesticides throughout Africa, Asia and Europe as well to poison used for predator control in livestock farming.
Combine the potential mortalities from poisoning with those from road accidents and other dangers associated with long distance travel. Add future dire predictions of climate change. Then consider the magnificence of watching kites in flight and perhaps come to a conclusion that the magnificent flyers are worth caring for.