by Hannah Thorne, University of Vermont
The Okavango Delta in northern Botswana is a species rich wetland system that is home to hundreds of different bird species. As in any region, some of these birds are more common than others, and a few are facing threats to their existence. As part of our data collection in the field, Round River has partnered with Bird Life Botswana, an organization that collects citizen science data on the presence of several “Birds of Concern” in the area. These birds include: Bateleur, Slaty Egret, Lesser Flamingo, Black-winged Pratincole, White-headed Vulture, Lappet-faced Vulture, Hooded Vulture, White-backed Vulture, Cape Vulture, Martial Eagle, Pallid Harrier, Wattled Crane, Grey Crowned Crane, Chestnut-banded Plover, European Roller, Kori Bustard, Ground Hornbill, Maccoa Duck, African Skimmer, and the Lesser Kestrel.
Every time we see one of these birds, no matter if we are on a transect collecting our daily herbivore data or just hanging around camp, we collect data for it. Collecting data for a Bird of Concern sighting includes writing down the species name, taking GPS coordinates of the location, specifying which concession of Botswana we are in, and recording the date, time, number of birds sighted, and their demographics. We also record who the observer was, and any other relevant comments about the birds behavior that are noteworthy.
A Kori Bustard seen in the grasslands of NG18
Some of these birds we see more than others. Many are more common in protected areas, as they are less vulnerable to outside threats. As is the case for many of the vultures and other scavenger birds, a major threat to their populations is actually people poisoning animals killed by large predators such as lions and leopards. Local cattle herdsmen believe that these predators are killing their livestock, which does occasionally happen. To retaliate, they poison the kills of these animals while the predator is sleeping or away. But the predators are not the only ones utilizing these kills, and scavenger birds also decline in population as a result of feeding off of poisoned carcasses.
A Vulture seen waiting by a giraffe killed by a pride of lions.
Personally, the Birds of Concern that I have seen are the Kori Bustard, Bateleur, Ground Hornbill, and a number of the Vultures. The Kori Bustard is the largest bustard, and one of the heaviest flying birds in the world. It is most often found in open savannah woodlands and dwarf scrublands. The Bateleur is a medium to large raptor that scavenges carrion. It can be identified when soaring by its white underwings that have a black strip at the base that is thicker in males than it is in females. The Ground Hornbill is a large, almost turkey-looking bird that feeds on small animals such as squirrels, lizards, and snakes. Interestingly, these birds are facing declines in numbers because they are prosecuted for breaking the windows of houses and cars. They hammer at their own reflection in the glass in a territorial aggression, unaware that it is not another bird they are looking at. The vultures are the most exciting to see, because their swarming presence means a fresh kill, and an opportunity to see one of the many charismatic predators that lurks in the bush of Botswana.
A pair of ground hornbills seen in NG19.