Bateleur Eagles.
By Kristie Weeks, University of Montana
One of my favorite scenes in Star Wars Episode 1: The Phantom Menace, is when Anakin Skywalker defeats his enemy and slave master in a pod race piloting a hovercraft that he built from scratch. He’s only a kid, but he flies with expert precision, winding around canyons and dodging missiles. Each time I watch this scene or any other Star Wars scene involving jets, space, and flying, I want to abandon my math and wildlife biology degrees and become a fighter pilot! The thought of racing through the sky with the wind whipping my face sounds so exhilarating. When I fly to and from my college town in Missoula, Montana, I always make sure to get a window seat so that I can admire the beautiful sky and watch the plane’s wings. As the plane accelerates during take-off, its angle slowly increases but never exceeds a certain steepness. As it lands, special flaps stand up on the wings that create resistance and slow the plane.
Southern Carmine Bee-Eater.
Last spring, I learned in my ornithology (the study of birds) class, that these characteristics in a plane are modeled after adaptations that help birds fly. Birds adjust their angle of attack so that it stays around 6 degrees, thus creating enough lift and drag to maintain flight. If the angle of attack becomes too steep in a plane, it will lose momentum and fall out of the sky. Birds also have tail wing feathers called rectrices that provide stability during flight and act as brakes during landing. I also learned about how birds memorize where constellations are to help them navigate, can see UV light, and have metals in their beak that act like a compass when flying. Researchers were able to do studies on birds around the world to discover these cool facts, because they’d already done basic research on local bird populations.
The Okavango Delta is the largest wetland in Botswana. Due to its variation in habitats, ranging from floodplains to desert-like Mopane forests, it supports 500 different bird species. The delta can support such a plethora of birds, because it contains a hydrological gradient and floods seasonally. These factors stir up nutrients and alter vegetation throughout the year, allowing a wide range of birds to inhabit the delta. Though scientists know that many birds live in the delta, few studies have been done regarding bird population dynamics or what particular habitats birds prefer. Until these studies are done, it is extremely difficult for Botswana to design conservation strategies for birds. This also means that they must wait to perform interesting research on the bird’s adaptations, because they first need to assess how healthy bird populations are.
African Fish Eagle.
Because of this lack of information, one of the other students, Sam Gerdts, and I are doing our semester long research project on the effect of habitat variation on bird species richness in the delta. We’re doing this by performing bird point counts in the Khwai, Sankuyo, and Mababe concessions (NG 18, 19, 34, and 41). Point counts involve spending 5-minute blocks recording every bird that we see or hear. For example, if we hear a call where it sounds like the bird is saying ‘work harrrrr-der work harrrr-der’, we record that there’s a Cape Turtle Dove at the point. One of our favorite birds to observe on transects is the African Fish Eagle. It is a majestic raptor, but it also looks ridiculous when it makes its call. When it screams its high pitched call, it snaps its head back so quickly that it looks like its neck is about to snap!
African Fish Eagle, calling.
We also record which tree, shrub, and grass species are present in each point count we do and which of those species are dominant. At the end of the semester, Sam and I will compile this data, use GIS to create maps of the areas, and perform statistical analysis to determine species diversity and which habitats specific bird species prefer throughout the delta. We will give our project’s results to Dr. Gas Masunga at the Okavango Research Institute, who will use the data to direct future bird research and conservation strategies in the Okavango Delta.