Colours of Wildlife: Presbyornis
Created | Updated Oct 4, 2015
Presbyornis, the Elder Bird
Willem is a wildlife artist based in South Africa. He says "My aim is simply to express the beauty and wonder that is in Nature, and to heighten people's appreciation of plants, animals and the wilderness. Not everything I paint is African! Though I've never been there, I'm also fascinated by Asia and I've done paintings of Asian rhinos and birds as well. I may in future do some of European, Australian and American species too. I'm fascinated by wild things from all over the world! I mainly paint in watercolours. . . but actually many media including 'digital' paintings with the computer!"
An ancient critter for y'all again this time! It is good old Presbyornis pervetus, the Elder Bird. It might as well be called the Flamingo Duck! Presbyornis was indeed closely related to ducks and geese, but because of its long legs, was first thought to be a flamingo. But that was before its skull was known. When a skull was at last found, it was recognized as being a close relative of the ducks. It has a typical long, flat duck-like bill, with a hook at the tip. It also had flat, webbed feet. Only its long legs and neck don't fit the duck image. Please note that the colours with which I reconstructed it are purely my imagination! We have no remains that tell us the details of its plumage.
After Presbyornis' duck affinities were known, for a while it was thought to be a link between the ducks and geese and the shorebirds and waders, the Charadriiformes, which includes the plovers, sandpipers and gulls. But it turns out there's no close relationship between the groups. Presbyornis developed its shorebird-like appearance independently. It is fairly close to the ducks, geese and swans, but different enough to warrant a separate family. It is not very closely related the screamers, the Anhimidae, the only other family surviving in the Anseriformes, the duck, goose and swan order.
The Surviving Dinosaurs
Catastrophe struck the Earth about 66 million years ago. An asteroid or comet impact might have been involved, though we're still not entirely sure. The result was the extinction of a vast number of species, on land and in the oceans. Hardest hit were the dinosaurs. These incredible and diverse creatures, dominating the land ecosystems, simply all died! All? Well – not exactly all! One group of dinosaurs survived. They were the smallest of the dinosaurs. They were all lightly built, covered in feathers, and able to fly. They were indeed the birds! At the time of the extinction of the dinosaurs, there was no clear separation between birds and non-bird dinosaurs. The feathery dinosaurs went from tiny birds up to large, ponderous meat-eaters. Many of the smaller ones might have been able to glide, if not all capable of flight. The extinction devastated them all. Only the very smallest of the feathery, flying dinosaurs survived. They found themselves in a changed world, barren and empty. The entire global ecology was in chaos. The tiny remnant of land animals found themselves inheriting a world empty of large predators or competitors.
It is thought that, of the critters that survived, some proved to be especially well-suited to this new world. Generalists had an edge over specialists. Apparently, especially birds that lived in marginal habitats, such as the shorelines of oceans and lakes, had an advantage. They were living in between land and water, taking sustenance from the one as well as from the other. There was still land, and there was still water, and these semi-aquatic birds found themselves with many feeding and living opportunities. They diversified rapidly.
Presbyornis was one of these. It lived not long after the extinction of the dinosaurs, 62 million years ago, surviving until about 55 million years ago. Their fossils show that they lived in large colonies, much like the flamingos. Their fossils were found in North America, in formations deposited along the shores of lakes. Inland there were vast forests. Presbyornis fed in the manner of flamingos as well, filtering out small plants and animals from the water using their broad beaks.
But evolution kept on happening. Empty ecological niches were filled. New kinds of birds evolved. New ecological roles emerged. Food webs grew more intricate. While the generalists initially did well, they soon found themselves with more specialized competitors. And so, Presbyornis, for long very successful, soon had to cede its place to newcomers on the scene. These included the ducks, geese and swans, and screamers, which diversified into numerous roles of dabblers, divers, and grazers on land. Storks, herons and cranes arrived and filled the role of long-legged stalkers. The flamingos themselves evolved, much better adapted to filtering out small food animals and plants. And so, the Elder Bird at last went extinct, having done much to lay the groundwork for all these diverse kinds of birds which followed.
Today, the Elder Birds are no more, but we still have the ducks, geese, swans and screamers. These, the Anseriforms, still constitute a link with the distant past. One of the most ancient of the bird lineages, extending back to before the extinction of the dinosaurs, and having included such bizarre birds as Presbyornis, the flamingo-duck, they are today still diverse, numerous and successful – and worthy of our respect, admiration – and conservation.
