How Seagulls Fly
This site contains information and facts about how seagulls, and birds in general, fly. While the information and facts on how seagulls fly that I have posted is not all-inclusive, I have done my best to list as much pertinent information and facts that I could find. My hope is that my site will make your reseach on seagulls much easier.
The first and most obvious thing that you will notice about a bird is its feathers. They are very light while at the same time very strong. They are very flexible while at the same time very tough. Oddly enough, feathers do not grow all over the bird. The entire body of the bird may appear to be covered with feathers, but this is not the case. A bird's feathers only grow in certain areas on its body called feather tracks. In between the feather tracks are tiny “down” feathers. These “down” feathers actually help to minimize the weight of the bird's body. The “down” feathers are extremely small and soft, providing a layer of insulation that protects the bird from extreme temperatures.
Feathers are made of a tough and flexible material called “keratin” which just happens to be what the bird's beak is made of. While feathers may look solid, they are actually not solid at all. The spine down the middle, called the Rachis(2), is hollow, and the pointed end, called the Calamus(5), or quill, is also hollow, which makes the feather very light weight. A small opening, called the “superior umbilicus” is located at the junction of the rachis and calamus. A small feather known as an after feather(4) is often attached to this small opening. There are vanes(1) are on the two halves of the Rachis. These vanes are made of thousands of branches called barbs(3). It is interesting to note that there are many spaces, or air gaps, between these barbs which means that a feather has as much air as matter.
A bird's survival depends upon the condition of its feathers. Because of this, birds take a lot of time caring for their feathers. This is called preening. They use their feet and beaks to carefully arrange and clean their feathers. When cleaning, they nibble each feather from the base of the tip. Birds also bathe a lot to keep their feathers in top notch condition. Seagull's have a preen gland, or “uropygial” gland, at the base of the tail. This gland produces uropygial oil which is a waxy substance that is used to waterproof and condition feathers. By rubbing the preen gland with its beak, the seagull picks up the oil and then distributes it onto its feathers by rubbing its beak over the feathers, It is possible that the oil from the preen gland also helps to make the feathers supple and strong and prevents them from drying out .
Birds have between 1,000 and 25,000 feathers, depending upon the size of the bird. A humming bird has fewer feathers than a swan. A bird's feathers can be divided into 6 categories:
- Contour feathers (cover the body of an adult seagull and determine its shape).
- Semiplume feathers (supply thermal insulation and a certain amount of shape).
- Filoplume feathers (keeps the other feathers in proper order and shape, and also provide sensory information about the position of adjacent contour feathers).
- Bristle feathers (provides protection around the eyes and mouths of some birds and have a sensory function).
- Down feathers (provide thermal insulation).
- Powder-down feathers (forms a waterproof barrier for contour feathers).