Beaks are an important part of a birds anatomy. Like many of the parts of a bird, they have evolved and adapted to help them survive in their chosen environment and niche. They are key to helping a species thrive by making the most of the food available to them. Just as there is a wide variety of food available to birds, there is a wide variety of different styles of birds’ beaks. And even those who may have similar uses may come in a wide variety of different shapes and sizes. They may even have a vastly different apearance in an individual species based on the sex and time of year.
Each one perfect for their chosen diet, from tearing meat to catching insects to cracking thick seeds. Not only is the beak used for eating though, it is also important for preening, picking up materials such as nesting matierials, courtship and feeding young.
While no matter what color or shape they are they are all made up of the same underlying structure. The very basis of each birds beak are two bony structures, the upper and lower mandible. On top of this is a thin keratin layer of epidermis which is called the rhamphotheca. This layer is what is often refered to as the bill sheath and is what contains the color and structure of the beak.
Illustrated below are some of the few basic stlyes
The first can often be seen on waterfowl, dabbling ducks in particular. Their flat wide shape with little protusions called lamellae are perfect for sifting though water and mud or grapping underwater plants. Many species of waterfowl have an adapted concept of this , from mallards foraging underwater for vegetation to flamingos catching krill, shimp and other invertabrates.
The next beak is perfect for probing, this design can be seem in a vastly different groups of birds such as hummingbirds and even shore birds. While hummingbirds may use this design to get the nectar at the back of flowers, other birds have this same design but for different reasons. Shorebirds like sandpipers use this design to probe in the mud to locate their prefered diet of crustaceans and invertabrates buried underneath.
Birds that are primarily insectavores have their own designs also. To catch insects a wide flat bill is best. This gives them a greater chance of catching their prey and securely holding onto it. Many times these species will have rictal bristles at the base of the beak, it is believed they help to funnel insects into their open mouths when catching airborn insects.
To crack open seeds, a birds beak needs to be strong. So species with a diet of primarily seeds will have a different design than others. To crack open thick shelled seeds, the beak needs to be thick to excert enough pressure. This can best be seen in species like the northern cardinal and grosbeaks.
This next style will be easily seen in bird of prey species. Their thick beak ends in a hook. This is perfect for ripping out bite sized pieces of meat from their prey. Some species of birds of prey like falcons have an extra adaption called the tomial tooth, this little notch in the beak helps them to dislocate the spine of their prey.
The last style illustrated can be best described as stabbing. This can range from woodpeckers up to herons. This shape is longer but thick and sturdy. For woodpeckers this helps them chisel away bark and wood to locate insects while for herons this same shape is perfect for spearing fish and other prey.
While this does not emcompass all the different varieties in bird bills it does touch on the most basic of designs found in the world of birds and shows how birds use these adaptions to survive.