What is the main characteristic that distinguishes birds from other vertebrates?<\/p>\n\n\n\n
You guessed it...feathers! (Beaks and wings would also have been good answers). But did you know that there are no fewer than \ud835\udff3 \ud835\uddf1\ud835\uddf6\ud835\uddf3\ud835\uddf3\ud835\uddf2\u0301\ud835\uddff\ud835\uddf2\ud835\uddfb\ud835\ude01\ud835\uddf2\ud835\ude00 \ud835\ude00\ud835\uddfc\ud835\uddff\ud835\ude01\ud835\uddf2\ud835\ude00 \ud835\uddf1\ud835\uddf2 \ud835\uddfd\ud835\uddf9\ud835\ude02\ud835\uddfa\ud835\uddf2\ud835\ude00, which are distributed over the bird's body according to their role? Some are used for flying, others for warmth, and still others for showing off or camouflage, depending on the season (and the bird's ego)... <\/p>\n\n\n\n
Firstly, there are the three most visible types of feathers on the bird's body. The \ud835\uddff\ud835\uddf2\u0301\ud835\uddfa\ud835\uddf6\ud835\uddf4\ud835\uddf2\ud835\ude00 are the stiff, but flexible, elongated feathers that cover most of the bird's wings. They are \ud835\uddf2\ud835\ude00\ud835\ude00\ud835\uddf2\ud835\uddfb\ud835\ude01\ud835\uddf6\ud835\uddf2\ud835\uddf9\ud835\uddf9\ud835\uddf2\ud835\ude00 \ud835\uddfd\ud835\uddfc\ud835\ude02\ud835\uddff \ud835\uddf9\ud835\uddf2 \ud835\ude03\ud835\uddfc\ud835\uddf9. The \ud835\uddff\ud835\uddf2\ud835\uddf0\ud835\ude01\ud835\uddff\ud835\uddf6\ud835\uddf0\ud835\uddf2\ud835\ude00 are also used for flying, and make up the bird's tail. As their name suggests, they provide direction during flight. Finally, the \ud835\ude01\ud835\uddf2\ud835\uddf0\ud835\ude01\ud835\uddff\ud835\uddf6\ud835\uddf0\ud835\uddf2\ud835\ude00, also known as contour feathers, are found on the bird's body. It is these that \ud835\uddf0\ud835\uddf5\ud835\uddee\ud835\uddfb\ud835\uddf4\ud835\uddf2\ud835\uddfb\ud835\ude01 \ud835\uddf1\ud835\uddf2 \ud835\uddf0\ud835\uddfc\ud835\ude02\ud835\uddf9\ud835\uddf2\ud835\ude02\ud835\uddff \ud835\uddfd\ud835\uddf2\ud835\uddfb\ud835\uddf1\ud835\uddee\ud835\uddfb\ud835\ude01 \ud835\uddf9\ud835\uddee \ud835\uddfd\ud835\uddf2\u0301\ud835\uddff\ud835\uddf6\ud835\uddfc\ud835\uddf1\ud835\uddf2 \ud835\uddfb\ud835\ude02\ud835\uddfd\ud835\ude01\ud835\uddf6\ud835\uddee\ud835\uddf9\ud835\uddf2, often becoming more colourful in males, and becoming dull again at the end of summer, the better to hide from potential predators. You only have to look at the Green-winged Teal, for example, to see the difference between the nuptial plumage of the male and that of the female.<\/p>\n\n\n\n
Less visible, but nonetheless part of the \ud835\uddfd\ud835\uddf9\ud835\ude02\ud835\uddfa\ud835\uddee\ud835\uddf4\ud835\uddf2 (all of the bird's visible feathers), are the \ud835\ude00\ud835\uddf2\ud835\uddfa\ud835\uddf6-\ud835\uddfd\ud835\uddf9\ud835\ude02\ud835\uddfa\ud835\uddf2\ud835\ude00 \ud835\uddf2\ud835\ude01 \ud835\uddf9\ud835\uddf2 \ud835\uddf1\ud835\ude02\ud835\ude03\ud835\uddf2\ud835\ude01. Hidden beneath the tectrices (remember; body feathers), the semi-feathers look very much like them, but have hooks (barbs) that give them a fluffy appearance. These serve \ud835\uddf1'\ud835\uddf6\ud835\ude00\ud835\uddfc\ud835\uddf9\ud835\uddee\ud835\ude01\ud835\uddf6\ud835\uddfc\ud835\uddfb \ud835\ude01\ud835\uddf5\ud835\uddf2\ud835\uddff\ud835\uddfa\ud835\uddf6\ud835\uddfe\ud835\ude02\ud835\uddf2, just like down. Down, however, lies directly against the bird's skin and has no hooks; it is a soft, silky feather. Humans have drawn inspiration from \ud835\uddf2\ud835\ude05\ud835\uddf0\ud835\uddf2\ud835\uddf9\ud835\uddf9\ud835\uddf2\ud835\uddfb\ud835\ude01\ud835\uddf2\ud835\ude00 \ud835\uddfe\ud835\ude02\ud835\uddee\ud835\uddf9\ud835\uddf6\ud835\ude01\ud835\uddf2\u0301\ud835\ude00 \ud835\ude01\ud835\uddf5\ud835\uddf2\ud835\uddff\ud835\uddfa\ud835\uddf6\ud835\uddfe\ud835\ude02\ud835\uddf2\ud835\ude00 \ud835\uddf1\ud835\ude02 \ud835\uddf1\ud835\ude02\ud835\ude03\ud835\uddf2\ud835\ude01 to make quilts. Down is sometimes the sole plumage of chicks and ducklings. As the chick grows, it will begin to develop remiges and may start to fly. That's when you can shout \u2018fly, little bird\u2019. <\/p>\n\n\n\n
Next: the \ud835\ude03\ud835\uddf6\ud835\uddef\ud835\uddff\ud835\uddf6\ud835\ude00\ud835\ude00\ud835\uddf2\ud835\ude00 (or silks). These \ud835\uddfd\ud835\uddff\ud835\uddfc\ud835\ude01\ud835\uddf2\u0300\ud835\uddf4\ud835\uddf2\ud835\uddfb\ud835\ude01 \ud835\uddf9\ud835\uddf2 \ud835\ude03\ud835\uddf6\ud835\ude00\ud835\uddee\ud835\uddf4\ud835\uddf2 and the eyes of certain species, such as owls. Finally, the best for last, we have the \ud835\uddf3\ud835\uddf6\ud835\uddf9\ud835\uddfc\ud835\uddfd\ud835\uddf9\ud835\ude02\ud835\uddfa\ud835\uddf2\ud835\ude00, the most mysterious feather of all; these are tiny feathers, which look like hairs, and which are the \ud835\uddff\ud835\uddf2\u0301\ud835\uddf0\ud835\uddf2\ud835\uddfd\ud835\ude01\ud835\uddf2\ud835\ude02\ud835\uddff\ud835\ude00 \ud835\ude00\ud835\uddf2\ud835\uddfb\ud835\ude00\ud835\uddfc\ud835\uddff\ud835\uddf6\ud835\uddf2\ud835\uddf9\ud835\ude00 \ud835\uddf1\ud835\uddf2\ud835\ude00 \ud835\uddfd\ud835\uddf9\ud835\ude02\ud835\uddfa\ud835\uddf2\ud835\ude00. It is these feathers that allow birds to track and \ud835\ude00\ud835\ude02\ud835\uddff\ud835\ude03\ud835\uddf2\ud835\uddf6\ud835\uddf9\ud835\uddf9\ud835\uddf2\ud835\uddff \ud835\uddf9\ud835\uddf2\ud835\ude02\ud835\uddff\ud835\ude00 \ud835\uddf0\ud835\uddf5\ud835\uddee\ud835\uddfb\ud835\uddf4\ud835\uddf2\ud835\uddfa\ud835\uddf2\ud835\uddfb\ud835\ude01\ud835\ude00 \ud835\uddf1\ud835\uddf2 \ud835\uddfd\ud835\uddf9\ud835\ude02\ud835\uddfa\ud835\uddee\ud835\uddf4\ud835\uddf2. Recent research even shows that filoplumes could send signals to make new feathers, when some are broken or lost.<\/p>\n\n\n\n
In waterfowl, the tectrices are waterproof (rather practical, in fact). As well as preventing our little flying friends from constantly catching a cold, these feathers trap a layer of air, which helps them float. For more information on how waterbirds avoid catching a cold in winter, please refer to the excellent book 67th 60seconds <\/a>...'Cold as a duck!<\/p>\n\n\n\n