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| INTERESTING ODDS & ENDS archive #4 |
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| PIPING PLOVER RECOVERY PROGRAMS Piping Plover programs across the Island and across New York State are meeting with great success. These preservation of species projects are working! Slowly plover populations have been growing over the past 15 years. In 1986 there were only 106 documented pairs of Piping Plover in New York State….now there are over 300! Biologists expect the populations to remain steady, or even to grow, with this year’s statistics. And Piping Plover patrols are dedicated people, often walking in front of beach trash-collection trucks to make sure the birds are not run over. They also build cage-like enclosures around the nests to protect against predators (although there is some argument about this, as some believe it eventually actually attracts smart predators to the area). All in all, though, between the dedicated volunteers and the US Fish & Wildlife Service, the outlook is good for these great little birds! Newsday, August 19, 2004 |
| CARING FOR CHICKS IS OFTEN A GROUP FUNCTION Many birds form “crèches” in order to look after their young. A crèche is sort of the equivalent of bird daycare. They are “groups of youngsters from more than one family that are guarded by one or more adults, usually non-breeders or adults that are unsuccessful breeders.” Usually the chicks are still fed by their parents. Increased survival, usually by reducing predation, is why these crèches are formed. Some birds that form crèches are: waterfowl (shelducks, geese, eiders, scoters & mergansers), pelicans, penguins, some gulls & terns, and sometimes with jays & blackbirds as well. Some studies with waterfowl, have shown a relationship between the condition of brooding females and the formation of crèches. Females in poor condition will be more willing to give up the care of their young to a crèche than a female in good condition. Not having to take care of their young will allow the female to build up strength for molting and migration. Some biologists believe with geese that young are actually pirated away from other geese in order to enlarge the crèche size and therefore lessen the risk of predation to their own young Birder’s World Magazine, August 2004 |
| FEATHERS As we know, a bird’s flight feathers are made up of the wing feathers and the tail feathers. However, there are other feathers that are also important to a bird’s well-being. Down feathers, hidden under the surface feathers help to keep a bird warm in the cold; surface feathers (contour feathers) provide a bird’s color, camouflage and flight. Some birds have bristles, around the eyes that help protect the eyes during hunting. There are also feathers called filoplumes, which are full of nerve endings and will let a bird know if it is time to preen and smooth the contour feathers out. Preening is done using oil from glands located at the base of the tail and helps keep feathers in good condition. The colors of a bird’s feathers come from two different types of feathers. Blues and greens are called “structural” colors. These type feathers get their color, not from pigment, but from the way light is reflected off of the feather. That is similar to the way iridescent colors work (like the feathers on a hummingbird’s throat patch, or the colors of the grackles). The other type feather is pigmented feathers, which means there is actual color in the feather (black, brown, yellow & red). Also, black feathers have the most melanin in them, which means they are stronger and wear more slowly than lighter colored feathers. That is why, if you have noticed, that many birds have wing tips that are black; wing tips taking the most stress during flight. Feathers also have hundreds of parallel barbs along the edges, with hundreds of barbules from each bard. These barbs and barbules work like hooks (similar to the way velcro works) and provides the feathers with the flexibility and rigidity needed for flight. NYS Conservationist, August 2004 |
| MOLTING Molting – when the birds replace their feathers – is usually done at least once a year., and is necessary to replace old and worn feathers. Molting becomes possible when the feather becomes weak in it’s follicle (like our hair follicle) and a new feather grows in it’s place, pushing the old feather out. However, since feathers are for flight and protection, molting must be done when it is easiest and safest for the bird. It also takes a great deal of energy to molt. Usually birds molt when demands on their survival are at a minimum (when food is abundant and other activities like breeding and migrating are not an issue). Therefore most birds molt after breeding and, for those that migrate, before migration begins. Most birds molt slowly, losing small amounts of feathers at a time, so that their ability to fly is not hindered. However, most waterfowl molt all at once and therefore become flightless for weeks at a time. (They become very secretive at this time.) Wildbirds, Sept/Oct. 2004 |
| WATER NEEDS FOR MIGRATION Lots of backyard birders notice the increase in numbers of migrating birds at their bird baths during late-spring and late-summer migration times. That’s because in order to fuel their often long non-stop hours of flight, water is critical, just as it is for any athlete. They need to replenish the water lost before they can forage or continue migrating. Flying generates more heat than other activities of birds. Using those muscles that are needed in flight, often for long continuous spans of time, creates body temperatures that can be dangerous. During tests performed on European Starlings, their normal resting temperature of 100-102 degrees (F) can increase to 105-108 degrees during tests in wind tunnels. Birds do not sweat like humans do. They use both convective cooling, when cool air blows over their body, and evaporative cooling, when heat is lost through the skin and tissue and in respiration through the lungs. As they cool they lose water as well. Even flying at night, which reduces loss of water and keeps body temperatures lower, is not enough along to protect muscle integrity. Therefore water replenishment is vital to the health of migrating birds, as well as their success in migration, Birders World, August 2004 |
| INTERESTING STATISITCS ABOUT BODY TEMPERATURE Species Body Mass (oz) Body Temp (F) Elephant 70,548 97.5 Humans 2,960 98.6 Brown Pelican 109 104.5 Mourning Dove 4.2 108.9 American Kestrel 4.2 102.7 Evening Grosbeak 2.1 105.8 Hummgbird 0.1 102.0 |
| HOW LONG DO BIRDS LIVE? One factor that determines bird longevity is size. Usually, the larger the bird, the longer it lives. (There are exceptions, of course, but this is the general rule.) Most small birds only approximately 3 years, while large birds like eagles can live 4 to 5 times that age. Mortality rate in juveniles is high and usually lowers as they mature. It is estimated that as much as 2/3 wild birds born each year will not live past one year due to starvation, bad weather, predators, accidents and man-made hazards. Information on bird longevity comes almost exclusively from bird banding records. The following gives some information on know maximum age attained through banding information. Usually, especially with smaller birds, these longevities have been reached by only one bird out of thousands banded. The Raptor Trust, 2004 |
| Bird Longevity Stats Species Age Mourning Dove 31 Bald Eagle 29 Canada Goose 28 Red-tailed Hawk 28 Great-horned Owl 27 Mallard Duck 26 Osprey 26 Great Blue Heron 24 Blue Jay 17 Northern Cardinal 15 American Crow 14 N. Mockingbird 14 A. Robin 13 E. Bluebird 10 Ruby-throat Hummer 9 Cedar Waxwing 8 Ruby-crowned Kinglet 5 Blue-gray Gnatcatche 4 |
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