BirdWalk Newsletter

Transcription

1 BirdWalk Newsletter Walks Conducted by Perry Nugent and Ray Swagerty Newsletter Written by Jayne J. Matney Cover Photo by Guenter Weber Feathers Why do birds fascinate us so much? Is it their beaks? Is it their feet? Is it their hollow bones? As fascinating as those things are, when it all boils down, it is the feathers; it is the flight. The feathers immediately attract us with a bird s outward appearance. They make us oh and ah in visual satisfaction. Therefore, feasting our eyes on the feathers displayed by birds brings out our initial fascination. Humans treasure beautiful things. Unusual things. Because of these structures, their flight is the cream on top. Watching a bird in flight, because of their feathers and hollow bones, has given humans hopes and dreams over the years. We envy and appreciate their ability to soar through the air above all others. Taking a closer look into these unique structures is this week s topic. Feathers are dead structures, similar to our fingernails and hair, in that once they are damaged, cannot repair themselves. The health is critical to a bird s life.

2 Therefore, they take care of these valuable structures by preening with the use of their beaks, feet, and oil glands. Because feathers go through a lot of wear and tear over the months, birds shed, or molt, to replenish feathers and start anewsimilar to a deer and its antlers or a snake and its Egret in display posture Photo by Jo Frkovich skin. Feathers can act as a protective layer for the bird, an insulator, a display mechanism for mate attraction or defense, camouflage, and a flight structure. A bird known as the male Club-winged Manakin, found in Central and South America, actually has singing wings to attract mates. When the specialized wing feathers of this bird are rubbed together, they make a loud, singing note. Feathers-what an amazing tool! If you have ever looked closely at turkey or chicken skin before preparing it, you may have seen small follicles on the surface, called papilla. This is where the feather grows out of the skin. Therefore, as the feather grows out of the skin, the base of the feather is the newer section of the feather. As the feather grows, it has a protective sheath around it which eventually disintegrates and the feather opens up fully. The feather is made of proteins, called Beta-keratin, which grow into branches, and some branches will fuse together to make up the thicker sections of the feather such as the rachis-that central rod of the feather. Small branches form off of that portion of the feather. Different types of feathers have a larger, more defined rachis. Once the feather opens fully, it is easier to see that the feather is a very intricate structure of hoops and hooks called barbs and barbules which interlock to keep the feather from getting mangled easily and become nonfunctional. When a bird preens, it is getting any of those interlocking parts, which may have gotten out of place, back into its proper form. Or, the bird may be conditioning the

3 feather with oils by rubbing in these oils onto the feather s surface. Feathers are very different from each other depending upon the use. Bald Eagle preening feathers Photos by Guenter Weber Large primary feathers such as wing and tail feathers, for example, have more barbs and barbules in a closely fitting structure. These are called pennaceous feathers, and they act as a stronger base specifically for flight. Many of these flight and rudder type feathers are overlapping for a constant solid surface. The primary and secondary feathers for flight are also anchored into bone by ligaments to withstand winds and flight use. Down feathers, however, have a looser structure because of fewer barbs and barbules for a softer, less dense surface. Those feathers are useful as insulators, giving more room for warm air (or cool air, depending upon the environmental conditions) Photo by Guenter Weber

4 around the body. Other types of feathers, such as the contour and semi-plume feathers, have down-like sections and pennaceous sections. Filoplume and bristle feathers are those which have a long rachis with barbs either only at the tip or only at the base ends. These are feathers used as whisker-like, sensitive structures or for protection of eyes and face. The colors of feathers are more for display or camouflage. When used for display, that can include mate attraction or aggression and defense. Color, color patterns, feather location, and feather arrangement can all aid a bird with camouflage. For example, an owl s spotted, barred, or dappled coloration helps them to hide in daylight in a forest. Also, a Great Horned Owl has tufts of feathers which are not a part of the ear or the functioning of the ear. It could possibly be for display or camouflage. No matter what a feather is used for or how it looks, they fascinate us. They are one of nature s engineering marvels and one of nature s artistic masterpieces. Photo by Angie Bridges Information for this article came from: Everything You Need To Know About Feathers- Feather Growth: How do feathers develop? All About Birds, Bird Academy, Cornell Lab; Everything You Need To Know About Feathers-Feather Anatomy: How do Feathers Work? All About Birds, Bird Academy, Cornell Lab; Everything You Need To Know About Feathers- Studying Feathers: How do scientists use Tinbergen s four questions? All About Birds, Bird Academy, Cornell Lab; Everything You Need To Know About Feathers- Feather Function: What do Feathers do? All About Birds, Bird Academy, Cornell Lab.

5 Charleston, as well as The Magnolia Plantation and Gardens, has been experiencing plenty of unusually cold weather this month. Record snows were recorded and followed with more days of consistent low temperatures. Night time temperatures have been in the 20 s and 30 s (sometimes 40 s) and the day light temperatures have not been much warmer. Despite the temperatures, there were 4 participants with 45 species located. The brave souls adventuring out on this day are highly appreciated! Ravenswood and the Audubon Swamp areas were the primary focus on this day. Wood Duck, Gadwall, Mallard, Blue-winged Teal, Pied-billed Grebe, Anhinga, Great Blue Heron, Great Egret, White Ibis, and Common Moorhen were among the species seen specifically on that side of the property. Along with these water oriented birds, Song Sparrow, Swamp Sparrow, and Rusty Blackbird were seen there. Over a half dozen Canadian Geese were fly-bys near the cabins, while 2 Red-shouldered Hawk were sighted in the area as well. Laughing Gull and Ring-billed Gull made the count. An enormous number (30) of Black Vulture and also a few Turkey Vultures were taking shelter in the trees again this week. Scattered throughout the property were Red-bellied Woodpecker, Downy Woodpecker, Yellow-bellied Sapsucker, and Northern Flicker. Also in this category were our passerines such as Eastern Phoebe, American Crow, Fish Crow, Carolina Chickadee, Tufted Titmouse, Carolina Wren, Ruby-crowned Kinglet, Eastern Bluebird, Hermit Thrush, American Robin, Northern Mockingbird, Yellow-rumped Warbler, Red-winged Blackbird, and Northern Cardinal. A Common Grackle made the list as well as a Black-and-white Warbler. Seven Cedar Waxwings were seen at the entrance gate. Pine and Palm Warblers were located near the cabin area. Chipping Sparrow and White-throated Sparrow were seen near the pavilion field. The Highlights of the Week: Bald Eagles are being seen in a few different locations because of the wanderings of 2 immature eagles. They have been spotted investigating the Ravenswood area. Also, an adult, of the adult pair seen near the boat dock area, was seen in addition to the immature eagles. Seeing Mallards on the ponds for the first week was an exciting sight. Quick note: On Thursday, , 6 Ring-necked Ducks were observed in Perry Field Pond mixed in with the other ducks.