Since the brown thrasher lives in Georgia throughout the entire year, it is easy to believe it does not migrate. However, banding studies have revealed some brown thrashers migrate while others stay at home. Consequently, ornithologists classify this master songster as a partial migrant.
Banding studies have revealed that some brown thrashers that breed in New England make their way to the Carolinas and Georgia in the winter. By the same token, brown thrashers that breed east of the Mississippi are often regular winter residents across a broad swath of the South from Arkansas to Georgia.
Consequently, when you see a brown thrasher scratching away the leaves beneath one of your shrubs this winter, you have no way of knowing whether it has been living in your backyard throughout the year or recently made the flight to Georgia from Massachusetts, Ohio or other state far to the north of the Peach Strata.
As for me, I care not whether the thrashers I host in the winter are permanent residents or not. I am just glad they chose to winter close to my home.
Remarkably, spiders annually eat more insects than bats and birds combined. In spite of this, they are one of the least appreciated animals that inhabit our yards.
With that in mind, the next time that you spot a spider in your garden, don’t kill it. Spiders play a key role in the ecology of our yards. As such, they help control all sorts of insects and other invertebrates. In addition, they are important sources of protein for scores of animals such as birds. For example, tiny ruby-throated hummingbirds and great crested flycatchers are just two of the birds that dine on spiders.
The American goldfinches that we see at our feeders right now (August) are in their breeding plumage. However, as we all know, the American goldfinches that visit our backyards in the winter appear to be totally different birds. This is because after the close of the breeding season the birds undergo a feather molt. As a result, a dull and somber winter plumage replaces their bright and beautiful breeding plumage. However, it is not commonly known that the color of the goldfinches bill, feet and legs change along with the feather molt.
At this time of the year, they are pale yellow. However, outside of the breeding season they are grayish brown. This change can best be appreciated if you compare the color of the feet, legs and bills of the American goldfinches you are currently seeing, with those of the bird in the photo (taken in winter) that accompanies this blog. The difference is truly remarkable.
After reading my latest post concerning how much force a pileated woodpecker can endure without harming itself a fellow blogger chastised me for not explaining how this is possible. In hindsight, I indeed did leave a major part of the story untold.
There is no simple answer to this question. The truth of the matter is a number different factors work together to enable a woodpecker is able to hammer a tree with a force some 1,000 times the force of gravity without injuring itself. To begin with, the woodpecker’s brain is oriented in such a manner that it is better able to absorb force from the front. In comparison, the human brain is far better able to cope with forces from below. The woodpecker’s brain also fits tightly into its cranium. This prevents the brain from easily moving about. The woodpecker’s aspect of the woodpecker’s hyoid bone also plays a critical role. This bone actually loops around the head of the woodpecker and helps dampen the force exerted on the bird when it hammers into the wood of a tree. A number of “spongy” plate-like bones found in different spots in the skull help spread out the force of a hammer-like blow.
The design of the bill is also important. Upon close examination it is obvious that the lower bill is a bit larger that the upper bill. Why is this important? Since the upper mandible is shorter than the lower mandible the force of the bill striking the wood passes through lower jaw before it reaches the bird’s skull. Whereas the force exerted on the upper bill is cushioned by spongy bones found at its base.
The fact that the woodpecker’s chisel-like bill is self-sharpening is also an important asset. Since is bird’s bill is always sharp the bird can hammer into wood using less force than would be required if its bill was dull.
It is also important that the woodpecker make every attempt to strike its bill directly at the wood. This helps ensure that the force of the strike originates from the same direction.
It is also important that woodpeckers possess strong neck muscles.
Research conducted by Chinese scientists was able to quantify how successful the complex design of the woodpecker’s head is in muting the extremely high forces it has to withstand. Their findings demonstrated that these modifications are so effective in transferring forces down the woodpecker’s body the head receives only 0.3 percent of the initial force of a blow. That is remarkable.
When a pileated woodpecker is drumming against a tree, it generates a huge amount of force. A human would experience the same amount of force if they were moving at a speed of 16 mph and smashed headfirst into a wall.
If this happened to one of us, we would undoubtedly suffer a number of serious head and neck injuries including a concussion. Yet the pileated woodpecker can drum against trees 17,000 times per day without suffering any injury whatsoever.
According to some reports, in backyard settings, hummingbird feeders are capable of daily supplying hummingbirds with the same amount of sugar produced by 2,000-5,000 flowers. While this is indeed amazing, hummingbird fanciers should not lose sight of the fact the sugar water offered in feeders cannot replace nectar produced by flowers. This is because naturally manufactured nectar is laden with nutrients and minerals needed by these tiny birds to stay in top physical condition.
Attempts to maintain captive hummingbirds on sugar water alone have not been successful.
Most hummingbird enthusiasts believe plant nectar is the primary food of the ruby-throated hummingbird. At the same time, they recognize small insects and spiders are essential to the rubythroat’s diet. However, according to entomologist Dr. Doug Tallamy, renowned native plant proponent, and a growing number of hummingbird experts, hummingbirds are actually insectivorous birds that also consume nectar. In fact, Dr. Tallamy has stated, Hummingbirds like and need nectar but 80 percent of their diet is insects and spiders.”
Research conducted by biologists at Cornell University’s Laboratory of Ornithology seem to corroborate this claim. When the researchers trapped and followed the movements of a female hummingbird for two weeks never once did she eat any nectar.