Category Archives: greeneville sun

Bird and humans can suffer impact from epidemic disease

Photo by Wileydoc/Pixabay • Pine siskins congregate at a feeder.

I wrote several columns about an abundance of finches earlier this winter and late last fall. Some of these flocks, consisting of such species as purple finches, pine siskins and evening grosbeaks, have persisted. Unfortunately, there is sometimes too much of a good thing as a Facebook post from Carolyn Dover Norman reminded me.

Carolyn posted on my Facebook page to share some concerns about an ongoing epidemic affecting some of our favorite feeder visitors.

“I read your article on the internet about the pine siskins and enjoyed it very much,” she wrote. “I live in Texas and have thousands ( it seems) of siskins in our trees this winter. Yes, they are a friendly bird and two allowed me to pick them up off the ground, but now I learn that they are sick with salmonella.” Carolyn said the infected birds don’t appear to be well and are extra tame. She wondered if I had ever heard of this species being more susceptible to this disease.

“I am having to remove and bleach all my feeders and take precautions,” she added.

Regrettably, I informed her that I have heard of outbreaks of various diseases that can affect different birds. Carolyn is to be commended for taking immediate action. She removed her feeders and disinfected them. By taking those steps, she could cautiously resume feeding the birds, although some careful monitoring of the flocks would seem to be in order.

Back in the 1990s, house finches were decimated by mycoplasmal conjunctivitis. Humans can get infected with conjunctivitis, which is commonly called “pink eye.” According to the Project FeederWatch website, infected finches have red, swollen, runny or crusty eyes. In extreme cases the eyes become swollen shut and the bird becomes blind. Observers might find an infected bird sitting quietly while clumsily scratching an eye against its foot or a perch. While some infected birds recover, many die from starvation, exposure or predation. Since the early outbreaks, the disease has affected several other wild bird species, including American goldfinch, evening grosbeak and purple finch.

I recall seeing both house finches and pine siskins suffering from this disease. I haven’t seen it as often in recent years, which is a relief.

Salmonella is another disease that can affect birds. As most people know, salmonella can also have serious consequences for human health. Finches, especially in the West Coast states of Oregon and California, have been hard hit by salmonella in recent months.

“Salmonellosis occurs periodically in pine siskins in some winters throughout their range. When large numbers of pine siskins congregate, the disease can spread rapidly causing high mortality. Most birds die within 24 hours of infection,” said California Department of Fish and Wildlife Senior Environmental Scientist Krysta Rogers, an avian disease specialist.

Birds become infected with salmonella when they ingest food, water or come into contact with objects, such as bird feeders, perches or soil, contaminated with feces from an infected bird. Sick birds often appear weak, have labored breathing, and may sit for prolonged periods with fluffed or ruffled feathers. Salmonellosis is almost exclusively reported from locations with bird feeders where birds congregate. Rogers advised that residents can help reduce disease transmission by removing bird feeders and bird baths. Allowing birds to feed on natural seeds rather than at bird feeders reduces contact between birds and helps slow spread of the disease. Some of the flocks of finches have been exceptionally large this winter, which is why it’s a good idea to closely monitor the birds at your feeders. At the first sign of illness, take steps to disinfect feeders. It’s a good idea to clean feeders on a regular basis. A spray with a weak bleach water solution followed by a few swipes with a clean towel can help. Once an outbreak is evident, however, the best course would be to stop feeding birds for a short period.

Photo by Veronika Andrews from Pixabay • A flock of snow geese takes flight.

Songbirds aren’t the only birds affected by disease outbreaks. Waterfowl are often vulnerable. Like finches, many species of ducks and geese also form large flocks. Some of the diseases that can run rampant in waterfowl populations include avian influenza, avian cholera and avian botulism. According to the Ducks Unlimited website, major avian botulism outbreaks have been reported throughout North America for more than a century. In 1910, avian botulism resulted in the deaths of millions of waterfowl in California and Utah, and another incident in 1952 killed an estimate 4 million to 5 million waterfowl across the western United States.

In 1999, the West Nile virus, a mosquito-borne disease, arrived in the United States. This disease is typically a mild nuisance for most infected people, but in some circumstances the virus can be lethal. The virus, which first appeared in the United States in 1999 after being discovered in 1937 in the African nation of Uguanda, also didn’t confine itself to the human population. Soon after its arrival in the United States, the virus began decimating American crows. Two decades later, experts have been able to study the consequences of West Nile virus on both humans and wild birds.

Photo by Jasmin Sessler from Pixabay • American crows suffered greatly from the spread of the West Nile virus.

According to an article by Hugh Powell published Oct. 15, 2010, on the All About Birds website, the disease afflicted crows more than any other bird species. “West Nile virus hit American crows particularly hard,” Powell wrote. “When the disease first appeared in New York City, in summer 1999, nearly 5,500 crows died in four months. Tests suggested the disease was 100-percent fatal to crows.” Many other species, from jays and magpies to gulls and chickadees, also proved susceptible, according to the All About Birds article.

Millions of birds died as West Nile swept across the continent in just five years. An interesting thing happened as the virus spread across the country. As viral diseases often tend to do, West Nile apparently became less virulent. The American crow population did hit frightening lows, but the species appears to have managed to rebound.

Where’s the silver lining in regard to all these stories? Here is a sliver of light through the dark clouds. Birds are resilient, just like humans. They can usually overcome anything nature might throw at them.

Keep feeding the birds, but play the diligent host. Put out only the amount of seed that visiting birds can eat in a single day. Monitor the flocks for any sign of illness and respond quickly if such signs are detected. Keep feeding the birds, but be safe and attentive while doing so.

Hermit thrushes brave East Tennessee winters

Photo by Bryan Stevens • A hermit thrush perched on a fence rail shows the reddish tail, a reliable field mark to separate this species from close relatives. The tail contrasts from the rest of the bird’s plumage.

Karen Miller sent me an email about a winter visitor in her yard at her home in Parrottsville, Tennessee. “I have seen a hermit thrush eating holly berries for 10 days,” Karen wrote. “Is he migrating or is he perhaps a winter visitor here in Parrottsville?”

To answer her question, I replied and informed her that the thrush is a winter visitor. The hermit thrush takes up residence after its kin have already departed the region in the fall, making it one of the few thrushes to remain in Northeast Tennessee during the winter months. I’ve always thought a good nickname for this bird would be the “winter thrush” because of its presence during the colder months of the year. Of course, for those who know where to look, a few hermit thrushes spend the summer nesting season at high elevation peaks such as Roan Mountain on the Tennessee and North Carolina border.

The hermit thrush is one of the larger brown thrushes, which also includes such related birds as Swainson’s thrush, veery, gray-cheeked thrush and wood thrush. Other less closely related members of the thrush family include the American robin, Eastern bluebird and Townsend’s solitaire.

USFWS • Hermit thrushes like to keep to the shadows.

The poet Walt Whitman employed a hermit thrush as a symbol in his poem, “When Lilacs Last in the Dooryard Bloom’d,” a moving pastoral elegy in honor of the assassinated President Abraham Lincoln. Whitman evidently knew his birds, and it’s not difficult for naturalists and bird enthusiasts to identify that he referred to the hermit thrush when he wove this songbird as a symbol into his stanzas honoring Lincoln. “Sing on there in the swamp,” Whitman wrote in his poem. “O singer bashful and tender, I hear your notes, I hear your call. I hear, I come presently, I understand you…”

Whitman evidently knew of this bird’s bashful, retiring habits, and he had obviously enjoyed the flute-like notes of the hermit thrush’s call. Whitman and many other Americans have been made fans of this gifted songbird. In fact, the citizens of Vermont even proclaimed the hermit thrush as their official state bird. The hermit thrush is well known for its song — a series of clear, musical notes, each on a different pitch, consisting of a piping introductory note and a reedy tremolo. The song had often been described as melancholy by various bird experts. The birds don’t usually sing in winter, but they do produce a call note when disturbed or alarmed that is described as a low “chuck.”

The visiting hermit thrush at her home has allowed Karen Miller to get to know this somewhat reclusive bird better. “He sits on the ground, cocks his head, spies a berry and then jumps up and gets it,” she wrote. She noted that her visitor has a good appetite. “He eats four or five at a time,” she said. “I’m so glad to see him.”

Photo by USFWS • Like many thrushes, the hermit thrush is fond of fruit and berries, especially during the winter.

According to the Smoky Mountains Visitors Guide website, the hermit thrush forages for most of its food from the ground. This bird’s diet includes insects, spiders, snails, and earthworms, plus considerable amounts of wild fruits during the fall and winter. Hermit thrushes may join up with mixed flocks of birds during the winter, often associating with such songbirds as kinglets, brown creepers, chickadees and titmice. For those not fortunate enough to host a wintering hermit thrush, this bird can be found during the summer months atop some high-elevation peaks. Close to home, look for this thrush in the Roan Mountain Rhododendron Gardens. The hermit thrush is also found at some locations in the Great Smoky Mountain National Park.

Female hermit thrushes collect nesting materials and construct the nest, within which she will lay three to six eggs. These thrushes nest once or twice a season. According to the website All About Birds, nesting habits differ between hermit thrushes in the western North America and their counterparts in the eastern half of the continent. Eastern thrushes tend to nest on the ground, but those in the west often place their nests in shrubs or tree branches.

At home on Simerly Creek Road, my first hermit thrush of the winter arrived in early November of last year. During a woodland stroll with neighbor Beth McPherson, the resident thrush put on an impressive show, hopping and scraping on the woodland floor beneath a rhododendron thicket bordering a mountain spring. In such surroundings, it’s not difficult to fathom why this bird has developed such a subtle plumage of muted browns and grays. Even when foraging actively, the bird blended remarkably with the background of fallen leaves and other woodland debris.

The hermit thrush is known by the scientific name, Catharus guttatus. The term guttatus is Latin for “spotted,” which seems appropriate. Surprisingly, the hermit thrush is not closely related to the other North American migrant species of Catharus thrushes. Instead, the hermit thrush is more closely related to the russet nightingale-thrush, a Mexican songbird. The hermit thrush could accurately be called the “red-tailed thrush” for the fact that this species has a rusty-red tail that stands apart from the warm brown-gray tones of the rest of its plumage. A white eye ring, pink legs and a heavily spotted breast complete the rest of this bird’s understated appearance.

Photo by Bryan Stevens • A hermit thrush perches on a branch in a winter woodland.

The wintering hermit thrushes in the region will likely stay put for the next couple of months, but they will mostly depart the area in April or early May. If you want to look for them, now’s the time.

••••• Bryan Stevens lives near Roan Mountain, Tennessee. To learn more about birds and other topics from the natural world, friend Stevens on Facebook at https://www.facebook.com/ahoodedwarbler. He is always posting about local birds, wildlife, flowers, insects and much more. If you have a question, wish to make a comment or share a sighting, email ahoodedwarbler@aol.com.

 

Winter season wouldn’t be complete without the splendor of cardinals

Photo by Jill Wellington/Pixabay.com • A male Northern cardinal grasps a branch of winter greenery.

I have enjoyed an opportunity to observe the many Northern cardinals visiting my feeders in recent weeks. The beauty of both male and female cardinals is undeniable, but it’s their behavior that’s worth a second look. Nervous, twitchy birds, they are always anxiously surveying their surroundings even as they linger on a feeder long enough to hull a sunflower kernel from its shell. It’s almost as if they know their bright plumage stands out in a drab winter landscape dominated by shades of gray.

The Northern cardinal, especially the brilliant red male, stands out against a winter backdrop of snow white, deep green or drab gray. Over the years, the cardinal has also become associated with the Christmas season. How many Christmas cards have you received this holiday season with a cardinal featured in the artwork? I’d wager that at least a few cards in any assortment of holiday greetings will feature the likeness of a Northern cardinal.

There’s some more evidence to put forward as testimony to the popularity of the Northern Cardinal. It’s the official state bird of seven states: North Carolina, West Virginia, Ohio, Illinois, Indiana, Kentucky and Virginia. Only the Northern mockingbird, which represents five states as official state bird, even comes close to the Northern cardinal in this respect.

The Northern cardinal belongs to a genus of birds known as Cardinalis in the family Cardinalidae. There are only two other species in this genus, and they range across North America and into northern South America.

The two relatives are the pyrrhuloxia, or Cardinalis sinuatus, of the southwestern United States, and the Vermilion cardinal, or phoeniceus, a bird found in Colombia and Venezuela. Two other South American birds — red-crested cardinal and yellow-billed cardinal — are more closely related to tanagers than to our familiar Northern cardinal. Both the Northern cardinal and red-crested cardinal have been introduced into the state of Hawaii, so two non-native birds from different parts of the globe are now resident in the Aloha State.

Photo by Jack Bulmer/Pixabay.com • A male cardinal grips a branch to make a quick survey of its surroundings.

The Northern cardinal is a native and abundant bird. Cardinals are a widespread species, ranging westward to the Dakotas and south to the Gulf Coast and Texas. The southeastern United States was once the stronghold of the cardinal population. In the past century, however, cardinals have expanded their range into New England and Canada.

The cardinal accepts a wide variety of food at feeders. Sunflower seed is probably their favorite, but they will also sample safflower seed, cracked corn, peanuts, millet, bakery scraps and even suet. While we may get the idea that cardinals feed largely on seed, that is a misconception based on our observation of the birds at our feeders. Cardinals away from our feeders eat insects and fruit, including the berries of mulberry, holly, pokeberry, elderberry, Russian olive, dogwood and sumac.

The cardinal uses its large beak to efficiently hull sunflower seeds or deal with other foods foraged in field and forest away from our feeders. The large, heavy beak hints at the cardinal’s kinship with birds such as tanagers and grosbeaks. In fact, some of America’s early naturalists referred to the bird as “cardinal grosbeak.” Other common names include the apt “redbird” moniker and “Virginia nightingale.”

Photo by Skeeze/Pixabay.com • A male Northern cardinal lands on a snowy perch. Cardinals are perfect symbols for the Christmas season with their bright red plumage.

Even once the holidays are past, there’s nothing like a glimpse of a Northern cardinal to add some cheer to a bleak winter day. People can also choose to further the cause of science by taking part in studies such as Project FeederWatch, a nationwide survey of bird populations focused on birds coming to feeders maintained by project participants.

Photo by Bryan Stevens • A male Northern cardinal pays a visit to a feeder.

In the 2015-16 winter season, 1,373 individuals participated in Project FeederWatch in the southeastern United States. The most common birds reported by observers were Northern cardinal, Carolina chickadee, mourning dove, American goldfinch and tufted titmouse. Finishing out the Top 10 feeder birds in this section of the nation were Carolina wren, house finch, blue jay, red-bellied woodpecker and downy woodpecker. Almost 98 percent of participants reported Northern cardinals at their feeders, which means the cardinal has become an almost universal feeder visitor in the southeast.

It’s not surprising that such a popular bird has also become associated with many trappings of the Christmas season.

“You see cardinals on greeting cards, stationery, paper plates, paper napkins and tablecloths, doormats, light switch plates, candles, candle holders, coffee mugs, plates, glasses, Christmas tree ornaments and lights, bookmarks, mailboxes, Christmas jewelry,” writes June Osborne in her book The Cardinal. “And the list goes on. Cardinals have become an integral part of the way that many people celebrate the holiday season.”

I can be included among such people. My Christmas decorations include an assortment of cardinal figurines and ornaments. There are other birds — doves and penguins for example — associated with the holiday season, but for me the holidays magnify the importance of one of my favorite birds. The cardinal, in its festive red plumage, appears made to order for a symbol of the holiday season.

Photo by Bryan Stevens • Northern cardinal seems much less descriptive of this popular bird than such common names as Virginia nightingale and Kentucky redbird.

Here’s some additional cardinal trivia to increase your knowledge of this fascinating bird:

• Cardinals differ in appearance based on gender. The male boasts crimson plumage, a crest, a black face and orange bill. The female, although less colorful, is also crested. Female cardinals are soft brown in color, with varying degrees of a reddish tinge in their feathers, particularly in their wings.

• The cardinal’s preference for dense cover makes them likely neighbors for such birds as Carolina wrens, Eastern towhees and brown thrashers.

• The oldest recorded Northern Cardinal was a female, and she was 15 years, nine months old when she was found in Pennsylvania, according to the website, All About Birds.

• An uncommon genetic variation sometimes produces a cardinal with yellow or orange feathers instead of the typical red. The scientific name for the condition that produces yellow cardinals is known as xanthochroism. This condition also often occurs in house finches.

• Nests are built by the female cardinal, but her mate delivers food as she incubates her clutch of eggs, which usually numbers three or four.

Photo by Bryan Stevens • A female Northern Cardinal feeds during a snowstorm at a hanging tray filled with sunflower seeds.