Mother Nature’s whims can produce major impacts on birds

Sooty_tern_flying

Photo by U.S. Fish and Wildlife Service/Duncan Wright The sooty tern, pictured, nests mainly in Hawaii, but some also nest on the islands of the Dry Tortugas, west of the Florida Keys. In 2004, Hurricane Frances blew one of these tropical birds to Holston Lake in Bristol. Severe storms also present devastating obstacles for other birds.

With Hurricane Florence dominating the headlines in recent weeks, it’s only natural to speculate on whether such storms can impact birds in a negative way.

According to a 2011 blog post made on the National Wildlife Federation website, hurricanes can be bad news for some birds. Naturally enough, sea birds and waterfowl are most exposed to the forces of a hurricane. Some birds will move inland to avoid the incoming storm. The birds that inhabit our yards and gardens will ride out the storm using special adaptations. Songbirds will automatically tighten their toes around their perches, riding out the winds of a hurricane by holding onto a branch with a death grip. It’s the same adaptation that lets them sleep on a branch without letting go and falling off during the night.

The blog points out that the news often covers the appearance of rare species after a major storm. Some of these birds transported to unusual locations are probably younger or weaker birds. Once transported far from their usual range by a hurricane, it can take weeks to return home — if they can find the right foods on their way back.

John-James-Audubon-Bachman_s-Swamp-Warbler.-1.-Male.-2.-Female.-Gordonia-pubescens.- (1)

Early naturalist and accomplished artist John James Audubon painted Bachman’s warbler without ever seeing a living one. A friend sent him some skins of the warbler collected near Charleston, South Carolina. A hurricane may have contributed to the extinction of Bachman’s warbler.

In a worst case scenario, hurricanes may have dealt fatal blows to some bird species. For instance, a hurricane may have delivered the knock-out blow to a species of warbler that went extinct last century, according to the website, Field Guide to Extinct Birds. A hurricane that slammed into Cuba in the 1930s when most of the Bachman’s warbler population was wintering on the island might have wiped out enough of the population to make the survivors too rare and far-flung to find each other to breed. The warbler, sensitive to habitat destruction from logging and already in a steep decline, never seemed to recover. It was the ultimate example of keeping all of one’s eggs — or birds — in one unlucky basket.

Discovered in 1832 near Charleston, South Carolina, by the Reverend John Bachman, this warbler attracted little attention for the first half century after its discovery. Bachman sent some skins of the bird to his friend, the artist and early naturalist John James Audubon. Subsequently, Audubon painted this warbler by using those skins and Bachman’s description of the bird’s habits for inspiration. Ironically, considering he described the species for science, Audubon never actually laid eyes on an actual living Bachman’s warbler.

The last specimens of Bachman’s warbler were collected in Mississippi in the early 1940s. The last strongholds for breeding Bachman’s warblers in the United States were Fairfax County, Virginia, in the 1950s and South Carolina’s I’on Swamp in the early 1960s. The last photograph documenting a Bachman’s warbler was taken in 1954. in Charleston, South Carolina, bringing the story of this warbler full circle from its discovery in the same vicinity back in 1832. No Bachman’s warbler sightings have been confirmed since 1961, despite reports in the 1970s and 1980s, as well as reports made in the spring of 2000 and 2001 in the Congaree Swamp National Monument in Richland County, South Carolina. None of those sightings could be confirmed.

Like the ivory-billed woodpecker and Eskimo curlew, Bachman’s warbler is another bird likely to be labeled for the near future with the tag “likely extinct” associated with its name. Like the large woodpecker and the shorebird with a penchant for long-distance migration, the Bachman’s warbler went out with a whimper, not a bang, with most of its viable population snuffed out by an October hurricane just as the species returned to Cuba for the winter season.

Ruby-throat

Photo by Bryan Stevens • Ruby-throated Hummingbirds make a non-stop crossing of the Gulf of Mexico. A hurricane in the Gulf during migration could have serious consequences for this small bird.

More recently, experts worried Hurricane Irma might have delivered a knockout blow to the population of another tiny species of warbler. The Barbuda warblers on the tiny Caribbean island of Barbuda were feared exterminated in the wake of Irma. When the storm hit the island in September of 2017, its path affected more than 90 percent of the island and nearly wiped out the available habitat for the warbler, which already had a Near Threatened status. After the passage of the storm, participants in searches for the warbler turned up sightings of the bird. Nevertheless, the population status and ability to fully recover remains uncertain.

Science keeps adding to its knowledge of how birds are affected by hurricanes and other storms. A 2017 study showed possible consequences for a seabird known as the sooty tern in relation to hurricanes.

The study, published in the peer-reviewed open-access journal PeerJ, is the first to map the birds’ annual migratory path and demonstrate how its timing and trajectory place them in the direct path of hurricanes moving into the Caribbean after forming over the Atlantic.

Climate change threatens to bring about more frequent and powerful hurricanes, which could be bad news for the terns. Migration is a stressful undertaking for birds. If they encounter a strong storm in a weakened state, the results could be catastrophic. The study revealed a strong relationship between the numbers and locations of bird deaths and the numbers and locations of hurricanes. The study also showed that it isn’t just monster storms with the potential to cause devastation. Tropical Storm Delia, a small storm in the Gulf of Mexico in 1973, killed a lot of sooty terns. Essentially, the terns were in the wrong place at the wrong time.

Shorebirds

Photo by Bryan Stevens • A mixed flock of Short-billed and Long-billed Dowitchers and a Ruddy Turnstone at Huntington Beach State Park in South Carolina. Hurricanes can interrupt the migrations of even these long-distance migrants.

Of course, the sooty tern is not a rare bird. About 80,000 or more of these terns are estimated to breed in the Dry Tortugas each year. That’s the entire point, however; Bachman’s warbler was also once considered a common bird.

All of these examples point to the resilience of birds, but there’s also a lesson to learn. We should never take any of our feathered friends for granted. While the winds and rains from a hurricane can decimate human lives, wildlife is not immune. Sadly, birds can weather many a storm, but sometimes they get swamped.

 

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