Migrating birds sprint in spring, but take things easy in autumn

 Radar station in Falsterbo, Sweden, for tracking migrating birds. Credit: Cecilia Nilsson

Radar station in Falsterbo, Sweden, for tracking migrating birds. Credit: Cecilia Nilsson

Passerine birds, also known as perching birds, that migrate by night tend to fly faster in spring than they do in autumn to reach their destinations. This seasonal difference in flight speed is especially noticeable among birds that only make short migratory flights, says researcher Cecilia Nilsson of Lund University in Sweden, in Springer’s journal Behavioral Ecology and Sociobiology.

Nilsson, in a group led by professor Thomas Alerstam, used a tracking radar to measure over three years the speed by which birds flew over Falsterbo Peninsula, a bird migratory hot spot in south-western Sweden. The seasonal differences they found correspond with those recorded for other nocturnal passerine migrants at other sites in southern and northern Sweden. Continue reading

The invisible killer threatening millions of migrating birds

A dead bird found on the streets of Washington, DC

A dead bird found on the streets of Washington, DC

Every year, hundreds of millions of birds are killed or injured when they fly into windows. Volunteers who document the collisions are now calling for architects and landlords to make their buildings more bird friendly to reduce the number of deaths.

Sometimes birds see plants or empty spaces beyond the windows – sometimes they just see the reflection of the sky or trees, but not the glass itself.

Most tend to cruise at 20-30mph (32-48kph) – if they hit a window at that speed the impact is usually fatal as their beak is jammed back into the brain. Continue reading

Ticks and endangered voles linked by migrating birds

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Migrating birds probably did it. That’s what University of California, Davis, epidemiology professor Janet Foley says after DNA detective work confirmed that a disease-carrying tick only found in the southeastern United States has colonized a federally endangered rodent population in an extremely isolated patch of Mojave Desert wetlands. Continue reading

Rome overwhelmed by faeces of migrating birds

Starlings fill the sky in Rome, with the dome of Saint Peter's silhouetted. Photograph: Stefano Rellandini/Reuters

Starlings fill the sky in Rome, with the dome of Saint Peter’s silhouetted. Photograph: Stefano Rellandini/Reuters

Romans are staying at home or shielding themselves with umbrellas when venturing out this autumn as the city is bombarded by tonnes of slippery and foul-smelling excrement from millions of migrating starlings.

The problem is an annual one, but this year the cash-strapped city has failed to muster the €40,000 it usually spends on hiring 20 people to walk under plane trees lining the Tiber – where the birds roost en route to Africa – with loudspeakers in order to scare them off with recordings of the screeching noise starlings make when predatory falcons approach. Continue reading

How One Bird Became a Better Migrant

[Audubon's Warbler; credit:  Pterzian/commons.wikimedia]

[Audubon’s Warbler; credit: Pterzian/commons.wikimedia]

Some of us are born with wanderlust, but what exactly spurs a bird to journey thousands of miles each year? The answer is in part genetic, and a recent study of yellow-rumped warblers in the journal Evolution reveals how changes over generations could improve a bird’s abilities to become a master, long-distance flyer.

The research, conducted by zoologists and physiologists at the University of British Columbia, began with a genetic puzzle. There are four different groups of yellow-rumped warblers, each distinct in behavior and appearance: the Goldman’s, myrtle, Audubon’s, and black-fronted. Their genes, however, tell a different story.

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Migrating songbirds at risk from hunting in Mediterranean

Songbirds like this female blackpoll warbler, which may be seen migrating through our area in a week or two, would not be spared in Mediterranean hunting practices. / Photo courtesy of Steve Golliday

Songbirds like this female blackpoll warbler, which may be seen migrating through our area in a week or two, would not be spared in Mediterranean hunting practices. / Photo courtesy of Steve Golliday

At this point in August, the birds are fairly quiet. No stunning choruses at dawn or dusk. Breeding finished, the season’s young look almost like their parents, if a little scruffy and naïve. But we know that in a couple of weeks, activity will pick up as songbird migration begins, with warblers and vireos rushing in from the north. Shorebirds are already on the move; you might see them wherever there is shallow water and exposed shoreline.

Americans treat migration as an awe-inspiring spectacle, and take for granted that migratory birds are protected, thanks to the Migratory Bird Treaty Act of 1918. Imagine if, instead of flocking to Atlantic or Gulf Coast migration hotspots with binoculars and high-tech cameras, waiting for tired birds to make landfall after long water crossings, we instead went with guns, nets and glue traps to capture as many birds as possible. Incredibly, that is currently happening to birds migrating across the Mediterranean between Europe and Africa.

Novelist Jonathan Franzen, also an impassioned birder, has investigated the indiscriminate songbird slaughter occurring throughout the Mediterranean. In July’s National Geographic, and in an NPR interview, “The ‘Uncool’ Passion of Jonathan Franzen” (available online), he describes what is likely unfathomable to most Westerners: each year, hundreds of millions of songbirds and larger birds are taken for food, trade and sport, contributing to a massive decline in European bird populations.

The killing of birds for extra sustenance has long occurred, but increased technology such as netting that covers entire trees and illegal playback recordings to lure birds has raised the death toll. Increasingly vulnerable from more insidious threats such as habitat loss, many bird populations can no longer sustain this direct stress, much of it on the commercial scale.

The legal status of hunting activity doesn’t necessarily change the reality. In Italy, France, and Cyprus, farmers sell songbirds to restaurants as delicacies, sometimes off-menu and illegally. Young Albanians express their freedom by shooting birds, a pastime formerly forbidden under totalitarian rule. Italians travel to Albania, where enforcement of hunting regulations is lax and difficult.

Franzen visited a lush national park on Albania’s Balkan coast, a crucial wetland stopover for birds, to find it empty of birds; he joined young Bedouins at Egyptian desert oases, where they might each shoot 50 orioles a day at one spot. Much of the Egyptian coast, where laws are nearly nonexistent, is rigged with netting, the birds sold in coastal town markets. Franzen is discouraged by cultural attitudes that see no difference between catching birds and catching fish, and ponders the “arbitrary ethical line we’ve drawn” in assigning charisma to birds.

Indeed, even in the United States, where bird hunting is highly regulated, we can see the arbitrary nature of what is deemed OK to hunt, and the influence of tradition. Most would cringe at the idea of hunting warblers, most don’t think twice about hunting turkeys or pheasants, but many other hunted birds such as ducks, rails, or sandhill cranes are also highly sought by birdwatchers. Twenty million mourning doves are shot in 39 states annually, and though not legal in New York, the DEC explains, there is little demand to change the laws because there is no tradition of hunting doves in the state.

The U.S. Fish and Wildlife Service classifies many species — swans, ducks, rails, cranes, plovers, sandpipers and doves — as migratory game birds, but says that “in actuality, (it) has determined that hunting is appropriate only for those species for which there is a long tradition of hunting. … It is inconceivable, for example, that we will ever see legalized hunting of plovers, curlews, or the many other species of shorebirds whose populations were devastated by market gunners in the last decades of the 19th century.”

Before we condemn Mediterranean cultures’ “long tradition of hunting,” we should remember these mistakes of our own past, such as the plume trade that decimated egrets and herons. I recently read an account of the indiscriminate slaughter of seabirds on Laysan Island in 1909, in which one Max Schlemmer assembled a crew, sailed from Honolulu, and worked for months collecting wings and skins, until a biologist got wind of it and the U.S. Navy was dispatched. He had brutally killed 300,000 seabirds and had clearly intended to strip the entire island of birds.

That is an extreme case, but many participated in the indiscriminate slaughter of the passenger pigeon. Gene Stratton-Porter, an early naturalist and writer, describes flocks so numerous that they’d break the branches off their roosting trees. In her Indiana childhood in the 1870s, it was common for men to search out these trees, “then half-a-dozen men would flash the lanterns (to) blind the birds, and with the clubs others would beat the birds from the limbs, strike them down and gather them up by the bagfull.”

One hopes that the Mediterranean region can catch up to evolved Western thinking in time. Franzen found some encouragement in his travels: Albanian hunters growing worried about the birds, hunters who became birders, stunning bird presence with simple law enforcement, the interest Bedouin hunters took in his field guide.

“It’s not that long a step from the culture of hunting to the culture of merely looking or shooting with a camera,” he says.

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