research

Do Power Lines Help Birds?

Debbie Blicher is Senior Producer of Ray Brown's Talkin' Birds.

A team of researchers in New Hampshire and Maine are investigating whether birds move into land that has been cleared along the route of a power line or has recently been logged. “Our goal is to get a better understanding for how these habitats function in our landscape,” says wildlife specialist Matt Tarr of the University of New Hampshire Cooperative Extension.

The study is being funded by the federal Natural Resources Conservation Service. A more controversial source is the National Fish and Wildlife Foundation’s New England Forests and Rivers Fund, to which the utility Eversource is a contributor. The controversy is that Eversource has proposed the Northern Pass energy transmission project, which entails building a 192-mile electricity transmission line from Pittsburg to Deerfield, New Hampshire. Property owners and tourism officials, among others, have criticized the project. 

Tarr explains that the study isn’t intended to find benefits in building a transmission line. Rather, it's to help determine how birds use the forests that emerge after such a project is built. Tarr's research could help inform policymakers as they work to create more young forests for birds and other species. It will focus on 24 transmission line rights-of-way and 12 logged areas in southeastern New Hampshire and southern Maine. “We might find these rights of way aren’t used as we think they are for mature forest birds," explains Tarr. "That would be important for us to know.”

Starting in late May, Tarr and his colleagues will catch songbirds and band them, then track them over the next two years. Tarr says as many as 40 songbird species nest in young forests, and another group nests in mature forests. Additional evidence suggests young birds that have just left the nest will often live in young forests while their development finishes. In some parts of the country, these younger forests have been found to provide food sources and protection for birds. 

We here at Talkin' Birds are all for the peaceful coexistence of humans with birds and other creatures. We appreciate careful research that leads to wise decisions. We wish Matt Tarr and his team good luck and clear results. 

 

Quiet, Please: How Human Noise Affects Wild Places

Debbie Blicher is Senior Producer of Ray Brown's Talkin' Birds.

People better at birding by ear than by eye can find it maddening to try to hear songs and calls over traffic noise. We wait for the bird to raise its voice once the rattling trucks have passed--only to discover that someone has fired up a leafblower nearby, drowning out everything the way radio static drowns out music.

As annoying as unwanted human noise is to us, it's devastating to other creatures. For example: if birds can't hear one another, they can't alert one another to approaching danger or attractive mates or good food sources. Prey animals can't hear predators in a noisy environment, which means more of them get eaten, affecting the ecological balance. Human noise pollution affects plant reproduction by scaring away birds that help distribute seeds, according to a recent paper in the Proceedings of the Royal Society of London B.

Rachel Buxton, an acoustic ecologist at Colorado State University, succinctly explains the essential problem with noise: “It really doesn’t have any boundaries.” Buxton and her colleagues reported recently in the journal Science that noise from humans at least doubles the background sound levels in most protected areas in the United States. “When we think about wilderness, we think about...going to see outstanding scenery,” says co-author Megan McKenna. “We really should think about soundscapes, too.”

Buxton and McKenna and their team used a model for predicting noise based on sound measurements taken all over the country by the National Park Service. Individual scientists hiked in to more than 400 listening stations to set up the equipment, each of which included a sound level meter and a recorder. Each recorder ran for 30 days, collecting every sound. The recordings were then analyzed by acoustic specialists. The researchers then constructed a model for predicting noise by figuring out which sounds were associated with geographic features such as elevation, annual rainfall, proximity to cities, highways and flight paths. By subtracting out natural sound sources, the scientists estimated the amount of noise pollution for each specific wilderness area.

The findings were mixed. Protected areas did show much lower levels of human-caused sound than the "buffer zones” of unprotected land near them, suggesting that these buffer zones really do insulate parks. But 63 percent of the protected areas showed an increase in sound levels of at least three decibels caused by noise pollution. Since decibels are logarithmic, three decibels indicates a doubling of background noise. More than a fifth of protected areas experienced 10 extra decibels of human noise. Sadly, the majority of areas considered “critical habitat” for endangered species were among the regions that dealt with the worst noise.

McKenna said that parks are taking steps to reduce human sounds, such as implementing shuttle systems to reduce the number of cars and posting library-style “quiet” signs. But the problem of pervasive traffic sound—all those low-frequency rumbles from ground and air—is not so easily solved. Buxton suggests that parks look into “quiet pavement” to muffle the sounds of rolling tires and establish noise corridors to align airplane flight paths with highways.

We here are Talkin' Birds plan to drive as little as possible in protected areas, opting instead for quieter transportation such as foot and bicycle. We'll try to keep our voices down, too. And we would never dream of playing a radio in the wilderness, not even to listen to our own show. We would rather not disturb the symphony of life around us, nor its musicians. 

Want to listen to a news story on this research? Click here for a piece from NPR's Morning Edition

Dressing Up Like Cranes, but Not For Halloween

Ask a wildlife biologist his or her reasons for going into that line of work, and we bet one of them WON'T be, "so I can wear a bird costume." 

Since 1966, scientists at the Patuxent Research Refuge in Laurel, Maryland have been rearing Whooping Cranes in a program that's bringing them back from the brink of extinction. In 1937, only 20 Whooping Cranes were known to exist in the world. By 1966, when their numbers had increased to 42 because of breeding efforts at zoos, an injured whooper was brought to the Patuxent Research Refuge for rehabilitation along with twelve wild eggs. These became the beginning of a captive flock from which many of the world's whoopers are now descended.

The difficulty with captive-rearing Whooping Cranes is that baby whoopers imprint on their caregivers. In other words, they think that whatever takes care of them is their parent. A baby whooper being cared for by humans wants to live with humans, does not trust other Whooping Cranes, and will not survive in the wild. So what's a wildlife biologist to do? 

This is where the costumes come in. At the Patuxent facility, as soon as a baby whooper can see beyond its egg, it's handled only by people dressed up as Whooping Cranes. Yes, really. The technicians wear poncho-like white costumes with hoods, which include camouflage netting to cover their faces. They manipulate a puppet crane head on a stick to convince chicks that an adult Whooping Crane, not a human, is raising them.  Some cranes are even taught to migrate by being allowed to imprint on an aircraft. 

This method of captive rearing is surprisingly effective. By keeping the babies surrounded by the correct sights and sounds, and by moving them to progressively more and more natural surroundings, these biologists are raising whoopers who can function in the wild. These days, the total number of Whooping Cranes in the world is over 600 individuals. It's still not many, but it's enough that a few adult cranes can now start rearing chicks on their own.

As pleased as we are here at Talkin' Birds by the success of this breeding program, we can't help but imagine the conversations some of these biologists must be having at home. "What did you do at work today, dear?" "I put on a bird costume and taught chicks to peck at worms. How about you, honey?" 

If you'd like to hear more about what's going on at the Patuxent Research Refuge, listen to our show from Sunday, November 1. It's in the archive, and you can find it right here.