Tucson Region

Goal is to stem bird deaths on electrified roosts

Researcher James Dwyer has scoured the bases of Tucson-area utility poles over the last two years in search of electrocuted raptors. "I'm kind of tired of seeing all this death," said Dwyer, a graduate student in the University of Arizona's School of Renewable Natural Resources. "It gets to you after a while." Dwyer has counted scores of electrocuted carcasses, a plight faced by urban raptors worldwide but one that is particularly prevalent in Tucson for a handful of reasons. His research has come to a few conclusions: Retrofitting the poles with safeguards works, and in the absence of reworking all the poles, targeting poles near nests is the most practical solution. Utilities have retrofitted poles since the 1970s, but research on the success of such measures is scarce. Dwyer's work tracks the electrocution rate, evaluates how well Tucson Electric Power Co.'s bird guards work and provides a strategy for choosing which poles to retrofit.

Why not just fix every pole? "It's just not practical or feasible," Dwyer said. More than 100,000 utility poles are in TEP's system. Bird-guarding one pole costs from $400 to $2,000, so the tab to ratepayers would come to at least $50 million, not to mention the time it would take. "TEP has a huge task ahead of them, but they are making a tremendous effort to do what they have to do," said Bill Mannan, Dwyer's mentor and a professor of wildlife and fisheries science at the UA. "This simply isn't going to be corrected overnight, no matter how much energy, money and time is thrown at it." The poster child for electrocuted raptors is the Harris' hawk, which for behavioral reasons is the North American raptor species most prone to electrocution. The elegant predators are a help to humans in that they prey on vermin, such as pack rats, as well as pigeons and doves. Dwyer's research indicates that electrocution accounts for 80 percent of all Harris' hawk deaths in the Tucson area. "The sad part is, the problem is much more prevalent than we realized, but James' research has affirmed that when you install bird guards adequately and appropriately, they're effective," said Sharon Foltz, director of community relations for TEP. The problem It's not the high-powered transmission lines that electrocute, but the smaller distribution poles that carry lower-voltage power to homes. Transmission lines are normally far enough apart that nothing can bridge that gap, but distribution lines and the equipment that comes with them offer a variety of deadly scenarios. Any animal that comes in contact with two hot wires - or what utility people refer to as energized or phase wires - or a phase wire and a ground completes a circuit that creates a shorter, fatal path of electricity, Foltz said. "People forget how deadly electricity is, because we've done a wonderful job in this country of making it an invisible, available resource," she said. "The reality is that any living thing that gets up there on that equipment has a good chance of dying." New poles are designed safer and are bird-guarded to begin with, and TEP also lays some electric line underground, provided the developer or customer pays for the trench, Foltz said. That still leaves a backlog of poles that have gone up in the last 80 or 90 years, said Joe Sheehey, TEP superintendent of operations. "Nothing was even covered until the late '80s," said Sheehey, who has been at TEP for 31 years. "Thirty years ago, there may have been a small awareness of this problem, but at the time, a raptor was thought of as vermin. People were shooting at them." A haven for hawks Tucson has some unique characteristics that make it a blessing and a curse for raptors. Prey is plentiful, and there are lots of eucalyptus, Aleppo pines and other large trees for raptors to nest in. Just as with people, the mild winters attract them. In other parts of the West, bird-guarding poles is a task made easier due to location and the kinds of raptors in a given area, Dwyer said. Given a choice, a hawk will seek out the highest part of the highest-situated pole it can find, Dwyer said. "In most of the West, the poles that electrocute raptors are in open areas and high ridgelines, so those are the poles you can concentrate on bird-guarding and have some success," he said. "We don't have poles in high places here because we tend to run lines through washes, and we don't really have open places in urban Tucson." Given that TEP can't retrofit 100,000 poles, Dwyer was charged with coming up with a strategy of deciding where the utility could get the most bang for its bird-guarding buck. His solution: Scout out all the Harris' hawk nests you can each year and then retrofit all the poles within about 1,000 feet of each nest. TEP will install bird guards on about 1,500 poles cloistered around 78 Harris' hawk nests identified this year by Dwyer. "It's good to see some effort, but TEP must eliminate the power-line threat to raptors," said Daniel R. Patterson, desert ecologist with the Center for Biological Diversity. "People don't want their power consumption to kill beautiful birds like the Harris' hawk." Why Harris' hawks? All but one species of North American raptors are nonsocial, meaning you'll rarely see more than one bird on one pole, and the bird will almost always seek out the highest place on the pole, which is usually safe. But Harris' hawks live in family groups of up to seven. While the dominant hawk will take the highest perch on a pole, the others will take to lower perches fraught with danger. Fledglings and their mothers are most likely to be electrocuted. "Babies are a big sufferer, because they're clumsy," Mannan said. "A lot of them get zapped on their first flights." Matriarchs are also electrocuted in huge numbers owing to the social nature of the species. Other hawks in the family group will help catch prey, but only the mother will feed the young, Dwyer said. "The prey has to be transferred to the dominant female, and those transfers happen on pole tops, and since the alpha female is involved in each of those transfers, she's the most likely to be electrocuted," he said. The remedy For now, TEP is following Dwyer's recommendations on bird-guarding every pole within 1,000 feet of a nest. Dwyer said that should protect young birds, but he'd like to see the perimeter increased to 1,650 feet to protect adult birds. For the last two years, Dwyer has spent about eight hours a day, six days a week, checking up on nests and walking under power poles. He has a slide show on his laptop computer of dozens of poles and the hazards they pose. To the Harris' hawk, great horned owl or red-tailed hawk - the three species most prone to electrocution - a utility pole is no different from a saguaro or a dead tree, Dwyer said. "Everything in their genes tells them this is a safe place to be, and then they get killed, so there is no learning curve, no 'I got hurt here, so I'm not going to go back,' " he said. "The other birds sometimes see it happen, but they're birds. They don't get it." Dwyer's research has also prompted TEP to use better bird-guarding equipment. "The equipment is getting better, but unfortunately a lot of this stuff is so new that it hasn't really been field-tested," Sheehey said. One piece of protection known as a center phase guard - a 6-foot-long sleeve that insulates the middle wire of a three-wire pole, has been particularly troublesome in the field, Dwyer said. "The brand they were using for the last two years, when I went back to check them, I noticed that most of them fell off in about 30 days, which is clearly not good enough," he said. The company now installs a newer, better phase guard, and also puts protective coverings on other parts of poles due to Dwyer's work, Foltz said. "We didn't know lightning arresters and ground wires could be a problem until James' research," Foltz said. "What he's also done is gone back and checked to see how well these retrofitted poles work, which is something that nobody had studied before." Dwyer estimates that a raptor is electrocuted in the Tucson area every four days. "Last year I could prove that about 100 raptors were electrocuted, and I could show evidence that I'm missing about half," he said. Dwyer's research is funded through the Arizona Game and Fish Heritage Fund and by TEP. The utility had hired on a wildlife biologist but now prefers to work with an independent biologist, Dwyer said. "Some people in the environmental community assumed she had been bought, so it made sense for TEP to funnel its money through Game and Fish and the university, so that TEP is removed from the decisions made by the scientists." Dwyer's research could have far-reaching implications, said Elissa Ostergaard, urban wildlife specialist with the Arizona Game and Fish Department. "One of the things that's become clear to me is that the utilities just really had no idea that this was such a big problem," she said. "There really hasn't been any research quite like this done before, and it has the potential to motivate power companies and regulatory agencies to really change the way they do things." Dwyer will keep checking nests through December, when he earns his graduate degree. "After I'm gone, TEP and Game and Fish will continue to work on this, and they're hoping to hire another grad student to take my place."