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Group of Ravens Find Pecking Playground in New England Power Substation

Aug. 5, 2019
Ravens flocked to a New England substation, hopping from tower to tower and pecking at shiny objects that caught their attention. Here is how GZA was able to safely deter the ravens from the site.

We’ve known for centuries that corvidae are unusually intelligent animals. It’s no coincidence the Norse pantheon has two ravens named “Thought” and “Memory” on Odin’s shoulders. That intelligence, however, can collide with the built world in some unexpected ways.

 A power substation located in New England found itself with an unusual number of outages, beginning almost immediately after the substation was constructed. There was no obvious flaw in the equipment, and diagnostics found it should be in working order. The problem, it turned out, was that the substation and surrounding area was a playground for young ravens, in an area perfect for flocks to thrive. The area had several sources of food, such as farms and refuse from nearby homes and businesses, that catered to their omnivorous diets. And while ravens have predators, particularly red-tailed hawks, broad-winged hawks and great-horned owls, those were relatively rare in the area and generally prefer small mammals or smaller birds. The raven’s intelligence play into this; they’ll remember animals, including humans, and react according to past experiences.

 Transmission lines to the substation allowed juvenile ravens to “hop” from tower to tower, following the treeline. We observed play behavior in the field, with ravens lazily circling the towers. And at the bottom were shiny objects, including switches, buses and heat insulation, the young birds found a delight to peck at. The concern was both for the utility’s customers and the animals, who were at risk of electrocution.

 The utility tried multiple strategies to drive off the ravens, including protective equipment covers and scarecrows, in the form of “air tube men,” but they were simply too curious to be put off by the covers and too smart to be fooled by the scarecrows. GZA was brought in to find an effective solution to let the birds and the substation coexist.

 First, we had to find and analyze the ravens, which took quite a bit of effort, including field interviews of local residents and tracking the flight path of ravens in an approximately five-mile radius. Once we determined they were engaging with the substation as a place to play, the question became how to deter them effectively. Research into ravens, and interviews with experts such as Professor John Marzluff, found several effective strategies.

 Key to raven deterrence is encouraging a fear response. The flock remembers dangerous areas; a behavior notorious on social media, with a flock circling a dead member, may be the birds noting possible danger. To this end, “dead ravens,” really feathered dummies, and loud noises such as propane cannons and horns, can be used to associate a place with danger in their minds without causing any injury. Another approach is to “tag” them with lasers, which causes no harm but agitates them enough to relocate them, an approach most popular in the Mojave to protect baby tortoises. These lasers can also be operated remotely, such as Raven Repel.

 The work of integrating a substation with the local wildlife is ongoing. But this offers a valuable lesson, that wildlife is full of surprises, and sees the things we build in a very different, and sometimes playful, light.

About the Author

Tracy Tarr | senior project manager

Tracy Tarr is a senior project manager at GZA. 

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