Double-crested Cormorants are survivors. Once in steep decline due largely to the effects of DDT, the sleek diving birds have rebounded mightily since a 1972 ban on the insecticide. But instead of celebration, their success has brought conflict.
Cormorants are prodigious piscivores, earning them the scorn of commercial and recreational fishers. For years they鈥檝e been the target of government culling programs aimed at easing tensions, which run high around the Columbia River estuary.
Since moving to Astoria, Oregon, in 2017, has been engrossed by the cormorant conundrum. She aims to both document the birds鈥 complicated relationship with humans and capture their beauty and intelligence. 鈥淚 want people to be challenged,鈥 Heim says. 鈥淗ow can we wonder at them and have empathy for them, even if they can be inconvenient?鈥
The Astoria-Megler Bridge spanning the lower Columbia River offers a case study in the cormorant鈥檚 knack for confounding people鈥檚 plans. Until recently, nearby East Sand Island hosted the continent鈥檚 largest cormorant colony, about 15,000 pairs. Each year they devoured some 11 million juvenile salmon and steelhead鈥攃onsuming up to 17 percent of smolts making their way to the sea, some protected by the Endangered Species Act.
To safeguard the fish, the U.S. Army Corps of Engineers and partners in 2015. The next year most remaining birds fled. A major colony has since formed at the bridge, where cormorants hamper renovation work and salmon and steelhead likely make up even more of their diet.
The more than 8,000 cormorants that have taken up residence on the bridge in recent years complicate the current $24 million phase of the repainting project. Hoping to persuade the birds to nest elsewhere, this spring the Oregon Department of Transportation partnered with Wildlife Services, part of the U.S. Department of Agriculture, to haze them with pyrotechnics and other deterrents. Before painting, workers must pressure wash the structure to remove cormorant guano, which is acidic and corrosive.
Photographing the bridge maintenance has opened Heim鈥檚 eyes to the costs and complexities of living with the birds. 鈥淚 think I鈥檓 a little more empathetic than I used to be about the people who are struggling with cormorants being here,鈥 she says. But Heim has also been disturbed by bursts of vigilante violence against the birds; she has watched cormorants fall from the sky after cracks of gunfire.
The Columbia River鈥檚 fishery relies on government subsidized hatcheries that raise and release tens of millions of juvenile salmon and steelhead each year. Double-crested Cormorants have caught on. The birds routinely travel up a tributary, the Youngs River, to gorge on captive-bred fish swimming to the Pacific Ocean.
To limit the casualties, workers at a facility farther downstream wait for a seaward tidal surge before releasing smolts from net pens at night, when cormorants are inactive. Though the birds undoubtedly eat huge quantities of fish, some experts say they鈥檙e unfairly scapegoated for doing what they鈥檝e always done, while dams, overfishing, and other human activities drive fishery declines.
鈥淚t鈥檚 easy to develop the perception that cormorants are having some impact on a fish species we鈥檙e interested in,鈥 says Don Lyons, director of conservation science for . 鈥淚t鈥檚 actually rarely substantiated that that impact is significant.鈥
Although Double-crested Cormorants tend to generate antipathy when they amass in noisy, noisome colonies, an individual bird can inspire a much different response.
In 2015 a wounded juvenile female arrived at the , an Astoria rehabilitation facility. Too injured for release, Cormie has stayed on at the center, charming its staff, volunteers, and visitors, and becoming an ambassador for her species鈥 elegance and charisma.
鈥淓verything about her is amazing,鈥 says Melisa Colvin, the center鈥檚 bird curator. Cormie has been a quick learner. Among her new skills: assisting staff with her health checks and soliciting donations. Colvin always liked cormorants, but forming a bond with Cormie, who excitedly flaps her wings when Colvin approaches, has deepened her belief that the species deserves more respect.
鈥淲hen I look out at those birds on the bridge,鈥 she says, 鈥淚 see her.鈥
This story originally ran in the Summer 2022 issue as 鈥淐onsider the Cormorant.鈥 To receive our print magazine, become a member by .