Killing One Animal To Protect Another

Wildlife agencies sometimes kill animals that are preying on rare species.

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Some Black-crowned Night Herons have been killed on Faulkner Island to protect the federally-endangered Roseate Tern.
Photo:Nancy Eve Cohen
Great Egrets fishing on Charles Island in Connecticut
Photo:Nancy Eve Cohen
Charles Island in Milford, Connecticut
Photo:Nancy Eve Cohen
Jenny Dickson and Julie Victoria of the CT D.E.P. put up signs to protect rare birds and nesting habitat on Charles Island.
Photo:Nancy Eve Cohen
Charles Island used to have more trees before deer arrived.
Photo:Nancy Eve Cohen
D.E.P. staff put up fences to protest nesting habitat.
Photo:Nancy Eve Cohen
Charles Island
Photo:Nancy Eve Cohen
Killing One Animal To Protect Another
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Killing One Animal To Protect Another

Many birds are now in the midst of nesting. When it comes to rare birds state and federal wildlife managers take extra care to protect them and their young. WNPR’s Nancy Cohen reports at times  biologists take extreme measures,  such as killing certain animals to protect a rare species.

It’s foggy morning on Charles Island off of Milford Connecticut. Wildlife biologist Jenny Dickson, with the Department of Environmental Protection, points up at a big, white bird nesting in the canopy of a tall tree.

“if you look through these trees right here there’s a Great Egret. It just flew off the nest and perched on branch in the open. He just took flight.” 

These large birds need the tippity tops of trees so they have room to fold their long legs and broad wings into their nests. But part way down the trees, about 20 feet off the ground there are no branches or leaves, That’s where smaller birds, that are rare in the state, used to nest.

“Some of the species we’ve historically had nesting on the island includes Glossy Ibis, Little Blue Herons.  Those are all birds that like the mid-canopy layer of habitat. And since that layer is no longer here, we’ve seen them either decline or completely disappear.”

Dickson says deer are mostly to blame. Deer came to the island by walking on a sandbar from Milford. Dickson say the deer ate twigs, buds and leaves. It changed the island

“It certainly made a lot of the existing trees more susceptible to winter storms, more susceptible to fungal invasion, more susceptible to out-competition from invasive species.”

Every spring the Department of Environmental Protection puts up fences to keep deer away from the trees. But this winter, the D.E.P. took a more extreme step. They shot and killed the deer.

“That was something that we thought long and hard about. Were there other ways that we could have managed that? And the most effective way was actually to do a controlled hunt out here, essentially, with trained staff to remove the deer that needed to be taken off  the island.”

They killed 17 deer. Dickson says the goal was to protect state listed birds. And their habitat. There are only a few islands like this, that aren’t developed, where these birds can nest.

“It’s always a hard decision  when you’re making choices because you’re really trying to say, ‘alright which species should we give priority to?’ It’s a little, I don’t want to say easier, it’s a little clearer  what kinds of decisions you need to make when you’re dealing with listed species, very few nesting areas, and other issues going on too.”

These species are more at risk because they nest in groups, called colonies. So all their eggs are essentially in one basket, on one site. If the birds leave the island due to habitat loss, they might not come back.

Audubon Connecticut supported the killing of the deer to protect the rare species. But the animal advocacy group, Friends of Animals protested against it.

“Deer are throw away animals and the ones we’re going to cherish and covet are the ones that are almost all the way extinct. I think this is a sham.”

Priscilla Feral, President of Friends of Animals, says shooting the deer may not even solve the problem because more deer could walk to the island. She says the D.E.P. could have intervened by removing the invasive plants that were affecting the habitat, rather than the deer.

 “The removal of Oriental Bittersweet and invasive Barberry. That’s an intervention. It just doesn’t involve a gun. I’d like them to go about the business of being environmentally sensitive without a gun.”

The D.E.P. plans to remove the invasives after the nesting season is over.

White tailed deer are very abundant, in part because people have eliminated their predators and created suburbs, where deer thrive. But sometimes animals that aren’t as common will threaten an endangered species. That’s been the case with a few Black-crowned Night-Herons.

Rick Potvin, Refuge Manager with the U.S. Fish and Wildlife Service says the herons fly at night to Faulkner Island, to prey on the young of the federally endangered Roseate Tern.

“They prefer to have the embryo  developing in the egg. So what they’ll do is enter the colony and they’ll split the egg open with the beak.  They’ll also take live chicks.”

In 1996, when the herons began going after the terns there were 157 nests of Roseate Terns on Faulkner. Now there are 44.  It’s the only nesting colony of Roseate Terns in Connecticut.

The Fish and Wildlife Service has tried to protect them. The staff have removed vegetation so the terns can see their predators and defend themselves. The agency provided nesting boxes and shelters to protect eggs and chicks.  They also harassed the Black-crowned Night-Herons, by shining laser lights on them. But Potvin says it wasn’t enough to stop the predation. He says killing some was the next step.

“I think we have  taken as many as eight birds in a season and as few as one bird in a season. We try just take as many that will give us the desired result, which is to stop predation on our Roseate Terns.”

Potvin says if the agency didn’t kill the individual predators he believes the tern colony would disappear, bringing the bird closer to extinction.  But at the same time the Fish and Wildlife Service is restoring habitat on other islands for the Black-crowned Night-Heron.”

“The Black-crowned Night-Heron..they’re certainly not doing anything wrong. They have to eat too.”

This kind of human intervention begs the question: is nature natural anymore? Ecologist Robert Askins from Connecticut College says humans have modified nature for thousands of years.

“In the last two or three hundred years our effects have become so profound that we’ve put a lot of species at risk of extinction. And I think we have a responsibility to pull these species back from the edge.”

Wildlife managers say they intervene to create a new balance in ecosystems that are out of whack because of humans. Sometimes it means killing an animal, even the 25-inch tall Black-crowned Night-Heron, with its showy white plumes. Again Robert Askins.

“If I had to make the decision I would also find it a tough decision. But I think the future of an entire species would outweigh having to kill one or two individual Night Herons.”

Since the herons were killed the Roseate Tern population has begun to stabilize on Faulkner Island. Rick Potvin says the goal now is to help the population grow and eventually remove this bird from the endangered species list.

For WNPR I’m Nancy Cohen.