Growth of starling population a cautionary tale, says N.S. expert

Environmentalists in Nova Scotia have long warned of the dangers invasive species of plants and animals can pose to native ecosystems.

The European starling is a case in point, according to Kristen Noel, council supervisor at the Nova Scotia Invasive Species Council.

The boisterous European starling, a common sight across Nova Scotia with its dark iridescent plumage, is — as its name suggests — not native to North America.

Predatory aquatic species like the chain pickerel and smallmouth bass were introduced as a sport fish in the 1900s and are now widespread in the province, according to Noel.

Likewise, introduced insects like the hemlock woolly adelgid and emerald ash borer are threatening local trees.

"The starling is a great example of what can happen when you release species that are non-native to an environment," Noel said.

The birds are known to have been introduced into the wild sometime in the 19th century.

Noel said it is thought that the population started with 50 breeding pairs released in New York's Central Park in the late 1890s.

A recent study from Duke University suggests the birds may, in fact, have been released at multiple locations, including Quebec, at various points during the 19th century.

200 million starlings

Today, it is estimated there are around 200 million starlings throughout North America — ranging from Alaska to Mexico.

Much of the starlings' success thriving in their new environment, Noel said, can be attributed to their rapid reproduction rate.

Starlings produce two nests a year with about four to six eggs per clutch, which is more than most native birds, Noel said.

Noel said starlings are generalists when it comes to eating and eat a wider range of items than their native counterparts.

A study from Cornell University in the United States suggests starlings may also have genetic advantages that help them adapt to different environments faster.

Impact

Because of their large numbers and gregarious nature, Noel said, starlings pose quite a few impacts to native biodiversity and agriculture. 

"They're cavity-nesters and ... they'll take over sites from our native species, such as woodpeckers, flickers, flycatchers or tree swallows," she said.

"In agricultural areas they can cause serious damage by feeding on the fruit in orchards or vineyards. And they've also been known to steal grain or feed from livestock."

Colleen Barber, a professor of biology at Saint Mary's University in Halifax, has been studying starlings with her students since 2007. She said there's no consensus about the impact of starlings.

Barber said she has heard claims that the birds are destructive, but she has also seen research that they are not damaging and are well adapted to the ecosystem.

'Almost naturalized'

Given the century-long head start starlings have in establishing themselves, Noel said there is little Nova Scotia can do about the bird that is now "so established and almost naturalized."

Noel said the council focuses on early detection of invasive species so it can create a management plan.

It's a view echoed by Hope Swinimer, founder of Hope for Wildlife, a Nova Scotia-based wildlife rehabilitation and education organization. 

"It's here, and when an invasive species first comes to our province, that's probably the time to tackle the issue," she said

"If they've been here over 100 years maybe now they are so integrated that they're actually in some aspects doing some good."

Hope for Wildlife has rehabilitated and released starlings in the past, as allowed by the Department of Natural Resources and Renewables, she said.

She recalled that someone once dropped off a pet starling that could talk and it "chatted up a storm." After they released the bird, it remained on the property for several years before it disappeared.

"They're quite amazing animals — they really are," she said.

'Amazing birds'

Barber said after studying the species for around 18 years, she, too, has come to appreciate what 'amazing birds' starlings are.

"Both of them care for the eggs and the young," Barber said. "They're incredible parents.

"They each have their own distinct personalities that you get to know. We have birds coming back ... for 10 years. You get to know them and we see them as individuals, not as a pest species."

Barber said after over a century of successful spread, the starling's success may be coming to an end as their population is in steep decline. 

She said this is likely attributable to pesticides and pollution.

Barber said many people, including some of her own students, feel animosity toward the starling.

She hopes people realize they're part of the ecosystem and have a role to play.

"The level of hatred for starlings by some people just catches me by surprise," Barber said.

"It's just such a narrow focus on one bird species that they see as being introduced and ... 'come from away.'"