Nova Scotia

Crow roost will likely survive nearby development, experts say

Two bird observers say the crows' overnight roosting area is not threatened by tree clearing

Two bird observers say the crows' overnight roosting area is not threatened by tree clearing

Two longtime observers of a crow roost on the Mount Saint Vincent University campus say birds may have to find new trees for their pre-roost socializing, but their overnight sleeping quarters aren't at risk. (Robert Short/CBC)

A longtime roost that's home to thousands of crows in Halifax will likely survive the construction of a large housing development next door, say two bird observers.

Up to 9,000 crows sleep overnight on the trees at Mount Saint Vincent University, and have done so for at least 60 years.

Residents became worried about the birds when tree-clearing began for the Seton Ridge development, a Southwest Properties project that will include single-family homes, townhouses and multi-unit mixed residential/commercial buildings ranging in height from six to 16 storeys.

The 25-hectare development will be home to about 7,000 residents when it is completed in eight to 10 years.

Fred Harrington, a retired professor who taught animal behaviour in the psychology department at Mount Saint Vincent University, said it's unlikely the crows will be deterred from their roosting spot by the development.

"It's very difficult, very difficult to convince birds to go elsewhere," he said. "It really takes a lot to move a roost."

Land next to Mount Saint Vincent University is being cleared for a large housing development called Seton Ridge. (Frances Willick/CBC)

Harrington said the crows fly in just before dusk and "socialize and get ready for bed" in the areas surrounding their roost. Then, as night falls, they fly to the trees at MSVU to sleep overnight.

Since the crows didn't sleep in the forest on Southwest's property, the tree-clearing won't affect the long-term roost, Harrington said. If the crows ever did used the now-removed trees as a "staging area" before they flew to their roost, they will now simply find a new area to hang out and socialize in.

"They're going to be staging wherever they can in the local area.… They're going to be on neighbouring trees. So they may now move from what used to be just woods to what is now woods and houses," Harrington said.

The crows have previously had disruptions to their pre-roosting and roosting areas, including when Hurricane Juan blew down hundreds of trees in 2003 and when the university constructed new buildings.

"There's always been this gradual encroachment of civilization," Harrington said.

An aerial shot of the planned Seton Ridge development shows where the buildings will be constructed. (Southwest Properties)

Bob McDonald is an avid birder and has been monitoring the crow roost for 30 years. He conducts an annual count of the crows at the university and took a keen interest in them during his long tenure there as chemistry professor.

"The crows are going to survive this," McDonald said. "Crows are extremely successful birds."

He said he visited the development site with Southwest chairman Jim Spatz and president and CEO Gordon Laing, and recommended they preserve the trees around the pond on the property — something the company has said it plans to do.

"They are quite flexible," McDonald said of the crows. "There's still lots of trees in Clayton Park. So whether people enjoy their company or not is another matter."

McDonald pointed out that the crows do not use the roost as a nesting area.

The councillor for the area, Russell Walker, visited the development site and crow roost recently and said he only observed the birds using the surrounding areas.

"When I was there, not one crow stopped on Southwest property," he said.

Nonetheless, Walker said he will make some more visits and monitor the crows' patterns to see if anything changes.

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