Wednesday, Jan 13, 2016 06:00 am
Crossbills swarm city
Twisty beaks are in this winter, suggests St. Albert’s recent Christmas bird count – crossbills have flocked to town in numbers greater than ever before.
About 162 people took part in the 25th annual St. Albert Christmas Bird Count last Dec. 28, the results of which were posted online last week.
The count was one for the record books, with all-time highs reported for 12 different species, including black-capped chickadees (1,269), pine siskins (249), and bald eagles (three).
Counters spotted some 8,365 birds from 43 different species on count day, said count co-ordinator Alan Hingston.
“The big story this year was the number of crossbills,” he said, with a record 634 white-winged crossbills counted – shattering the previous record of 386 set in 1991.
Red crossbills were also abundant, with an unprecedented 73 spotted this winter (compared to the previous record of 33 in 1998).
The Edmonton Christmas count also reported record numbers of red and white-winged crossbills.
Crossbills are finch-sized birds known for their beaks, the tips of which are twisted so they don’t meet, reports the Cornell Lab of Ornithology. By sticking these tips between the scales of a conifer cone, they can use their powerful jaw muscles to leverage the cones open.
You’ll often spot crossbills fluttering around the tops of spruce trees knocking down cones, Hingston said.
Male red crossbills are brick red while white-winged ones are more pinkish, the Cornell Lab reports. White-winged crossbills also have two white bars on their black wings that red ones lack.
Lu Carbyn, wildlife biology professor at the University of Alberta, suspected that last year’s abundant spruce cone crop was the cause of this crossbill surge.
“There was a lot of food in the springtime, and that means a lot of the nestlings survive.”
Although there were no new species spotted in the St. Albert count (apart from a barred owl spotted shortly after count day), Hingston said spotters did notice a gray jay – the first one spotted in the count since 1997.
The “deceptively cute” gray jay has a round head and solid gray feathers, reports the Cornell Lab. It’s known for sticking food to the underside of branches with its spit and stealing food from campers.
Information from the count will now be sent to Bird Studies Canada to track trends in bird populations.
Count results can be found at sacbc.weebly.com/results.html.
A St. Albert researcher has discovered that chickadees have regional accents.
Chris Sturdy, a St. Albert resident and psychology professor at the University of Alberta, has a paper out this month in Animal Behaviour on how black-capped chickadee songs vary by region.
While researchers have previously found regional accents in birds such as white-crowned sparrows, Sturdy said they had long assumed that all black-capped chickadees sang the same two-note “fee bee!” song to demarcate territory everywhere – the only ones that didn’t were in two tiny spots in the U.S.
But when they did detailed analyses of chickadee calls from B.C. and Ontario as part of a different project, Sturdy’s team found subtle differences between them akin to regional accents.
“We can’t tell the difference just casually,” Sturdy said, but the B.C. calls appear to be slightly longer.
Sturdy’s team used Alberta chickadees to see if they could tell the difference between these accents. The birds were trained to stand on a perch in exchange for food if they heard particular calls from B.C. or Ontario chickadees. When the team exposed these birds to a different set of B.C. and Ontario calls, the birds reacted to them as they had been trained – they had learned to recognize all B.C. or Ontario-type calls instead of just memorizing particular ones.
Sturdy said he’s not sure how the birds tell calls apart, but suspects that the length of each is a factor.
Sturdy said that telling accents apart could help birds find mates whom are adapted to the local environment. Other research suggests that humans rank people with accents similar to their own higher than those with different ones.
He now hopes to study the size of these accent zones to determine if, say, St. Albert chickadees sound different than Edmonton ones.