Birders fooled by imposter Bullock's oriole in Pakenham, Ont.

Hundreds of birdwatchers flocked to Pakenham, Ont. to catch what they thought was a glimpse of a west-coast oriole far from its normal range — but the results of a DNA test show they were mistaken.

DNA test shows bird is at least part Baltimore oriole

Spotted in Pakenham, Ont., in the fall, this small bird was believed to be a Bullock's oriole. DNA testing, however, has proved otherwise. (Michelle and Paul Martin)

Hundreds of birdwatchers flocked to Pakenham, Ont. to catch what they thought was a glimpse of a west-coast oriole far from its normal range last fall.

It turns out they were mistaken.

What was believed to be a female Bullock's oriole was first spotted in late 2015 and rescued from frigid temperatures earlier this month after being found, weak and thin, lying in the snow under a tree.

It tricked all of us.- Birder and researcher Jeff Skevington

Jeff Skevington, a fly researcher by day and an avid birder in his off time, decided to test the bird's mitochondrial DNA.

His preliminary results identify it as a Baltimore oriole, which has a breeding range that includes eastern Ontario.

Still, the young bird's resemblance to a Bullock's oriole leads him to believe that it may be a hybrid.

"It's fun for the field craft, too. I think it goes to show that not every bird can be comfortably identified in the field," he said.

Skevington travelled to Pakenham to see the bird — and at the time believed himself that it was a Bullock's oriole.

"It tricked all of us," he said. "It's always painful to take something off your list."

'Future of birding'

Bird writer and columnist Bruce Di Labio helped save the bird on Jan. 5, driving it from Pakenham to the Wild Bird Care Centre on Moodie Drive in Ottawa for treatment.

Before leaving the bird at the centre, he collected samples of its droppings to pass along to Skevington in the hopes of confirming its identity for provincial records.

Jeff Skevington, a fly researcher at Agriculture and Agri-Food Canada, tested the DNA of a suspected Bullock's oriole. He found it was not a pure Bullock's oriole. (CBC)

The samples provided mitochondrial DNA, which allowed for the testing of maternal genes — which in this case proved the bird is "definitely" not a pure Bullock's oriole,  Skevington said.

Additional testing of its nuclear DNA, which includes maternal and paternal genes, would provide more conclusive results, Skevington said.

The results of the DNA test doesn't bother Di Labio.

"That's one of the fun parts of birdwatching — you're always learning something new," he said. "This may be the future of birding. We're all going to have our little own DNA kits ...  with some kind of mechanism to capture the bird, take some blood and feathers and confirm it to what it is."

Di Labio added that the results will also call into question other rare sightings of Bullock's orioles, including a recent encounter in Nova Scotia.

As for the Pakenham bird — whatever it is — it's expected to remain at the Wild Bird Care Centre until the spring, when it will be released back into nature.