Research students on Bon Portage Island found themselves in a winged gold mine recently during a bird fallout.
The term is used by birders and refers to the aftermath of severe weather preventing migratory birds from reaching their destination. The exhausted birds often end up resting in one area.
“This kind of setup late in the season can suck birds up from the south, and it just happened that this one was a significant event,” said David Bell, a Sault Ste. Marie native and Acadia University biology student who spent many weeks on Bon Portage Island this summer with fellow graduate student Lucas Berrigan from Jeddore Harbour, banding birds they caught in a net.
The fallout was an incredible experience for them.
“Having flocks of indigo buntings hopping at your feet, and every net run yielding some new vagrant that we might only see once or twice a season in a normal year, is what we normally can only dream of,” Bell said.
“To give it a bit of perspective, in a normal year we see one or two white-eyed vireos; we had 13 one day. I’ve seen two yellow-throated warblers in the past five autumns on the islands; in the fallout we had 11 in a day.”
Netting, banding winged vagrants
He noticed that the setup on Oct. 25 and 26 was similar to a weather system that brought a large fallout of birds in October 1998, with a front moving offshore quickly from Florida, but stalling and “bombing” out over the Maritimes.
“When Lucas found some indigo buntings and a gray catbird on the evening of the 26th, I had a suspicion that we were in for some good birding the next day,” Bell said.
He’s learned over time that Nova Scotia is a great place for finding winged vagrants.
“The average winds in North America converge here, bringing birds from all over the continent into the province,” Bell said.
During the fallout he added two new birds to the list of those he’s spotted on Bon Portage: summer tanager and golden-winged warbler. That’s “something that is tough to do these days as I’ve now seen 269 species of birds on the island. Even better, we managed to capture and band both of them.”
Bon Portage Island, located just off Shag Harbour, is owned by Acadia University and is home to a field station maintained by the school’s biology department. Acadia offers its natural history field course on the island, and it is an important site for student research. The Atlantic Bird Observatory also operates banding stations there.
For Berrigan, the fallout event was definitely the most interesting time he’s spent on Bon Portage, which he first visited in 2006. “But I could even say the best in my days as a birder,” he added.
Berrigan even went out to see new arrivals in the rain at around 4 p.m. on Oct. 26. It didn’t take long before he found the three indigo buntings and a gray catbird; only a small taste of what was to come.
“Rare birds really started pouring in the next morning on the 27th as we started work,” he said. They also spotted six yellow-throated warblers and about a dozen more indigo buntings, a clay-coloured sparrow and a few yellow-billed cuckoos.
On Oct. 28 Berrigan and other students saw 81 species, including 22 types of warblers.
Part of their work on the island included attaching tiny radio transmitter to vagrants. The transmitters send a unique ID to receivers within range. A large network of receivers has been deployed around Atlantic Canada and the northeastern U.S. that allows researchers to track birds.
Bell employs the tags to determine what birds are on the island.