Groups of turkey vultures headed for the southernmost tip of Vancouver Island during fall migration south are capturing the attention of outdoor enthusiasts across Greater Victoria.
This is prime time for Cara Herrington, a UVic PhD working with Duncan wildlife sanctuary The Raptors to study the birds and their migratory habits.
She has a team of volunteers posting up on the Aylard Farm beach most days, peering through binoculars and scopes, seeking out the kettles – think flocks – of turkey vultures.
The raptor is in its peak migratory window right now – continuing through the end of the month – and a bottleneck point in East Sooke affords a great place to watch and learn.
“At this time of year, we will easily count at the one viewpoint up to 1,000, but we know there are a few different areas on the coastline where there could be more, so it’s hard to get a hard and fast number,” Herrington said, noting the nearby Rocky Point Bird Observatory once counted 2,500 in a day.
The birds come up to B.C., and specifically Vancouver Island, to breed and enjoy the high biodiversity here each spring through summer before heading back to Mexico in the fall, “to avoid the winter months in this area.”
The vultures rely on passive forms of lift, columns of warm rising air and wind deflection off hills and rivers. Mainland birds don’t have to worry about crossing a body of water, but the Islanders face that daunting task each fall.
“They don’t have that physical capability … to just flap across the water,” Herrington explained. “The birds that are here on Vancouver Island, the landscape features of the Island are going to sort of funnel them to that tip (at Rocky Point).”
At that point, they hit a barrier – the Strait of Juan de Fuca.
“You get all of these vultures congregating and waiting for ideal weather conditions to reduce the risk for the crossing.”
There, they have the shortest distance to cross, but it’s still crossing 20 kilometres of water, so the raptors kettle and wait before taking the leap. What they’re waiting for, wind strength, direction and other variables to give them some help along the way, is what Herrington and her team hope to learn by watching and documenting.
Pacific Northwest Raptors in Duncan is spearheading her study to determine a specific set of weather variables the vultures are looking for – if it’s a sweet spot or range of variables the birds rely on. This research helps us understand vulture migration but also highlights if and how climate and geography interact to shape movement, survival and species persistence.
Living in the Mesachie Lake area, Herrington is happy to have the diverse group of volunteers doing the observation work at Aylard Farm beach. The site looks across Beecher Bay to Rocky Point. “That’s where we can see that congregation of turkey vultures happening.”
Volunteers are on the beach daily from 10 a.m. to 4 p.m. – in good flying weather – and visitors are welcome to borrow some binoculars and ask questions.
