Massive ring of birds captured on radar sparks interest in Long Point birds and migration
In the ornithologist world, a spark bird" is one which ignites passion and interest.
For Birds Canada field technician Julia Marshall, it was the female belted kingfisher, who features a bright orange breast band in defiance of traditional colourful male plumage.
And she's quite fearsome," smiled Marshall, who enjoys boisterous rattling belted kingfisher calls and the bird's ability to zip down in flight and grab fish from the stream."
The recent social media post of a U.S. National Weather Service Station radar signature of an estimated 500,000-member bank and barn swallow and purple martin roost ring" (or bird doughnut) over Long Point also sparked fascination, along with the hope it will lead to a deeper understanding of a unique area and the birds whose very existence is inextricably linked to it. For example, that the size and beauty of the bird doughnut" may obscure the fact numbers of aerial insectivores - birds that feed on insects while flying - have fallen an estimated 59 per cent since the 1970s.
The annual bird migration
Their migration is an annual phenomenon, says Long Point Bird Observatory acting program manager Kyle Cameron. Roost ring radar impressions of massed dawn takeoffs appearing as an outwards-expanding doughnut ring" have been used for quite some time" to help identify area bird populations.
This one in particular was quite large and really grabbed some attention," he said. It was pretty exciting to see it, and to see so many people get excited about birds from it was the really exciting part."
Long Point doesn't give up all her treasures so easily - the ring roost location was far less accessible than the Long Point causeway's Big Creek National Wildlife Area's viewing platform. But the point" was generous enough to offer a passing bald eagle, northern harrier, multiple great blue and a green heron or two, along with the mixed wingbeats and calls from flights of red-winged blackbirds and common grackles. Amid the encroaching darkness, the experience brought to life something similar to the numerically vast, sky-darkening, tornadolike vortex of a half-million chattering calls backdropped by one million beating wings captured on a radar screen.
Just to see that many of one species, just to see that many birds even, it's just a spectacle, really," said Marshall.
Deafening," added Cameron, who has seen flocks of purple martins transform a line of dead trees into what appeared to the naked eye to be live foliage.
And then, all of a sudden, the leaves fly into the air and you realize it's all birds and it's quite amazing."
Aerial insectivores occupy a unique avian category. They are sociable, vocal birds with the incredible acrobatic ability to take prey on the wing.
They're nature's insect control, if you will," credits Marshall.
Bank swallows burrow into banks or cliffs along lakes. Barn swallows, also as their name suggests, tend to create nests inside barns or other structures. Purple martins, who historically colonized holes in dead, old-growth trees, are now dependent on artificial bird hotels.
They rely on those almost exclusively to live and breed," says Cameron.
Overwintering in the Amazon basin, Martins nesting in our area make the tortuous flight northward in the spring. Causes for return migration include shorter fall days and dropping temperatures, factors tied into their biological clocks and instinct, corresponding to fewer insects and a diminishing food supply.
Those are all things that start to make them want to go south," Cameron explained.
Birds Canada staff watch for light northerly tailwinds on clear nights, conditions helping push migration, birds percolating out of nowhere, making little chirps" as they pass in the darkness.
An exciting time of year, for sure," said Marshall.
Why so many birds in Long Point?
Long Point is a crucial migration stopover or staging area - effectively an avian service centre offering fuel, rest and the opportunity to minimize flight time over water.
We end up with hundreds of thousands of these swallows in one area coming in to roost every night, to sleep in the reeds out along the point away from predators," says Cameron.
Social birds to begin with, strength in numbers provides additional incentive to congregate.
You're less likely to be picked off if you're one in a million, and there's also a million others to tell you about a threat that's coming in," Cameron explains.
A you go, we go" mentality extends to a communal morning takeoff instigated by a few early birds, into a swarming flock large enough to show up on weather radar from the other side of the lake.
We see this doughnut that's happened overtop of Long Point, but every night during fall or spring migration you can actually see these birds really explode on a weather radar heading south or north, depending on the season," said Cameron.
The swallows and martins tend to begin to group up early in August, he continued, and are typically gone by early September in a gradual progression of arrival, staging and departure, maintaining a significant yet ever-changing population through the period.
Some of that will keep moving south until we get fewer and fewer out there and then they'll all be gone for another year."
We've got to do something'
Birds Canada's monitoring of both spring and fall migration includes daily staff meetings to compare and co-ordinate visual observations. Secondly, Long Point Bird Observatory banding stations at Long Point's tip (operational since 1960), roughly halfway out at the Breakwater, and at Old Cut (open to the public until noon during banding season) humanely capture birds in mist nets. The birds are then sexed, assessed and banded with a unique nine-digit code providing insight upon potential recapture.
It also allows you to look at trends, rises and decreases in populations and kind of evaluate what could possibly have been going on in their environment," said Marshall.
As crucial as data compilation, interpretation and action are however, Cameron emphasizes the importance of Birds Canada public education and outreach. The organization (BirdsCanada.org) welcomes and relies on citizen science initiatives including Christmas bird counts for adults and kids, Project Feeder Watch, the breeding bird atlas, virtual and in-person field trips, banding station access and the Young Ornithologist Workshop. And if an impressive ring roost's foray through social media helps that effort take flight, all the better.
I think it's really great to use that attention in order to help people understand birds a bit more," said Cameron, hoping enthusiasm for deeper comprehension has been sparked. And once people understand birds a little bit more, the desire to conserve them just comes hand in hand with that."
Excitement generated by the ring roost should not obscure the fact over half the population of aerial insectivores has been lost over the past 50 years, he concluded.
That's our canary in the coal mine really telling us we've got to do something because things aren't going too well for them. And that means things won't be going well for all sorts of other things, including people."
Special to The Spectator