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Crows are part of raptor crew
Al Grass
Contributing Writer
Have you ever strolled along a woodland trail where the only sounds that you hear are the rustling of leaves, and the lonesome croaking of a tree frog?
Or perhaps you've been watching a flock of mixed ducks dabbling along the shore, only to have them suddenly burst into a swirling cloud in a state of panic. In both cases it is probable that a raptor flew past, or is lurking about.
Another common sight on the North Shore is a flock (called a murder) of crows diving at a tree, and cawing madly. This "mobbing" behaviour means that the crows have discovered something, often a hawk or an owl. It might be a Cooper's hawk, red-tailed hawk, or even a raccoon, raven or somebody's pet cat. It's always a good idea to follow the crows and see what there are doing. I recall vividly the day at Maplewood Conservation Area when we saw a beautiful great horned owl thanks to the crows; they didn't let us down.
Talons do tell the tale, or at least part of it, along with the bill, wing, tail shape and keen vision. All of these features make raptors superbly suited for their roles as hunters.
The North Shore, and particularly the Conservation Area at Maplewood, affords excellent raptor viewing opportunities. Your backyard, however, is a good place to start, especially if you feed wild birds.
Bird feeders attract several raptors locally, including the Cooper's hawk (most common), sharp-shinned hawk, and merlin (a small falcon). The Cooper's and the sharpie (short for sharp-shinned) are a type of hawk called an accipiter that specializes in hunting small birds and, to a lesser extent, rodents. The Cooper's hawk, for example, takes pigeons, squirrels and rats.
The red-tailed hawk is a typical buteo, with broad wings and a broad fan-shaped tail. This is the species that is often seen circling (and screaming) high, or as someone said, "Drawing lazy circles in the sky."
The locally rare rough-legged hawk, a buteo, is a winter visitor from the far north. The light-phase colour of the rough-leg is sometimes mistaken for a bald eagle at a distance. It is a good reminder that raptors can vary a great deal in colour, from very light (light phase) to very dark (dark phase), adult versus immature birds. Locally, the red-tail has many variants, so it pays to check each bird carefully.
Another local raptor often seen soaring high above is the bald eagle, especially if there are air columns to ride on. A good place to watch eagles on the North Shore is the tidal flats at Maplewood Conservation Area.
Here, they are often seen perched atop dolphins and pilings. Not all the eagles that you see will have white heads and tails. Some are immatures that are various shades of brown. It takes four to five years for a bald eagle to develop its white head and tail. Be careful about trying to turn an immature bald eagle into a golden eagle (locally very rare). One clue is that the legs of a bald eagle are bare, whereas they're feathered to the feet in the golden eagle. This is where a good spotting scope comes in handy.
Accipiters have been mentioned as regular backyard birds, but they are seen anywhere food is available. Cooper's and sharp-shinned are the two locally common species, with a third, the northern goshawk, being locally rare.
The speediest raptors are the falcons, with two species, the peregrine falcon and the merlin, as regulars. It is said that the peregrine can reach speeds of 320 kilometres per hour in a dive (called a stoop).
Small waterfowl, like green-winged teal, and shorebirds are on the bill-of-fare of the peregrine. The smaller merlin, once known as the pigeon hawk, hunts for small birds, mammals and even dragonflies. You can identify falcons in flight by their pointed wings and long tails shaped like a fighter plane. The northern harrier, once called the marsh hawk, is often seen cruising over fields and meadow, hunting for voles in its special coursing, undulating flight. A large, white rump patch and wings that are held in a V identify this harrier.
The male and female harrier are coloured differently, with the male a ghostly grey with black (dipped in ink) wing tips, and the female a rich brown. Its habitats are grassy fields and meadows, such as Maplewood's, which it shares with the short-eared owl, rough-legged hawk and western meadowlark.
Two bird species that hunt but are unrelated to raptors are the turkey vulture (a relative of storks) and the northern shrike (a songbird). Both have talons and hooked bills, which are adaptations similar to those seen in raptors.
Standing on the shore at Maplewood's Osprey Point, you can see the nest of our beloved ospreys, which have left us for the winter. But this beautiful raptor, once called the fish hawk, will be back next spring. We can't help but wonder where our ospreys are now, perhaps on a sunny beach in Mexico, or hunting fish along some jungle river.
The total number of raptor species on the new (2006) bird checklist for the Conservation Area at Maplewood is 13, and when you include the turkey vulture and northern shrike, it's 15.
Al Grass is a naturalist with Wild Bird Trust of British Columbia, which sponsors free walks at Maplewood Flats Conservation Area on the second Saturday of every month. The next walk is Saturday, Nov. 11. We will look for the raptors in their special habitats. Meet at 10 a.m. at Maplewood Flats, 2645 Dollarton Highway (two kilometres east of the Iron Workers Second Narrows Memorial Crossing). Walks go rain or shine. Website: www.wildbirdtrust.org.
published on 11/08/2006
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