I have recently become addicted to a Facebook page entitled ‘What’s this Bird?” People from all over the country (and sometimes from other parts of the world) post photos of birds they’ve seen that they want help with identifying. Often the birds seem obvious and would, it seems, be immediately apparent if the poster had leafed through a field guide. Occasionally, and these are fun to see, people will share photos of extremely rare birds. These will get computers and phones abuzz as birders ask for more details and make travel plans.
The most famous of these “What’s this Bird?” rare finds is undoubtedly the great black hawk discovered in Maine in August. I was online when the first request for identification came through, and it was an education and very entertaining to see the first stabs at figuring out this second record for the United States. There were quite a few back and forths before the true identity of the bird was revealed, and then pandemonium ensued.
There’s an interesting postscript on this bird. The hawk remained in Maine after its discovery, and this week it was discovered on the ground and close to death after a blizzard had moved through Maine. It was picked up, taken into rehabilitation and ascertained to have severely frostbitten toes. Tropical birds thinking of wintering here, take note.
There is one pair of birds that features on “What’s this Bird?” daily, and this is the sharp-shinned and Cooper’s hawk. I find these birds easier to separate in the field than by looking at photographs, but it’s fun to try to put a name to the picture before reading through the comments. These birds are indeed similar and belong to the Accipiter genus.
The Cooper’s hawk is the larger of the two and is the one most commonly seen in Santa Barbara. Size isn’t always a good way to distinguish these birds because a male Cooper’s can overlap in size with a female sharp-shinned. A male sharp-shinned is quite small, not much bigger than a robin. A female Cooper’s is large, about crow-sized.
I’d say I see 10 Cooper’s to every sharp-shinned. It wasn’t always this way. The Cooper’s hawk was formerly an uncommon breeder in the canyons of our county, but in recent years, the population has exploded as the hawks seem to have realized that there was a niche to be filled in suburban and even urban areas. If you see an accipiter hawk in the summer months, it will be a Cooper’s; sharp-shinned move out early in spring and have not been known to nest in the county.
These hawks have long tails and short wings, ideal for agile hunting in woodland — and backyards. If you have a hawk terrorizing the birds at your feeder, chances are it’s one of this pair. Both fly with snappy wing beats and glides, and will circle at altitude when on the move; it’s at such times that good identification features can be readily seen. The sharp-shinned has a comparatively tiny head and bill, and when soaring, the wings are pushed forward, accentuating the small-headed look. The tail feathers are all the same length, which gives the sharp-shinned’s tail a square-edged look, whereas those of the Cooper’s are graduated, giving the tail a rounded appearance.
When you come across a perched bird, structural features are good clues. Cooper’s has a flat-topped crown, giving its head a blocky look, whereas the sharp-shinned has a rounded head. An adult Cooper’s has a dark cap, accentuated by a pale nape, while its cousin lacks the capped appearance.
There are many more subtle features that help separate these two, and if you’re interested in these, I’d suggest checking out “What’s this Bird?”
Hugh Ranson is an active birder with 36 years of experience in Santa Barbara County. His column appears Saturdays. Email him at firstname.lastname@example.org.
This sharp-shinned hawk shows a square-edged tail and is holding its wings forward, both good features to distinguish it from the Cooper’s.