Grab Your Binoculars!
The Mt. Sutro Open Space Reserve offers mystery and intrigue to those willing to explore its century-old trails. This lush forest is home to a most beautiful and vocal raptor, the Red-shouldered Hawk (Buteo lineatus). Because of its habit of watching with a sharp eye while hiding quietly in the canopy above, the silent, still presence of the Red-shouldered Hawk adds to the mystery of the Mt. Sutro Preserve. It is probable that, as you wander the paths on Mt. Sutro, the Red-shouldered Hawk is perched above, waiting and watching. Only its head, with large and sharp eyes, moves about, showing bright attention. When the perched hawk is seen from below, its cinnamon-colored breast and belly, its striped tail and its black wings dappled with white are visible. In the past this was called the Red Hawk. The Red-shouldered Hawk is more often perched than in flight.
This hawk is classified as a broad-winged hawk, known as a buteo. The buteo shape is shared with vultures and eagles. The Red-shouldered Hawk is also recognized by its quick and choppy wingbeat. The wingspan of the Red-shouldered Hawk ranges from 37 – 43 inches. The female is larger than the male. The other broad-winged hawk that the sky-gazing public can often see is the larger Red-tailed Hawk which soars prominently in the skies above the neighboring hilly neighborhoods, parks and open grasslands.
The Red-shouldered Hawk is among the most vocal of the American hawks. This hawk will emit a series of loud calls, an upward-raising kee-aah, particularly during mating season. Often the hawk will be perched when calling, therefore making his presence known to the bird watcher. This call is often imitated by another bird, the Steller’s Jay. During mating season, the Red-shouldered Hawk will be seen making tight raising circles in the air, flapping and gliding while giving voice to his presence in the territory that he claims.
I was able to see a Red-shouldered Hawk calling and circling on the wing above the Mt. Sutro Nursery this past week in late February. The bird could be seen above the forest canopy, his finely streaked cinnamon breast and belly aglow, wings and tail patterned with dark and light stripes, calling for attention as he circled. The brick-red patch on the shoulder that gives this hawk its name was difficult to see from below.
Red-shouldered Hawk (left) and Red-trailed Hawk (right)
The Red-shouldered Hawk is seen year-round on Mt. Sutro. Mt. Sutro may have resident birds that nest here. If so, nesting occurs in the summertime. The young hawks fledge in July and August, dispersing north, east and south. During the summertime molt the adults are least conspicuous.
The combination of broad and relatively short, rounded wings and a long tail allows the Red-shouldered Hawk to have extreme acceleration and maneuverability when chasing for prey that hides in the vegetation of the Mt. Sutro woods. The hawk is diurnal (active during daytime). Using his strong hooked beak and talons, he catches and eats meat: squirrels, frogs, reptiles and small birds. Perhaps the recent drenching rains that followed years of drought will lead to a proliferation of prey in the coming months. Sometimes the Red-shouldered Hawk will be seen on the ground, picking up earthworms after a rain. Meat is dense in protein and fat and is easily digested, very different from the nutrients of a vegetarian diet.
The Red-shouldered Hawk is found throughout the eastern half of the United States. The hawk found in the east is much less red than the bird found in the west. On the west coast, a land with much less water than the east, the Red-shouldered Hawk’s territory is much more confined than in the east. The Mt. Sutro Reserve is an important part of the western riparian woodland territory that this hawk is designed to inhabit. The Sutro Stewards’ effort to restore the Mt. Sutro Preserve is a key part of conservation of the most beautiful Red-shouldered Hawk.
To learn more and to hear a recording of its call, go to the following link:
Peeters, Hans and Peeters, Pam. (2005). Raptors of California; California Natural History Guides. University of California Press.
Sibley, David. (2000). The Sibley Guide to Birds. Chanticleer Press, Inc.
Photos from www.canstockphoto.com