The Sharp-shinned Hawk & California's Raptor Diversity

Winter is the season for raptors in California's Great Central Valley, as a number of species move south in latitude and down slope from the Sierra Nevada mountains to spend the coldest months in the Valley's mild climate.  On a really good day birding across the Valley's wetland and grassland habitats, it is possible to encounter an astounding FIFTEEN species of diurnal raptors (also known as birds of prey.)  And that's not even including at least an additional FIVE species of nocturnal raptors: the owls!

The Valley's diverse mosaic of habitats, which includes wetland, grassland, farmland, oak woodland, riparian forests, and even suburban neighborhoods provides an abundance of specialized niches and prey to support this wide array of species.  

Around open bodies of water, look for Osprey and Bald Eagles.  

On open grasslands, keep an eye on the sky for Golden Eagles, Prairie Falcons, Rough-legged Hawks and Ferruginous Hawks.  

While also present out on the grasslands, American Kestrels and Red-tailed Hawks are very common on farmland as well.

Wetland habitat is the realm of the Northern Harrier, Peregrine Falcons patrol mudflats for shorebirds to nab, and White-tailed Kites and Merlin both seem to prefer areas of edge habitat, where wetland, grassland and stands of trees are all adjacent.  

In riparian forests and areas with mixed stands of trees, including neighborhoods with ornamental trees, be on the lookout for Red Shouldered Hawks, Cooper's Hawks, and the small but mighty Sharp-shinned Hawk.

Sharp-shinned Hawk with prey

Sharp-shinned Hawks, or "Sharpies," as they are affectionately known by birders, are Accipiters, agile forest-dwelling raptors that specialize in predating other birds, particularly songbirds.  Closely related and similar in appearance to our resident Cooper's Hawk, the Sharp-shinned Hawk is a winter visitor in the Central Valley.  

While they look almost identical at first glance, Sharpies can be differentiated from "Coops" by their large, buggy eyes; small, stubby bill; proportionately very thin legs; and darkly colored nape.  Other subtle differences factor in as well, such as head shape, tail shape and size, but I find these to be less reliable and more difficult to discern in the field.  While Sharpies land on the size scale somewhere between a robin and a crow, they do vary in size, with the females larger than the males.  Large female Sharpies approach the size of small male Coops, so size is not usually the best guide for separating the two species.

Note the Sharpie's large, buggy eyes; small, stubby bill; very thin legs; and dark nape.

Sharp-shinned Hawks (so named for a sharp ridge that runs the length of the front of their legs) prey largely on small songbirds, like warblers and sparrows, which they pluck before eating.  As North America's smallest hawk, Sharpies are agile and well-adapted to life in dense forests, where they may ambush prey from vegetative cover, or pursue it at high speeds through thick vegetation.  They tend to fly low and keep to cover, though in migration and during the winter they do spend more time in the open skies.

Searching for raptors is a fun way to spend a winter day of birding in the Valley, and coming across a Sharpie is always a treat. 

If you're curious about the owls I mentioned earlier, it is possible to find Barn Owl, Burrowing Owl, Great Horned Owl, Short-eared Owl and Western Screech-owl all in one exceptional day of winter birding in the Great Central Valley!