Hawks are amazing raptors. Take their razor-sharp eyesight: it’s eight times greater than that of humans. Why? Hawks have a multitude of photoreceptors in their retinas and another multitude of nerves that connect those receptors to the brain. Add to that a second set of eye muscles and an indented fovea, a spot on the back of the eyeball which magnifies their central vision field, and — well, you get the picture. In this article, we’re learning more about hawks in California.
Well-built and athletic, hawks leverage that great eyesight with powerful legs, sharp talons, and hooked bills to hunt, grab hold, and tear apart their quarry. Hey, they aren’t called birds of prey for nothing!
Hawks are comprised of two categories: accipiters and buteos, the defining difference being an opening in the front of the coracoid shoulder bone in buteos where there is none in accipiters. And while you can’t see this difference with the naked eye, accipiters are more easily identified by their shorter wings and longer tails which aid maneuverability in flight. They also have longer legs and toes for grabbing their prey, often in flight.
There are over 200 species of hawks worldwide, and while we wish they all could be California birds, there are only sixteen types in the United States and only nine which regularly make California their home. Let’s get to know a little about each of them, shall we?
1. Red-Tailed Hawks
Of all the hawks in California, red-tailed hawks are the most prevalent and one of only three species that makes the state a year-round home. These large buteos feature broad wings with rounded edges and short wide tails with a splash of red color on the upper feathers. They tend to have brown backs with pale undersides with brown and black stripes.
Rats, mice and small mammals make up nearly 95 percent of the red-tailed hawk’s diet which they obtain by perching patiently, then swooping in for the kill. Pairs mate for life and are highly adaptable, nesting in tall trees or, in urban settings, atop billboards or building ledges. They have few natural enemies but will compete with crows and great-horned owls for nesting spaces, the latter sometimes destroying their eggs or killing their young in an effort to steal their nesting site.
Red-tailed hawks average 18 to 26 inches in length. Males max out in weight at about 2.75 pounds, the larger females at 3.25 pounds. Wingspan can be up to 4-1/2 feet. They can live 10 to 15 years in the wild.
2. Northern Harrier
With the word circus in their scientific name, perhaps it gives Northern Harrier males license to put on a show during mating season. Whatever the reason, they perform a sophisticated sky dance with wing-over-wing barrel rolls and corkscrews. Northern Harriers breed from as low as sea level at the coast to as high as 9,000 feet in the Glass Mountain region in California’s Inyo National Forest.
These hawks prefer open, treeless habitats, including grasslands, wet meadows, and fresh and saltwater marshes. They make their nests on the ground and hunt for small rodents and waterbirds flying low to the ground as they tip from side to side. Between 1945 and 1980, California lost about 26 percent of its native grasslands and that degradation of breeding habitat is believed to be the cause behind their declining numbers in California. Presently, they are considered a Bird Species of Special Concern by the California Department of Fish and Wildlife.
Northern Harrier males tend to have gray coloring on top with white bellies, black wingtips, and black-banded tails. Females, on the other hand, tend to be brown with white coloring underneath that is streaked with brown. Both males and females have a noticeable patch of white on the rear portion of their bodies. Slender, with long broad wings and rounded tails, these hawks top out at about 20 inches in length and 27 ounces in weight with a wingspan as much as 46-1/2 inches. They live about 8 years in the wild.
3. Swainson’s Hawk
Birders may see Swainson’s hawks in Calfornia just six months of the year from April to late August during their breeding season. These hawks then bid farewell and head south in huge “kettles” with thousands of assorted birds to winter in Argentina and Brazil, a two-month-long, 6,000-mile trip.
Californians may be glad to see Swainson’s hawks return each year as that possibility was seriously threatened in the early 1990s when tens of thousands of dead and dying birds were found in their winter home littered across the land. It was found the hawks had become poisoned after feeding on grasshoppers (a favorite food) that had been exposed to toxic pesticides used on sunflower crops. A concerted effort was made to outlaw the use of this pesticide, and today Swainson’s hawk population levels have improved.
As buteos, Swainson’s hawks have short tails and long, broad wings, which they hold in a slight V-shape when flying. Swainson’s are dark brown on top with paler-colored bellies. Their wings are bright white nearer to their body which creates a striking contrast to their black-tipped flight feathers. Often sighted on telephone posts or treetops or soaring, these birds attain a maximum length of 22 inches, 48 ounces in weight, and a wingspan of 4-1/2 feet. They can live 16 to 19 years in the wild.
4. Red-Shouldered Hawk
These birds of prey can be found along the California coast in woodland areas with open upper canopies and near wetlands and marshes. It is also not uncommon to find them in wooded suburban neighborhoods, their distinctive “kee-ahh” scream often heard before they are seen.
Red-shouldered hawks make that same scream frequently during courtship. In an odd courtship ritual, they’ll sometimes take flight together rolling over and flying short distances on their backs.
Male and female work together to build nests of sticks in crotches of trees. They feed mostly on small mammals and hunt by perching and swooping in to grab their prey. Do you enjoy having a cold treat in the heat of the summer? Red-shouldered hawks do too! During the warmer months, they’ll treat themselves to cold-blooded prey like frogs and crayfish.
More colorful than their east coast counterparts, Red-shouldered hawks have long, banded tails, squarish, checkered wings, and reddish-brown and barred bellies. These raptors average 15 to 19 inches in length and can weigh up to 27 ounces. Maximum wingspans are about 42 inches. Life expectancy in the wild is only two years.
5. Cooper’s Hawk
If you love seeing songbirds at your birdfeeders, hope you don’t have Cooper’s hawks in your midst. These stealthy hunters will hide under dense cover then attack small birds in a sudden burst of movement. They also enjoy dining on mice and squirrels. With that kind of behavior, it’s no wonder they go by other names like Striker and Big Blue Darter.
Year-round California residents, Cooper’s hawks are recognized for their steel-gray tops and white coloring beneath with orange barring. They grow to a maximum length of 20 inches and 24-ounce weight, and their wingspan can reach 35-1/2 inches.
Short, crow-sized birds with rounded wings and tails, these often defensive hawks in California build their nests in dense, mature forests but in areas where there are also sufficient open spaces for hunting. Females generally lay 3 to 5 eggs and it is the males, rather than the females, that usually build their nests. They live up to 12 years in the wild.
6. Sharp-Shinned Hawk
Of the various hawks in California, Sharp-shinned hawks are another that can claim year-round residency mostly in the state’s mountainous regions. They share similar coloration to Cooper’s hawks with gray coloring on top and are paler beneath with orange barring. They have short rounded wings and squarish tails. It would be difficult to spot both Cooper’s hawks and Sharp-shinned hawks together in the wild, but if you did, you’d find Sharp-shinned hawks to be the smaller of the two.
Like Cooper’s hawks, these quick-darting, agile raptors enjoy sneaking up on songbirds and ambushing them, particularly at birdfeeders. But while other birds like robins and thrushes make up 90 percent of their diet, they are also known to eat insects, frogs, lizards, and small mammals.
Sharp-shinned hawks grow up to 13.5 inches in length. Males can weigh 3 to 4 ounces, while females average 5 to 7 ounces. Wingspans reach 17 to 22 inches on average. They typically live to three years in the wild.
7. Northern Goshawk
Territorial, secretive and fierce, this year-round California resident prefers nesting in old-growth, generally coniferous forests with dense canopies. Breeding territory includes the northern mountain ranges and Los Padres National Forest. Timber harvesting and wildfires have resulted in some loss of population, and they are presently designated as a Bird Species of Special Concern.
The Northern Goshawk’s upper body is typically a slate gray color, while their undercarriage is light gray with barring. They have dark-colored heads, a distinctive white eyebrow, and dark red eyes. Opportunistic hunters, Northern Goshawks feed on insects, mammals, birds, and reptiles.
These raptors grow 16 to 27 inches in length and can weigh up to 50 ounces. They can have wingspan up to 50 inches. Northern Goshawks live up to seven years in the wild.
8. Rough-Legged Hawk
Whereas Swainson’s hawks spend their springs and summers in California, Rough-legged hawks consider California their winter get-away. The rest of their year is spent in the Arctic tundra. While in the Arctic, they feed on plentiful lemmings, but as hawks in California, they turn to small rodents such as mice, voles, and shrews.
Rough-legged hawks, also known as Rough-legged buzzards and Rough-legged falcons, typically make their nests on cliffs and in low forests. They’ll survey open land in search of food while perched on poles or hovering in the air facing the wind.
Remember the start of this article and what was said about the excellent eyesight hawks have? Hawks can also see color and many of them can see ultra-violet light. Interestingly, studies have found that Rough-legged hawks will hunt more in areas treated with vole urine as they know they will find prey. Can they smell it from such a great distance? No. Rough-legged hawks can actually see the waste as it is visible to them in ultra-violet light.
Chunky birds, Rough-legged Hawks can reach a maximum length of 25 inches. Males weigh up to 3 pounds, with females reaching as much as 3-1/2 pounds. These raptors have wingspans of nearly five feet. The plumage on Rough-legged hawks covers their bodies all the way to their feet, an adaptation that helps keep them warm in the cold, Arctic climate. They live up to 18 years in the wild.
9. Ferruginous Hawk
Ferruginous Hawks prefer dry, open country, including grasslands, prairie, and woodland edges. They’re known to build enormous nests wherever suitable, such as in trees, on rock ledges, and on power poles or man-made structures.
They are the largest of the North American hawks and are recognizable by their long, broad wings and wide gray tails. Coloring is varied on Ferruginous hawks. Some may be lighter with a rust-colored back and pale-colored bellies, while others are dark brown with chestnut coloring on their underparts. Ferruginous hawks enjoy a diet of mostly small mammals. They can be spotted facing the wind hovering over their feeding grounds in search of food, but they are also known to hunt on the ground even chasing after prey on foot.
Ferruginous hawks can reach lengths as great as 27 inches, a weight of five pounds, and a five-foot wingspan. They live 16 to 20 years in the wild.
On Being Bird-Brained
Have you ever been called bird-brained? Think of it as a compliment.
Those who observe hawks in California have to admit these birds are clever-minded and quick learners able to change their hunting behaviors as the situation may dictate. In fact, Canadian ornithologist Louis Lefebvre, credited with inventing the only avian IQ index based on innovations in feeding habits, names hawks near the top of the intelligence heap, second only to corvids.
With their fantastic eyesight, powerful flying ability, gripping, tearing claws, and beaks, and basic cunning, hawks have a more-than-amazing set of attributes. Knowing all that, perhaps being bird-brained isn’t quite the insult we once thought it was!
- Interested in learning a little more about hawks, specifically Cooper’s hawk? We detail their interesting nesting habits in Cooper’s Hawk Nesting Habits, take a look.
- California has its healthy share of birds to watch, but if you happen to be an avid birder, there may be other places in the United States world renowned for their birding opportunities! We outline all of them in the Best Places To Live For Birders.