Raptors: Hawks and Vultures

Mar 25, 2022

Raptors: Hawks and Vultures

Mar 25, 2022

Raptors are birds of prey that hunt and feed on vertebrates. The term encompasses a group of birds consisting of hawks, owls, eagles, kites, falcons, and vultures. Because of their acute eyesight, strong beaks, and powerful feet with hooked talons, raptors are effective hunters. These birds are protected under the Fish and Game code and California Code of Regulations because of their value to the state. Let's look at hawks and raptors: California is home to a variety of these birds and it is fascinating to watch them soaring through our sky.

Nine species of hawk are found in California either seasonally or year-round. Year-round residents include the Red-tailed, Red-shouldered, and Cooper's hawks. The Red-tailed hawk is the largest and heaviest of this group, and it is the most commonly seen hawk in all of North America. If the wind is strong, these hawks can hover in the air like helicopters (without flapping their wings) while searching for small rodents. Red tailed hawks are found pretty much anywhere that offers them trees or other tall perches.

Red-shouldered hawks are often heard before they are seen. Their distinctive “kee-ah” call is a clue that one is near. In California, the Red-shouldered hawk may be visible in more open habitats like riverside forests and oak woodlands. They are also found in urban and residential areas, parks, and cemeteries, nesting in non-native trees, particularly eucalyptus.  Red-shouldered hawks dine on small mammals, amphibians, reptiles, and other birds. Their keen vision and sense of hearing make them formidable predators able to kill animals their own size. Red-shouldered hawks have rusty, copper-colored heads and a distinctive white crescent on the tip of each wing.

Cooper's hawks are more difficult to spot because of their stealthy behavior. This species is smaller than other hawk species, often just crow-sized, so they are less obvious than other hawks. Cooper's hawks prey on other birds by using dense forest and woodland trees to their advantage. Tree limbs become perches from which to stalk and sneak up on their prey. When the opportunity arises, the Cooper's hawk will take off after a smaller bird, chasing it through the trees until it is caught.

Often confused with the Cooper's hawk is the Northern Goshawk, which has nearly identical coloration. These hawks can be seen during the winter months stalking backyard bird feeders and chasing unsuspecting songbirds.

The largest of the hawks seen in California is the Ferruginous hawk. With a wingspan between 52 and 56 inches, this raptor soars high in the air with its wings held in a distinctive raised V-shape. The Ferruginous hawk can be spotted during the winter over grasslands and plains throughout the state. Their light-colored undersides and the rusty plumage on their wings and back have given them their name: “ferruginous” is defined as containing iron oxides or rust. Unfortunately, the population of these enormous raptors has declined, and their status in California is threatened.

Swainson's Hawks, Rough-legged Hawks, Northern Harriers, and Sharp-shinned Hawks are also seen throughout the state, although some of these birds can be tricky to identify. Swainson's hawk, for example, can only be seen during breeding season in wide open spaces nesting in the scattered trees; the population of Swainson's hawk in California has faced serious decline in recent years. Non-breeding populations of Rough-legged, Northern Harriers, and Sharp-shinned hawks may be spotted throughout the state, mostly during the winter months.

Wherever you are in California, you're apt to see vultures. The three species in our state are the Turkey vulture, Black vulture, and the California condor. They are carnivorous and perform an important health service by eating the carrion (decaying flesh) of dead animals found lying in fields and at the sides of the roads. By eating the dead animals that other predators can't stomach, vultures help deter the spread of both tuberculosis and rabies. Their powerful stomach acids and strong immune systems allow these birds to be exposed to disease with no detrimental effect. In addition to tuberculosis and rabies, diseases such as distemper, anthrax, salmonella, and botulism are no problem for these raptors. 

The Turkey vulture (Cathartes aura), also called the Turkey buzzard, is the most common vulture found in California. So named because of their resemblance to wild turkeys, these raptors are easy to identify – they have skull-like bald red heads, pink beaks, white bills, and brown-black bodies. Turkey vultures hiss when they are agitated or fighting over carrion. They are often seen soaring over open fields looking for food or at the side of a road, eating the meat of an animal killed by a car. Turkey vultures can become so loaded down with their meal that when threatened they will sometimes projectile vomit their food in order to fly away quickly. They have also been seen to projectile vomit up to ten feet in self-defense. Turkey vultures will defecate on their feet to cool off during hot weather. This defecation may also provide an antiseptic wash, as the vultures' digestive juices kill bacteria.  In the fall they are sometimes seen in large flocks of nearly 100 birds migrating south on thermals (upward currents of warm air). Turkey vultures can live up to twenty years in the wild.

The Black vulture (Coragyps atratus) is so named because of its black head and black feathered body. Smaller than the turkey vulture, it is easy to tell the difference between the two, especially in flight. Black vultures display their silvery wingtips in fight, while turkey vultures slightly raise their primarily gray-feathered wings in a V-shape when flying. Although these raptors eat carrion, they also feed on freshly-killed animals such as skunk, opossum, and young farm animals. Black vultures mate for life and build their nests on the ground in stumps, caves, hollow trees, brush piles, and thickets. Baby vultures are fed by their parents for eight months; Black vulture families develop communal attachments and will periodically meet up with relatives. Like the turkey vulture, the black vulture hisses when agitated or threatened. Black vultures are most often seen in tropical to temperate regions. They will live about ten years in the wild.

The California Condor (Gymnogyps californianus) is the largest bird in the United States and one of the rarest species on earth. Like other vultures, condors feed on carrion, eating anything from ground squirrels to beached whales. California condors roost in large trees and nest in tree cavities or on rocky cliffs. These vultures are social, curious, and playful birds They can fly up to two hundred miles in a day with minimal effort due to their wide wingspan.  Condor numbers suffered as the human population increased in the West in the late 1800's. Their numbers continued to decline in the twentieth century due to poaching and poisoning, and in 1967, the California Condor was listed as an endangered species. In 1980, all 22 known wild condors were captured and placed into breeding programs to restore their population. Female condors release just one egg at a time, but biologists were able to trick female birds into laying a second egg. The first egg was removed and raised by humans using puppets to mimic the parent bird. The second egg, when hatched, was cared for by the condor. The program was effective in saving the California condor from extinction and since 1992, birds bred in captivity have been released back into the wild at a number of sites including Pinnacles National Park, Big Sur, Hopper Mountain Wildlife Refuge Complex, and Vermillion Cliffs. The flocks are monitored for behavior and mortality. Condors bred in captivity continue to be released into the wild; due to this reintroduction program, California Condor populations are slowly beginning to increase. California condors are believed to live for up to sixty years in the wild.

The health of our planet depends on the health of our bird populations, and especially the vultures that clean up dead animal carcasses as they feed. California skies are brimming with a variety of raptors to observe and study. All you need to do is look up.

Vegetable Plant Sale! Stock up on popular varieties of vegetable plants at our Plant Sale on Saturday, April 2, 2022 from 9 to 11 am.  The sale will take place at the Master Gardener Demonstration Garden at Patrick Ranch (10381 Midway, Durham) rain or shine.  For more details, including a plant list, check our Vegetable Plant Sale webpage.

UC Master Gardeners of Butte County are part of the University of California Cooperative Extension (UCCE) system. To learn more about us and our upcoming events, and for help with gardening in our area, visit our website. If you have a gardening question or problem, email the Hotline at mgbutte@ucanr.edu (preferred) or call (530) 538-7201.