Goshawks and Cooper’s hawks are two species of accipiter hawks found in North America. They are similar in size and shape, which can make differentiating between them challenging for birders. However, with close observation, there are several key differences that can be used to identify them.
Size
Goshawks are larger than Cooper’s hawks. Adult goshawks have an average length of 17-25 inches and a wingspan of 34-48 inches. Adult Cooper’s hawks are smaller, with an average length of 14-20 inches and a wingspan of 26-32 inches.
There is some overlap in their sizes, but if you see a large accipiter hawk, it is most likely a goshawk. Smaller accipiters are more likely to be Cooper’s hawks. Juvenile birds are harder to differentiate by size alone though since they are closer in size before the Cooper’s hawk reaches its full adult dimensions.
Shape
Goshawks have proportionally longer wings and a longer tail than Cooper’s hawks. When perched, goshawks appear more slender and elongated while Cooper’s hawks are more compact.
Goshawks have a larger head that projects forward from the body. Their wings are held closer to the body at rest. Cooper’s hawks have a smaller head that appears flush with the body contour. Their wings are held looser from the body when perched.
Plumage
Adult goshawks are slate blue-gray on the head and back with a white underside streaked in gray. Their eyes are bright red.
Adult Cooper’s hawks are dark gray or blackish on the back with a paler nape and reddish barring on the underparts. Their eyes are orange-red.
Juveniles of both species have brown backs and streaked underparts until they molt into adult plumage around 1-2 years old. The streaking underneath helps camouflage them in the trees as juveniles.
The juvenile goshawk may be identified by its larger size, chunkier body, and bigger head. The juvenile Cooper’s has a more elongated, slender look and a smaller head.
Behavior
Goshawks and Cooper’s hawks occupy different forested habitats. Goshawks are more likely to be found in large tracts of mature, open woodland like deciduous and mixed forests. They build nests high in the trees.
Cooper’s hawks inhabit more fragmented woodlots interspersed with open areas and are common even in urban and suburban parks and neighborhoods with some tree cover. They nest lower in trees at mid-level.
Goshawks are bold, powerful hunters that prey on other birds like grouse and crows as well as small mammals. They perform swift aerial dashes through the forest in pursuit.
Cooper’s hawks are more agile flyers that dart and weave through vegetation hunting small birds and mammals. They often lurk at backyard bird feeders to ambush prey.
Range
Goshawks have a transcontinental range across northern North America. They are found as a year-round resident through much of Canada and the northern United States including the Rocky Mountains and northeastern states.
During winter they migrate south into more northern parts of the continental U.S. They are uncommon and local outside of their core range.
Cooper’s hawks are widespread throughout woods habitats across most of North America from southern Canada through Mexico. They can be found year-round throughout their range.
So if you spot an accipiter hawk during summer or winter in the northern U.S. or Canada, it is much more likely to be a goshawk outside of migration. In other areas, either species may be present.
Spotting Tips
Here are some quick tips for differentiating a perched goshawk from a Cooper’s hawk:
Goshawk
- Very large headed
- Intense red eyes
- Gray back with white streaked underparts
- Long, loose wings
- Long tail
- Hunkered posture, slowly turns head
Cooper’s Hawk
- Smaller head
- Orange-red eyes
- Dark back with reddish barring below
- Shorter wings held closer to body
- Shorter tail
- Upright posture, quickly swivels head
The most reliable differences to look for are relative head size, eye color, overall body shape and proportions, and habitat. Plumage and size are less reliable guides, especially with juveniles.
Encounters
Here are some example encounters that illustrate the key differences in appearance between these two hawk species:
Goshawk encounter
While hiking through a mature oak forest I noticed a large raptor perched 30 feet up in a tree ahead of me. Its bulky body and very large head projecting forward stood out immediately, giving it an almost menacing appearance. As I cautiously moved closer, its bright red eyes glared at me unblinkingly before it took off in a blur of gray wings. Based on its hefty proportions, size, and bold behavior in defending its territory, I identified this bird as a northern goshawk.
Cooper’s hawk encounter
I caught a flash of movement in my peripheral vision while gardening and looked up to see a small hawk perched on a low branch just 10 feet away. It swiveled its head from side to side watching me intensely with its orange-red eyes. The bird appeared slender and long-tailed, with a smaller head that blended into its body contour. After a few minutes, it took off in a quick burst, deftly maneuvering through the dense backyard vegetation. I recognized it as a sharp-shinned Cooper’s hawk from its petite size, agile flight, and use of my yard as a hunting perch.
These types of field encounters highlighting differences in appearance, behavior, and habitat use are often the best teachers for identification. With practice, the distinctions between these two woodland hawks will become more intuitive.
Nest Identification
The nest sites and structures of goshawks and Cooper’s hawks also differ in ways that aid identification.
Goshawk nests
- Bulky structure of sticks high in mature tree
- Lined with bark strips and greenery
- Usually 30-50 ft up near tree trunk
- Often in deciduous forest interior
Goshawk nests are large, sturdy platforms built to support these heavy hawks. They are placed high in large trees in the open understory of mature forests.
Cooper’s hawk nests
- Smaller structure of twigs and bark
- Lined with grasses and pine needles
- Usually 20-35 ft up near branch forks
- Often in forest edge or woodlots
Cooper’s hawk nests are more roughly built to accommodate the smaller birds. They are placed in shorter trees in transitional forest with denser cover.
The different nest sites match the differing habitat preferences of these two woodland raptors. Finding an accipiter nest can provide a clue as to which species built it.
Vocalizations
Listen for vocal clues to identify a perched accipiter hawk as a goshawk or Cooper’s hawk.
Goshawk calls
- Loud, repetitive cackling cries
- Wailing kee-ah kee-ah kee-ah
- Mellow chattering ka-ka-ka-ka-ka
Goshawks are vocal and make bold, loud calls from perches to advertise territories.
Cooper’s hawk calls
- Loud kik-kik-kik
- Short, repeated kek kek kek
- High pitched whining squeals
Cooper’s hawk calls are higher pitched and harsher than goshawk calls. They make short, repeated contact calls when alarmed.
If you hear boisterous cackling calls, odds are good it comes from a watchful parent goshawk. High squealing calls are more characteristic of Cooper’s hawks.
Hunting Habits
Goshawks and Cooper’s hawks employ different hunting techniques suited to their forest habitats. Observing their strategy can help confirm an ID.
Goshawk hunting
- Swift pursuit through dense woodland
- Uses trees and vegetation for cover in chase
- Takes large bird prey like grouse in flight
- Crashes down through branches to grab prey
Goshawks are agile, powerful hunters able to pursue prey recklessly through cluttered forest at high speed.
Cooper’s hawk hunting
- Swift darting flights from perch to perch
- Ambushes unwary prey from concealed perch
- Favors small bird prey like doves and jays
- Thrusts through branches to grip prey
Cooper’s hawks are stealth hunters that beat prey with quick surprise attacks after lying in wait camouflaged in the trees.
The goshawk’s brazen pursuit flight and the Cooper’s stealth strike are well-matched to their preferred forest homes. Observing an accipiter hawk’s method of hunting can provide additional clues to confirm its identity.
Prey Items
The prey remains and feathers left at plucking perches and nest sites also offer identification clues.
Goshawk prey remains
- Large feathers like grouse, ducks, crows
- Tufts of fur and bones from hares, squirrels
- Large feathers plucked in bunches
Goshawks take sizeable prey and leave correspondingly large feathers and bones. The feathers are plucked out in tufts.
Cooper’s hawk prey remains
- Small feathers like songbirds, doves
- Individually plucked body feathers
- Fur from small mammals
Cooper’s hawks take smaller prey, leaving delicate songbird feathers and small bones. The feathers are neatly plucked one by one.
These prey remains provide good retrospective clues to identify which hawk species has been actively hunting an area.
Identification Challenges
There are some scenarios that can still make differentiating goshawks and Cooper’s hawks tricky:
Juveniles
Juvenile plumage is similar for both species. Identity must be determined mainly by size, proportions, and behavior. Look for the larger, bold juvenile goshawk vs. the smaller, sneaky juvenile Cooper’s.
Backlighting
When a hawk is backlit, plumage colors and marks can appear washed out. Focus instead on silhouette and flight style.
Dense vegetation
Heavy leaves can obscure field marks, requiring you to rely more on size comparisons. Look for visible clues like the large goshawk head.
Brief sightings
Fast hawk movements mean you need to quickly assess size, shape, flight pattern, and habitat. Eliminate unlikely species based on geography.
Unusual plumages
Aberrant color variants and bleached feathers can create confusion. Fall back on structural features like proportions.
Distant birds
Use basic attributes like size, flight style, and habitat at long range. Unique field marks are hard to discern.
With practice, the distinctive traits of goshawks and Cooper’s hawks will become more recognizable. Patience and persistence are key when identification is challenging.
Conclusion
Telling a goshawk from a Cooper’s hawk requires careful observation of several key differences:
Goshawk
- Very large, chunky accipiter
- Long wings and tail
- Bright red eyes
- Large fierce expression
- Gray with white streaks below
- Loud, wailing calls
Cooper’s Hawk
- Smaller, slender accipiter
- Short wings and tail
- Orange eyes
- Smaller head
- Dark with reddish bars below
- Harsh, high-pitched calls
Size and proportions provide the most useful field marks, supplemented by variations in plumage, behaviour, habitat, voice, and other traits. Patience is needed when differentiating juvenile birds or brief sightings. Understanding the nuances between these two forest hawks takes practice but close observation will reveal their identities.