Raptor Behaviour & Calls Flashcards
What FOUR aspects of a raptor’s behaviour can help you identify a bird?
- Flight style
- Foraging method
- Sociability
- Bobs & twitches
What are the TWO major flight styles of raptors?
Soaring and direct flight
If a raptor is riding the thermals, gliding in great circles, and hardly flapping its wings at all, then it is soaring.
If, on the other hand, it is flying straight and fast, and flapping its wings constantly to maintain speed, then the raptor is engaged in direct flight.
Most raptors use both flight styles but some, like the California Condor soar much more often than the others, like Sharp-shinned Hawk, which typically only soar during their migration.
When soaring, what aspect of a raptor’s shape can provide useful clues for identification?
The angle at which the wings are held to the body.
For example, Northern Harrier and Turkey Vulture soar with their wings in a V-shape or what is referred to as a “dihedral” shape above their bodies.
Bald Eagle and Black Vulture, on the other hand, align their wings with their bodies, creating a much more flattened profile.
What FIVE foraging methods do raptors use (and can be useful for ID)?
- Hover & drop
- Perch & survey
- Ambush & chase
- Soar & swoop
- Low ambush
Hovering is an adaptation by raptors who dwell in grassland habitats where there aren’t many tall perches.
Perching is also done by birds of the open country where telephone poles offer the perfect vantage point to perch and survey.
Ambushing & chasing is great for forest-dwelling raptors who rely on concealment and camoflage to opportunistically pounce on birds, oftentimes with a fierce chase involved.
Soaring & swooping is the foraging method of choice for hunters who like a high vantage point. They then swoop down to pounce on unsuspecting prey or scavenge on a fallen creature.
Low ambush involves flying low and slow over grassland and marsh habitats, searching for prey, and then pouncing on them unseen.
Which FOUR raptors hunt by hovering and then swooping to catch their prey?
- American Kestrel
- White-tailed Kite
- Osprey
- Rough-legged Hawk
When it’s really windy, Red-tailed Hawk will also hover, although it is more like they are surfing the wind than actually hovering the way the afore-mentioned raptors do.
Which FIVE species of raptors like to perch on telephone poles and hunt for prey?
- Red-tailed Hawk
- Rough-legged Hawk
- Harris’s Hawk
- Swainson’s Hawk
- American Kestrel
All of these raptors are birds of the open country, from grasslands to desert.
Which FOUR species of raptors typically ambush and then chase their prey?
The forest-dwelling hawks:
1. Cooper’s Hawk
2. Sharp-shinned Hawk
3. Broad-winged Hawk
4. Northern Goshawk
These raptors will ambush their prey—usually smaller birds—and then chase after them. Their relatively short, broad wings allow them to fly through thick woods, while their long tails act as powerful rudders for quick, sharp maneuverability.
Which FOUR species of raptors dash after prey, relying on sheer speed to hunt?
- Merlin
- Gyrfalcon
- Peregrine Falcon
- Prairie Falcon
What SIX species of raptors like to hunt by soaring and then swooping down on prey?
- Golden Eagle
- Zone-tailed Hawk
- Short-tailed Hawk
- Turkey Vulture
- Black Vulture
- Mississippi Kite
Black and Turkey Vultures soar at height to look for fallen animals (or other vultures). They then swoop down to feast on the carrion. They don’t catch live prey.
What THREE species of raptors forage by flying low and slow over habitats like grasslands and marshes?
- Northern Harrier
- Snail Kite
- Rough-legged Hawk
Rough-legged Hawk also hover over the habitat and perch on telephone poles. So while some raptors tend to specialize in a certain foraging techniques (and are built accordingly), they can use multiple methods to acquire prey.
Why is sociability (or gregariousness) a useful clue for raptor ID?
Very few species of raptors hang out in large groups of other raptors!
Knowing which species of raptors are gregarious can help you determine what you’re looking at pretty quickly.
Most raptors are solitary or will pair up to nest. What are THREE exceptions to this rule?
- Vultures scavenge and roost communally.
- When there is an abundant food source, different species of raptors might congregate.
- Some raptors migrate in enormous mixed flocks.
What is meant by the term “kettle”, usually used during raptor migration?
A kettle is a group of raptors—often several different species—that are soaring, wheeling, and circling in the air.
An example of this “kettling” behaviour is exhibited by raptors like Swainson’s Hawk, Broad-winged Hawk, and Swallow-tailed Kites, which soar in groups of dozens, if not hundreds of individuals during migration.
Most raptors, however, do not do this.
What do we mean when we talk about bobs and twitches in reference to bird’s behavior?
Unique, ideosyncratic movements that are particular to a species of raptor (or bird).
American Kestrel bob their tails when perched on a wire. There doesn’t seem to be any apparent reason for it; it’s just a unique behavior to this bird and one that can help you tell it apart from the similar-looking Merlin.
What raptor can be heard calling in this audio recording?
Audio credit: Bruce Lagerquist, Xeno-Canto.org
American Bald Eagle
A high-pitched twittering or whistling that is often made around their nests.
