California Condor (Gymnogyps californianus) Fact Sheet: Behavior & Ecology

Active hours

• Before flying (Snyder and Snyder 2000; Finkelstein et al. 2015a)
• Preen
• Extend wings in the morning sun
• Dry feathers
• May aid in thermoregulation
• Foraging activity strongly influenced by winds (Snyder and Snyder 2000; Cogan et al. 2012; Finkelstein et al. 2015a)
• Strongest thermals during middle of the day
• Begin foraging by mid-morning
• Return to roost by mid-afternoon
• Some late-evening flights observed
• Narrow time window for foraging
• 5-6 hours per day in winter (Snyder and Snyder 2000)
• 7-8 hours, at most, during summer (Finkelstein et al. 2015a)
• May take two or more hours to reach foraging grounds (Snyder and Snyder 2000)
• Spend more time perched than flying (Koford 1953)
• Sometimes spend entire day at roost (Rivers et al. 2014b)

Resting (Finkelstein et al. 2015a)

• Roost and sleep
• On limbs of tall trees or on ledges/cliffs
• In the company of other condors
• While sleeping
• Tuck heads into their feathers or let heads dangle
• Usually lie flat; sometimes stand upright

Movement patterns

• Influenced by location of nests and foraging habitat (D'Elia and Haig 2013)
• Fly long distances to forage (Birdlife International 2015)
  • Up to 250 km (155 mi) (Campbell 2015)
• Restricted to areas with enough upward air movement and lift (thermals) (D'Elia and Haig 2013)
  • Cannot sustain flapping flight; tire easily
• Regional habitat use influenced by wind characteristics (Rivers et al. 2014b)
• No long-distance migrations (D'Elia and Haig 2013)
  • Exhibit shorter, seasonal movements to take advantage of changes in food supplies

Home range

• Home ranges of immature birds smaller than adults (Rivers et al. 2014a)
  • Immatures spend first two years close to natal area
  • Home range size gradually increases with age
    • Immatures may learn locations of foraging grounds from adults
• Similar home range sizes between (Rivers et al. 2014a):
  • Females and males
  • Breeding and non-breeding individuals
  • Wild and managed care-reared individuals
• Home ranges much larger in summer than winter (Rivers et al. 2014b)
  • More daytime hours to forage
• Home range affected by seasonal changes in atmospheric conditions (Rivers et al. 2014a)
  • Caused by daylength-driven changes in solar radiation

Agonistic behaviors

• Generally agonistic towards predators but not other condors in their territory (Snyder and Snyder 2000; Finkelstein et al. 2015a)
• For specific behaviors, see Social Interactions

Around food (Finkelstein et al. 2015a)

• Not known to defend feeding sites from other condors
• Will act aggressively towards other bird species, such as Common Ravens and Golden Eagles
  • See Group Interactions (Feeding)

During breeding

• Some individuals territorial toward other condors (Finkelstein et al. 2015a)
  • Aggressively fly after and chase intruders from nesting area
  • Isolated reports of birds knocking one another from perches

Often gregarious (Finkelstein et al. 2015a)

• Large groups gather at roosts, bathing sites, and feeding sites
• Ephemeral groups
• Otherwise found individually, in pairs, or in small groups

Preening

• Adult breeding pair members engage in mutual preening (Finkelstein et al. 2015a)
• Complex preening interactions between parents and their chick (Snyder and Snyder 2000)
• Intertwine necks, rub heads, nipping

Agonistic behavior (Finkelstein et al. 2015a, except as noted)

• Condors commonly interact at close range (often without aggression)
• Agonistic behaviors observed
• Chase in flight or on the ground
• Take another condor’s perch position
• Inflate air sacs, while perched
• Erect body posture
• Jabs with an open bill (in flight or on the ground)
• Lunge at opponent
• Peck or bite rump of opponent (Koford 1953)
• Minor aggression between pairs
• Over access to egg or chick
• Other causes unknown
• Minor aggression frequent between immatures (Koford 1953)
• Bite one another
• Wrestle with their heads
• Submissive bird may appease dominant bird by loosely flapping wings, similar to a begging nestling
• Males usually dominant to females, but not always
• Dominant birds frequently act agonistically to maintain status (Sheppard et al. 2013)
• Generally more curious than aggressive towards humans (Snyder and Snyder 2000)

Calls

• Make few sounds (Snyder and Snyder 2000; Finkelstein et al. 2015a)
• Lack a syrinx
• Not considered true vocalizations by some
• Adults (Finkelstein et al. 2015a)
• Hisses and snorts at close range to protect nests
• Chicks (Koford 1953)
• Rapid hisses or hiss-grunts
• Duration and frequency increases as chick grows

At feeding sites

• Compete with Golden Eagles for food (Snyder and Snyder 2000)
• Usually dominant over Turkey Vultures and Common Ravens (Campbell 2015)

At nesting sites

• Large falcons and California Condors may nest near each other (Finkelstein et al. 2015a)
• Condors sometimes experience considerable harassment from attacking falcons, especially Prairie Falcons (Falco mexicanus)
• May benefit when falcons exclude other predatory birds
• Wood rats use California Condor nesting sites (Snyder et al. 1986)
• Small birds sit close to California Condor nesting sites (Koford 1953)
• Swallows, swifts, flycatchers, jays

In the air

• Soaring flight (D'Elia and Haig 2013)
• Low energetic cost compared to flapping flight
• Glide on uplifts (thermals) (Finkelstein et al. 2015a)
• Restricted to areas with enough upward air movement (D'Elia and Haig 2013)
• Sustained, flapping flight rare; tire easily
• Flap during take-off and landing (Snyder and Snyder 2000)
• Also, to chase predators away from nests (Snyder and Snyder 2000)
• Can fly at high speed (Snyder and Snyder 2000)
• Up to 40-70 kph (25-43 mph) (D'Elia and Haig 2013)
• Average over 50 kph (31 mph) (Finkelstein et al. 2015a)
• Cannot fly and forage in bad weather (Snyder and Snyder 2000)

On the ground (Finkelstein et al. 2015a)

• Remarkably agile; walk and run
• Run and hop during takeoff

Self-cleaning and bathing (Finkelstein et al. 2015a)

• Rub head/neck on surfaces after feeding or after feeding chick
• Bathe in water frequently
• Pools at top of waterfalls

Play (Finkelstein et al. 2015a)

• Nestlings wander on slopes adjacent to nest site
• Pretend to capture objects and vegetation
• Leap about with exuberance, then rest

Additional behaviors

• Peck at inedible objects (Koford 1953)
• More common in immatures than adults
• Commonly fly low to inspect livestock (Snyder and Snyder 2000)
• Vulnerable to shooting

During the morning hours, California Condors are often observed with their wings open, oriented towards the sun.

This is thought to help dry their feathers and warm their bodies after cool nights.

Image credit. © San Diego Zoo Wildlife Alliance. All rights reserved.

Though often found singly or in pairs, California Condors form large groups at roosts, bathing sites, and feeding sites.

Image credit: © San Diego Zoo Wildlife Alliance. All rights reserved.

California Condors depend on thermal air currents to soar.

Image credit: © San Diego Zoo Wildlife Alliance. All rights reserved.