Laughing Kookaburra (Dacelo novaeguineae) Fact Sheet: Behavior & Ecology

(Cooper et al. 2008)

• Kookaburras make most of their calls each day before dawn (Keast 1985)
• Active during the day (diurnal); roost for an average of 12 hours a night
• In wild, remain roosting longer when weather is unfavorably wet or cold
• Reduce basal metabolic rate significantly at night to conserve energy (Buttemer et al. 2003)
  • Body temperature at night is up to 9.1°C (16.4°F) lower
  • Also use huddling behavior while roosting to stay warm
  • Most birds (like owl) with low nighttime metabolism and temperatures also have low values during the day; kookaburras' metabolism and temperatures in daytime are much higher
    • Wild kookaburras elevate body temperature in daytime by generating their own heat; they don't wait for the sun to warm them up
  • Such an extreme variation in body temperature is an example of heterothermy (fluctuation in temperatures seen in animals that undergo hibernation or a daily torpor)
    • Heterothermy is more common in mammals than in birds (Geiser et al. 2006)
  • Birds in managed care do not undergo such temperature fluctuations, presumably because (Geiser et al. 2006):
    • Their food supply is steady and predictable; energy conservation is thus less important
    • They may not feel secure enough to enter a largely unresponsive state of torpor

Complex social relationships

• Breed in nuclear family groups with a monogamous pair assisted by up to six helper-birds (Legge & Cockburn 2000)
• Roost communally at night (Cooper et al. 2008)
  • Juveniles may roost separately from adults (Higgins 1999)

Territories

• Territories range from 16-244 ha (39.5-603 acres)
• Larger groups have larger territories

Migration

• Kookaburra do not migrate (Higgins 1999)

Dispersal

• Female helpers often leave their group during the first year (Legge 2004)
  • Females will usually immediately join another group, filling a vacancy with a dominant, breeding male
  • Occasionally a male and female from different groups will make a partnership and establish a new territory of their own
• Male helpers typically leave later, after an average of two seasons (Legge 2004)

• Unlike other kingfishers, kookaburras are territorial year-round and are also resident ("sedentary") (Schodde & Tideman 1997)
  • Birds are careful to honor territorial boundaries (Parry 1970)
  • In one experiment by a researcher, a kookaburra would not cross into a neighbor's territory even to grab food tossed across the invisible line (Parry 1970)
  • Much energy is expended in complex, boundary-marking displays by the whole group (see below, Displays)

• Kookaburra chicks display significant aggression from the moment they hatch; in studies near Canberra, Australia (Legge 2000c, 2004):
  • Chicks use the sharp downturned tip of their upper beak to attack nestmates; this hook is absent by the time the chick fledges
  • 33% of nests with two or three young had chicks killed by nestmates (siblicide)
  • Other species of birds that experience this type of aggression have siblicide rates over 90%
  • Factors creating conditions for siblicide:
    • First and second chicks hatch close together in time (fight to establish dominance)
    • When these two eggs are of similar size, siblings fight to establish dominance
    • Where a male chick is born first, a female second (male's initial dominance from birth order quickly challenged by faster-growing larger female)
    • When the group lacks a male helper (females are poor helpers, chicks not as well provisioned by females)
  • An underlying reason for siblicide is female's physical condition at time of laying
    • Eggs don't begin developing until the female begins sitting on them (incubating)
    • Females in good condition can begin incubating each egg as it is laid; they don't need to keep hunting between egg-laying days
    • Delay of incubation until all the eggs are in the nest produces eggs that hatch close in time - a hyper-competitive situation
  • Levels of aggression decline with each day as clear dominance patterns are established
• Aggression between fledglings is common in the form of "sparring" (Parry 1973)
  • Opponents grab each others' bills
  • Twist bodies back in forth to throw opponents off balance
  • Serious injury rare

Displays

•  Aerial displays in ritual defense of territory (Higgins 1999) (Parry 1970)
  • Trapeze flight
    • A defense perch is occupied near the boundary, in view of a similar perch across the boundary in neighbor's territory
    • A bird swoops from the perch to a nearby tree in its own territory, lands, and returns
    • A second bird may begin to swoop as the first bird returns; they pass in mid-air like trapeze artists
    • Following this display, the birds may pause to allow birds in the neighboring territory to do the same display
    • Alternating swoops to a tree and back may continue for as long as 30 minutes
    • Much loud calling (by the the rest of the group) may accompany these displays
  • Circle flight
    • One bird flies above trees
    • Makes quick dash into neighboring birds' territory
    • Flies in large circles around neighboring birds
    • Much loud calling by the whole group ensues
• Agressive posture threats, then actual physical attacks are used to rid a territory of an intentionally or accidentally invading kookaburra (Parry 1970) (Higgins 1999)
  • Wings held down with rump exposed
  • Head and upper body thrust forward
  • Feathers made sleek
  • Tail wagged up and down
  • Vigorous attack and chase of intruder may follow
• Alarm posture (Higgins 1999):
  • Body lifted off perch
  • Bill opened
  • Feathers on crown raised or plumage on back is sleeked
  • Head may be turned from side to side
  • May call also, depending on nature of threat

Vocalizations        

• A laughing chorus by two or more birds
  • Occurs at dawn or dusk, often in response to another group (Woodall 2001)
    • Also call on moonlit nights and before and after solar eclipses (Higgins 1999)
  • Vocalization studies suggest the sounds made by a group resemble each other and are different from an outside group (Baker 2004)
  • Chorusing helps a group advertise its claim to a territory (Baker 2004) (Legge 2004)
    • A larger group makes a louder chorus, perhaps signifying a stronger claim
  • Has five elements (Woodall 2001:
    • "Kooa"
    • "Cackle"
    • Rolling - "ooo-ooo-ooo" repeated for 2 seconds
    • "HaHa" - loudest element; lasts 2-5 seconds and is used before attacks
    • Gogo - by male is loud "go-go-go"; by female is lower-pitched "gurgle"
    • Hear a laughing kookaburra call
• Blue-winged kookaburras' vocalizations sound like "barks and hiccups" (Legge 2004)
  • Much less varied than the laughing kookaburra repertoire

• Terrestrial locomotion (Legge 2004)
  • Feet are relatively weak
  • When nesting in tree hollow, parents prefer to build the nest space at the same level as opening for ease of entry and exit
• Flight
  • Relatively slow flying
    • Kookaburras investigating road kills are vulnerable to car strikes

• Gliders and opossums are primary predators on kookaburra eggs (Eastman 1970)
• Quolls, goannas, and snakes may take chicks (Legge 2004)
• In a study in Queensland, Australia, many species besides kookaburras depended on tree hollows for either nesting, shelter, or roosting sites (Moloney et al. 2002):
  • 13 species of mammals
  • 63 species of birds
  • 23 species of bats
  • 35 species of reptiles and amphibians
• Other avian predators in kookaburras' ecosystem in New South Wales, Australia included (Zanette & Jenkins 2000):
  • Currawong, butcherbird, magpies, ravens

Kookaburras call as a group to advertise ownership of a territory.

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

Baker (2004)
Buttemer et al. (2003)
Cooper et al. (2008)
Geiser et al. (2006)
Higgins (1999)
Keast (1985)
Legge (2000c, 2004)
Legge & Cockburn (2000)
Moloney et al. (2002)
Parry (1970)
Schodde & Tideman (1997)
Zanette & Jenkins (2000)