Skip to main content
sdzglibrarybanner San Diego Zoo Global Library

Australian Brush-turkey (Alectura lathami) Fact Sheet: Reproduction & Development

Courtship

Attracting a mate

  • Adult males each build and defend 1-2 incubation mounds to attract females (Göth 2007a)
    • Carefully select the mound site (Jones and Göth 2008)
    • Use large feet to move 2-4 t (4,400-8,800 lb) of material into a pile (Jones 1988b)
    • If a male builds two mounds, both must be tended and protected (Jones 1990b; Jones and Göth 2008)
      • Usually located close together
      • Beneficial in receiving more eggs, or if the first mound is damaged or taken by another male
    • See Incubation Mounds
  • After construction, males arrive at their mound early in the day and wait for females (Jones et al. 1995)
  • Compete over possession of incubation mounds (Jones 1990b)
  • Males produce boom vocalizations (Jones et al. 1995)
    • These might advertise their location and status
  • Females begin visiting the mounds about one month after construction begins (Jones and Göth 2008)
    • Allows sufficient time for decomposition, which heats the mound’s interior in preparation for the eggs
  • Males attempt to attract females to their nesting mounds (Wells et al. 2014)
    • Aggression and harassment of females not uncommon
      • Coercion tactics infrequently lead to mating success

Mating system

  • Males and females do not form pair bonds (Birks 1997; Birks 1999)
    • Meet only briefly at incubation mounds
  • Simultaneous polygyny
    • Males mate with multiple females at once (Elliott and Kirwan 2017)
  • Serial polyandry
    • Females mate with different males during a breeding season (Elliott and Kirwan 2017)
      • Loyal to one male at a time

Courtship habitats

  • Incubation mounds typically constructed in moist gullies and woodlands (Kaveney 1958; Jones and Göth 2008)
  • See Incubation Mounds

Mate choice

  • Göth (2007b) suggests that females select mounds, not males
    • Certain male characteristics (e.g., colored neck skin, courtship behaviors) may also attract females
  • Females compete with one another for access to a mound (Göth 2007b)
    • May show loyalty to a male for several weeks
    • Usually chase other females away from the male’s mound
    • May be competing for access to more ideal incubation temperatures within a mound
      • Females observed to lay more eggs and larger eggs in the ideal temperature conditions of 32-35°C (89-95°F)
    • Females often visit the mound without laying (Birks 1999)
      • May gain information to assess mound or mate quality (Jones 1990b)

Courtship behavior and copulation

  • Female behavior approaching a mound (Jones et al. 1995)
    • Moves slowly and quietly
    • Assumes a crouched position
      • Neck tucked in and tail folded
      • May fluff body feathers, droop wings, and spread tail
  • Male behavior in response to female (Jones et al. 1995)
    • Male slowly walks around the top of the mound
    • Pecks at mound material
  • Male display to female, away from the mound (Coles 1937; Dow 1988b; Jones et al. 1995)
    • Less common than female approach
    • Male displays by lowering his body to the ground and spreading his wings widely
  • Males usually aggressive to females (Jones et al. 1995)
    • Females tolerate or avoid male advances that are unsolicited (Birks 1999)
    • Females sometimes solicit males, possibly to avoid harassment while digging and laying (Birks 1999)
    • Some males force copulations (Jones 1990a; Birks 1999)
    • Males appear to expect females to copulate in return for access to the mound (Birks 1999)
      • Have little direct control over female copulation behavior, except when female use mounds to lay eggs
      • Males may chase away females that they did not mate with (Birks 1999)
  • Copulations
    • Often occur at or near the mound (Jones et al. 1995)
    • Last about 5 (range: 3-11) seconds (Jones 1990a)
    • Often take place in the hour prior to egg laying and within a few minutes of a female’s arrival at the mound (60% of cases) (Birks 1999; Elliott and Kirwan 2017)
      • Rare among birds
      • Descending egg probably interferes with fertilization
    • Do not occur after egg-laying (Birks 1999; Elliott and Kirwan 2017)

Reproduction

Breeding

  • Sexual maturity
    • Not known (Jones and Göth 2008)
    • Females (observations from captivity)
      • Göth et al. (2006) report that females did not lay eggs before 11 months of age
        • Possibly because mound sizes were unacceptable to females, aggression displayed by males, or other developmental factors
    • Males (observations from captivity)
      • Göth et al. (2006) report a range in first mound building behavior: 4.5 to 9 months of age
        • Some of this activity may have been “practice” nest building
        • All males in the study produced testosterone by 11 months
  • Breeding season
    • Lasts 6-8 months (Elliott and Kirwan 2017)
      • May be up to 8-10 months (Jones 1988a)
      • Mound building starts May/June (Australian winter) (Jones 1988a)
    • Breeding activity lasts until January/February (southeast Queensland)
  • Changes in physical characteristics during breeding
    • Wattle fuller during the breeding season (Elliott and Kirwan 2017)
      • Shrinks outside of the breeding season
    • Head and neck skin color can be much brighter during courtship (Elliott and Kirwan 2017)
      • Duller outside of the breeding season

Incubation Mounds

Incubation strategy

  • Mound incubation allows for development of more and larger eggs (Vleck et al. 1984)
    • Bird species that sit on their eggs can only incubate one small clutch at a time
  • Mounds must be able to retain heat and moisture (Jones 1988b)
    • Male chooses a site in deep shade

Characteristics

  • Materials
    • Mainly damp leaf litter and soil (Elliott and Kirwan 2017)
    • May also contain roots, sticks, and pebbles (Göth 2007b)
  • Size
    • On average, about 85 cm (33.5 in) high and 300-410 cm (118.1-161.4 in) across (Jones 1988a; Elliott and Kirwan 2017)
      • Sometimes larger
  • Mass
    • Contain 2-4 t (4,480-8,960 lb) of material (Elliott and Kirwan 2017)
    • Much more material on Kangaroo Island: 3-11 t (Seymour and Bradford 1992)
  • Internal temperature (Elliott and Kirwan 2017, and as noted)
    • 31-36°C (87-97°F)
    • Large mounds retain enough heat to maintain stable temperatures for weeks, possibly months (Seymour 1995)
      • Influenced by moisture content

Construction

(Elliott and Kirwan 2017, except as noted)

  • Mounds built by breeding males
    • Usually build a new mound (Jones 1988b)
      • Built in a different location than past few years
      • Not uncommon to build on top of an old mound
    • Takes about 37 (range: 14-77) days
    • Use strong legs and feet to rake together leaf litter and soil into long, narrow strips
      • Up to 100 m, or 330 ft, long (Jones and Göth 2008)
      • Does this for up to two weeks before forming material into a mound
    • Nesting materials initially piled high, but flatten with time (Jones et al. 1995)
  • Usually built in shady areas with closed canopy and an abundance of leaf litter (not eucalyptus)
  • Exception to mound building
    • This species is known to occasionally use human-made compost heaps (Elliott and Kirwan 2017)

Maintenance

  • Males actively maintain their mounds (Seymour 1995; Göth and Astheimer 2006; Göth 2007a)
    • Activities (Jones 1988a)
      • Raking
        • Gather leaf litter and add it to mound
      • Mixing
        • Incorporate new mound material and mix surface layers (horizontal mixing)
        • Dig and refill holes (vertical mixing)
      • Assess mound temperatures while digging holes
        • Exact mechanism untested
          • May use head and neck skin
    • Maintain for up to 8 months (Jones et al. 1995)
  • Stay near mounds for most of the day (Jones et al. 1995)
  • Defend mound site against more dominant males trying to steal the mound (Jones 1988b; Jones and Göth 2008)
    • Younger males often can’t defend their nests against older, more dominant males (Jones 1990b)
  • Spend considerable time adding vegetation/soil and rearranging mound material (Jones 1990a; Frith 2008; Jones and Göth 2008)
    • Far less time intensive, compared to construction phase
    • Mix mound material (Jones and Göth 2008)
      • Horizontally rake surface layers
      • Dig deep holes for vertical mixing
      • Benefits
        • Aids decomposition, stabilizing heat for incubation
        • Underground spaces supplied with more oxygen
          • Important to newly hatched chicks, which breathe heavily, as they dig to exit the mound
  • Temperature regulation (Göth 2007a)
    • Adjust the nests’ temperature by adding material (warmer) or removing material (cooler)
    • Males vary in their ability to regulate the mound’s incubation temperature
      • Ability likely increases with age and experience
  • See Incubation and Hatching

Incubation and Hatching

Egg

  • Size
    • Large (Birks 1999; Göth 2007b)
    • Dimensions
      • A. l. lathami (Vleck et al. 1984; Jones et al. 1995)
        • Approximately 83-94 x 59 mm (8.3-9.4-5.9 cm)
      • A. l. purpureicollis (Jones et al. 1995)
        • Approximately 81-99 x 54-61 mm (8.1-9.9 x 5.4-6.1 cm)
  • Weight
    • Heavy (Birks 1999)
      • About 10% of a Brush-turkey’s body mass
    • About 200 g (7 oz), on average (Göth 2007b; Eiby and Booth 2009)
  • Yolk
    • Large
      • Makes up 50% of all egg contents (Vleck et al. 1984; Seymour 1991)
      • Supplies the energy a chick needs during the long incubation period and to dig out of the incubation mound
  • Shell
    • Color
      • White (Jones et al. 1995)
    • Thickness
      • 1.5 times thinner than a chicken’s eggshell (Grellet-Tinner et al. 2017)
      • Thin surface makes shell more permeable to oxygen (combatting the loss of oxygen to microbes during decomposition) (Seymour 1991)
    • Surface
      • Covered in tiny, microscopic spheres made of calcium phosphate (D’Alba et al. 2014; Grellet-Tinner et al. 2017)
        • Rare – most bird eggshells contain calcium carbonate and glycoproteins instead
        • Protects egg from organic acids in nest material (Grellet-Tinner et al. 2017)
          • Acids cause eggshell thinning
        • Rough surface makes eggs hydrophobic (D’Alba et al. 2014)
          • Prevents bacteria from attaching and infecting the egg
          • Prevents biofilms (e.g., from raindrops) from forming on the shell
            • Biofilms can block the pores that allow oxygen to pass to the embryo
      • Contains Y-shaped pores not found in any extant bird (Grellet-Tinner et al. 2017)
        • Also present in eggshells of a group of dinosaurs called titanosaurs

Egg laying

  • Female Brush-turkeys lay more eggs than most other bird species (Birks 1999)
  • Egg production
    • A female lays eggs over a period of up to eight months (Jones and Göth 2008)
      • Lays one egg at a time (no clutches)
    • Can lay 15-27 eggs in a season (Elliott and Kirwan 2017)
  • Laying in relationship to mound and males
    • Several females may lay in a single mound, protected by a single male (Elliott and Kirwan 2017)
      • Up to 58 eggs observed in a single mound in a season (Jones et al. 1995; Elliott and Kirwan 2017)
      • The average may be closer to 15 eggs per mound
    • A female lays series of eggs with different males (Birks 1999)
      • 5-10 eggs with one male
      • Then a new series of eggs with a different male
      • May lay eggs in up to five different mounds in a season
    • Eggs may be located anywhere within the mound, not just the center (Grellet-Tinner et al. 2017)
  • Behavior
    • To access warmer areas of the mound, a female digs a long, tunnel-like “egg chamber” (Grellet-Tinner et al. 2017)
      • Takes 30-45 minutes (Jones 1988a; Jones et al. 1995)
    • When the female approves of the chamber’s temperature, she lays the egg into it (Jones et al. 1995; Grellet-Tinner et al. 2017)
      • After laying, she stamps her feet to backfill the tunnel
      • Takes about 20 minutes
    • Male often disrupts the female’s work (Jones et al. 1995, except as noted)
      • After laying, male usually chases her away
      • Male closes the hole, if the female does not, to prevent heat loss (Jones and Göth 2008)
      • Male then makes repairs to the nest
  • Paternity
    • In some cases, 20-44% of eggs laid within a mound may not have been sired by the mound owner (Birks 1997)

Incubation and hatching

  • Incubation occurs as microbes (i.e., “microorganisms”) and fungi decompose organic matter that makes up the nesting mound (Jones and Göth 2008)
    • Male adds new material to the mound throughout the breeding season to maintain heat production
  • Incubation period
    • 47-52 days (in captivity) (Elliott and Kirwan 2017)
      • Eiby and Booth (2008) report 42-47 days in Queensland
    • Relatively long incubation period
      • May allow time for a chick’s wings to more fully develop, to aid dispersal and to escape from predators (Dial and Jackson 2011)
  • Effects of incubation temperature
    • Mechanism for sex determination in Brush-turkeys is unclear (Ortega et al. 2017)
      • Brush-turkeys possess classic avian sex chromosomes, but maternal conditions prior to ovulation might also affect egg composition and offspring sex ratio
    • Very high or very low temperatures increase embryo morality (Göth and Booth 2005)
      • Sex-biased mortality (Eiby et al. 2008)
        • Male mortality higher at high temperatures
        • Female mortality higher at low temperatures
    • Eggs incubated at lower average temperatures take longer to hatch (Göth 2007a; Eiby and Booth 2008)
      • Less benefit to chick at hatching:
        • Have less stored energy in their residual yolk
        • Weigh less
        • Take longer to dig out of the mound
  • Nest temperatures (Eiby and Booth 2008)
    • Average 34-35°C (93-95°F); range: 24.5-40.7°C (76-105°F)
    • Embryos experience prolonged periods of less-than-optimal temperatures, but appear to cope with extremes of hot and cold
      • Heavy rain cools the eggs, resulting in delayed hatching and smaller young
  • Hatching
    • Chicks in the same mound hatch at different times (Göth 2001)
    • Hatch at a large size (Starck and Sutter 2000)
      • Weight at hatching: about 80 g (2.82 oz) (Jones et al. 1995)
      • At 20 days old, weigh about 200 g (7 oz) (Marchant and Higgins 1993)
    • Break eggshell with their legs, feet, and back (Seymour 1991; Göth 2002)
      • This may create a space for breathing, while underground
      • Do not use an “egg tooth,” unlike other bird species
    • Begin breathing after breaking through the eggshell (Marchant and Higgins 1993)

Exit from the mound

(Seymour 1991; Göth 2002, except as noted)

  • Parents do not assist
  • Hatching occurs up to 1 m ( 3 ft) deep within mound (Darryl Jones, personal communication, 2018)
  • Chicks rest after hatching
    • On average, 16 hours
    • Their lungs develop full breathing function
  • After resting, dig upwards to the surface
    • Lay on back and scrape at soil with feet
    • Maintain space around themselves in order to breathe
    • Preen in between bouts of digging
      • Mud on feathers could cause hypothermia
  • Takes 40 hours (range: 26-55), on average, to dig out of the mound
    • Includes resting time
  • Also see Development

Parental Care

Role of males

  • Regulate temperature of the incubation mound (Jones et al. 1995)
  • Provide no other care (Göth 2002)

Role of females

  • Provide no care (Göth 2007b)
    • Do not participate in incubation or after-hatching care
  • Invest considerable time in mound/mate choice (Göth 2007b)

Development

Chick description

  • Feathers soft and downy (Elliott and Kirwan 2017)
  • Cryptic coloration (Jones et al. 1995)
    • Body brown
    • Head often a lighter brown
    • Some parts reddish (chest, crown) or buff (neck, chin, throat, some of the head)
    • Chest and belly faintly barred with gray
    • Iris light brown
    • Bill, leg, and foot coloration similar to adults
  • Wings
    • Large (Dial and Jackson 2011)
    • Well-developed feathers, fully developed at hatching (Elliott and Kirwan 2017; Starck 1993; Göth 2002)

Chick adaptations and behaviors

  • Chicks are physically and behaviorally well-developed (Elliott and Kirwan 2017)
  • Highly independent
  • Solitary (Marchant and Higgins 1993)
    • Do not roost communally
    • May congregate around food or for shelter
  • Seek high roosts and refuges when they sense danger (Jones and Göth 2008)
  • Appear to learn to select edible foods through trial-and-error (Göth and Proctor 2002)

Reaching adulthood

  • Grow quickly (Jones and Göth 2008)
    • By nine months of age, juveniles are nearly indistinguishable from adults (Jones and Göth 2008)
    • By 10 months, reach adult body mass
  • Changes in plumage
    • At two weeks of age (Jones and Göth 2008)
      • Tail feathers first appear
      • Lose head and neck feathers
        • Colorful bare skin is exposed
    • By 13 weeks of age, brown feathers are replaced by black feathers (Wong 1999)
    • Also see Plumage

Longevity

In the wild

  • Not well-studied (Jones and Göth 2008)
  • At least nine years (Jones and Göth 2008)

In managed care

  • Maximum of 10-11 years (Comfort 1962)

Mortality and Health

Survival rates

  • Hatching success rates are high (Jones 1988c; Eiby and Booth 2008; Elliott and Kirwan 2017)
    • More than 85% of eggs hatch
  • Chick survival rates
    • Intense predation pressure during the first three weeks of life
      • 0-12% survival in one study in Brisbane, Queensland (Göth and Vogel 2002)
  • Survival to subadult stage is low (Elliott and Kirwan 2017)
    • Only 3-10% survival

Predators

  • Eggs, chicks, young
    • Cats (Marchant and Higgins 1993; Elliott and Kirwan 2017)
    • Foxes (Marchant and Higgins 1993; Elliott and Kirwan 2017)
    • Pigs (Marchant and Higgins 1993; Elliott and Kirwan 2017)
      • Eggs
      • Damage incubation mounds
    • Powerful Owl (Ninox strenura) (Göth 2012)
    • Monitor lizards (Kaveney 1958; Marchant and Higgins 1993; Jones and Göth 2008)
    • Possibly snakes (unconfirmed) (Marchant and Higgins 1993)
  • Adults (Göth et al. 2006; Elliott and Kirwan 2017, except as noted)
    • Cats
    • Foxes
    • Dogs and dingoes
    • Quoll (Jones and Göth 2008)

Under Construction

1887 illustration of a male brush turkey building a mound

 

An 1887 illustration of a male Australian Brush-turkey scratching leaf litter behind him, while building an incubation mound.

Image credit: G. Mirtzel. In: "The Brush Turkey." Scientific American 57(11): p. 162. No known copyright restrictions.

Small Steps

Australian Brush-turkey chick walking

Australian Brush-turkey chicks have brown body plumage, often with tints of red on their head.

Chicks live independently of their parents and other chicks.

Image credit: Maureen Goninan via Wikimedia Commons. Creative Commons License 3.0.

SDZG Library Links