Giant Panda (Ailuropoda melanoleuca) Fact Sheet: Reproduction & Development

Timing/seasonality

• Breed seasonally (Schaller et al. 1985)
• Mating season
• Typically, March to May (Reid and Gong 1999; Garshelis 2009b), when females come into estrus

Mating system

• Polygynous (Reid and Gong 1999; Swaisgood et al. 2016)
• Both sexes mate with multiple (about 3 to 5) partners (Garshelis 2009b)
• Mate sequentially, with pairs staying together for days to weeks before mating (Zhu et al. 2001) (Garshelis 2009b)
• A breeding male will mate with multiple females, sequentially (Schaller et al. 2002; Swaisgood et al. 2016)
• Male–male competition
• Males compete for access to breeding females (Schaller et al. 1985; Reid and Gong 1999)
• Competition initially high but declines as male status/rank is established (Nie et al. 2012a)
• Larger males generally perceived by rivals as being more competitive (more dominant) (Nie et al. 2012a)
• Similar to other bear species

Courtship behavior and copulation

• Finding potential mates
• Both sexes use scent marking, posturing (visual displays), and vocalizations to find and assess potential mates (Charlton et al. 2009; Owen et al. 2013; Wei et al. 2015)
• Female behavior
• Increased scent marking and mating calls, compared to nonbreeding season (Schaller et al. 1985; Swaisgood et al. 2004)
• Influence of other females (Owen et al. 2016b)
• May use odor to advertise receptivity if other females nearby, instead of vocal cues and visual displays (Owen et al. 2016b)
• Male behavior
• Multiple males may pursue a female at the same time (Zhu et al. 2001)
• Also see Communication

Breeding

• Sexual maturity
• About 5 to 7 years (Brambell 1976; Chorn and Hoffman 1978 citing Peking Zoo 1974a; Garshelis 2009b)
• Estrus
• Short estrus period
• Peak estrus lasts less than a week (Garshelis 2009b)
• Females receptive for 10 days, on average (Chorn and Hoffman 1978 citing Peking Zoo 1974a)
• Range: 4 to 14 days (Chorn and Hoffman 1978 citing Peking Zoo 1974a)
• In wild populations, occurs March to May (Chorn and Hoffman 1978)
• Second estrus can occur in autumn, if female does not conceive (Chorn and Hoffman 1978)
• Interbirth interval (time between litters)
• 2 to 3 years (Garshelis 2009b)
• Lifetime reproductive success
• Females can give birth to 6 or more cubs in their lifetime (Garshelis 2009b)
• Not “poor breeders,” as once believed

Gestation

• Duration
  • Variable, but on average, about 3 to 5.5 months (Garshelis 2009b)
    • Variable, as embryo development and/or implantation sometimes delayed (occurs in other mammals, as well) (Garshelis 2009b)

Birth

• Timing
  • Cubs usually born in August or September (Chorn and Hoffman 1978; Garshelis 2009b)
• Location
  • Females give birth in sheltered cavities inside rock caves or trees with a hollow base (Schaller et al. 1985; Zhu et al. 2001; Garshelis 2009b)
    • More enclosed spaces than surrounding environmental, perhaps offering protection and warmer temperatures (Zhu et al. 2001)
      • Newborn pandas cannot yet regulate their body temperatures (Zhu et al. 2001)
    • Often located close to water, perhaps to allow the mother to drink while the cub is still developing (Swaisgood et al. 2016)
  • May seek sites at lower elevations prior to birth (Zhu et al. 2001)
• Litter size
  • Usually 1 cub raised by mother in wild populations—the first born, if healthy (Garshelis 2009b)
    • Often 2 (rarely 3) cubs born but mother very challenged to hold, suckle, and produce milk for more than one cub at a time (Brambell 1976, referring to Peking Zoo observations; Chorn and Hoffman 1978)
      • In managed care, animal care specialists help mother care for twin cubs by swapping/rotating them during the day
    • Only bear species that regularly gives birth to more cubs than can be raised (Garshelis 2009b)
      • Benefits/explanation for this reproductive strategy not yet understood (Garshelis 2009b)
• Newborn
  • Appearance
    • Pink skin exposed; only sparse white hairs (Chorn and Hoffman 1978 citing Peking Zoo 1974a; Garshelis 2009b)
    • See “Newborn” in Life Stages for early development
  • Weight at birth
    • About 90 to 130 g (Brambell 1976; Chorn and Hoffman 1978 citing Peking Zoo 1974a)
      • Garshelis (2009b) states 80 to 200 g, or 0.1% of the mother’s weight
    • Rapidly gain weight (Schaller et al. 1985)
  • Size at birth
    • 80 to 200 g (3 to 7 oz) (Garshelis 2009b)
      • Across bear species, all newborns are small relative to their mother’s weight (Ramsay and Dunbrack 1986)
        • Giant panda newborns particularly small—may weigh less than 0.1% of its mother's weight, one-third to one-quarter that of other bears (Garshelis 2009b)

Denning behavior

• Investment in care
  • Mother stays in den to care for newborn for about 2 to 4 weeks (Zhu et al. 2001)
    • Stays with infant and keeps it close to keep it warm (Zhu et al. 2001)
    • Mother fasts during this time (as they do other bear species) (Zhu et al. 2001)
• May occupy (and move the cub) to several new den sites (Zhu et al. 2001)
• Mother may place branches at the den entrance (Zhu et al. 2001)
  • Zhu et al. (2001) proposed this might better conceal the cub or stop it from crawling away
• Mother and cub stop using dens when cub can regulate its body temperature, when cub can thermoregulate without an enclosed shelter (Zhu et al. 2001)

Mother’s interactions with young

• Mother usually keeps newborn in physical contact with her chest (near nipples for suckling) for several weeks after birth (Schaller et al. 1985)
  • Provides warmth and protection (Schaller et al. 1985)
  • Mother often sits upright or sometimes rests her head on a hindleg “as a pillow” (Schaller et al. 1985)
• Picks cub up in mouth, if she needs to walk or move dens (Schaller et al. 1985)
  • Does not carry newborn around with front paws (Schaller et al. 1985)
• Licks cub for cleaning and to stimulate waste elimination (excretion) (Schaller et al. 1985)
  • Mother consumes cub’s waste, presumably to prevent odors from attracting predators (Schaller et al. 1985)
• Also see Newborn

Newborn (days to 1 month old)

• Giant pandas most underdeveloped of all bears at birth—and even all placental mammals
  • Grow rapidly, similar to other bears (Chorn and Hoffman 1978)
• Newborns entirely reliant on mother
  • Cannot move around independently (Brambell 1976)
  • See Parental Care
• Eyes closed (Brambell 1976; Chorn and Hoffman 1978 citing Peking Zoo 1974a)
• Skin pink, with sparse white hairs (Chorn and Hoffman 1978 citing Peking Zoo 1974a; Zhang et al. 1996; Garshelis 2009b)
  • Skin turns gray where fur will be black after about 8 to 10 days old (Zhu et al. 2001)
  • Black hairs begin to appear at 1 to 2 weeks (Brambell 1976; Chorn and Hoffman 1978)
  • Well-developed coat by 3 weeks (Garshelis 2009b)
  • By 30 days, have full adult coloration (Chorn and Hoffman 1978)
• Tail long, relative to body size (Brambell 1976; Schaller et al. 1985)
• No teeth (Chorn and Hoffman 1978 citing Peking Zoo 1974a)
• Behavior
  • Suckle frequently
  • Make sharp, high-pitched chirps and “squawks,” which draw mother’s attention and care (Schaller et al. 1985)

Infant (1 month to 1 year old)

• By 40 to 50 days
  • Eyes usually fully open (Schaller et al. 1985)
  • Can raise head and hold it steady (Schaller et al. 1985)
  • Attempt crawling (Schaller et al. 1985)
• Around 2 months
  • Attempt first steps (Schaller et al. 1985)
• By 3 months
  • Vocalize much less (Swaisgood et al. 2003b)
  • Vision better developed (Chorn and Hoffman 1978)
  • First (deciduous) teeth begin to erupt (Chorn and Hoffman 1978; Zhang et al. 1996; Edwards et al. 2006b)
  • Able to take more coordinated steps (Schaller et al. 1985)
  • Hind limbs support full body weight (Chorn and Hoffman 1978 citing Peking Zoo 1974a)
• By 5 months
  • More active, walking and running, rolling, and climbing on mother (Chorn and Hoffman 1978) (Schaller et al. 1985)
  • Suckle only once or twice per day (Schaller et al. 1985)
• By 6 months
  • Young has canine, incisor, and premolar teeth, and begins to eat solid food (Schaller et al. 1985)
• By 1 year
  • All permanent teeth have erupted (Zhang et al. 1996)

Managed care

• Check AZA Species Survival Statistics (if available)

Survival rates

• Li et al. (2017) reported higher mortality in winter and early spring, likely because of scarce bamboo resources
• Mortality may be higher among subadults and females compared to adults and males (Li et al. 2017), at least in some populations/regions

A giant panda mother holds her newborn cub against her body.

Cubs develop slowly. Teeth begin erupting during the third month but nursing continues for 8 or 9 months.

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

Garshelis (2004)
Howard et al. (2006)
Nie et al. (2012)
Owen et al. (2016b)
Pan & Lü (1993)
Reid & Gong (1999)
Schaller et al. (1985)
Snyder et al. (2004)
Swaisgood et al. (2003b)
Zhang et al. (2007b)
Zhu et al. (2001)