American Flamingo (Phoenicopterus ruber) Fact Sheet: Reproduction & Development

• Opportunistic, erratic breeders.
• Breeding season varies within and among populations. Rainfall most important cue.
• First breeding at approximately 3 to 6 years
• Only fully colored adults participate in breeding.
• Most populations require a large colony for successful breeding (at least 50, but ideally hundreds or thousands). Exception: Galapagos populations will breed in groups of 5 to 10 pairs.
• Form long term pair bonds that last through several breeding seasons
• Courtship displays are used to synchronize breeding in colonies. Copulation does not occur until the pair leaves the group.

Nesting

• Make nests of mud by scooping with lower jaw and piling bits of mud on top of one another, smoothing with their feet. Form small, cone-shaped mounds with scooped out top.
• Approximately 30 cm (12 in.) high
• Usually a small moat is excavated around the base.
• Sometimes twigs or roots used. On rocky islands without mud, may be pile of stones.
• Both sexes build nests.
• Old nests often reused.
• Nests in a colony are built close together.

Egg Laying

• Eggs white. Pinkish on rare occasions.
• Egg is laid on the bowl-shaped top of the mud nest
• Clutch size: one egg; rarely two
• Incubation: 27-31 days; done by both parents
• Broods: one per year

Nestlings

• Covered with white/gray down
• Leave nest after 5-8 days
• Form "crèches," groups of chicks, after leaving the nest. Small number of adults care for the crèches, which can contain hundreds or thousands of chicks.

Young

• Bills are straight for first two weeks, and then begin to develop the characteristic shape and the filtering apparatus.
• Eyes are dark brown.
• Fed "crop milk" for the first couple of months (see Diet and Feeding). Drip milk from adult beak into young's mouth. Both parents feed young this way.
• Mortality estimated at 30% during the first year.
• Feed independently at 28-42 days, but parents continue to feed until birds fledge
• Fledge at 9-13 weeks.
• In about 4 weeks, downy plumage turns dark gray.
• In 6 to 10 months, down gives way to regular feathers; plumage turns whitish gray, primaries black; beak is a light pink with black tip; legs a grey brown and begin to turn pink.

Subadult

• Plumage begins to turn pale pink; darker pink on the wings.
• As adulthood is approached, pale pink turns deeper and brighter
• Base of the neck turns first, giving the appearance of a collar.

Adult

• Overall color a deep red/orange when sexual maturity is reached, at 3-5 years.
• Eyes are light yellow.
• Upper wings are last to show full color.
• Legs and feet turn deeper pink-red color; beak is yellow at base, red/orange in the middle, and black at the tip.

Wild populations

• Unknown

Managed care

• Median life expectancy
  • 26.3 years (AZA 2024)

• Tropical storms and hurricanes can be lethal to coastal dwelling flamingos
• Flooding, reduced salinity reduces food resources
• Predators
• Raccoons, margay, gray fox, jaguar, crocodiles, humans, and probably birds of prey

The San Diego Zoo and San Diego Zoo Safari Park raise several different kinds of flamingos.

Together, the Zoo and Park have successfully hatched over 450 chicks.

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

del Hoyo et al. (1992)
Ehrlich et al. (1988)
Rooth (1965)
Sprunt (1973)