Marsh, 1995:

"The literature and recent unpublished data on the breeding cycle and life history of the dugong (Dugong dugon) are summarised. The studies were based on the analysis of carcasses from animals accidentally drowned in shark nets or killed by native hunters in northern Australia and in Papua New Guinea. Age was estimated by counting the dentinal growth-layer groups in the tusks, the deposition rate deduced from the seasonal pattern of growth-layer group deposition. The maximum estimated age was 73 years, and the minimum pre-reproductive period was 9 or 10 years in both sexes. The pre-reproductive period was variable and ranged 15 to 17 years in some animals. Neither males nor females were continuously in breeding condition and breeding was diffusely seasonal. A single calf was usually born after a gestation period of about 13 months. Calves suckled for at least 18 months. Estimates of mean interbirth interval based on pregnancy rates and placental scar counts ranged from 3 to 7 years in various samples. Variation between years was marked in the proportions of breeding male and females. Reliable data on age-specific fecundity or mortality are not available. Population simulations indicated that, with even the most optimistic combination of life history parameters and a low rate or mortality, a dugong population probably does not increase at more than about 5% or 6%/year."

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Citation and/or URL

Marsh, H. 1995, The life history, pattern of breeding and population dynamics of the dugong, In: Population and Biology of the Florida Manatee, eds. T.O'Shea, B.B. Ackerman and H. Pereival, US Fish and Wildlife Service, Washington, D.C., 75-83

Spatial Coverage

Northern Australia and Papua New Guinea.

Temporal Coverage

1970's through to late 1980's

Update Frequency

Not applicable 

Other Information

None