Journal of Zoology · 2001 · 371 citations · 42 references
Life SciencesDemographyZoologyHistorical DemographyMammalogyReproductive DemographyMammalian Life HistoryMammalian Population BiologyMammalian ReproductionMortality ProfilesWildlife DemographyBirth Interval DynamicsBirth Interval PatternsBirth Rate AnalysisCalf Survival RatesMammalian Population HistoryMortality RatesSex Ratio DynamicsVital Rates Estimation
Abstract This paper presents basic demographic parameters of African elephants ( Loxodonta africana ) living in and around Amboseli National Park, Kenya. The study was conducted from 1972 to the present and results are based on the histories of 1778 individually known elephants. From 1972 to 1978, the Amboseli elephant population declined and then increased steadily from 1979 to the present. Births occurred throughout the year but over 80% occurred between November and May. Birth rate varied from year to year with a pattern of peaks and troughs at 4‐ to 5‐year intervals. The birth sex ratio did not differ significantly from 1:1. Mean age at first birth was 14.1 years, determined from a sample of 546 known‐age females. Mean birth interval ( n = 732) was 4.5 years for 255 females. Fecundity and calf survival varied by age of the females. Mortality fluctuated from year to year. Sex‐specific mortality rates were consistently higher for males than females at all ages.
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The Intrinsic Rate of Natural Increase of an Insect Population
L. C. Birch · Journal of Animal Ecology · 1948 · 2.6K citations
Reproductive Effort and Terminal Investment in Iteroparous Animals
Tim Clutton‐Brock · The American Naturalist · 1984 · 956 citations
Life Sciences, Biology, Zoology +17
AGE CRITERIA FOR THE AFRICAN ELEPHANT
R. M. Laws · African Journal of Ecology · 1966 · 483 citations