Modeling longterm viability in African elephants

The longer-term viability of African elephant populations in semiarid regions was modeled by Peter Armbruster and Russell Lande. Their stochastic model of individual births and deaths used twelve 5-year age classes and discrete 5-year time steps. The main feature of their model is the range of environmental fluctuations incorporated in the form of 10-year (mild), 50-year (moderate), Population viability analysis in Asian elephants. Probability of survival for 100 years is plotted as a function...

Home range size

The big-game hunting literature of colonial Asia and Africa has many tales of the propensity of elephants to trek long distances using well-trodden paths, often across steep mountain slopes. Elephant bulls and family herds usually restrict their daily movements, as measured in a straight line, to a few kilometers or at most 10-20 km, but exceptional distances of 90-180 km have been observed in the dry Etosha region of Namibia. Of greater ecological interest is the range size of elephants on a...

Causes of death and mortality rates

Survivirship Curve Southern Sea Otter

The causes of death and the mortality rates are notoriously difficult to estimate for most wild mammalian species, including the elephant. Carcasses in the field are usually putrefied, making it difficult to identify the cause of death, especially if a pathogen is involved. Juveniles in the population are usually under-represented in a collection of remains discovered thus, estimation of age-specific mortality rates for the younger age classes, vital for understanding population dynamics,...