David M. Pratt

Giraffe social behaviour

Many features recommend the giraffe (Giraffa camelopardalis) for behavioural study: it is big, abundant, conspicuous, active by day, reasonably trusting of people, deliberate, and the best self-marked animal in existence. Surprisingly, its social behaviour has been largely neglected. We studied giraffe exclusively for the following periods: February–March, 1975 and January–December, 1977 in the Serengeti National Park, July 1979–June 1980 in the Arusha National Park, and January–October, 1981 in the Tarangire National Park, totalling 3264 hours of observation directed principally to social behaviour. All of these parks are in northern Tanzania. An earlier paper (Pratt and Anderson 1979) presented the results of a years investigation of giraffe cow-calf relationships in the Serengeti National Park. That study demonstrated the strength of the cow-calf bond in agreement with the findings of Langman (1977) and described in quantitative fashion the behavioural patterns and interactions of mother and young, es...

Population, distribution, and behaviour of giraffe in the Arusha National Park, Tanzania

Summary In a years study of the giraffe population of the Arusha National Park we identified 462 individuals. The cumulative first sightings of individuals were fitted to a logistic model that gave an estimated total population of 471. Immatures accounted for only 24% of the population. Twenty-two calves were born during the period of study. The giraffe of the Park are divided into ‘North’ (more precisely northeastern) and ‘South’ (southeastern) subpopulations, and although there is no barrier between them, only 3% of the population (all bulls) were ever seen in both the northern and southern parts of the Park. The northern region is further divided into four areas, each with its own assemblage of individuals, which were seldom seen elsewhere. Bulls and male juveniles were seen less often relative to their numbers than were cows and female juveniles. This indicates that they spend a greater proportion of the time in the forest than do the females. A partial list of plants eaten by giraffe in the Park is ...

Intraspecific signalling of hunting success or failure in Urosalpinx cinerea say

Abstract In a choice chamber, starved oyster drills ( Urosalpinx cinerea Say) were repelled by the effluent of starved oyster drills and attracted to the effluent of satiated oyster drills. This combination of responses may be expected to increase foraging efficiency by directing the snails away from unproductive areas and toward their prey.