Proximate factors influencing dispersal decisions in male mountain gorillas, Gorilla beringei beringei

We examined demographic and behavioural influences on the dispersal decisions of 31 male mountain gorillas living in mixed-sex groups. Approximately half (45%) of silverback males dispersed from the groups in which they matured. Mean dispersal age corresponded with the age of physical maturity. For two-thirds (64%) of males, dispersal was a one time decision. The […]

Birth sex ratio in captive mammals: Patterns, biases, and the implications for management and conservation

Abstract 10.1002/(SICI)1098-2361(2000)19:13.3.CO;2-M Sex allocation theory predicts that a female should produce the offspring of the sex that most increases her own fitness. For polygynous species, this means that females in superior condition should bias offspring production toward the sex with greater variation in lifetime reproductive success, which is typically males. Captive mammal populations are generally […]

Public information in selection of nesting colony by lesser kestrels: which cues are used and when are they obtained?

The use of public information is an important component of breeding habitat selection in birds, especially for colonial species. In this way, individuals can reduce the costs of information acquisition, allowing them to make faster and better settlement decisions based on the quality of breeding sites. We studied the roles of two possible sources of […]

Adaptive effects of natal experience on habitat selection by dispersers

Despite considerable interest in the effects of natal experience on habitat selection, little attention has been paid to the adaptive significance of this behaviour. Here we suggest that experience in the natal habitat may provide dispersers with information that improves the decisions they make while searching for a new habitat. In animals with time-limited sequential […]

Leaving home: A study of laboratory mouse pup independence

Juvenile wild house mice leave their mothers at 8 weeks (+). In contrast, laboratory strains of mice (lab mice) are typically ‘weaned’ at postnatal day (PND) 21. Lab mice might mature faster than their wild forebears; but if they do not, standard laboratory weaning likely involves maternal deprivation. We therefore investigated when lab mice voluntarily […]

The Behaviour After Release of Captive-reared Fox Cubs

The release of animals from captivity frequently leads to a period of erratic movement behaviour which is thought to expose the animal to a high risk of mortality. Twenty-six faxes which had been reared at a wildlife hospital or captive-bred, were radio-collared when nearly full-grown and released without site acclimation. Immediately after release there was […]

Understanding avian vision: The key to using light in bird management

Vision is a primary and highly developed sensory pathway in birds. Light, both diffuse and wavelength-specifc (e.g., as produced by lasers) has recently been demonstrated as a potential means of effecting changes in timing and consistency of flock response to an approaching vehicle (simulating an aircraft) and as an avian dirsal method. However, in experiments […]

Spatial and Temporal Variability in the Foraging Areas of Breeding King Penguins

King Penguins (Aptenodytes patagonicus) from breeding islands in the Indian Ocean (Crozet and Kerguelen Islands) and the Atlantic Ocean (South Georgia and Falkland Islands) were equipped with global location sensors to compare their foraging patterns during different times of the year. In summer, all birds investigated traveled toward the Antarctic Polar Front (APF), irrespective of […]

Differences in social behaviour between group-living and solitary African striped mice, Rhabdomys pumilio

Little is known about the extent to which solitary individuals differ in their social behaviour from group-living ones within the same species. Using the socially flexible African striped mouse, we tested through a series of dyadic encounters in a neutral arena whether group-living mice that later became solitary differed from their philopatric conspecifics. We compared […]

Promiscuity, inbreeding and dispersal propensity in great tits

Mating with relatives leads to inbred offspring, which are likely to experience reduced fitness owing to the expression of deleterious recessive alleles. Constraints in social mate choice do not always allow individuals to avoid pairing with kin. A possible means of inbreeding avoidance is to engage in extrapair copulations with unrelated extrapair individuals. In a […]