Abstract: lsquoLekrsquo breeding systems, where males defend small, clustered mating territories, are thought to occur where the distribution of females is heavily clumped but males are unable to defend resources used by females. In this paper, we describe a breeding system in fallow deer where males are able to defend resources used by females but the most successful bucks instead defend small territories on a traditional mating ground; where the lek is sited in an area not heavily used by females at other times of year and is visited primarily by females in or close to oestrus; and where mating success on the lek is related to territory position and to male phenotype but not to the resources available on different lek territories. Comparisons with other ungulates suggest that lek breeding species fall into two groups: those where leks are regularly visited by herds of females many of which are not in oestrus and those, like fallow deer, where leks are visited primarily by oestrous females. In the latter species, it is unlikely that females visit the lek for ecological reasons.

Abstract: Abstract The preflight behaviour of whooper swans Cygnus cygnus and Bewick's swans Cygnus columbianus bewickii was examined to determine the adaptive significance of the ritual. Analysis of the preflight sequence revealed that the rate of signalling became significantly faster as the time of takeoff approached. This provides the first quantitative evidence that a threshold of excitability is responsible for triggering synchronised flight in social units. Two ultimate and two proximate factors that affect this threshold were uncovered. They are: 1) Maintaining proximity to partners—flight was delayed by birds with non-attentive mates and signalling lasted on average four times longer than those whose mates showed more interest. 2) Maintaining flock cohesiveness—birds which performed signals for longer periods while swimming among uninterested birds were successful in attracting followers 61% of the time. 3) The bird's feeding performance related to dominance status—less successful feeders (potentially hungry birds), flew after little time and few signals. 4) The type of feeding opportunity at the eventual destination—birds which flew to provided feeds (nutritious barley) spent less time performing preflight signals than when they flew to forage on grass fields.

Abstract: The Asian wild horse, or Przewalski's horse (Equus przewalskii), is believed to currently survive only in captivity. There are more than 660 individuals in over 70 zoological collections, and animals are available for reintroduction. The Przewalski's horse had been bred in captivity for 12 generations, and inbreeding has occurred. Genetic variability has been lost, and released animals will require acclimatization on or near release sites. In China, a program is under way for acclimatization, breeding, and release of wild horses, and plans are being made for a similar program in Mongolia. (LCA)