RESUMO
Black-crested gibbons (Hylobates concolor concolor) inhabit the subtropical forests of Southern China and Northern Vietnam, and have never previously been the subject of any systematic behavioral or ecological study. This report presents the findings of a three-month census and survey of black-crested gibbons in the Wuliang and Ailao Mountain Game Reserves in Yunnan province, China. The censusing methods used here were similar to those techniques used during other census studies of gibbons. The sites visited were subtropical broadleaf evergreen forests, with trees belonging to the families Fagaceae, Theaceae, Magnoliaceae, Lauraceae and Elaeocarpaceae. A total of 23-25 groups of black-crested gibbons were documented from 4 sites visited, and a group density estimate from all sites averaged 0.82 groups/km2. These gibbons were found to be polygynous with an average family group size of 7-8 animals, comprising 1 adult male, 1-4 adult females and numerous offspring of various ages. Some of the ecological and evolutionary implications of these findings are also presented.
Assuntos
Hominidae , Hylobates , Animais , China , Demografia , Feminino , Masculino , Dinâmica Populacional , Especificidade da EspécieRESUMO
A new estimate of the phylogenetic relationships among the nine gibbon taxa is presented, based on a compatibility analysis of 55 morphological and behavioural characters. The phylogeny presented here differs somewhat from those of other studies, but there appears to be a basic consensus that: the siamang and concolor gibbons represent the earliest forms to speciate; the agile, lar, moloch, Müller's, and pileated gibbons represent the lates forms to speciate; with the Kloss and hoolock gibbons representing intermediate forms. Although the hypotheses regarding the evolutionary direction of these characters remain subjective due to the lack of gibbons in the fossil record, the method used is totally objective in its approach and is repeatable when further data become available.
