More than 70 h of positional behaviour data were collected on the red-shanked douc langur Pygathrix nemaeus, Delacour's langur Trachypithecus delacouri, Hatinh langur Trachypithecus laotum, and the white-cheeked crested gibbon Hylobates leucogenys in January and February of 2001 at the Endangered Primate Rescue Center of Cuc Phuong National Park, Ninh Binh Province, Vietnam. Equal amounts of instantaneous and continuous bout data were collected for each of the four species. All animals were housed in enclosures of 10×5×3.5 m with similar substrates, and lived in small, species-appropriate social groups. The positional behaviour of white-cheeked crested gibbons was as expected with >80% of locomotor bouts and 60% of postures being suspensory in nature. The positional behaviour of the Delacour's and Hatinh langurs was similar to that reported in the literature for other Asian colobines with >90% of the locomotor bouts being quadrupedal walking, running, and bounding on tops of arboreal supports. Postures were dominated by sitting in and sitting out with forelimb suspension associated with <10% of these behaviours. The positional behaviour of the red-shanked douc langur is intermediate in nature between the Delacour's and Hatinh langur and the white-cheeked crested gibbon. Locomotion is nearly evenly divided between arm-swinging (46%) and quadrupedal walking and running bouts (54%). Forelimb suspensory postures were three times more frequent for the red-shanked douc langur than they were for the Delacour's langur.

Secondary flightlessness has evolved independently many times in birds. Morphological changes in the pectoral girdle and flight feathers and changes in body size have been associated with the evolution of flightlessness, and it has also been suggested that flightless birds have relatively small brains. We therefore tested whether flightlessness is related to changes in relative brain size. Relative brain size was compared between volant and flightless species using both conventional statistics and modern comparative methods within nine taxonomic groups. No significant difference was found between flightless and volant species in six of these groups, regardless of whether body mass or tibiotarsal measurements were used as estimates of body size. Species with relatively smaller brains compared with their volant relatives were the great auk Pinguinus impennis, the kakapo Strigops habroptilus and some species of penguin. Thus, we found no evidence of a general correlation between the evolution of secondary flightlessness and the evolution of relatively small brains in birds. This suggests that neural requirements are not significantly different between flightless and volant species, although our methods may have overlooked subtle neurological changes that do not result in markedly different endocranial volumes.

Senescence can be defined as accelerating phenotypic deterioration with old age. For traits that grow throughout life, such as the horns of some ungulates, senescence may be expressed as a decrease in annual growth rates, or an increase in asymmetry, in the years preceding death. Age-specific yearly horn-growth segments of 378 male Alpine ibex Capra ibex L. that died from natural causes were analysed in the Gran Paradiso National Park (Italian Alps). Horn annuli displayed fluctuating asymmetry. The hypothesis that asymmetry and size of the annuli of the horns could predict annual survival probability was tested. It was found that between 5 and 11 years of age, male ibex that grew shorter annuli than the average for the population had a greater probability of mortality over the following years than those with greater rates of horn growth. Horn asymmetry and mortality rates were not significantly correlated. Annulus size, reflecting the onset of senescence, seemed to be a better indicator of individual quality than annulus asymmetry.