2 resultados para morphological adaptation
em BORIS: Bern Open Repository and Information System - Berna - Suiça
Resumo:
Two sympatrically occurring bat species, the greater mouse-eared bat (Myotis myotis (Borkhausen, 1797)) and the lesser mouse-eared bat (Myotis blythii (Tomes, 1857)) (Chiroptera, Vespertillionidae), share numerous similarities in morphology, roosting behaviour, and echolocation and are often difficult to distinguish. However, despite these similarities, their foraging behaviour is noticeably different. Our aim was to examine the extent to which these different foraging strategies reflect morphological adaptation. We assessed whether the morphology of the wing, body, and tail differed between M. myotis and M. blythii. In addition, in a laboratory experiment involving an obstacle course, we compared differences in manoeuvrability by relating them to our morphological measurements. The two species differed in their overall size, wing-tip shape, and tail-to-body length ratio. The generally smaller sized M. blythii performed better in the obstacle course and was therefore considered to be more manoeuvrable. Although differences in wing-tip shape were observed, we found the most important characteristic affecting manoeuvrability in both species to be the tail-to-body length ratio. Additionally, when we compared two bats with injured wing membranes with unharmed bats of the same species, we found no difference in manoeuvrability, even when the wing shape was asymmetric. We therefore postulate that morphometric differences between the two species in their overall size and, more importantly, in their tail-to-body length ratio are the main physical characteristics providing proof of adaptation to different foraging and feeding strategies.
Resumo:
This study aims to characterize Azikheli, an undocumented buffalo breed, in its home tract (Khwazakhela, Swat, Pakistan) under traditional farming conditions. For this purpose, 108 buffalo cows and 27 bulls were randomly selected. Mean, standard error, Student's t test and Chi-square test were used for various comparisons. The results show that the majority of animals have a brown coat colour. Cows have significantly higher heart girths, longer horns, longer necks and wider faces at the level of the eyes than bulls, whereas bulls have significantly longer bodies, longer ears, thicker horns, thicker necks and larger hooves than cows. Horns are flat laterally, directed backwards and then slightly upwards without twisting, leading to a sickle to semi-sickle appearance. Owing to its small body size and brown coat colour, the breed is well adapted to mountain slope grazing and thrives well away from swamps. Its adaptation to mountainous ecosystems warrants its in situ conservation.