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Relative size of hearts and lungs of small bats

100%

Canals M., Atala C., Grossi B., Iriarte-Diaz J.

Acta Chiropterologica

2005

tom 07

nr 1

We estimated the heart and lung size of several species of small bats (Tadarida brasiliensis, Mormopterus kalinowski, Myotis chiloensis, Histiotus macrotus, H. montanus, Lasiurus borealis and L. cinereus) and compared these values to those of bats of larger size and other mammals. Our results confirmed that bats have the largest relative heart and lung size of all mammals. This is associated with the high energetic costs of flight. As expected, the mass-specific lung and heart sizes of small bats were larger than those of large bats. However, although relative heart mass decreased according to body mass, Mb−0.21, lung volume was nearly isometric with body mass (exponent = 0.90). This exponent was close to unity, and between exponents reported previously (0.77 and 1.06). This suggests that small bats compensate the energetic cost of flight mainly by changes in cardiovascular morphology. The relative heart mass of both H. macrotus and H. montanus was particularly large, representing 1.71 and 2.18% of total body mass, respectively. These values correspond to 121.3 and 162.7%, respectively, of the expected values from allometric relationships. In these big-eared bats, the large hearts could be attributed to the energetic costs induced by the ears' drag.

Biomechanic consequences of differences in wing morphology between Tadarida brasiliensis and Myotis chiloensis

100%

Iriarte-Diaz J., Novoa F. F., Canals M.

Acta Theriologica

2002

tom 47

nr 2

The wing morphology of bats is very diverse, and may correlate with energetic, behavioural, and ecological demands. If these demands conflict, wing shape may reflect compromise solutions. In this study, we compared the wing morphology of two bats, Tadarida brasiliensis (Geoffroy, 1824) and Myotis chiloensis (Waterhouse, 1828), that differ in body size, habitat, and foraging behaviour. We analyzed features of bio- mechanical and energetic relevance, and sought evidence of compromise solutions to energetic, ecological, and behavioural demands. We found that wing span of both species conformed to expectations based on allometric relationships, but that although the wing area of M. chiloensis did not differ from predictions, the wing area of T. brasiliensis was lower. M. chiloensis possessed an unusually low second moment of area of the humerus. Wing form of M. chiloensis is consistent with highly maneuverable flight needed to live between shrubs and wooded habitats, and its low aspect ratio and low wing loading indicate a high energetic cost and a low flight speed, respectively. The low humeral second moment of area may be related to a reduction of wing mass and may result in decreased inertial power. In contrast, T. brasiliensis showed high aspect ratio and wing loading, characteristic of high speed, energetically economic flight.

Ograniczanie wyników

1 Acta Chiropterologica

1 Acta Theriologica

2 Canals M.

2 Iriarte-Diaz J.

1 Atala C.

1 Grossi B.

1 Novoa F. F.

1 2005

1 2002

Wyniki wyszukiwania

Relative size of hearts and lungs of small bats

Biomechanic consequences of differences in wing morphology between Tadarida brasiliensis and Myotis chiloensis