Behavioural adaptations to flight into thin air.
Biol Lett
; 12(10)2016 Oct.
Article
em En
| MEDLINE
| ID: mdl-28120805
ABSTRACT
Soaring raptors can fly at high altitudes of up to 9000 m. The behavioural adjustments to high-altitude flights are largely unknown. We studied thermalling flights of Himalayan vultures (Gyps himalayensis) from 50 to 6500 m above sea level, a twofold range of air densities. To create the necessary lift to support the same weight and maintain soaring flight in thin air birds might modify lift coefficient by biophysical changes, such as wing posture and increasing the power expenditure. Alternatively, they can change their flight characteristics. We show that vultures use the latter and increase circle radius by 35% and airspeed by 21% over their flight altitude range. These simple behavioural adjustments enable vultures to move seamlessly during their annual migrations over the Himalaya without increasing energy output for flight at high elevations.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Falconiformes
/
Voo Animal
Limite:
Animals
País/Região como assunto:
Asia
Idioma:
En
Revista:
Biol Lett
Assunto da revista:
BIOLOGIA
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
Butão