Flying high: limits to flight performance by sparrows on the Qinghai-Tibet Plateau.
J Exp Biol
; 219(Pt 22): 3642-3648, 2016 11 15.
Article
em En
| MEDLINE
| ID: mdl-27609759
ABSTRACT
Limits to flight performance at high altitude potentially reflect variable constraints deriving from the simultaneous challenges of hypobaric, hypodense and cold air. Differences in flight-related morphology and maximum lifting capacity have been well characterized for different hummingbird species across elevational gradients, but relevant within-species variation has not yet been identified in any bird species. Here we evaluate load-lifting capacity for Eurasian tree sparrow (Passer montanus) populations at three different elevations in China, and correlate maximum lifted loads with relevant anatomical features including wing shape, wing size, and heart and lung masses. Sparrows were heavier and possessed more rounded and longer wings at higher elevations; relative heart and lung masses were also greater with altitude, although relative flight muscle mass remained constant. By contrast, maximum lifting capacity relative to body weight declined over the same elevational range, while the effective wing loading in flight (i.e. the ratio of body weight and maximum lifted weight to total wing area) remained constant, suggesting aerodynamic constraints on performance in parallel with enhanced heart and lung masses to offset hypoxic challenge. Mechanical limits to take-off performance may thus be exacerbated at higher elevations, which may in turn result in behavioral differences in escape responses among populations.
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Base de dados:
MEDLINE
Assunto principal:
Ecossistema
/
Pardais
/
Voo Animal
Tipo de estudo:
Prognostic_studies
Limite:
Animals
País como assunto:
Asia
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article