TY  - JOUR
AU  - Watanabe Yuuki Y, Takahashi Akinori
PY  - 2011//
TI  - Poor flight performance in deep-diving cormorants.
T2  - J. Exp. Biol.
JO  - The Journal of experimental biology
SP  - 412 -21
VL  - 214
IS  - Pt 3
KW  - Animals
KW  - Biomechanics
KW  - Birds
KW  - Birds: physiology
KW  - Body Weight
KW  - Diving
KW  - Diving: physiology
KW  - Energy Metabolism
KW  - Female
KW  - Flight
KW  - Animal
KW  - Animal: physiology
KW  - Male
KW  - Muscle
KW  - Skeletal
KW  - Skeletal: physiology
KW  - Respiration
KW  - Seawater
KW  - Swimming
KW  - Swimming: physiology
KW  - Water
KW  - Wing
KW  - Wing: anatomy & histology
KW  - Wing: physiology
KW  -
N2  - Aerial flight and breath-hold diving present conflicting morphological and physiological demands, and hence diving seabirds capable of flight are expected to face evolutionary trade-offs regarding locomotory performances. We tested whether Kerguelen shags Phalacrocorax verrucosus, which are remarkable divers, have poor flight capability using newly developed tags that recorded their flight air speed (the first direct measurement for wild birds) with propeller sensors, flight duration, GPS position and depth during foraging trips. Flight air speed (mean 12.7 m s(-1)) was close to the speed that minimizes power requirement, rather than energy expenditure per distance, when existing aerodynamic models were applied. Flights were short (mean 92 s), with a mean summed duration of only 24 min day(-1). Shags sometimes stayed at the sea surface without diving between flights, even on the way back to the colony, and surface durations increased with the preceding flight durations; these observations suggest that shags rested after flights. Our results indicate that their flight performance is physiologically limited, presumably compromised by their great diving capability (max. depth 94 m, duration 306 s) through their morphological adaptations for diving, including large body mass (enabling a large oxygen store), small flight muscles (to allow for large leg muscles for underwater propulsion) and short wings (to decrease air volume in the feathers and hence buoyancy). The compromise between flight and diving, as well as the local bathymetry, shape the three-dimensional foraging range (<26 km horizontally, <94 m vertically) in this bottom-feeding cormorant.
SN  - 0022-0949
UR  - http://dx.doi.org/10.1242/jeb.050161
N1  - exported from refbase (http://publi.ipev.fr/polar_references/show.php?record=2682), last updated on Mon, 01 Jul 2024 19:43:09 +0200
ID  - WatanabeYuukiY2011
ER  -