spacer gif spacer gif spacer gif spacer gif spacer gif
QUICK SEARCH:   [advanced]


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

This Article
Right arrow Full Text (PDF)
Right arrow References
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Chai, P.
Right arrow Articles by Dudley, R.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Chai, P.
Right arrow Articles by Dudley, R.

Journal of Experimental Biology, Vol 199, Issue 10 2285-2295, Copyright © 1996 by Company of Biologists

JOURNAL ARTICLES

Limits to flight energetics of hummingbirds hovering in hypodense and hypoxic gas mixtures

P Chai and R Dudley
Department of zoology, University of Texas, Austin 78712, USA. pengchai@utxvms.cc.utexas.edu

Hovering hummingbirds offer a model locomotor system for which analyses of both metabolism and flight mechanics are experimentally tractable. Because hummingbirds exhibit the highest mass-specific metabolic rates among vertebrates, maximum performance of hovering flight represents the upper limit of aerobic locomotion in vertebrates. This study evaluates the potential constraints of flight mechanics and oxygen availability on maximum flight performance. Hummingbird flight performance was manipulated non-invasively using air and gas mixtures which influenced metabolism via variable oxygen partial pressure and/or altered flight mechanics via variable air densities. Limits to the locomotor capacity of hovering ruby-throated hummingbirds (Archilochus colubris) were unequivocally indicated by aerodynamic failure in either air/helium or air/heliox mixtures. Air/helium mixtures are hypodense and hypoxic; failure to sustain hovering flight occurred at 63% of the density of sea-level air and at an oxygen concentration of 12%. Air/heliox mixtures are hypodense but normoxic; failure in hovering occurred at 47% of sea-level air density. Thus, hummingbirds demonstrated considerable power reserves in hovering flight as well as hypoxic tolerance. In air/helium mixtures, hovering was limited by oxygen supply and not by flight mechanics. Birds hovering in air/helium mixtures increased their mechanical power output but not their rate of oxygen consumption. By contrast, birds hovering in air/heliox mixtures increased both mechanical performance and metabolic expenditure. Under hypoxia, hovering hummingbirds demonstrated non-negligible, but still limited, capacities for anaerobic metabolism and/or oxygen storage. Depending on the physical context, hummingbird flight performance can therefore be limited by oxygen availability or by flight aerodynamics.


This article has been cited by other articles:


Home page
 J. Exp. Biol.Home page
B. W. Tobalske, D. R. Warrick, C. J. Clark, D. R. Powers, T. L. Hedrick, G. A. Hyder, and A. A. Biewener
Three-dimensional kinematics of hummingbird flight
J. Exp. Biol., July 1, 2007; 210(13): 2368 - 2382.
[Abstract] [Full Text] [PDF]

Home page
 Proc. Natl. Acad. Sci. USAHome page
D. L. Altshuler, R. Dudley, and J. A. McGuire
Resolution of a paradox: Hummingbird flight at high elevation does not come without a cost
PNAS, December 21, 2004; 101(51): 17731 - 17736.
[Abstract] [Full Text] [PDF]

Home page
 J. Exp. Biol.Home page
B. W. Tobalske, D. L. Altshuler, and D. R. Powers
Take-off mechanics in hummingbirds (Trochilidae)
J. Exp. Biol., March 15, 2004; 207(8): 1345 - 1352.
[Abstract] [Full Text] [PDF]

Home page
 J. Exp. Biol.Home page
S. P. Roberts, J. F. Harrison, and R. Dudley
Allometry of kinematics and energetics in carpenter bees (Xylocopa varipuncta) hovering in variable-density gases
J. Exp. Biol., February 22, 2004; 207(6): 993 - 1004.
[Abstract] [Full Text] [PDF]

Home page
 J. Exp. Biol.Home page
D. L. Altshuler and R. Dudley
Kinematics of hovering hummingbird flight along simulated and natural elevational gradients
J. Exp. Biol., September 15, 2003; 206(18): 3139 - 3147.
[Abstract] [Full Text] [PDF]

Home page
 J. Exp. Biol.Home page
R. Dudley and Y. Winter
Hovering flight mechanics of neotropical flower bats (Phyllostomidae: Glossophaginae) in normodense and hypodense gas mixtures
J. Exp. Biol., December 1, 2002; 205(23): 3669 - 3677.
[Abstract] [Full Text] [PDF]

Home page
 J. Exp. Biol.Home page
D. L. Altshuler and R. Dudley
The ecological and evolutionary interface of hummingbird flight physiology
J. Exp. Biol., August 15, 2002; 205(16): 2325 - 2336.
[Abstract] [Full Text] [PDF]

Home page
 J. Exp. Biol.Home page
R. Dudley
Limits to human locomotor performance: phylogenetic origins and comparative perspectives
J. Exp. Biol., March 11, 2002; 204(18): 3235 - 3240.
[Abstract] [Full Text] [PDF]

Home page
 J. Exp. Biol.Home page
R. Nudds and D. Bryant
The energetic cost of short flights in birds
J. Exp. Biol., January 5, 2000; 203(10): 1561 - 1572.
[Abstract] [PDF]


© The Company of Biologists Ltd 1996