QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online June 11, 2007
Journal of Experimental Biology 210, 2146-2153 (2007)
Published by The Company of Biologists 2007
doi: 10.1242/jeb.005389

This Article Summary Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Related articles in JEB Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Welch, K. C. Articles by Suarez, R. K. Search for Related Content PubMed PubMed Citation Articles by Welch, K. C., Jr Articles by Suarez, R. K.

Oxygen consumption rates in hovering hummingbirds reflect substrate-dependent differences in P/O ratios: carbohydrate as a `premium fuel'

Kenneth C. Welch, Jr^1,*, Douglas L. Altshuler² and Raul K. Suarez¹

¹ Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA 93106-9610, USA
² Department of Biology, University of California, Riverside, CA 92521, USA

View larger version (16K): [in this window] [in a new window]   Fig. 1. Mass-specific oxygen consumption rate (O2/Mb) in relation to respiratory quotient (RQ) in (A) Anna's (C. anna) and (B) rufous hummingbirds (S. rufus).

View larger version (14K): [in this window] [in a new window]   Fig. 2. Oxygen consumption rate per unit hovering power output (O2/W) in relation to respiratory quotient (RQ) in Anna's hummingbirds (C. anna) assuming (A) perfect (Pper) or (B) zero (Pzero) elastic storage.

View larger version (17K): [in this window] [in a new window]   Fig. 3. Oxygen consumption rate per unit hovering power output (O2/W) in relation to respiratory quotient (RQ) in rufous hummingbirds (S. rufus) assuming (A) perfect (Pper) or (B) zero (Pzero) elastic storage.

View larger version (9K): [in this window] [in a new window]   Fig. 4. The relationship between whole-animal oxygen consumption rate (O2; ml O2 h–1) and whole-animal ATP turnover rate per unit power output (mmol ATP h–1 W–1, assuming either perfect, Pper, or zero, Pzero, elastic storage) to respiratory quotient (RQ). The slope of whole-animal O2 in relation to RQ is significantly different from zero (F1,22=10.4134, P=0.0039). The slopes of whole-animal ATP turnover rate per unit power output in relation to RQ are not significantly different from zero (assuming Pper, F1,22=1.8537, P=0.1871; assuming Pzero, F1,22=1.1524, P=0.2947). Note that >90% of O2 and ATP turnover rate during hovering are accounted for by flight muscles. Example using Anna's hummingbird (C. anna) number 3.