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

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 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 Butler, P. J. Articles by Wikelski, M. Search for Related Content PubMed PubMed Citation Articles by Butler, P. J. Articles by Wikelski, M.

The relationship between heart rate and rate of oxygen consumption in Galapagos marine iguanas (Amblyrhynchus cristatus) at two different temperatures

Patrick J. Butler^1,*, Peter B. Frappell², Tobias Wang^1, and Martin Wikelski³

¹ School of Biosciences, The University of Birmingham, Birmingham, B15 2TT, UK
² Department of Zoology, La Trobe University, Melbourne, Victoria 3086, Australia
³ Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544-1003, USA
Present address: Department of Zoophysiology, University of Aarhus, Universitetsparken, Aarhus 8000C, Denmark

View larger version (20K): [in a new window]   Fig. 1. Daily body temperatures Tb (means ± S.D.) of Galapagos marine iguanas measured in the field by radiotelemetry during the summers of 1991/92 and 1992/93. The data were collected every 15 min and are from 27 animals in 91/92 and 10 animals in 92/93. The transmitters were implanted for 14-81 days (M. Wikelski and F. Trillmich, unpublished data).

View larger version (13K): [in a new window]   Fig. 4. The relationship between mass-specific rate of oxygen consumption and heart rate for three marine iguanas from Santa Cruz, Galapagos at 27 °C (open symbols) and 36 °C (filled symbols). The squares represent data obtained from animals during the pre-exercise period and while walking/running at different speeds, while the circles represent data obtained from the animals during recovery from the preceding exercise (see text for further details). The lines represent the least-squares regressions through all of the data points. At 27 °C, sO2=0.011fH-0.240, r2=0.76. At 36 °C, sO2=0.011fH-0.572, r2=0.92.

View larger version (14K): [in a new window]   Fig. 2. The relationship between mass-specific rate of oxygen consumption (sO2) and heart rate (fH) for seven marine iguanas from Santa Cruz Island, Galapagos, at 27 °C (open circles) and 36 °C (filled circles). The group regression equations are: sO2=0.013fH-0.361, r2=0.86, and sO2=0.011fH-0.561, r2=0.91, respectively.

View larger version (12K): [in a new window]   Fig. 3. The regression line for mass-specific rate of oxygen consumption (sO2) plotted against heart rate (fH) for seven marine iguanas from Santa Cruz Island, Galapagos, at 36 °C (see Fig. 2) together with the 95 % prediction intervals when sO2 is estimated from four measurements of fH from four animals. Also included are the values (mean ± S.D.) for sO2 and fH from four marine iguanas from the island of Santa Fé, Galapagos, during the pre-exercise period (filled circle) and at maximum exercise (open circle) at 36 °C.

View larger version (61K): [in a new window]   Fig. 5. The relationships between mass-specific rate of oxygen consumption, heart rate and body temperature for marine iguanas (N=7). Data are from Fig. 2. The mesh is described by the equation: sO2=0.0113fH-0.2983Q10(Tb-27)/10 (see text for further details).