Maximal performance is an essential metric for understanding many aspects of an organism's biology, but it can be difficult to determine because a measured maximum may reflect only a peak level of effort, not a physiological limit. We used a unique opportunity provided by a frog jumping contest to evaluate the validity of existing laboratory estimates of maximum jumping performance in bullfrogs (Rana catesbeiana). We recorded video of 3124 bullfrog jumps over the course of the 4-day contest at the Calaveras County Jumping Frog Jubilee, and determined jump distance from these images and a calibration of the jump arena. Frogs were divided into two groups: ‘rental’ frogs collected by fair organizers and jumped by the general public, and frogs collected and jumped by experienced, ‘professional’ teams. A total of 58% of recorded jumps surpassed the maximum jump distance in the literature (1.295 m), and the longest jump was 2.2 m. Compared with rental frogs, professionally jumped frogs jumped farther, and the distribution of jump distances for this group was skewed towards long jumps. Calculated muscular work, historical records and the skewed distribution of jump distances all suggest that the longest jumps represent the true performance limit for this species. Using resampling, we estimated the probability of observing a given jump distance for various sample sizes, showing that large sample sizes are required to detect rare maximal jumps. These results show the importance of sample size, animal motivation and physiological conditions for accurate maximal performance estimates.
↵† Present address: Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, CA 92697, USA
All authors contributed to writing the paper and devising the study; H.C.A., R.L.M., T.J.R. and E.M.A. attended the fair and gathered the video; H.C.A. and E.M.A. processed and digitized the video; all authors were involved in analysis.
Supplementary material available online at http://jeb.biologists.org/cgi/content/full/216/21/3947/DC1
No competing interests declared.
This work was supported by the National Science Foundation (grant 642428 to T.J.R.).
- © 2013. Published by The Company of Biologists Ltd