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

First published online March 30, 2006
Journal of Experimental Biology 209, 1376-1384 (2006)
Published by The Company of Biologists 2006
doi: 10.1242/jeb.02150

This Article Figures Only 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 Warkentin, K. M. Articles by McDaniel, J. G. Search for Related Content PubMed PubMed Citation Articles by Warkentin, K. M. Articles by McDaniel, J. G.

Temporal pattern cues in vibrational risk assessment by embryos of the red-eyed treefrog, Agalychnis callidryas

Karen M. Warkentin^1,*, Michael S. Caldwell¹ and J. Gregory McDaniel²

¹ Department of Biology, Boston University, Boston, MA 02215, USA
² Department of Aerospace and Mechanical Engineering, Boston University, Boston, MA 02215, USA

^* Author for correspondence (e-mail: kwarken{at}bu.edu)

Accepted 6 February 2006

The embryos of red-eyed treefrogs, Agalychnis callidryas, use vibrations transmitted through their arboreal egg clutch to cue escape hatching behavior when attacked by egg-eating snakes. Hatching early increases the risk of predation in the water, so embryos should avoid it unless they are in danger. We exposed egg clutches to intermittent vibrations with different combinations of vibration duration and spacing to examine the role of simple temporal pattern cues in the escape hatching response. Stimuli were bursts of synthetic white noise from 0 to 100 Hz, including the range of frequencies with substantial energy in snake attacks, and had approximately rectangular amplitude envelopes. Embryos hatched in response to a small range of temporal patterns and not in response to many others, rather than hatching to most vibrations except for certain patterns perceived as safe. Neither cycle length nor duty cycle predicted hatching response, except at extreme values where no hatching occurred; the highest energy stimuli elicited little or no hatching. Both vibration duration and inter-vibration interval strongly affected the hatching response. The highest levels of hatching were to durations of 0.5 s combined with intervals of 1.5–2.5 s, and hatching decreased gradually with increasing difference of either duration or interval from these most effective stimuli. Vibration duration and interval appear to function as two necessary elements of a composite cue, rather than as redundant cues. This increases response specificity and reduces the range of stimuli that elicit hatching, likely reducing the chance of hatching unnecessarily in a benign disturbance. Vibration-cued hatching in A. callidryas embryos offers an opportunity to experimentally assess the behavioral decision rules underlying an effective and costly anti-predator defense.

Key words: hatching, predation, predator detection, defense, seismic, playback, duty cycle, duration, spacing

Related articles in JEB:

EMBRYOS SENSE SEISMIC EVETNTS

Kathryn Phillips
JEB 2006 209: i. [Full Text]  

This article has been cited by other articles:

				K. M. Warkentin, M. S. Caldwell, T. D. Siok, A. T. D'Amato, and J. G. McDaniel Flexible information sampling in vibrational assessment of predation risk by red-eyed treefrog embryos J. Exp. Biol., February 15, 2007; 210(4): 614 - 619. [Abstract] [Full Text] [PDF]

				K. Phillips EMBRYOS SENSE SEISMIC EVETNTS J. Exp. Biol., April 15, 2006; 209(8): i - i. [Full Text] [PDF]