Behavioral Ecology Advance Access originally published online on November 17, 2004
Behavioral Ecology 2005 16(2):327-334; doi:10.1093/beheco/arh166
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Countershading enhances crypsis with some bird species but not others
a School of Biological Sciences, Liverpool University, Crown Street, Liverpool L69 7ZB, U.K., b Biology, Liverpool Hope University College, Childwall, Liverpool L16 9JD, U.K., c Department of Zoology, Trinity College Dublin, Dublin 2, Ireland, and d Institute of Biomedical and Life Sciences, Graham Kerr Building, University of Glasgow, Glasgow G12 8QQ, U.K.
* Address correspondence to M.P. Speed. E-mail: speedm{at}liv.ac.uk.
Although the theory of self-shadow concealing countershading is over a century old, there are very few direct empirical tests to substantiate the prediction that prey that are dorsally darkened and ventrally lightened (generally termed countershaded) suffer lower rates of attack than other prey. In this paper, we report experiments designed to determine whether artificial, countershaded prey are chosen by predators less often than those that are all light, all dark, or reverse shaded (i.e., dorsally lightened and ventrally darkened). Artificial prey were presented in gardens and parks to free-living birds, either on white backgrounds or on backgrounds with some degrees of color matching. In one experiment, birds were unmarked, and in the other, they were individually identifiable. We found that in three experimental trials, countershaded baits were attacked at a rate not significantly different from that of uniformly dark baits. In one experimental trial, countershaded baits were at some advantage. When we examined the data set for this trial more closely, it was apparent that blackbirds were taking countershaded baits least often, but blue tits and robins conferred no special advantage to countershaded baits. Hence, the efficacy of countershading may vary with species of predator.
Key words: countershading, crypsis, predator, prey.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  H. M Rowland From Abbott Thayer to the present day: what have we learned about the function of countershading? Phil Trans R Soc B, February 27, 2009; 364(1516): 519 - 527. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Tankus and Y. Yeshurun Computer vision, camouflage breaking and countershading Phil Trans R Soc B, February 27, 2009; 364(1516): 529 - 536. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. M Rowland, I. C Cuthill, I. F Harvey, M. P Speed, and G. D Ruxton Can't tell the caterpillars from the trees: countershading enhances survival in a woodland Proc R Soc B, November 22, 2008; 275(1651): 2539 - 2545. [Abstract] [Full Text] [PDF]
|
|