Quail Really Know Their Camouflage

Jan. 17, 2013 — When it comes to camouflage, ground-nesting Japanese quail are experts. That’s based on new evidence published online on January 17 in Current Biology that mother quail “know” the patterning of their own eggs and choose laying spots to hide them best.

 

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“Not only are the eggs camouflaged, but the birds choose to lay their eggs on a substrate that maximizes camouflage,” said P. George Lovell of Abertay University and the University of St Andrews. “Furthermore, the maximization seems specific to individual birds.”

Karen Spencer, also of University of St Andrews and a co-author, had earlier noticed that female quail lay eggs that vary a lot in appearance, and that those differences are repeatable. Some birds consistently lay eggs covered in dark spots; others have many fewer spots or, in some cases, almost none at all.

That pattern led the researchers to an intriguing idea: that birds might make optimal egg-laying choices based on the special characteristics of their own eggs. To find out, they gave female quail in the lab a choice between four different backgrounds on which to lay their eggs.

Those choice experiments revealed that most quail mothers lay their eggs on background colors to match the spots on their eggs. That’s an effective strategy known as disruptive coloration, in which contrasting patterns on surfaces make the outline of an object harder to detect. Birds laying eggs with little patterning instead choose lighter surfaces to match the predominant background color of their eggs.

The findings suggest that quail in the wild lower the chance that their eggs will be found and eaten by predators through careful decision-making, the researchers say.

“Animals make choices based upon their knowledge of the environment and their own phenotype to maximize their ability to reproduce and survive,” Lovell said. “In this specific case, birds know what their eggs look like and can make laying choices that will minimize predation.”

 

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Story Source:

The above story is reprinted from materials provided byCell Press, via EurekAlert!, a service of AAAS.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

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Journal Reference:

1. P. George Lovell, Graeme D. Ruxton, Keri V. Langridge, Karen A. Spencer. Egg-Laying Substrate Selection for Optimal Camouflage by Quail. Current Biology, 2013; DOI: 10.1016/j.cub.2012.12.031

Cell Press (2013, January 17). Quail really know their camouflage. ScienceDaily. Retrieved January 27, 2013, from http://www.sciencedaily.com/releases/2013/01/130117133122.htm

Camouflage of Moths: Moths Actively Seek out Best Hiding Places

ScienceDaily (July 31, 2012) — Moths are iconic examples of camouflage. Their wing coloration and patterns are shaped by natural selection to match the patterns of natural substrates, such as a tree bark or leaves, on which the moths rest. But, according to recent findings, the match in the appearance was not all in their invisibility.

Fig. 1 shows two species of moths that, according to the recent study of evolutionary biologists from Seoul, “know” how to find a spot on a tree bark to become invisible to predators: (a) – Hypomecis roboraria; (b) – Jankowskia fuscaria. (Credit: ©entomart NonCommercial-ShareAlike 2.0 Generic (CC BY-NC-SA 2.0))

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Despite a long history of research on these iconic insects, whether moths behave in a way to increase their invisibility has not been determined. A research team from the Laboratory of Behavioral Ecology and Evolution at the Seoul National University has conducted an experiment to directly answer this question. Chang-ku Kang, Jong-yeol Moon, Sang-im Lee and Piotr Jablonski have found out that moths walk on the tree bark until they settle down to rest; the insects seem to actively search for a place and a body position that makes them practically invisible.

Instead of placing moth specimens on a tree bark in various positions to see how body orientation of moths make them invisible to birds, which has been done by several researchers, “we let the moths to do the job for us” says Changku Kang, the PhD student who conducted the experiment. The researchers let inchworm moths of two species (Jankowskia fuscaria and Hypomycis roboraria) land on tree bark and freely choose the final resting spot and body orientation. Many moths did not remain at the spot of landing. They walked around with stretched wings as if they were looking for that one perfect spot that may make them invisible to predators.

To determine whether this final spot indeed made the moth really invisible, the researchers photographed each moth at its landing spot (initial spot) and at the final spot at which the moth decided to rest. Next, the researchers asked people to try to locate the moth from the photograph as quickly as possible. People had more difficulty finding the moths at their final spots than the same moths at their initial landing spots.

Amazingly, this was even true for the species (Hypomecis roboraria) that only changed its resting spot on the tree bark without changing its body orientation. Therefore, the researchers concluded, that moths seems to actively choose the spot that makes them invisible to predators. How do they know how to become invisible? The research team is now trying to answer this question as the next step.

 

Link:

http://www.eurekalert.org/pub_releases/2012-07/lobe-com073112.php

Journal Reference:

1. C.-K. Kang, J.-Y. Moon, S.-I. Lee, P. G. Jablonski. Camouflage through an active choice of a resting spot and body orientation in moths. Journal of Evolutionary Biology, 2012; DOI: 10.1111/j.1420-9101.2012.02557.x

Citation:

Laboratory of Behavioral Ecology and Evolution at Seoul National University (2012, July 31). Camouflage of moths: Moths actively seek out best hiding places. ScienceDaily. Retrieved August 2, 2012, from http://www.sciencedaily.com­ /releases/2012/07/120731123521.htm