Quails have become experts in camouflage, because their eggs are loved by many predators. As it turn out, the Japanese quail can disguise their eggs the best.
According to the University of Nebraska-Lincoln, Japanese quail are a ground-dwelling and nesting bird. They build strong, sturdy nests on the ground and usually camouflaged under vegetation. This type of quail matures at six weeks of age and are in full egg production by 50 days of age.
According to researchers reporting in the journal Current Biology, a mother quail is familiar with the patterning of her own eggs, so she can chooses where to lay her eggs to hide them best.
“We currently do not know the mechanisms by which the (mother) bird learns its own egg patterns,” lead author P. George Lovell of Abertay University and the University of St. Andrews, told Discovery News.
Researchers discovered the maximization of camouflage appears specific to each individual bird. They believe that a quail makes an optimal egg-laying decision based on the characteristics of their own eggs.
“It’s as if they knew the characteristics of their own eggs and chose the best substrate with which to lay them,” said George Lovell, lead study author and an expert on animal camouflage at Abertay University and the University of St. Andrews in Scotland.
To test this theory, they offered female quail in the lab a choice between four different backgrounds on which to lay their eggs. The experiment showed that quail mothers would lay their eggs on background colors that matched the spots on their eggs.
A female, for example, that tends to lay eggs with few spots, selected surfaces that most closely matched the overall color of the egg, utilizing a background-matching tactic. A female, that laid eggs largely covered in dark spots will usually chose a dark background to take advantage of disruptive coloration. And because females tend to lay similarly patterned eggs over time, the findings suggest that the birds are choosing a laying location rather than controlling the appearance of their eggs based on their environs.
That strategy is known as disruptive coloration, in which contrasting patterns on surfaces make the outline of an object, such as an egg, more difficult to see.
“Interestingly, all birds seem more concerned in minimizing the mismatch between nest and the darker speckles on their eggs than the mismatch between nest and the underlying, predominant egg color, but particularly so for birds with more dark speckling,” said Innes Cuthill of the University of Bristol’s School of Biological Sciences.
“It’s possible that they learn the patterning through seeing eggs that they’ve laid,” Lovell said. “In the wild, there is some evidence that birds are often less successful with their first clutch of eggs. It may be that at that point in time, they’re not able to select the best place to lay their eggs.”
“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 a prepared statement. This example of the quails’ egg-laying behaviors “should encourage camouflage to be seen not simply as a function of the appearance of an organism, but as a function of both appearance and behavioral traits,” he and his colleagues noted in their paper.