Camouflage is a widespread strategy to avoid predation and is of particular importance for animals with reduced mobility or those in exposed habitats. Camouflage often relies on matching the visual appearance of the background, and selecting fine-scale backgrounds that complement an individual’s appearance is an effective means of optimising camouflage. It was investigated whether there was an active selection of microhabitats and nest materials in three ground-nesting birds.

Solar radiation is an important driver of animal coloration, not only because of the effects of coloration on body temperature but also because coloration may protect from the deleterious effects of UV radiation. Indeed, dark coloration may protect from UV, but may increase the risk of overheating. In addition, the effect of coloration on thermoregulation should change with egg size, as smaller eggs have higher surface?volume ratios and greater convective coefficients than larger eggs, so...

A user-friendly tool, called SpotEgg, has been developed to analyse colour and pattering in digital images. The tool, operated through a Graphical User Interface, runs over Matlab 2012b or latter and was primarily aimed to analyse colouration in bird´s eggs. Nevertheless it can also measure reflectances and spottiness in any other type of objects as insects, feathers, frogs, etc.

In ground-nesting birds egg colour and appearance may have evolved due to opposite selection pressures. Pigmentation and spottiness make the eggs darker and have been suggested to improve camouflage. However these eggs may reach higher temperatures, which may be lethal for embryos. Some authors suggested that this trade-off may not exist. In this study the occurrence of a trade-off between camouflage and overheating of eggs is tested.