Individual egg camouflage is influenced by microhabitat selection and use of nest materials in ground-nesting birds

摘要: Camouflage is a widespread strategy to avoid predation and of particular importance for animals with reduced mobility or those in exposed habitats. often relies on matching the visual appearance background, selecting fine-scale backgrounds that complement an individual’s effective means optimising camouflage. We investigated whether there was active selection microhabitats nest materials three ground-nesting birds (pied avocet, Kentish plover, little tern) camouflage their eggs using avian modelling. Plovers avocets selected substrates which were better camouflaged, choice done at individual level. Terns have lighter, less spotted eggs, while they did select lighter background than other species, poor match backgrounds. The worse tern likely due compromise between thermal protection because breed later, when temperatures are higher. Finally, addition improved egg terms luminance, although pattern matching, may be associated different roles play. Active level crucial improve success species sites. Many bird ground sites no vegetation cover where nests predators. studied females chose eggs. Using images vision modelling, we found nesting two level, so optimised. In addition, such even able by into nests. However, this not observed another paler reflect trade-off overheating it breeds later season. Although individuals try choose factors offspring survival hamper this.