Test of an adaptive hypothesis for egg speckling along an elevational gradient in a population of Mexican jays Aphelocoma ultramarina

摘要: The adaptive significance of avian egg speckling patterns has been a subject ongoing debate. We examined in population Mexican jays Aphelocoma ultramarina exhibiting extreme eggshell variability. sampled 167 eggs at 55 nests from sites ranging across steep elevation gradient within the Sierra del Carmen mountain range Coahuila, Mexico, order to test recent hypothesis that lends structural support and should therefore be more prevalent females reduced environmental calcium. Although we documented high variation amount distribution jays, found no relationship between local soil calcium levels pattern speckling. Our results indicate explanations addition are necessary explain birds.