摘要:Leucism is a partial hypopigmentary congenital disorder previously recorded in several species of mammals. This abnormal coloration is unusual in the wild. In August 2013, in the Baja California State, México, we collected two Peromyscus fraterculus (one female and one male) exhibiting leucism. Leucism has not been reported before ingenus Peromyscus, therefore, we documented the first known record. Leucism is a reflex of low levels of genetic diversity in natural populations. It may increase selective pressure on individuals.