title: A case of infant swapping by wild northern muriquis (Brachyteles hypoxanthus).
abstract: Allo-parenting has been observed in a variety of female primates, and typically infants are reunited with their biological mothers assuming that their mothers are alive. We observed an exception to this pattern when two wild northern muriquis (Brachyteles hypoxanthus) exchanged infants of different sexes and then reared their adopted infants through weaning. The process of this exchange began when the infants were 4 and 8 days old, respectively. The mother of a 4-day old female carried and nursed her own daughter and the 8-day old son of a second female. The exchange ended when the second mother was first observed carrying the wrong infant 1.5 days later. This observation raises questions about the age and mechanisms of mother-infant recognition in this species, and about assumptions of mother-infant relatedness based on behavioral observations alone.
authors.affiliation: Pós-Graduação em Ecologia, Conservação e Manejo da Vida Silvestre, Departamento de Zoologia, Universidade Federal de Minas Gerais, Caixa Postal 486, Belo Horizonte, MG 31270-901, Brazil.
authors.forename: Waldney Pereira
authors.initials: WP
authors.lastname: Martins
authors.forename: Vanessa
authors.initials: V
authors.lastname: de Oliveira Guimarães
authors.forename: Karen B
authors.initials: KB
authors.lastname: Strier
mesh_terms: D000818:Animals; D051077:Atelidae / Q000523:psychology*; D001938:Brazil; D005260:Female; D007774:Lactation / Q000502:physiology*; D008425:Maternal Behavior; D012919:Social Behavior