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The Role of Non‐reproductive Helpers in Infant Care in Captive Callithrix jacchus
Author(s) -
Yamamoto Maria Emília,
O.Box Hilary
Publication year - 1997
Publication title -
ethology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.739
H-Index - 74
eISSN - 1439-0310
pISSN - 0179-1613
DOI - 10.1111/j.1439-0310.1997.tb00184.x
Subject(s) - callithrix , offspring , captivity , cooperative breeding , paternal care , demography , biology , psychology , zoology , primate , ecology , pregnancy , genetics , sociology
Callitrichids have been proposed as communal breeders, with non‐reproductive animals acting as helpers. Reports in the literature attest to the high variability in the behaviour of helpers. The present study assessed four proximate factors involved in helping in captive Callithrix jacchus: age, gender and experience of helpers and composition of their groups. Forty‐eight helpers from 15 families from Natal (Brazil) and Reading (UK) colonies were observed during the first 4 weeks of life of new‐born twins. Infant carrying, transfers and retrieval, and duration of carrying bouts were registered. Results showed that the presence of helpers decreased the costs of infant carrying, with a negatively significant correlation between group size and mean percentage of carrying. Age, but not gender, was a significant factor for infant carrying, transfers and retrieval, and mean duration of carrying bouts, with older helpers contributing more than younger ones. Singletons and oldest non‐reproductive offspring carried infants more, and longer, than twins and offspring with older siblings present in the group. Experience decreased motivation and actual carrying time, but not to a significant level. Age, experience and group composition appeared important factors in the display of infant care by helpers in captive Callithrix jacchus.