THE ROLE OF NONREPRODUCTIVE HELPERS IN INFANT CARE IN CAPTIVE CALLITHRIX-JACCHUS

Citation
Me. Yamamoto et Ho. Box, THE ROLE OF NONREPRODUCTIVE HELPERS IN INFANT CARE IN CAPTIVE CALLITHRIX-JACCHUS, Ethology, 103(9), 1997, pp. 760-771
Citations number
30
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Psychology, Biological",Zoology,"Behavioral Sciences
Journal title
ISSN journal
0179-1613
Volume
103
Issue
9
Year of publication
1997
Pages
760 - 771
Database
ISI
SICI code
0179-1613(1997)103:9<760:TRONHI>2.0.ZU;2-J
Abstract
Callitrichids have been proposed as communal breeders, with non-reprod uctive animals acting as helpers. Reports in the literature attest to the high variability in the behaviour of helpers. The present study as sessed four proximate factors involved in helping in captive Callithri x jacchus: age, gender and experience of helpers and composition of th eir groups. Forty-eight helpers from 15 families from Natal (Brazil) a nd Reading (UK) colonies were observed during the first 4 weeks of lif e of new-born twins. Infant carrying, transfers and retrieval, and dur ation of carrying bouts mere registered. Results showed that the prese nce of helpers decreased the costs of infant carrying, with a negative ly significant correlation between group size and mean percentage of c arrying. Age, but not gender, was a significant factor for infant carr ying transfers and retrieval, and mean duration of carrying bouts, wit h older helpers contributing more than younger ones. Singletons and ol dest non-reproductive offspring carried infants more, and longer, than twins and offspring with older siblings present in the group. Experie nce decreased motivation and actual carrying time, but not to a signif icant level. Age, experience and group composition appeared important factors in the display of infant care by helpers in captive Callithrix jacchus.