Infant transport and mother-infant contact from 1 to 26 weeks postnatal in Coquerel's sifaka (Propithecus coquereli) in northwestern Madagascar.

Abstract

Lactating females face energetic constraints absent in conspecifics and must compensate for higher energy requirements. Infant transport is the most energetically costly mammalian activity after lactation. Nonetheless, infant transport and mother-infant contact are seldom measured. The extreme seasonality characteristic of Madagascar coupled with lactation costs and infant transport is a trifold energetic challenge encountered by lemur mothers. We hypothesized that Coquerel's sifaka (Propithecus coquereli) mothers spend more time caring for infants during the early/earlier-mid lactation period, coinciding with the resource depletive austral winter, relative to later-mid/late lactation. We tested this hypothesis by measuring infant carrier identity, transport position, and frequency of mother-infant contact for 678 focal hours over two consecutive birth seasons from 1 to 26 weeks postnatal (N = 10 infants, N = 10 mothers, N = 19 adult males, N = 8 adult females) in Ankarafantsika National Park (ANP), Madagascar. Quantifying P. coquereli postnatal care strategies demonstrates how a species with a "slow" life history lives in an energetically challenging environment, thereby providing data on maternal energetic responses and infant development in an endangered strepsirrhine. Mothers were the primary infant transporters. Adult males and non-lactating females participated in infant transport, but for significantly less time. Infants spent significantly more time in the ventral transport position than dorsally or independently. Infants were still transported 26% of the time at 6.5 months postnatal. Infants initiated and broke bodily contact with mothers more frequently than mothers initiated and broke contact with infants. Infants were dependent on their mothers for longer durations than suggested by previous studies and carried dorsally until later ages than in other comparably sized wild lemurs. Am. J. Primatol. 78:646-658, 2016. © 2016 Wiley Periodicals, Inc.