Abstract # 3201 Event # 18:

Scheduled for Saturday, September 17, 2011 10:45 AM-11:00 AM: Session 5 (Meeting Room 408) Oral Presentation


MATERNAL INVESTMENT AND NURSING BEHAVIOR IN URSINE COLOBUS MONKEYS (COLOBUS VELLEROSUS) AT BOABENG-FIEMA MONKEY SANCTUARY, WEST AFRICA

L. J. MacDonald and P. Sicotte
University of Calgary, Calgary, Alberta T2N 1N4, USA
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     Lactation can be the most costly form of parental investment. Mothers must energetically support infant growth and nutrition while forgoing reproduction until infants are weaned. This study reports the first quantitative data on nursing patterns, including nutritive suckling (milk transfer) rates and the length of lactation, in a wild, arboreal primate. Data on 24 infants of ursine colobus monkeys (Colobus vellerosus) were collected ad libitum and via focal-animal sampling from May-November 2008 (N=189 hours) at Boabeng-Fiema Monkey Sanctuary, Ghana. Suckling patterns were determined using three measures: ventral contact, on nipple and active suckling. Active suckling was observed using a spotting scope (20-60x). When analyzed according to age/coat color, we found that older, black and white infants displayed significantly longer durations of ventral contact than white and grey infants (F=16.42;df=2,27;p<0.001; white: t=4.14;df=27;p=0.0009; grey: t=4.71;df=27;p=0.0002) and longer active suckling bouts than grey infants (F=10.36;df=2,24;p=0.0006;t=4.54,df=24;p=0.0004). They also made more nipple contacts/bout than white infants (F=3.67;df=2,27;p=0.039;t=2.50;df=27;p=0.048). Nutritive suckling occurred at an average rate of 2:1 (2 sucks per second) in older infants. These data suggest that energetic costs of lactation for C.vellerosus mothers likely increase with infant development until the weaning phase. The length of lactation ranged from 60-83 weeks (N=4 individuals). Future research will examine the relationship between nursing patterns and infant growth rates, as well as implications of the length of lactation on female reproductive strategies.