Abstract # 13167 Event # 130:

Scheduled for Friday, August 10, 2018 11:15 AM-11:30 AM: (Chula Vista ) Oral Presentation


YOUNG LEAF AVAILABILITY PARTIALLY INFLUENCES WEANED AGE IN A WILD COLOBUS

T. C. Rissling1, I. Badescu2, A. Crotty1, S. A. Fox3, A. Gibson-King1, L. MacDonald1, J. V. Vayro1, E. C. Wikberg4 and P. Sicotte1
1University of Calgary, 2500 University Dr. NW, Calgary, AB T2N 1N4, USA, 2Université de Montréal, 2900 Edouard Montpetit Blvd, Montreal QC, Canada, H3T 1J4, 3University of New Mexico, Albuquerque, NM 87131, USA, 4University of Texas at San Antonio, 1 UTSA Circle, San Antonio, TX 78249, USA
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     The attainment of weaned age is the life history milestone that signifies the transition between infancy and juvenility. Weaned age often varies intraspecifically, particularly in non-seasonally breeding species. For Colobus vellerosus, weaned age ranges from eight to 24 months. To examine the factors that regulate this variation, we extracted which month weaned age was achieved for 72 infants at the Boabeng Fiema Monkey Sanctuary from 2008-2018. Infants were observed three times per week for the presence of nipple contact. Food availability was determined via biweekly phenology surveys. Weaned age events were not uniformly distributed throughout the year (Rao’s spacing test for uniformity, ? = 0.05). Higher frequencies occurred in November and in July (16.7% and 12.5% of weaned ages, respectively). On average, other months account for 7.1% of weaned age events. Young leaf availability is highest in December to March, so the increase in weaned age events in November may be due to the upcoming abundance of foods that are easier to process than the foods that are available at other times of the year. The increase in weaned age events in July cannot be explained by young leaf availability and may be influenced by other factors like extrinsic mortality risk or maternal parity. These findings conform with other primate studies showing intraspecific variation in weaned age can be modulated by food availability.