Weaned age variation in the Virunga mountain gorillas (Gorilla beringei beringei)

Hdl Handle:
http://hdl.handle.net/10034/604848
Title:
Weaned age variation in the Virunga mountain gorillas (Gorilla beringei beringei)
Authors:
Eckardt, Winnie; Fawcett, Katie; Fletcher, Alison W. ( 0000-0003-2003-8033 )
Abstract:
Weaning marks an important milestone during life history in mammals indicating nutritional independence from the mother. Age at weaning is a key measure of maternal investment and care, affecting female reproductive rates, offspring survival and ultimately the viability of a population. Factors explaining weaned age variation in the endangered mountain gorilla are not yet well understood. This study investigated the impact of group size, group type (one-male versus multi-male), offspring sex, as well as maternal age, rank, and parity on weaned age variation in the Virunga mountain gorilla population. The status of nutritional independence was established in 69 offspring using long-term suckling observations. A Cox-regression with mixed effects was applied to model weaned age and its relationship with covariates. Findings indicate that offspring in one-male groups are more likely to be weaned earlier than offspring in multi-male groups, which may reflect a female reproductive strategy to reduce higher risk of infanticide in one-male groups. Inferior milk production capacity and conflicting resource allocation between their own and offspring growth may explain later weaning in primiparous mothers compared to multiparous mothers. Sex-biased weaned age related to maternal condition defined by parity, rank, and maternal age will be discussed in the light of the Trivers-Willard hypothesis. Long-term demographic records revealed no disadvantage of early weaning for mother or offspring. Population growth and two peaks in weaned age within the Virunga population encourage future studies on the potential impact of bamboo shoots as a weaning food and other environmental factors on weaning.
Affiliation:
University of Chester; The Dian Fossey Gorilla Fund International
Citation:
Eckardt, W., Fawcett, K., & Fletcher, A. W. (2016). Weaned age variation in the Virunga mountain gorillas (Gorilla beringei beringei). Behavioral Ecology & Sociobiology, 70(4), 493-507. DOI: 10.1007/s00265-016-2066-6
Publisher:
Springer
Journal:
Behavioral Ecology & Sociobiology
Publication Date:
2-Feb-2016
URI:
http://hdl.handle.net/10034/604848
DOI:
10.1007/s00265-016-2066-6
Additional Links:
http://link.springer.com/article/10.1007%2Fs00265-016-2066-6
Type:
Article
Language:
en
Description:
The final publication is available at Springer via http://dx.doi.org/10.1007/s00265-016-2066-6
EISSN:
1432-0762
Appears in Collections:
Biological Sciences

Full metadata record

DC FieldValue Language
dc.contributor.authorEckardt, Winnieen
dc.contributor.authorFawcett, Katieen
dc.contributor.authorFletcher, Alison W.en
dc.date.accessioned2016-04-08T13:57:41Zen
dc.date.available2016-04-08T13:57:41Zen
dc.date.issued2016-02-02en
dc.identifier.citationEckardt, W., Fawcett, K., & Fletcher, A. W. (2016). Weaned age variation in the Virunga mountain gorillas (Gorilla beringei beringei). Behavioral Ecology & Sociobiology, 70(4), 493-507. DOI: 10.1007/s00265-016-2066-6en
dc.identifier.doi10.1007/s00265-016-2066-6en
dc.identifier.urihttp://hdl.handle.net/10034/604848en
dc.descriptionThe final publication is available at Springer via http://dx.doi.org/10.1007/s00265-016-2066-6en
dc.description.abstractWeaning marks an important milestone during life history in mammals indicating nutritional independence from the mother. Age at weaning is a key measure of maternal investment and care, affecting female reproductive rates, offspring survival and ultimately the viability of a population. Factors explaining weaned age variation in the endangered mountain gorilla are not yet well understood. This study investigated the impact of group size, group type (one-male versus multi-male), offspring sex, as well as maternal age, rank, and parity on weaned age variation in the Virunga mountain gorilla population. The status of nutritional independence was established in 69 offspring using long-term suckling observations. A Cox-regression with mixed effects was applied to model weaned age and its relationship with covariates. Findings indicate that offspring in one-male groups are more likely to be weaned earlier than offspring in multi-male groups, which may reflect a female reproductive strategy to reduce higher risk of infanticide in one-male groups. Inferior milk production capacity and conflicting resource allocation between their own and offspring growth may explain later weaning in primiparous mothers compared to multiparous mothers. Sex-biased weaned age related to maternal condition defined by parity, rank, and maternal age will be discussed in the light of the Trivers-Willard hypothesis. Long-term demographic records revealed no disadvantage of early weaning for mother or offspring. Population growth and two peaks in weaned age within the Virunga population encourage future studies on the potential impact of bamboo shoots as a weaning food and other environmental factors on weaning.en
dc.language.isoenen
dc.publisherSpringeren
dc.relation.urlhttp://link.springer.com/article/10.1007%2Fs00265-016-2066-6en
dc.rights.urihttp://creativecommons.org/licenses/by-nc-nd/4.0/*
dc.subjectWeaningen
dc.subjectMountain gorillaen
dc.subjectParityen
dc.subjectDominance ranken
dc.subjectOffspring sexen
dc.titleWeaned age variation in the Virunga mountain gorillas (Gorilla beringei beringei)en
dc.typeArticleen
dc.identifier.eissn1432-0762en
dc.contributor.departmentUniversity of Chester; The Dian Fossey Gorilla Fund Internationalen
dc.identifier.journalBehavioral Ecology & Sociobiologyen
dc.date.accepted2016-01-16en
or.grant.openaccessYesen
rioxxterms.funderxxen
rioxxterms.identifier.projectxxen
rioxxterms.versionAMen
rioxxterms.licenseref.startdate2216-02-02en
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