Chimp mothers carry mummified infants
26 April 2010
New observations of wild chimpanzees in Bossou, Guinea, have given insights into the behaviour of chimp mothers who carry the mummified remains of their dead infants with them.
An international team report in Current Biology that, in late 2003, an outbreak of respiratory disease in Bossou killed five chimps, including two infants. Following these deaths the team observed the mothers of both infants carrying the dead bodies of their offspring, with one mother carrying her infant's body for 68 days, the other for 19 days.
'This behaviour shows just how strong the bond is between chimpanzee mothers and their offspring, that it carries on even after death,' said Dr Dora Biro of Oxford University's Department of Zoology, an author of the paper. 'Over time the bodies become desiccated and effectively 'mummified'. Despite this the mothers continue to treat the bodies much like live infants, even though the way they carry the infant 'mummies' suggests that they may be aware that their infant is dead.'
The researchers observed that both mothers treated their dead offspring in a similar way, carrying and grooming them and chasing away flies - one was videoed using a stick as a 'fly whisk'. In general other chimps within the community were very tolerant of this behaviour and were seen to poke, lift and sniff the infant mummies without being aggressive towards them or trying to drag them away from the mothers. In later stages the mothers sometimes allowed youngsters to carry the bodies a short distance as part of playful behaviour.
The researchers believe hormonal changes associated with the mother's body preparing itself ready to reproduce again could contribute to the gradual 'letting go' of an infant's remains after a period of time.
The new evidence closely matches an incident in 1992 of a mother at Bossou carrying a dead infant for at least 27 days, which was reported by Tetsuro Matsuzawa of Kyoto University, Japan.
'What we are learning from these new observations is that the behaviour of chimp mothers carrying the remains of her infant for an extended period may not be that unusual in this small community,' said Dr Biro. 'This finding reinforces just how precious such isolated and threatened chimpanzee communities are because of what they can tell us about ape behaviour.'
For more information contact Dr Dora Biro on her mobile +44 (0)7815 910986 or email dora.biro@zoo.ox.ac.uk
Images relating to the research can be downloaded at http://www.ox.ac.uk/media/news_releases_for_journalists/100422.html
Video of chimps interacting with infant mummies can be viewed at: http://picasaweb.google.com/dora.biro/BossouInfants?authkey=Gv1sRgCN22xvzVpLvUcQ#
Alternatively contact the University of Oxford Press Office on +44 (0)1865 283877 or email press.office@admin.ox.ac.uk