I found a very interesting passage in a new book, titled "Great Ape
Societies", edited by William C. McGrew, Linda F. Marchant, and Toshisada
Nishida, 1996, Cambridge University Press.  This passage is in a chapter
titled "Conflict as Negotiation" by Frans B. M. DeWaal, who is a famous
primatologist (person who studies primates).  He is writing about a family
of chimpanzees studied by Jane Goodall, the famous anthropologist.

"If the mother brings superior strength to the weaning battlefield, the
offspring brings a well-developed larynx and blackmailing tactics.  The
youngster cajoles its mother with signs of distress, such as pouts and
whimpers.  If everything else fails, the youngster may resort to a temper
tantrum at the peak of which he almost chokes in his screams, or vomits at
her feet.  This is the ultimate threat: a literal waste of maternal
investment.  Moreover, the commotion may attract unwanted attention to the
mother.  Sometim4es other adults attack a mother of a particularly noisy
juvenile.  Thus, apart from undermining his mother's determination by
raising concern about his welfare, the offspring exterts social pressure.
        The mother has weapons, too.  Goodall (personal communication)
offers a striking example with regards to the interbirth intervals of Fifi
at Gombe National Park. [NOTE: Fifi is a chimpanzee]  Fifi had had regular
5-year intervals, almost like clockwork.  Faustino was the first offspring
born after a shorter interval: 4.5 years after the previous birth.  This was
only a minor deviation, however.  She next gave birth in 1992, when Faustino
was only 3.5 years old.  The abrupt drop in maternal attention and
opportunities for nursing caused unprecedented tantrums in Faustino.  To
him, life definitely must have seemed 'unjust.'  Fifi did not completely
wean him, however, but continued to allow him to sleep in her nest, and even
to nurse along with his new sibling.
        One of Fifi's answers to Faustino's tantrums was to climb high up in
a tree and throw him to the ground, while at the last instant holding on to
an ankle.  The young male would hang upside down for 15 seconds or more,
screaming his head off, before his mother would retrieve him.  Goodall saw
Fifi employ this scare tactic twice in a row, after which Faustino stopped
having tantrums that day." (pp. 164-165)

Fifi's response is a little dramatic, but I just had to share this, as this
is the first time I've read about tandem nursing in a non-human primate species.

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Katherine A. Dettwyler, Ph.D.                         email: [log in to unmask]
Anthropology Department                               phone: (409) 845-5256
Texas A&M University                                    fax: (409) 845-4070
College Station, TX  77843-4352