Biology and Non-Monogamous Relationships
For many years authorities taught that monogamy was "natural"
and had its base in biology. In retrospect, much of the scholarship
supporting this view was shoddy and based on little more than wishful
thinking. This page attempts to present a more accurate and balanced
perspective.
General
Ted Bergstrom,
Primogeniture, Monogamy and Reproductive Success in a Stratified Society
Study Guide For Ecology
Mammals
- Chimpanzee
- Frans B. M. de Waal,
Bonobo Sex and Society
"The species is best characterized as female-centered and egalitarian
and as one that substitutes sex for aggression. Whereas in most other
species sexual behavior is a fairly distinct category, in the bonobo it
is part and parcel of social relations--and not just between males and
females. Bonobos engage in sex in virtually every partner combination ...
This finding commands attention because the bonobo shares more than
98 percent of our genetic profile, making it as close to a human as,
say, a fox is to a dog."
Birds
Dr. Bob
Montgomerie of Queen's University (Ontario, Canada) observes that
most studies of bird mating systems in the 1950s were done by observing
the birds and hence were "social". At that time, it was believed that
90% of species were socially monogamous, 6% polygynous, 2% polyandrous
and 2% promiscuous. From the mid-1980s, studies using DNA fingerprinting
(which is much more reliable) showed that the actual sexual mating system
is often far different from the social one. So far, 99 of 100 socially
monogamous species have been shown to be sexually polygynous at least.
- Les Beletsky & David Beadle(Illustrator), "The Red-Winged Blackbird :
The Biology of a Strongly Polygynous Songbird", Academic Press, 1996
- Emu Production
"Individual pens and shelters usually are provided for breeding pairs;
however, polygamous arrangements have been successful. ... Males and
females usually are paired in a 1:1 ratio although polygamous mating
(more than one female per male) has been successful in some cases."
- D.B. Lank,,
L.W. Oring and S.J. Maxson, "Mate and nutrient limitation of egg-laying
in a polyandrous shorebird", Ecology 66, pp.1513-1524 (1985).
- Robert Montgomerie,
Reproductive Strategies
"In birds, especially, it is clear that the long-held notion that most
species are monogamous is not correct."
- L.W. Oring, R.C. Fleischer, J.M. Reed and K.E. Marsden,
"Cuckoldry via sperm storage in the sequential polyandrous
Spotted Sandpiper", Nature 359, pp.631-633 (1992).
- L.W. Oring & R.D. Saylor, "Waterfowl mating systems",
in Batt. B.D.J. et al., eds.,
The Ecology and Management of Breeding Waterfowl,
pp. 190-213 (1992).
- L.W. Oring, J.M. Reed & J.A.R. Alberico,
"An experience-based mating system: Polyandry in spotted sandpipers",
Behav. Ecol. 5 pp.9-16 (1994)
- William A. Searcy & Ken Yasukawa, "Polygyny and Sexual Selection in
Red-Winged Blackbirds" (Monographs in Behavior and Ecology),
Princeton U. Press, 1995
- Bruno J. Ens, "Love thine enemy?", Nature 391, pp.635-637 (1998)
"Oystercatchers are socially and sexually monogamous birds, but a new
study reflects another side to their lifestyle. Occasionally, an
usurping female will try to break up a pair, and, after fighting with
the resident female, she may stay to
form a polygynous trio. The male is mated by both females, and they
cooperate to defend their territory and raise a brood. Although
polygyny is very rare in oystercatchers, the authors suggest that both
females benefit in terms of elevated social status."
- Warwick Tarboton,
"The Bird That Walks On Water",
Africa - Birds & Birding v.1 #3, pp.22-30
- D. Heg & R. van Treuren, "Female-female cooperation in polygynous oystercatchers",
Nature 391 p.687 (1998)
"Waders (Charadrii) provide biologists with an astonishing variety of
mating systems to study. Male and female birds establish breeding units
in which behaviour varies from monogamy, polygyny, polyandry, double
clutching, lekking and serial monogamy to sex role reversal, and many
mixed mating systems exist. This diversity is currently explained by
the costs and benefits of males and females either cooperating or
defecting during breeding attempts. The oystercatcher (Haematopus
ostralegus) is a typically monogamous species: removal experiments
show that both parents are needed to raise chicks to fledgings.
However, occasional polygyny has also been reported. Here the authors
describe polygynous oystercatcher trios and the reproductive
consequences of such polygyny. There is a 'classical' form of
polygyny (two female territories within the male territory), but
oystercatchers also show a remarkable variant, accompanied by
female-female cooperation, female-female copulations and joint
nesting."
Arthropods
©1998, 1999
Howard A. Landman /
howard@polyamory.org
Last updated 1999 April 28