Extra-pair copulations

Extra-pair copulations (EPC's) and Extra-pair paternity (EPP's) best studied in birds and humans, where they are surprisingly common in species that were presumed to be monogamous or polygynous. 95% of birds presumed monogamous, but across species the mean rate of EPP is 13% (range 0-76). Extrapair copulations are not restricted to monogamous species; they also **

Schwagmeyer, P.L. and E. D. Ketterson 1999. Breeding synchrony and EPF rates: the key to a can of worms. Trends in Ecology and Evolution. 14:47-48.

Kempenaers, B., B. Congden, P. Boag, and R. J. Robertson. 1999. Extrapair paternity and egg hatchability in tree swallows: evidence for the genetic compatibility hypothesis? Behav. Ecol. 10:304-311.

Westneat, D. F. and P. W. Sherman. 1997. Density and extra-pair fertilizations in birds: a comparative analysis. Behav. Ecol. Sociobiol. 41:205-215.

Stutchberry, B.J.M. 1998. Breeding synchrony best explains variation in extra-pair mating system among avian species. Behav. Ecol. Sociobiol. 43:221-222.

Petrie, M., D. Doums, and A. P. Moller. 1998. The degree of extra-pair paternity increases with genetic variability. P. N. A. S. (USA) 16:9390-9395. Could be characterized as cryptic polyandry.