Peter began studying tree swallows in 1985 at Beaverhill Lake, near Edmonton, Alberta. He continued to study them with Raleigh Robertson at the Queen’s University Biological Station, where he also met Linda Whittingham. After some swallow-free years in Australia, Linda and Peter set up their own swallow study at the University of Wiscosin in 1997, where Peter is an assistant professor. They are primarily interested in the mating behavior of tree swallows, which have one of the highest rates of extrapair mating among birds. Up to 76% of young may be sired by extrapair males. In contrast to most other birds, these extrapair fathers do not appear to be immediate neighbors. In fact, most sires do not appear to be resident males on the study grids at Saukville. They have recently begun radiotracking birds to find out where the extrapair copulations are occurring.

Linda is an assistant professor in the Department of Biology, University of Wisconsin, Milwaukee. Her interest in parental investment patterns and mating systems in birds is well served by her expertise with molecular-genetic techniques for determination of paternity and phylogeny.