His ecological research centred on the Hudson-James Bay system, especially the region surrounding Churchill, Manitoba, where his studies of nesting Snow Geese helped to make this one of the best-understood northern ecosystems worldwide. While Bob was an unusually broad-minded scholar, he was recognized internationally as the dean of goose-plant interactions in Arctic environments, a field of study he almost single-handedly created. Bob’s research documented the consequences of changing climate and wildlife populations on the region, and his efforts played a central role in setting North American wildlife management policy and the establishment of Wapusk National Park.