Wing-clipped mallards were introduced on breeding lakes before the arrival of teal to induce resource limitation and interspecific competition, hypothesized to reduce lake use by teal. Experimental lakes had 2.9-8.0 times higher pair density of mallards than controls, but there was no negative response by teal to the treatment. We believe this is the first combined observational-experimental demonstration of lack of interspecific competition in waterfowl. Our results indicate that heterospecific attraction may affect co-existence in dabbling ducks.