Values of (± SE) and statistical variation (GLM) in response variables of parental thick-billed murres at Coats Island relative to the independent variables of year, sex and handicap.

P = partners of handicapped birds. Note that adult blood sample analyses were not obtained in 2004 and adult delivery rates were not obtained in 2003. Statistically significant relationships are shown in bold (post-hoc t-test). Surface pauses and chick growth are residuals on dive duration and chick age, respectively.1The first year of experimentation was 2003 and the second year of experimentation was 2004 for all experiments except the dive experiments. The first year of experimentation was 2004 and the second year of experimentation was 2005 for the dive experiments.2Day 6 after attachment of handicaps.3Day 12 after attachment of handicaps.4P-values from Fisher’s exact tests.5Interaction between sex and experiment.6Interaction between sex and year.7Interaction between year and experiment.8Three-way interaction.