Table 3.

Nest fidelity (proportion of time spent with nesting female) of anadromous growth hormone transgenic and nontransgenic Atlantic salmon males during paired competitive breeding trials. Each breeding trial included phases of competition and no competition. During competition, both the transgenic and the nontransgenic males competed directly for breeding opportunities with the female. During no competition, males had sole access to a spawning female. Data from each trial were analysed 60 min before (prespawn) and 30 min after (postspawn) each spawning event. In trials with no spawning (n = 4; all transgenic males in the absence of competition), analyses were based on observations conducted for 5-min intervals every 30 min for the duration of the phase (i.e. a total of 360 min of observation time). For statistical analyses, nest fidelity during the no competition phase was not segregated into periods

Phase	Period	Genotype	N	Median	0.25 Quantile	0.75 Quantile	Range	Statistics
Competition	Prespawn	Transgenic	11	0	0	0.06	0–0.98	χ2 = 19.33, P < 0.001
		Nontransgenic*	11	1	0.89	1	0–1
	Postspawn	Transgenic	11	0.07	0	0.52	0–0.88	χ2 = 14.85, P < 0.001
		Nontransgenic*	11	0.83	0.58	1	0–1
No Competition	–	Transgenic	8	0.91	0.64	0.97	0.02–1	χ2 = 7.09, P < 0.01
		Nontransgenic*	6	0.96	0.94	0.98	0.89–1

^*The genotype with greater nest fidelity for each comparison.