The effect of GnRHa on body weight and normalized testes size, were analyzed using a: (1) Two-way ANOVA (Treatment × Age) in year 1 and 2, (2) Two-way ANOVA during breeding and non-breeding season. Effects of age and treatment on spatial orientation were assessed with data from the first attempt of the maze, across all ages (41, 83 and 95 weeks of age), using a two-way ANOVA (Treatment × Age). Effects of treatment on spatial learning, over three consecutive maze attempts, were assessed with two-way ANOVA (Treatment × Maze attempt) at each respective age. One-way ANOVA was used to assess the effects of treatment on the ease of maze training (number of training attempts at 95 weeks of age), as well as traverse times upon completion of training. Effects of treatment on long-term spatial memory were tested by comparison of traverse times at: (1) 99 weeks of age only (one-way ANOVA); (2) 95 (last training attempt) versus 99 (the assessment attempt) weeks of age (two-way ANOVA: Treatment × Time); and 99 (GnRHa-Recovery) versus 45 (during GnRHa-treatment) weeks of age (two-way ANOVA: Treatment × Time). The effect of maze design familiarity was examined by comparison of the traverse time of maze layouts 1 and 2 at 83 weeks of age, or layouts 2 and 3 at 95 weeks of age (two-way ANOVA: Treatment × Maze Layout). The effects of treatment and age on testes size was evaluated with a two-way ANOVA. All statistical tests were followed by a Tukey Honest Significant Difference post hoc test, to assess where significant differences existed between treatment groups. All graphs represent means and standard errors of the mean. Statistical P-values ≤ 0.05 were considered significant.