Variable | Sampling technique | Sample size and factors | Tests performed |
---|---|---|---|
Annual peak aggregation density | UVC permanent belt transects (transect volume = 50*10*5 m3) | N = 10 transects Year (2013, 2014) Habitat (slope, shelf) | – |
Size-assortment: male and female density distribution | UVC points (point volume = π*5*5 m3) | N = 23 points Year (2013, 2014), Habitat (shelf, slope) Size (large, small) | Negative-binomial glm, likelihood ratio tests |
Frequency of male courtship tactics | Focal individual sampling, 1 min underwater observations | N = 72 (2014) focal males Habitat (shelf, slope) | 2 × 2 Contingency table, Fisher’s exact test |
Benefits: association rates (potential mating opportunities) | Focal individual sampling, 1Â min underwater observations | NÂ =Â 72 (2014) focal males Habitat (shelf, slope) | 95% Bootstrapped confidence intervals |
Costs: intra-sexual competition | Focal individual sampling, Activity budgets, 5Â min videos | NÂ =Â 65 (2014) focal male videos Habitat (shelf, slope) | Quasibinomial glms, likelihood ratio tests |