Behaviour of the specific frequency, S_N, as a function of key host properties. Top: dependence of S_N on the host galaxy stellar mass, central surface brightness (μ₀), and local density (log(ρ₁₀)), shown from left to right. There are no obvious trends, except with ρ₁₀, which shows an increase in specific frequency as the local density becomes less dense. Bottom: dependence of S_N on host galaxy g − r colour, axis ratio, and effective radius (R_e), shown from left to right. The bottom dependencies show the most prominent trends, with an increase in GC counts with bluer colours, increased roundness, and larger size. For all plots, the running average and standard deviation, computed using only non-zero values of N_GC, is shown as the red dashed line and light red region, respectively.