Colour preferences in North Island robins (Petroica australis): Implications for deterring birds from poisonous baits

There is growing awareness and concern in New Zealand about native birds eating poisonous baits intended for pest species such as brushtail possums (Trichosurus vulpecula) and rats (Rattus rattus, R.,norvegicus, R. exulans). We investigated the colour preferences of North Island robins (Petroica australis) a species known to be vulnerable to poisoning. The main aims were to determine if: (1) robins had colour preferences, (2) the preferences were consistent between two separate populations and 3) the preferences were similar to those found previously in weka (Gallirallus australis), another native species. Robins in Pureora Forest Park and Te Urewera National Park were individually offered a choice between differently coloured versions of a novel food (red, yellow, brown, green, light blue and medium blue) daily, for six consecutive days. Robins showed food colour preferences pecking more at the red, yellow and green cake than the medium blue, light blue or brown cake. No difference was evident in the colour preferences of the two populations. The colour preferences of robins were similar to those reported previously with weka. Dyeing poisonous baits may be sufficient to stop a proportion of robins from eating them. Further work is needed to determine how colour preferences vary across seasons, populations and species.