Colour preferences and coloured bait consumption by weka Gallirallus australis, an endemic New Zealand rail

Abstract

Native birds are among the non-target species that are killed in poisoning operations directed at introduced mammalian pests in New Zealand. By identifying colours that birds find unattractive, and incorporating them into poisonous baits, some deaths may be avoided. The colour preferences of weka, Gallirallus australis, an endemic New Zealand rail, were tested over 6 days by offering individual weka a choice between six different colours of a novel food pellet. Weka ate significantly more red and yellow pellets on the first day than green, mid-blue, light-blue, or brown pellets but consumption of all colours increased sharply on subsequent days. The colour preferences found agree well with published studies on other bird species. If colour preferences are general across species colour may be useful in deterring birds from poisonous baits. Weka however with their opportunistic and adaptable feeding style rapidly increased their consumption of baits, even those colours they initially avoided. It appears that a more active deterrent than colour will be needed for weka.