Antipredator Colouration in the Forests of Aotearoa

Abstract

The relationship between predator and prey relies on the cues they communicate with each other. These cues include anti-predation indicators prey species communicate to predators. Aposematic cues are an example of an anti-predation strategy that prey use to reduce the attack rates they experience. Aposematism is the association between conspicuous colouration and the presence of toxins that make the prey unpalatable to the predator. Other species that want to remain inconspicuous to predators may use other anti-predation methods such as camouflage. This thesis looks at whether birds in Aotearoa-New Zealand have experienced aposematic cues from insect prey. Furthermore, it specifically looks at whether this is influenced by a naïve population, as well as the proportion of endemic/native species compared to introduced species. The experiments in this thesis were conducted in the Waitākere Ranges and Riverhead Forest, both within Auckland, New Zealand. Artificial prey was used to simulate both aposematic and non-aposematic insects. The colour of the insect model did affect whether the mealworm was eaten (F-Value = 8.9, p-value = 0.03). The proportion of endemic/native avian species compared to introduced species in the area did affect whether the artificial prey was predated (F-value = 120, p-value<0.001). Finally, the experience of the population, and whether they had been exposed to aposematic species prior to the experiments did not affect whether the artificial prey was predated or not (F-value<1, p-value >0.05). Therefore, this thesis concludes that birds of Aotearoa have been exposed to aposematic insects and have learned to reduce their attack rates against them.