Analyzing avian incubation with a computer algorithm
Abstract
A stable nest environment is necessary for incubation and development of offspring. Birds vary behaviour to regulate temperature for successful hatchlings. I used a hidden Markov model (HMM) to test how environmental conditions affect incubation behaviour. I examined nest temperatures and behaviours collected from Zebra finches that incubated at 30 °C or 14 °C, then incubated in the same or opposite condition for a second clutch. Data loggers and cameras recorded nest temperature and number of parents on nest. The HMM inferred behaviour from recorded behaviours and temperatures. Temperature and offspring success affected incubation duration. Birds that had successful offspring incubated at higher temperatures than unsuccessful birds. The HMM could not accurately predict number of birds from the temperature data because birds maintained nest temperature irrespective of behaviour. This study shows that birds can change behaviour in relation to the environment. Previous offspring success and ambient temperature are drivers of change in incubation behaviour.