Our recent work investigating the effects of the southern hemisphere climatic oscillations La Niña and El Niño on the timing of breeding by 64 temperate breeding species, and 15 species breeding in the arid zone. As illustrated below, La Niña is characterised by milder wet conditions in the main avian breeding period, and in such years, egg laying periods were typically longer for most species. There was a lot of variation in the response of different species and partly this was related to whether they breed early in spring. We found no obvious adverse effect of dry La Niña conditions, contrary to a prior expectation.

This study represents the most intensive examination of the effect of the southern climatic oscillation on breeding phenology in Australian birds and is focused on over 80,000 breeding records collected by a wide variety of sources over the past century.

The full paper can be found here.