Predicting the hatching date of Malleefowl Leipoa ocellata eggs without excavating the mound

Abstract

The Malleefowl Leipoa ocellata (Family Megapodiidae) has suffered a major contraction in its distribution across Australia and is considered vulnerable to extinction. It incubates its eggs in a mound. A key conservation concern for this species is the level of recruitment of young into the breeding population. One approach for measuring recruitment success is to mark chicks as they emerge from the mound. Traditional methods have involved excavating the mound in order to determine the rate of egg production, hatching success and to predict the timing of hatching. This is laborious, involves significant disturbance and may pose a risk to the eggs or chicks. A less invasive method, using remote cameras to determine the date of egg-laying and hatching, and length of incubation, was tested to help predict when chicks emerge from their mound. In the mound studied at Matuwa in central Western Australia, 19 eggs were laid from 26 August 2017 to 27 January 2018, with eggs being laid earlier in the day as temperature increased and as time progressed. An average incubation period of 61.25 days was observed for four chicks that were recorded emerging from the mound. This study has provided evidence that remote cameras can be used to help determine the number of eggs laid and their hatching success and to predict emergence times of Malleefowl chicks without needing to excavate mounds. Further development of this technique as a more cost-effective and passive alternative for providing information on chick recruitment is recommended to help facilitate the recovery of the species. It was also of interest to record details of the mound observed here as the study site was located on the north-eastern limit ofthe known Malleefowl range in Western Australia, where there are few detailed records.