A grey-headed flying fox colony photographed in December 2019 during an extreme heat stress event. The temperature exceeded 43C and in a desperate search for somewhere cooler and less exposed, the flying foxes descended from the safety of the tree canopy. Ironically and sadly, this behaviour resulted in what experts call ‘clumping’ – where the number of bats in close proximity means the animals get even hotter. It is often a precursor to mass deaths. More than 4,500 grey-headed flying foxes died at the Melbourne Yarra Bend colony, 56% being infants.

Photograph: Douglas Gimesy