‘What’s left?’ is an important question conservationists are often trying to answer, so this issue is dedicated to ‘leftovers’ and remnants of all kinds. Remnant habitats are vital refugia for rarities that somehow remained unscathed, tucked away while the rest of the landscape dried or was altered by human activities, or while populations moved on or declined.

In this issue:

- In biology, a vestige is a trait or characteristic that evolved for a particular function, has subsequently become obsolete, and has typically begun to degenerate. Evolutionary Biologist Timothy Jackson guides us down the rabbit hole of vestigiality to explore the evolution of obsolescence and makes the case that exploring these remnants of our past, and these basic evolutionary concepts, can help us better understand ourselves.

- A bold plan is underway to bring the mallee emu-wren back to South Australia after wildfires wiped out the last birds in 2014. Simon Verdon documents the decline of this mysterious bird and the efforts underway to save the species.

- Without anything to drink, reproductive female Children’s pythons are burdened with transferring massive amounts of water into their developing eggs, giving Environmental Physiologist Dr George Brusch an opportunity to examine how dehydration impacts physiology from multiple angles.