If you live anywhere on the eastern side of Australia, you’ve probably noticed that bogong moths are back in a big way .

While we don’t yet have figures from ecologist-led surveys to compare with previous years, there is a wealth of data on the great moth revival being generated by citizen scientists across the eastern states.

In this animated map you can see bogong moth observations posted to the citizen science platform iNaturalist via the Bogong Watch project . Every dot is a sighting, which may include one or more moths.

How Bogong Moths swarmed eastern Australia

While there are some caveats to keep in mind with citizen science data (observation numbers over time can be skewed because of differences in effort and participation, for example), it does clearly show how the moth population has exploded this year.

A rise from a great fall

Bogongs were once so common they numbered in the billions, according to researchers , with as many as 4 billion moths migrating to the Australian Alps in summer to…