Critter Corner: the annual bogong migration

By CSIRO

10 October 2013

I was sitting around a campfire in southern New South Wales on a warm spring night a couple years back when something crashed right into my face, bounced off and into the outer perimeter of the fire. I fished the offending object out with a stick and discovered that it was a giant moth; a bogong moth to be precise. The heat had killed it. I rolled it back into the coals for a few seconds before retrieving it and popping it into my mouth for a bite. It tasted great. I don’t know why I did that, it happened a bit instinctively I guess. The friend I was with was pretty surprised but when he saw how I was enjoying it he was quick to ask if he could have a bite too.

People living in Sydney and Canberra, or around and in between, may have noticed that these same large moths (wingspan of 4-5 cm) have been descending on their cities and towns over the last month. The annual bogong moth migration is underway and, in fact, this year’s migration was the earliest recorded since 1986.

Bogong moth on wall

Bogong moth, Agrotis infusa. Image: Donald Hobern, Atlas of Living Australia

Each year in spring bogong moths (sometimes incorrectly referred to as ‘bogan’ moths – a bogan is an entirely different beast, I can assure you) fly to the high country of the Snowy Mountains in southern New South Wales and the Victorian Alps. They are fleeing their winter breeding areas, places like the Darling Downs of Queensland, the western slopes and plains of NSW and the drier inland regions of Victoria, which become harsh hot environments through the summer. They spend the summer sleeping in rock crevices and caves in the highlands and in autumn return to their breeding places once again.

large group of moths gathered on the wall of a building

Bogong moths shelter on a building in Sydney during the day. The moths sleep in clusters with a roof tile-like formation. Image: jjprojects/Flickr

When migrating they fly at night and shelter in dark crevices through the day. They are attracted by light, which affects their navigation and causes all sorts of interesting conundrums in the well lit cities and towns that these travellers pass through along the way. In 1988, the moths invaded the newly completed Parliament House in great numbers and every year since the lights have been dimmed during spring to lessen the onslaught.

No doubt it was the campfire light that delivered my bogong treat that spring night, which regrettably is still the only moth I have eaten. My typically bogong-free diet is in stark contrast to my Wiradjuri ancestors though. When I was living in Canberra, Ngambri Elder Shane Mortimer (whose family has a fascinating place in Canberra’s history) told me how Wiradjuri people, as well as other neighbouring groups, gathered in the region and feasted on the migrating moths in years gone by. Bogongs are a great source of protein and so were an important bush tucker.

I’m not exactly sure how my ancestors prepared the bogong but I can certainly recommend a light roasting on hot coals.