The Boorish Bassian Thrush

Photo credit: J.J. Harrison via Wikipedia

Last week I completed Tasmania’s epic South Coast Track.  This 85 km track is renowned for its rugged wilderness, unpredictable weather, steep ascents and descents, and knee-deep mud.  It also happens to spotlight some of this Australian state’s wildlife treasures.  For example, it’s thought that there are only about 50 orange-bellied parrots left in the wild.  Yet, soon after stepping off the plane at the trailhead in Melaleuca, we spotted two juveniles.  A couple of days later, trekking through rain forest, we came across several Bassian thrushes.  There’s some remarkable lore around this bird.

The Bassian thrush is a medium-sized relative of the most-well known thrush in North America:  the American robin.   It’s also related to the common or Eurasian blackbird, native to Europe and introduced to Australia.  However, the Bassian thrush is native to Down Under, occurring in the Eastern states from Queensland down to Tasmania.  While it’s not endangered, it is shy and I’d never seen one before until the South Coast Track.

I first heard about it on another Tasmanian walk, the Three Capes Track.  In one of the huts, the Parks and Wildlife Service had left a booklet with fun bits of trivia about Tasmanian wildlife.  It said the Bassian thrush was known for a special hunting technique:  it farts on the ground and then picks off the critters who get scared to the surface.  According to what I read, this was an entirely unique ability amongst birds.

Being the curious type, I’ve done some research to sniff out the truth.  In 1983 a study was published in the South Australian Ornithologist.   J.S.L. Edington reported seeing this behaviour amongst a population of Bassian thrushes in South Australia.  He repeatedly observed “a noise similar to a jet of air and somewhat louder (clearly audible at five metres and lasting less than 0.25 sec.) than the bird’s footfalls was produced immediately after stopping and was in turn, followed by probingor more hopping.”  A follow-up study some years later verified Edington’s findings.

Did we see, hear (or smell) this percussive hunting technique on the South Coast Track?  Regrettably, no.  In fact, some ornithologists doubt they even do it.  Certainly it’s incredibly rare for birds to pass gas.  Besides chickens, no other birds are definitively known to do it.  Digestion usually happens so quickly in birds that there’s no time for gasses to build up.  In Edington’s study, however, he hypothesized that the behaviour was caused by the birds gulping air quickly, rather than expelling gasses related to digestion. 

It could be that this story is just blowing a bunch of hot air.  But if it’s true (I’d like to think it is!), it’s another example of the zany creation around us and the wonderfully creative God behind it.  He’s certainly gifted birds with the ability to sing in beautiful and diverse ways – and perhaps he’s even endowed some to use flatulence to get food in their beaks.