Australian Logrunner

Within their range and suitable habitats in NSW, Australian Logrunners are uncommon to rare. We recently found Australian Logrunners in the Booyong Flora Reserve (1), a Big Scrub lowland rainforest remnant near Bangalow in Northern NSW. With close to 100% forest canopy cover, the floor of the Booyong Reserve is rather dark with little understory growth, though there is a tangle of vines and fallen branches and some struggling shrubs including Walking-stick Palms etc. The canopy above drops litter including spent flowers, fruit, leaves, twigs, branches, large limbs and occasionally whole trees and the resulting forest floor eco system suits the Logrunners well.

Our encounter with a small party of three Logrunners (there may have been four?) was brief. Out of only half a dozen photos snapped in the low light at ISO 6,400, with a fully open aperture and even then only 1/100th of a second shutter speed, just two photos were fortunately free of obstructions and reasonably sharp, and luckily one was a male and one a female. 

Please click on photos to enlarge.

The adult male Australian Logrunner

The adult female Australian Logrunner

The Orthonyx genus of logrunners contains just three species, one from New Guinea and two, the Australian Logrunner (Orthonyx temminckii) and the Chowchilla (Orthonyx spaldingii) which are both endemic to Australia. Logrunners have an ancient lineage dating back at least as far as the Middle Miocene (16 to 11 million years ago) – Walter Bowles published a paper in 1993 in the EMU (2) on the fossil remains of Orthonyx found in the Miocene fossil beds at Riversleigh in North-west Queensland. 

The Australian Logrunner has developed a unique foraging technique as part of its adaption to life on the floor of temperate, subtropical and tropical lowland rainforests. The origins of these forests date back to before Australia split from Gondwana some 41 million years ago. These forests were once much more widespread in Australia however as the climate has slowly dried over millions of years they have shrunk and since white settlement logging and clearing for agriculture and urban development has seen further significant declines in these types of forest habitats. 

Logrunners (Orthonyx species) have developed short broad tails with feathers ending in strong spines that they use to prop against while using their strong legs and feet to move rainforest floor leaf litter and then scratch in the exposed soil for invertebrate food. Further, the sideways sweeping action of their legs which they use to shift leaf litter is unique to logrunners. They have evolved a short and broad pelvis with stout femurs which have strongly developed projections to support their strong leg muscles enabling them to shift large quantities of leaf litter to expose their food.

I am now keen to find the Chowchilla (Orthonyx spaldingii), the Australian Logrunner’s close relative, in its much more restricted range but similar habitat in north-east Queensland. 

Notes:

(1) The Booyong Flora Reserve is a protected nature reserve located in Booyong in the Northern Rivers region of New South Wales, Australia. The 13-hectare sub–tropical jungle is situated 18 kilometres northeast of Lismore and is a remnant of the Big Scrub, of which less than one percent of the original Big Scrub remains. Wikipedia

(2) BOLES, W. E. 1993. A Logrunner Orthonyx (Passeriformes, Orthonychidae) From the Miocene of Riversleigh, North-western Queensland. - Emu, 93: 44-49.