BACK TO NATURE - Life in the Canopy

By Jamie Walker

Australia has some of the world’s tallest trees. They may exceed 80m in height, but even specimens of 30 t0 40m have canopies which present a distant world to us ground dwellers.

And those canopies are full of lives which are a challenge to see, even through the finest optics. Small birds, like Honeyeaters and Gerygones, can look no bigger than bees and may be impossible to recognise visually among thousands of leaves. We may, in the end, resign ourselves to the use of our ears to achieve identification.

Bigger birds are easier if they sit out in open tree crowns. Hefty Topknot Pigeons (once a staple food for our ancestors) will do this. Cumbersome, they also capture attention by the loud clatter of their wings as they shift for better purchase and balance in order to feed on fruit.

And there are raptors up there too. Pacific Bazas (Crested Hawks) and Square-tailed Kites are specialised canopy hunters, seeking birds and their nestlings, frogs, geckos, large insects and small mammals. They often pass over unnoticed – hidden from our vision by overlapping foliage.

A globe-shaped nest of grass and leaves in a very high point where branches meet, is often the work of a little native mouse, which glories in the name of Fawn-footed Melomys. Warm chestnut brown and as arboreal as an old-world squirrel, by night it eats leaves, buds and fruit in the treetops. 

Before the construction of the present Centre at the Mary Cairncross Reserve, the old “temporary” building was not fully proofed against nocturnal penetration by wildlife of all kinds. Long-serving volunteers may remember opening the building in the morning, to sometimes discover a Melomys in the wastepaper basket. Perhaps the bin offered security, like a hollow log.

Gaps between the trees, where warm air gently rises without interference by wind, attract butterflies (often different Jezebel species). These places are also exploited by thin clouds of floating dragonflies: Graphic and Yellow-striped Flutterers. They are effective hunters of other insects in these calm conditions. Scientists have estimated that each flutterer will consume up to 100 mosquitos per day.

Towards the end of a relatively uneventful walk with friends, to Gheerulla Falls near Mapleton, we were treated to the appearance of two female Paradise Riflebirds moving between treetops. Excited, in one of those birding moments, we forgot the small spinal discomforts caused by leaning back and looking up. The birds were very obliging. Views were good and identification was certain. 

Then, I noticed a feature I cannot find referred to in Field Guides or i.d. apps – as the birds passed overhead, their wing feathers looked a warm, pinkish cinnamon colour and were translucent: something new to look for on another occasion.

A forest canopy is a difficult field of study. Height and distance are uncomfortably great, and the light of the sky is unhelpfully behind the objects of our interest. Yet, just like any other theatre of activity, it has its moments