Backyard Birds

I often say it - but having REMNANT BUSH on your property is fantastic! It not only provides a cooler environment for your home (studies have shown that treed suburbs are 3˚C cooler than those which are open and concreted or bitumenised), but it also suits local native wildlife seeking food and shelter. This applies especially to birds - like the Djaryl pictured above, the Noongar word for one of our most beautiful, endemic species, the Red-capped Parrot (Purpureicephalus spurius).

For the last few weeks I have been delighted to work in my home office to the sounds of Endangered Kaaraks (Forest Red-tailed Black-Cockatoos, Calyptorhynchus banksii naso), calling softly as they forage on the fruits of Marri (Corymbia calophylla) trees that adorn out backyard. There have been up to 10 individuals but most often there is one family trio (male, female and immature) who feed together. It has been interesting to observe first-hand some information recently published by cockatoo experts Ron Johnstone and Tony Kirkby, that juvenile/immature cockatoos can take about 6 minutes to open and extract seeds from inside a honkey nut (Marri fruit), whereas adults can do this in less than one third of the time! This shows how these long-lived, highly intelligent birds rely on observing their parents and having lots of practice to forage efficiently. Here are a few pictures of the cockatoos

A Male Red-tail has jet-black plumage and a darker bill.

Female Red-tails have a pale bill and are beautifully marked with yellow-orange bands and speckles on their head.

Looking carefully at these chewed Marri fruit discarded by Black-Cockatoos after feeding, you can determine which species is responsible. In the below photo, there are 2 culprits. The older fruit faded brown was dropped by a Kaarak, which leaves a 'dish-shaped' imprint with its broad lower mandible, about the width of your index finger. The freshly chewed fruit have much smaller, square-edged 'trough-shaped' imprints, only half the width of your 'pinky' finger, made by the more delicate lower mandible of one of two White-tailed Black-Cockatoo varieties. Large shredding around the top of each nut tells us the species responsible was Gnolyenok, the Carnaby's Black-Cockatoo (Calyphtorhynchus latirostris). Baudin's Black-Cockatoo (C. baudinii) is 'the surgeon' and only leaves a few, small 'trough-shaped' marks near the stalk and no damage to the top of the fruit. Which species can you find evidence of in your area?