Welcome to the News section of the iNSiGHT Ornithology website (
www.simoncherriman.com). This blog contains updates about various things I've been up to, interesting environmental issues and observations I make regularly while going about my day. It is designed to be fun AND educational, and inspire you about our wonderful natural world. Happy reading!

Tuesday, 4 October 2016

Three Little Pigs

 
Many people don't realise that feral Pigs (Sus scrofa) are an environmental issue in parts of the Perth Hills. In fact, there is a sector of the community who actively hunt pigs and in recent times people have been caught and fined for illegally breeding and releasing them into several catchment areas to ensure they have a constant supply of 'hunting game'. Waterways such as the Avon and Helena Rivers, and Wooroloo and Gidgegannup Brooks, are particularly attractive to pigs as they are remote, and at this time of year offer a reliable water supply and lots of food. Land management authorities such as Parks and Wildlife and the Australian Wildlife Conservancy go to great lengths to remove pigs, but as with any feral control, its a labour-intensive and ongoing battle.

While at a Wedge-tailed Eagle nest yesterday, I was delighted to find one pair were doing 'their bit' for removing pigs from the ecosystem surrounding their eyrie. I decided to write a little story about my discovery, which goes like this...

One day a small & weak Wailitj (Wedge-tailed Eagle) chick was suffering head injuries after attacks from its larger sibling, when mama eagle flew in with a sudden delivery of fresh prey: pork! One little piglet had wanted to build a house of straw, one a house of bricks, & the third couldn't decide WHAT house he wanted to build... when suddenly, a large bird of prey decided they should ALL move into a biiiiig house of sticks. So it dived down, lifted them up with its powerful talons, & carried them high over the Wandoo woodland.



"My eaglet is weak", thought mama Wedgie.
"But this food might just help save its bacon!!"

Many people had been worried about the damage feral pigs cause to the precious Perth Hills bushland, but now they knew of an amazing house of sticks where Three Little Pigs (and hopefully many more) had died happily ever after. And that is the end of the story!!

As part of my current research project on Wedge-tailed Eagle movements, I am fitting colour-rings to eagles to help identify individuals and find more information about their dispersal. This involves lowering eaglets from their nest to the ground in a handling bag for ringing/banding. Mike Lohr, an experienced bird-bander currently doing a PhD research project on Googamits (Southern Boobook owls), assisted with ringing the larger chick.
At only 3 weeks of age, the smaller one was too small to be banded, and its chance of surviving sibling attacks currently seemed slim... but we decided that if it is still on the nest when we return to check this site in a month or so, we might be able to colour-ring it then.

It was interesting to note the difference between the two eaglets - the weaker chick had damage to its crown, a result of sibling attacks, and normally chicks in this condition gradually decline in condition and eventually die. However, this one's wounds seemed to be healing well and the chick's full crop suggested it had recently been fed, so perhaps some sudden 'intensive care' from its parents will help it against the odds.

The smaller eaglet had many feathers missing from its brows, but this seemed not to be related to sibling damage, as there were no scars or evidence of bleeding.

The larger chick had well developed pin-feathers on the wings, and its wing length suggested it was just under 4 weeks of age. You can see the differences in physical development clearly in the below photo (note that the size difference is accentuated by the proximity of the more dominant chick to the camera):


 After ringing/banding and measuring were complete, we hoisted the eaglets back into the canopy and I placed them back in the centre of their massive eyrie, about 18 m above the ground. The dominant chick sat up and gazed back at me, and I was thrilled to see a hint of the yellow colour-ring on its leg, which will hopefully give a good chance of this bird being resighted at a later date.

I wonder what will be for dinner tomorrow? Maybe a nocturnal bird, like a Boobook, or perhaps more pork?!?

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