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!

Friday, 2 June 2017

Armadale Kaaraks


Early last year the City of Armadale gave me the wonderful opportunity of installing a variety of nest-boxes for wildlife throughout several bushland reserves, many of which were designed for Black Cockatoos. I was extremely excited when Tony Kirkby, a cockatoo biologist, who, along with Ron Johnstone from the WA Museum's Cockatoo Care Project, has studied Kaarak's (Forest Red-tailed Black Cockatoos Calyptorhynchus banksii naso) for many years, emailed me through the above photo. This was a fantastic sign that less than a year after installation, one box was being used for breeding!

Fresh chew-marks on the sacrificial chew-posts provide convincing evidence of cockatoo occupancy.

Today I was installing more nest-boxes (this time for microbats) in the area and took the opportunity to visit the active cocky box. Under Tony's guidance on the phone, I walked quietly through the bushland to the nest tree, and after observing for a few minutes then 'raking' (knocking on) the nest tree, discovered the female did not emerge. This was a good sign that a chick had hatched because adult Kaaraks are known to only brood their nestling for a week or so, then leave it on its own for most of the day while away foraging. Tony was happy for me to scale the tree and confirm there was a chick present, and also to photograph in order for its age to be estimated. When I reached the rim of the nest-box, I was met with this absolutely remarkable view!


A tiny ball of yellow natal down-feathers huddled in one corner of the nest-box, swaying ever so gently from side to side. This beautiful new gift to the world was only the second Kaarak chick I had seen in real life, and appeared a lot smaller than I expected. I lowered my camera inside the box to snap a few closer photos from a side angle, then film a few short video clips (watch a short one of this beautiful young bird on my Facebook feed here), just as a large flock of Baudin's Cockatoos flew noisily over the treetops. The nestling made a few soft rasping noises and swayed from side to side, but otherwise showed no reaction to the goings on in the outside world. Keen to keep disturbance to a minimum, I snapped some descending gear onto my rope and left the canopy behind, then walked away from the nest tree as quietly as I had come. The only sign of adult red-tails was a single, distant 'kreeee'.


After seeing these photos, Ron and Tony tell me this young Kaarak is just under a week old, and is quite young to be left alone by itself, but it does happen. I am most grateful to Tony and Ron, who mentored me during the successful use by Carnaby's Cockatoo of a nest-box in the Mundaring Shire just over a year ago, and who continue to offer guidance with various ornithological projects I am involved in. What a lucky find - and an awesome way to end the week!

Monday, 29 May 2017

Eagles & Drones


Interactions between Wedge-tailed Eagles and drones are becoming more frequent as humans intensify our land use and make increasing use of aerial vehicles for survey work. In the last few weeks, many people have sent me a link to this ABC News article which featured the above image, taken by Leigh Nairn while using a drone to taking photos of his farming activities, of an eagle just before it attacked the camera. Today I received a timely call from the ABC who were keen for my opinion about possible impacts of such attacks to the eagles, which came just as I was driving to the vet with the carcass of Walyunga, a Perth-born Wedge-tail that flew to the Pilbara region less than a month after beginning juvenile dispersal. Walyunga died suddenly and the evidence suggests this was because his wing feathers were chopped by a small, fast-spinning rotor-blade, like that on many drones (i.e. those larger and with more blades than the typical commercial example of a DJI Phantom or similar, which is what most people imagine when they think of a drone). As I mentioned to the ABC, it's not only drone operators who suffer losses as a result of these interactions, and it places emphasis on the importance of research that may potentially determine ways to minimise their occurrence. Part of my PhD research aims to investigate 3-dimensional space use of territorial adult eagles, but a big gap at this moment is funding. I'm applying for grants but am always keen to hear from anyone that may wish to sponsor my research. If this is you, please email me!

You can read more about tracking eagles using GPS/Satellite technology at the Wedge-tailed Eagle Tracking website here, and also listen to the interview on the ABC's Country Hour website here (the segment on eagles and drones starts at 32 minutes). Let's hope we are able to combine eagle tracking and drone operations to help find a solution to this human / wildlife conflict.

Thursday, 20 April 2017

Change in the Feather


While out in Wailitj (Wedge-tailed Eagle) Kala's home range today, I came across this dead Yonga (Western Grey Kangaroo), a common prey item for eagles during this time of year. Closer inspection reveal some fresh scats (the white blotch in the bottom left of the photo), and footprints in the sandy gravel told me eagles had fed on the carcass very recently. Suddenly, some crumbling bark falling from above made me look up, and THERE, peering down at me with gimlet eyes, was Kala! The hairs on the back of my neck stood up, and I rush to get my camera, but the eagle launched and flew to another tree and I only managed a fleeting snap as he let out a begging call to his mother, who was perched on the other side of the river, and disappeared behind the trees. The next morning, however, I woke up in the dark and headed back to see if I could catch the family back at the 'roo at first light, and sure enough, Kala's golden juvenile feathers were the first thing I saw glowing in the rising sun's rays.

Kala's PTT aerial and yellow colour-ring are clearly visible in the morning sunlight.

These beautiful blonde wing covert feathers provide a great example of the wide dorsal wing-bar typical of juvenile wedgies.

Juvenile eagles like Kala have in their first year a very golden or even blonde appearance. While their breast and belly is often dark brown with pale flecks, the crown, nape (back of the neck), mantle ('shoulders'), and the 2 main layers of wing coverts (median and lesser primary and secondary coverts) are very pale in colour. As the bird ages, its overall appearance becomes brown after 3-4 years, then black after 6-7 years. The 4-5 rows of very pale covert feathers on the dorsal surface of the wing, as seen clearly in the above photograph, are a key feature which allows the bird's age (within a year or two) to be determined, thanks to the detailed observations of Michaels Ridpath and Brooker, who published this information in the 1980's. Despite looking at eagles for so many years, I have not been able to take a photograph of a wild bird which shows this detail so clearly.

What was also very interesting was to notice how Kala's pale feathers had become much lighter in colour since fledging. When I watched him take his first flight from the nest nearly 5 months ago, his juvenile feathers had quite a reddish-brown appearance. Check the last photograph on this news post to see the amazing change!

After walking right beneath Kala, who this time seemed much more accepting of my presence, I spotted his parents perched in a dead tree on the side of the rugged valley slope. Sneaking closer, I was thrilled to be able to photograph both birds together before they slunk away.

Kala's parents, a classic pair of dark, adult Wedge-tailed Eagles. The male is on the right.

The first thing I noticed about this pair was how dark the female (on the left in the above photo) had become since I last saw her 5 months prior. Here's a closer image of this magnificent bird, which shows her overall black appearance, with evidence of some pale nape feathers and a few 'blonde' covert feathers on her wings.

The pale 'lump' in this eagle's throat is her bulging crop, half full of the kangaroo on which she had fed earlier.

When Kala was still a nestling, I managed to photograph the same pair perched near their eyrie, and back then the female had a much paler nape and her wing. This suggests she has undergone a significant moult since her chick fledged at the end of 2016.


Winding back the clock a little further, the same female was even paler in 2015 when I first noticed her as a particularly young bird and a 'new addition' to the territory. After successfully breeding in 2013 (when I managed to capture quite a bit of footage of this pair's nesting behaviour), the resident (very dark and mature) female had gone missing, and I'd seen the male on his own on a couple of occasions. Then I spotted him with a very pale bird, at first thinking this could be his offspring from the previous breeding season. I soon realised it was his new mate, however, when I observed him 'showing her the real estate' by performing exhilarating dives from above the valley and landing on several eyries. She followed him closely and the pair perched together in several nest trees, keeping a close eye on me while scanning the valley below. On that day I didn't have a zoom lens with me, but did manage to capture a few distance photographs (in very low light!) that show how pale the female was in August 2015.

Kala's mother was very pale in August 2015 when she first paired up with the resident male.

The new female's nape was very pale in 2015 when I estimated her to be ~3 years old.

Although Wedge-tailed Eagles do not normally enter the breeding population while immature, there are certainly records of birds breeding before reaching the normal 6-7 years of age, when they can be more or less considered 'full adults'. Kala's mother was certainly in immature plumage when she joined the resident male in this home range, and it has been amazing to see her darken over the past 3 years and attain her stunning adult appearance now.


When Kala's parents met in 2015, the pair only inspected and refurbished nests and did not attempt to lay eggs until 2016. This behaviour is quite typical of long-lived birds that do not necessarily breed every year anyway, and it has been very exciting to have a bird that is recognisable and allowed me to follow the pair's progress. The changeover in females provides good evidence that when existing birds die or leave a breeding home range, they can be replaced quite quickly and the home range can continue to be productive. Knowing that we will be able to follow with satellite tracking the movements of Kala, the beautiful eagle that is (almost certainly) his mother's very first offspring, is indeed an exciting feeling!

My last view of this eagle family was seeing Kala swoop in to join his parents on a tall, dead perch tree, and begin to preen his feathers. With this magic sight in my mind, I glanced at my phone to check the time. 8 am. Perfect time to start my day!

You can see more images of these and other beautiful eagles, and a short video from this exciting find, on my Instagram account here. Happy eagling folks!


Saturday, 15 April 2017

Recovered Roadkill


It's never pleasant to find dead animals killed by vehicle collisions along our roads, but taking the time to investigate a carcass can lead to important scientific data being gathered. Peter Jephcott, who was recently crossing the Nullarbor, had stopped to take a closer look at a dead Wedge-tailed Eagle when he noticed it had a yellow ring/band on its left leg. He then took the time to locate the second stainless-steel ring on the bird's other leg, obtain the contact details of the ABBBS, and report the recovery. As it turns out, this bird (#003) was one I ringed as a nestling 15 months ago in the Avon Valley east of Perth, a location ~960 km away from where Peter found it!


While it is sad that the bird was found dead, it is wonderful to have obtained the information about it travelling such a huge distance, considering this was only the third wedgie marked as part of the current colour-banding study. This recovery is now the longest movement recorded (by ringing/banding) for a Wedge-tailed Eagle, with the previous longest distance of 821 km being recorded in 1965 after an eagle banded in Canberra during 1964 was recovered in Cunningham, Queensland, after being shot. It is truly amazing to continue learning how far juvenile birds can move over such (relatively) short periods of time. Thank you so much Peter for your fantastic contribution to eagle research! I'm hoping that this discovery will inspire others to sharpen their 'eagle-eyes' and make more reports of banded and colour-banded wedge-tails - dead or alive!

Sunday, 29 January 2017

Giant Eagles of the Forest


I've recently returned from Tasmania where I spent the last 2 weeks volunteering with University of Tasmania student James Pay, who is also studying Wedge-tailed Eagles for his PhD. Some of James' work has involved satellite-telemetry, so I was thrilled when he gave me the opportunity to visit Tassie and assist with the attachment of transmitters to juvenile eagles, something I have been slowly gaining experience doing since Wallu was satellite-tagged in 2013.

More information is coming soon, but for now I wanted to post a few images of the magnificent bird that is the Tasmanian Wedge-tailed Eagle (Aquila audax fleyii), a subspecies of wedgie that, as I was totally amazed to discover first-hand, is so much bigger than its mainland cousin!

Tasmanian Wedge-tails are normally very wary but this female was an exception to the rule.

The eagle's habitat in this southern-most part of its range is usually tall Eucalypt forest.

Eyries like this one built in a tall Mountain Ash (E. regnans), are very camouflaged in the canopy.

The characteristic pale head and dark bill of a juvenile Wedge-tailed Eagle.

Woldja, an 11-week old Tasmanian Wedge-tailed Eagle that I was thrilled to capture.

Bill Brown holds Woldja while James Pay fits a harness-mounted satellite transmitter to her back.

Woldja's feet were eNORmous (nearly the same size as my hand!) - an adaptation for taking the larger prey animals like possums and paddymelons found in Tasmania.

All juvenile eagles have a pale head but Woldja's was an incredibly beautiful blonde colour.

A beautifully calm 8-week old Wedge-tail with a transmitter being fitted.

The incredible tree-climbing skills of Dave James allowed access to some very high eyries!

Thursday, 5 January 2017

Trails in the Sky


As the warmer season of Birak takes shape and rising thermal air-currents become more frequent, last year's Wailitj / Wedge-tailed Eagle fledglings are beginning to gain experience in the sky. My local eagle Yirrabiddi (above), who was named by Noongar elder Noel Nannup when she was satellite-tagged in late November last year, has made wonderful progress since she first fledged in early December. Below is a photo diary of her progress, which shows her well on the way to living up to her beautiful, magical name, that translates to 'trail in the sky'!!

When I checked Yirrabiddi just after fledging, she sat confidently on a sturdy limb on the outer reaches of the nest tree.


A week later I found her perched in a tall Marri about 50 m from her eyrie. She only remained perched for a minute before launching on her massive wings.


When I followed her flight path, I was amazed to see Yirrabiddi perched high in a live Jarrah tree at the edge of the open paddock near the centre of her natal territory. You can see her golden head glowing in the beautiful afternoon light.


Before I had a chance to step into the clearing, she took off again and set sail in a long glide across the paddock. A mob of Yonga / Western Grey Kangaroos were grazing in the open, and it was incredible to see several react to the oncoming eagle by standing up tall and throwing their arms skyward. Barely able to fly (let alone hunt!), she is not yet a threat to them at all, but her parents are frequent hunters of this mob, especially the smaller joeys like the one pictured here.


Just after Christmas I visited Yirrabiddi with friend and fellow Parkervillian Brendon Gough, who kindly gave me easy access with a lift on his quad bike. We found her perched near the nest again, sitting proudly in the golden sunlight, with the antenna of her PTT just visible.


We watched as she made a confident flight to a tall perch tree over 1 km from her nest. I managed to sneak around behind her and snap this photo, in which you can just make out the PTT between her shoulder blades, partially covered with feathers.


Yirrabiddi took to the wing once more, but this time really showed me what she was made of! Instead of making a direct flight back towards another perch, she glided into a clearing above the paddock, then began flapping powerfully and wheeling around in big circles, taking advantage of the strengthening westerly wind to gain height.


As I watched in absolute awe, this majestic bird quickly soared into the blue, gaining confidence but still having a slightly nervous look in her powerful eyes. Then, as if wanting to join in on the celebration of their daughter's first big flight, her parents suddenly appeared WAY up above, staying as tiny specks but slowly descending in slow circles, all the while watching Yirrabiddi's every move.


It was truly amazing to think that this bird, which I had seen as a tiny white nestling only months earlier, was now performing some of the most powerful flights in the animal kingdom! I can't wait to continue following Yirrabiddi's movements as she makes further progress and leaves even more magic trails in the sky.