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!

Sunday, 29 October 2017

Twin Brothers

These two amazing Wedge-tailed Eaglets hatched on a nest built by the parents of Wailitj - the Perth Hills' first juvenile eagle to be satellite-tracked - about a month ago. Given that Wailitj only survived for 2 months post-fledging, it was thrilling to discover his parents had doubled their 'output' this season.

At the end of September, with the help of some beautiful young boys (sons of some Perth Hills friends of mine) who have been keen to learn first hand about my eagle research, we fitted this brood of 'twins' with colour rings, weighed and measured the birds, then made ourselves scarce. With both having reached the age of 5 weeks, the odds were that they should continue growing healthily to fledging age of 3 months, but nothing is certain in the ever-changing natural world.

I was very excited to return to their eyrie this morning with my great friends Mick and Rianna and their two young sons Jarrahn and Bhodi, and find both eaglets (now juvenile eagles!) still alive and well! We fitted these birds with satellite transmitters - the second set of 'twin' WA wedgies to be sat-tagged - and I paused to photograph the partially consumed ibis on the eyrie as I placed them back 'home'. With this nest site definitely having the theme of 'two boys', I decided to give Jarrahn and Bhodi some homework: to come up with names for each eagle, with the only rule being that (as with all my Perth Hills eagles) they had to be in Noongar language.

The next day Mick rang me to let me know that the birds were to be called Naakal (= quiet) and Ngooni (= bother), two very appropriate Noongar words. It will be a privilege to follow the movements of these young brothers when they fledge and begin to wander around WA. I wonder if they will stay together on their journey?!

Naakal (left) and Ngooni sit next to a freshly killed Australian Ibis on their eyrie.

Monday, 23 October 2017

Ticking Off Eagle Nests

The time of year for Wailitj / Wedge-tailed Eagle (Aquila audax) ringing is upon us again, with most nests having quite large eaglets that are the perfect age for fitting with colour rings. Having just returned from my arid zone eagle research site at Matuwa last week, I was ready to carry on 'eagling' in the Perth Hills over the weekend and visited an amazing eyrie to ring/band the chick with my beautiful friend Dani on Sunday morning.

This eaglet 6-week old eaglet's eyrie was framed beautifully by the nest tree's limbs.

The eagle nest was located high in a live but very old and partially hollow Powderbark (Eucalyptus accedens) tree, which made the climb a nerve-racking but spectacular experience. I scaled the main trunk using ropes, then tied a safety line around the huge limb that I followed out towards the nest, inching my way along and trying not to pay too much attention to the multiple entrances to its hollow cavities, all covered in chew-marks from prospecting activities by local parrots.

This Powderbark tree has been growing in the landscape for several centuries.

I reached the young Wedge-tail and admired his view across the beautifully forested surrounds, before lifting him gently into a handling bag and lowering him safely to the ground below. Dani took him into the shade where we both worked quietly to weigh, measure and fit the two types of rings/bands. Having the bird so close allowed me to notice a small Kangaroo Tick (Amblyomma triguttatum) at the edge of its eye.

A kangaroo tick is visible just below the eaglets brow, smaller than the ever-present bush fly in the centre.

While ticks are perfectly good climbers and probably capable of ascending into the canopy on their own, I suspect this parasite may have been transported into the eagles' eyrie 'on board' a Yonga / Western Grey Kangaroo (Macropus fuliginosus) joey, common food for eagles nesting in the Perth Hills. Once the joey had been eaten, the tick probably went crawling for an alternative host, with the eagle chick being the nearest new victim. I chose not to remove this parasite as I know that these animals do drop off eventually, and risking damage to such an important part of such a young bird's body was not worth it.

Ringing and processing complete, it was great to place the eaglet back on its lofty nest and take in more off the amazing view. Now onto the next nest!

Monday, 28 August 2017

Eaglets & ABC Afternoons

It's the time of year again in this beautiful season of Djilba when our marvellous Wailitj / Wedge-tailed Eagles are welcoming their new eaglets into the world. Yesterday I was thrilled to come across a wedge-tail 'suspiciously' gliding into the trees and a few minutes later, locate a new nest, one of those 'rare' ones in which both eaglets had hatched successfully and survived their first ~5 weeks.

On most nests I monitor, the larger eaglet kills the smaller one during the first fortnight, so it was very exciting to find both chicks looking fat and healthy.

The arrival of 2017's first eaglets has recently inspired me to post a few images on my Instagram and Twitter accounts, which prompted 720 ABC Perth to get in touch. Last week I was very fortunate to be given the opportunity by Gillian O'Shaughnessy to talk on her WA Afternoons program, so I had the idea of arranging this to be done live from the canopy of a tall Marri tree in the Perth Hills! The interview was booked for 2 pm on Thursday, and just beforehand, I was thrilled to climb another of this year's new nests, peer over the edge, and be greeted by this magical sight...

This eaglet is almost 4 weeks old, and as you can see in the below photo, still has a tiny egg-tooth, something which, after helping the chick break out from within its calcified prison, remains present on the end of its new bill for about 5 weeks. His first amazing primary feathers were emerging too, just visible as tiny feather pins in the above photo.

This egg tooth has a trail of dried salt which extends along the bill, the result of 'gaping' behaviour - the bird equivalent of panting - which helps lose heat in warm conditions.

It was very exciting to share this sight with ABC listeners, talk about my ongoing eagle research, and also mention the 'Where's Wailitj' Crowdfunding campaign that I'm currently running via the awesome team at Pozible. This publicity, and the fantastic article published by the Hills Gazette the following day (which talked about some of the threats to juvenile wedgies like drones that may have killed Walyunga earlier this year), created some nice media attention and helped the crowdfund climb even closer to its target! I am so grateful to all those who helped publicise my research!

If you missed the interview you can listen to it now on the ABC WA Afternoons blog here.

And if you haven't pledged to the crowdfunding campaign yet, watch this video and then visit the Pozible campaign website to make your pledge!

*POZIBLE 2017 from Simon Cherriman on Vimeo.

Thursday, 27 July 2017

Hawk-Owl Boxes for Christmas

This fabulous nest-box is one of 30 that were recently constructed by a fantastic bunch of school students from the Christmas Island District High School, under the supervision of their teachers Brad and James, a project initiated by Range to Reef Environmental and supported by Christmas Island Phosphate. These artificial tree-hollows were made for a unique, endemic and Vulnerable species of nocturnal bird of prey, the Christmas Island Hawk Owl (Ninox natalis). Range to Reef engaged me to become involved in the work, and after having closely related Southern Boobook Owls successfully use nest-boxes I installed in Perth and the WA Wheatbelt region early last year, I recommended that Range to Reef supply the same design to the school. I very privileged to be asked to assist with installation and have just returned from the island (which is one of the most amazing, unique places I've ever been!) where I worked with Range to Reef to find an arboreal home for all 30 boxes. I'll write more on this soon, but for now, here are a few snaps from the trip!

Boxes were installed using the tree-friendly 'Re-Cyc-Ology method with wire and hose-pipe.

Spot the Hawk-Owl nest-box! This one was hung about 20 m up in a beautiful Sysigium tree.

The awesome team from Range to Reef: Roget, Sophie and Andrew!

Despite spending over a week 'hanging out' in the rainforest, most of work was conducted during the day when Hawk Owls are roosting, and I was a little sad to climb on the plane and leave the island without having seen one! However, I know that one day I'll be back - hopefully to find owls nesting inside one of their new homes! In the meantime, I know the island's beautiful Frigatebirds will be soaring above the rainforest and keeping an eye out.

Tuesday, 13 June 2017

Kala & Aus Geo

You might remember a few weeks ago when I was thrilled to find Kala, our sat-tagged juvenile Wailitj hanging out with his parents, and be lucky enough to take some close-up photos of him perched in the morning sun. Today Australian Geographic reported on a recently published journal article about Wedge-tailed Eagle movement ecology (as studied by DNA), and one of these photos of Kala featured as the headline image! You can read the article, which contains some very interesting findings about the ecology of wedgies in Tasmania, at the Aus Geo blog here.

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!