Wednesday, 23 December 2015

Further Down the Track

It's been a very busy past couple of months in the eagle tracking world, with the 'Where Do Wedgies Dare?' crowdfunding campaign taking up much of my time... but the good news is, the time I spent marketing paid off, and the campaign was successfully funded! This means a couple more eagles are set to be tracked in the New Year! As 2015 comes to a close, I can hardly believe it's been two-and-a-half years since this project began. The data gather so far has given us incredible insights into the Wedge-tailed Eagle's ecology, and as I prepare to (officially) commence my PhD at Murdoch University in 2016, there are no doubt even more exciting discoveries awaiting us! :-D

So, what has been happening in the lives of Wallu and Kururnpa?

Ladies first! If you've been following this blog closely, you might remember that, in October, our young girl returned from a long stint at her 'second home' at Roy Hill Station and was last recorded back in the vicinity of Lake Carnegie. Information from the WA Department of Agriculture and Food's Feral Herbivore Eradication team, who have regularly flown over this area in recent months, reveals there are several sites at Carnegie with surface water present, and many other Wedge-tails of various ages were recorded at this location. This explains why Kuyurnpa is spending time here: surface water means food, and other eagles means friends (birds of a feather flock together)! Similar patterns of young, non-breeding eagles 'living together' have been observed in the Golden Eagle (Aquila chrysaetos) by my Scottish pal Ewan Weston.

The above map shows Kuyurnpa's tracking data for the months of October and November. Interestingly, she flew across the north-eastern corner of Matuwa in late October, then actually came in and roosted less than 10 km from her natal nest on Matwua on 9th December. After a brief overnight stop, she winged her way a lazy 120 km east to roost north of Lake Carnegie again. (Remember you can click these maps to view large images).

Then her interest in her birthplace seemed to strengthen. A week later, Kuyu flew over her natal territory (shown approximately by the blue triangle) around 2 pm, drifting back to Wongawol Station (the easterly neighbour of Matuwa) to roost:
Kuyurnpa's roosted on Wongawol Station on 16th December 2015.

The next day (17th December), Kuyurnpa drifted south-west back onto Matuwa, and at 9 am was soaring at 1800 m above Lindsay Gordon Lagoon, less than 2 km south of Wallu's home range. By nightfall, after another day of floating high above the red dirt, she was roosting just 11 km south-east of her previous night's roost:

Kuyurnpa's roost on 17th December is shown by the green dot in the centre of this map (click to enlarge).

Kuyurnpa flew south and east on 18th December, then, keen for some more time on Matuwa, she headed north-west and spent the night of 19th December in a patch of tall Gidgee (Acacia pruinocarpa) trees not far north of the Lorna Glen homestead. This roost site was in the middle of four active breeding territories on Matuwa:

On 20th December, it was time for our girl to head back to Carnegie. This map shows the latest few days of tracking data, with all roosts being either on Wongawol or Carnegie. 

You can 'watch' a slideshow of consecutive days showing Kuyurnpa's travels by clicking the first map and scrolling through to see additional points from each day.

What will the next week of tracking data show? Will this trend of homeward wanderings continue?

Now... what of Wallu?

Wallu's tracking data for the past month, showing most roost sites near his nest, and the nearby rabbit warren.

Having two large daughters to feed has no doubt kept him and mate Wurru very busy! Djentu and Minyma, which were photographed, colour-ringed and named in October, are now well and truly into their post-fledging period. I would love to have satellite-tagged them in October and be closely following their progress, but unfortunately we can only assume they are safe and well, and hope for a re-sighting of their '006' or '007' colour-rings one day in the future. Although the rain season should be approaching with the coming summer period, less than 30 mm has fallen at Matuwa in the past two months, meaning food could well be in short supply. Increasing daily temperatures, which we already know can kill juvenile eagles in the arid zone (see this post for more information), also add to the challenges these young birds face, and will no doubt claim more juvenile lives this season. Unless these birds are marked in some way, many of these deaths will go undetected, leaving us with little knowledge of the impact (positive or negative) to the Wedge-tail population.

As you can see in the above map, Wallu has remained focused around his 2015 nest site, with regular (almost daily) visits to one of the key rabbit warren hunting sites. Interestingly, though, we did record another short 'Wallu Walkabout', similar to the one recorded in January 2014, in the past five days:

On 18th and 19th December, Wallu's 9 am and midday GPS fixes showed him to be 12 and 17 km (respectively) south-east of his home-range. For an adult breeding eagle that we consider to be 'sedentary', the reasons for these forays are a mystery, but new research will always pose further questions, some of which we may never know the answer to. Perhaps more eagle tracking will help us find out!

Monday, 30 November 2015

Crowdfunding Round 2

The second round of Crowdfunding which aims to raise money for TWO MORE GPS/Satellite transmitters, ends in only SEVEN DAYS! If you or anyone you know of are willing and able to contribute, please spread the word about this campaign:

Wedgie Tracking - from Simon Cherriman on Vimeo.

Wednesday, 11 November 2015

Nest Cam: Inside Wallu's Eyrie

Djentu & Minyma from Simon Cherriman on Vimeo.

During my recent research stint at Matuwa, I placed a motion-sensing camera on Wallu and Wurru's nest, as a way of monitoring Djentu and Minyma's behaviour after they had been colour-ringed. Here are some of the interesting insights gained from the motion camera. Enjoy!

Friday, 23 October 2015

Djentu and Minyma

Yesterday I had the privilege of spending some time on country with three local Aboriginal girls from Wiluna, whose teachers Chris and Anni had arranged a school adventure to enable students to learn about researching Wallu-wurru (Wedge-tailed Eagle) ecology at Matuwa. I began by drawing in the sand a story about our tagged adult male wedgie Wallu, showing his home-range and nest sites, and described the successful nest I'd visited last week. We then set off into the bush to check Wallu's nest, in the hope we would get some nice views of his two daughters.

When we reached the nest tree, I was very happy to spend time showing everyone the evidence used to determine that an eagle nest is active - lots of 'whitewash' (scats), fresh eucalypt sprigs dropped from the nest cavity's lining, and the remains of prey items delivered in the past few days. I climbed the nest to check on the juvenile eagles' progress, and was pleased to see them both standing tall on their sturdy legs, with the blue colour rings showing nicely. 

It was a marvelous view looking down from the nest tree and seeing the students and their teachers talking happily :)

When I descended to show the group close-up photos, the students asked if the two eagle chicks had names, to which I replied "No, we haven't given them any." Then something amazing happened: the girls said "Can we give them names?" This excited me greatly and I of course agreed. After a short discussion, the girls decided on 'Djentu' (pronounced 'jen-doo', which means 'sun') for the older chick, and 'minyma' ('min-muh') which is a local Martu translation for 'girl'.

Djentu (left) and Minyma stand proud and tall on their parents' Wallu and Wurru's eyrie. These two juvenile eagles are now about 10 weeks old and are about 2 weeks away from fledging.

Although they are not being satellite-tracked, Djentu and Minyma still have unique identification numbers on their colour rings, so provided these can be read if the birds are resighted, we will be able to determine who is who!

The bulge in Minyma's neck indicates a full crop, an encouraging sign of a recent feed.

Naming ceremony complete, it was then time to walk back to the car, with special thoughts of the eagles' new names in mind, and a magic outback sunset to look back at.


Saturday, 10 October 2015

'Twin' Girls!

After a short walk through the Mulga scrub today, I was super excited to spy Wallu perched at the top of a tall Cue York Gum, watching my every move. He stayed for only a few minutes, just long enough for me to snap the above photo, before launching and flapping away with large wing-beats, his PTT aerial waving in the wind. As I had suspected earlier this year, Wallu and Wurru had constructed a new nest, which I spied close to Wallu's perch tree, built 10 m up in another Cue York Gum.

Well hidden among the foliage of a Cue York Gum, Wallu and Wurru's new nest is only the fourth of over 90 wedge-tail nests built in this tree species at the Matuwa/Lorna Glen study site.

My prediction was that Wallu's regular visits to the nest site recorded by our tracking data over the past 2 months indicated that a chick had hatched and continued to be fed on a daily basis. It was most exciting to discover that this also proved to be true, and a split second after spying the nest, I noticed an eaglet standing on it, looking large and healthy. Climbing the nest, however, gave me an even better surprise: not one, but TWO large, healthy eagle chicks!

Two large female eaglets, aged about 8 weeks old.

As part of my research on the movements of juvenile eagles from Matuwa, individuals are being ringed with blue leg-rings (you can read about the first year of conducting such research in 2014 here). The 'twins' from Wallu's nest were lowered to the ground in a handling bag, then removed and held for processing. Even at this age, eaglets have powerful talons which can inflict severe wounds to a human, so care is always taken to hold the birds firmly but gently, ensuring no injuries are sustained to them or the handler.

Removing one of the juvenile eagles from the handling bag - feet first!

                                                                                                                      Taking measurements from the eaglets: the tarsal length (left), and rear talon (right).

After data on their morphometrics such as weight, wing length, tarsal (lower leg) length and size of the rear talon were taken, two leg rings (a blue, numbered colour-ring, and a stainless steel ring from the Australian Bird and Bat Banding Scheme) were fitted to the birds' tarsi (all ringing is conducted under appropriate licenses from State and Federal Government authorities). The blue colour rings are unique to this study site, so we know that any eagles bearing a ring of this colour that are subsequently sighted elsewhere in Australia originated from Matuwa/Lorna Glen. As we've seen from Kuyurnpa's amazing travels, eagles can move thousands of kilometres in their first year, so no matter where you are in Australia, keep your eyes peeled!

Holding an eaglet firmly by the tarsi and tucking up the wings prevents it from causing any injuries to itself or the researcher (left). The blue colour-rings have a unique number which identify the individual birds (click images to enlarge).

It was encouraging to record both juvenile eagles were large females, each weighing over 3 kg! And at eight-weeks of age, they still have some mass to put on, so will probably have fledging weights much greater than their father Wallu (male eagles are smaller than females, weighing about 3 kg at the most, with females occasionally exceeding 5 kg).

When the processing was complete, the 'twins' were returned to the shady canopy and replaced on their nest.
These juvenile eagles are the first record of a brood of two surviving to near-fledging age in four years of research on more than 30 resident breeding wedgie pairs at this study site. Due to an overall low food supply, most pairs rear 0 young per year, and a maximum of 5 pairs have reared 1 young each in previous years. Such findings are typical for long-lived raptors and are consistent with previous research on this Australian eagle species in arid parts of its range, where rainfall is erratic. Perhaps having satellite tracking devices on eagles increases their breeding success!?! ;-) Well done Wallu, on a fantastically successful breeding season in 2015!

Monday, 5 October 2015

Tracking Well

We didn't have much to report on our two satellite-tagged wedgies Wallu and Kuyurnpa during most of September - both stuck to a fairly similar pattern in their behaviour as previously recorded, with Wallu still tending his (apparently) successful nest site regularly, and Kuyurnpa drifting back up to Roy Hill again and spending most of the month there. Towards the end of the month though, our girl appeared to get itchy talons again and on 20th September embarked on a 1300km desert wander which saw her pass over the Matuwa homestead and continue further south-west than she has ever previously ventured! Today's latest waypoints show Kuyurnpa has again revisited the familiar ground on the north-western side of Lake Carnegie. This journey is shown on the above map (click to enlarge).

Here is a map of Wallu's past month of regular visits to the nest site (large cluster of red dots centre right), and the nearby rabbit warren (smaller cluster to the south-west of the nest). This week I will be heading to Lorna Glen to carry out more research on the breeding and diet of this eagle population during 2015, which will include a check on Wallu's nest. Watch this space for a few more regular updates!

Sunday, 2 August 2015


Kuyurnpa remains in close proximity to her birthplace! A month ago she completed a 230 km 'home run' across her natal territory, starting and finishing at a roost site located about 40 km north-east of Matuwa. Not long after that, the young eagle headed west again, spending three nights at the edge of a large claypan, as shown by the green cluster of GPS fixes in the above map. The 15th July saw her cross her natal nest site again, and this time continue further east. Kuyurnpa has spent the two weeks since that date skirting Lake Carnegie, a giant inland claypan situated in the middle of the West Australian desert.

During the latest journey east, Kuyurnpa travelled very close to our resident adult male Wallu. GPS fixes from 15th July at 3 pm show these two eagles were only 15 km apart - but both birds have different priorities in life right now. While Kuyurnpa is still very much in her juvenile wandering phase, traversing the country widely on her own, Wallu is seemingly very busy providing food to his mate Wurru (and perhaps a new chick) at a new nest site in the woodland area. Will we find later this year the first successful hatching of a Wallu eaglet since satellite tagging?  I can't wait to find out!

Monday, 6 July 2015

A New Nest?

As the eagle breeding season approaches, I've been tracking the daily movements of our male wedgie Wallu, and paying particular attention to where he has roosted each night. In the last 2 weeks he has spent more than half of his nights at a particular tall gum-tree in a small patch of woodland about 700 m north-east of his favourite rabbit warren hunting place. This is shown by the cluster of GPS fixes in the above picture (click to enlarge). I have inspected this site a few times in the past year and discovered the perch tree is a tall Cue York Gum (Eucalyptus striaticalyx) with quite a few nice horizontal perches, perfect for eagles to land on. When not roosting at the actual tree, Wallu has still remained close by, spending every night within a 1 km radius of it. It has been interesting to observe a shift in his behaviour - over the summer period he often roosts in tall Gidgee trees on the high ridge that forms the northern border of his territory, close to his two existing nest sites, and only visits the Rabbit Ridge every few days.

The fact Wallu has spent an increasing amount of time in this area as Wedge-tailed Eagles are preparing to breed makes me think him and Wurru have built a new nest here. When I learned how often he visits the nearby rabbit warren, I did wonder why this pair persisted at attempting to breed (and subsequently failing) in nests which were so far from their apparent key source of food. It would make sense to build at a site much closer to an abundant and readily portable supply of prey. I am very much looking forward to visiting the territory later this year to see if my prediction is right!

Friday, 3 July 2015

Home Run

Kuyurnpa has continued her urge to return home! After her recent long journey south, she stopped to rest for a few days 70 km north-east of her natal territory (scroll down to read more). In the next 2 days the satellite tracking data showed her head south-west from here and, around 2 pm on 2nd July, pass right above the nest on which she hatched nearly 2 years ago. Kuyurnpa then flew directly south and roosted not far from the site where she spent her first ever night alone (on 29th March 2014), clocking up 115 km for that day. By dusk tonight (3rd July 2015), she was back at the northern roost site again, completing a 2 day, 230 km 'home run' loop. Does this behaviour indicate she is wanting to return home, or is searching for a vacant breeding territory near where she was born? I still feel it is a little early for Kuyurnpa to breed, and although we know from the CSIRO's work in the 1970's that most breeding eagles are adults aged more than 6 years, we have no data on when Wedge-tailed Eagles might begin their settlement. We will only gather some insight by continuing to track Where Eagles Dare - and you can assist with that by pledging your support to help this eagle tracking project continue. Visit the Crowdfunding Campaign for information on how you can help!

Wednesday, 1 July 2015

230 Clicks South

Kuyurnpa has in the last week been on the wing again, clocking up more remarkable kilometres during a sudden journey southward. Our young eagle, who is approaching her 2nd birthday next month, added 460 km to her odometer in a 4-day flight that saw her leave Roy Hill and fly back towards home soil. On one of these days, Kuyurnpa moved an amazing 230 km between 10 am and 4 pm, with one GPS fix recording her travelling at just over 90 km per hour! Just when I thought she might settle in the Pilbara region for a while (Kuyu has just spent 6 consecutive months on an area of Roy Hill that is approximately 100 km wide), this wandering wedgie has zipped across to the Gascoyne region, stopping about 70 km north-east of her natal territory. This is the closest she's been to her 'home' since roosting 60 km away from it on 27th October last year. Will she stay here longer, or will she continue to move on? The only way to know is to check in again soon!

Don't forget to view the video to the Crowdfunding Campaign I launched just over 2 weeks ago, where you can pledge your support to help this eagle tracking project continue.

Kuyurnpa's journey south south-east, showing 4 days travel.

Saturday, 13 June 2015

Wallu: 2 Year Anniversary

Here is Wallu, doing what he does best - flying high and about to launch into a dive, fast! Just like our eagles, time has flown fast since this photo was taken at the end of last year. We are now half way through this year and have rapidly got to today's important milestone: the 2 year anniversary of Wallu's capture. It seems like only last week that I experienced the exhilarating adrenalin rush and launched from the car toward the trap in which Wallu was caught, before fitting his PTT to see where this eagle would 'dare' (you can read all about that here).

This male eagle has now been satellite-tracked for 730 consecutive days and has roosted every single night in the same home range. A massive concentration of the GPS fixes recorded by Wallu's PTT has occurred adjacent to what is clearly this eagle's main food source: a highly active rabbit warren along the edge of a seasonal lake. Wallu visits this location virtually every day.

More than 10 000 GPS fixes have been recorded from Wallu's PTT during the 2 years of tracking.

Wallu's very concentrated home range lies just north of Lindsay Gordon Lagoon, a large seasonal clayplan on Matuwa.
It is quite fitting that today, on the 2 year anniversary of his capture, Wallu will for the first time be shown to a Blue Mountains audience at the Leura screening of the documentary 'Where Do Eagles Dare?'. I am super excited about showing the film to a different audience in what is certainly a beautiful part of Australia.

Friday, 12 June 2015

Crowdfunding Campaign Launched

I'm super excited to announce the launch of a crowdfunding campaign to continue with this eagle tracking project. Info below!

Thursday, 4 June 2015

Kuyurnpa Sighted!

Today, after trekking over 2 km through water-logged country surrounding a Pilbara flood-plain on Roy Hill station, I was delighted to see Kuyurnpa, alive and well! She was satellite-tagged in October 2013 but has not been sighted since she began juvenile dispersal in March last year. The above photo was taken just before this gorgeous girl, now in her second year, took to the air and sailed away in a long glide, disappearing behind the shrubs.

After recording some information about her morning perch, I then investigated her overnight roost site, which was located in a tree a few hundred metres away.

Kuyurnpa's roost tree, where she spent last night, surrounding by flat, cattle-grazed floodplain.

This tree was one of the only eucalypts among an otherwise flat plain. Such trees are probably preferred because they provide a large raptor with easy access and a good view at dawn and dusk when potential prey might walk past. On the way to this location, I sighted three more eagles, two of which were adults. This suggests Kuyurnpa is perhaps hanging around other eagles, a tactic which probably helps her find food and increases her chance of forming bonds with other birds. Such behaviour has been observed with Golden Eagles in Scotland ('birds of a feather flock together'!). Here you can see the horizontal limb on which our girl spent the night, only about 2.5 m above the ground, as well as a fresh pile of whitewash below:

A closer look at the eucalypt bough showed very fresh imprints made by Kuyurnpa's talons. I smiled with excitement to think I was standing almost level with where this beautiful eagle had sat and gripped with those massive weapons, the same ones I had held firm when removing her from the nest to attach a PTT nearly 2 years ago!

Fresh talon imprints show exactly where Kuyurnpa sat.

Friday, 15 May 2015

Ten Thousand Fixes

Yup! TEN THOUSAND is the number of GPS fixes we have obtained from Wallu's PTT, which, as of today, has been tracking this very sedentary adult male wedgie for 700 consecutive days. The last time we checked in with Wallu we saw how he had not moved from his home range since the beginning of this tracking study. Not much has changed, and as you can see from the above 3D image, we have a very concentrated cluster of points clearly defining 'home'. As part of the process of publishing this preliminary research, I am now starting to look at this data in finer detail to analyse the points and look for patterns in daily behaviour, determine favourite roost sites, and search for other patterns in this eagle's behaviour. Watch this space for news of upcoming publications.

Thursday, 30 April 2015

Settling In?

Has Kuyurnpa found a new home? It would seem so, for it has now been over 6 months since she settled in the one place in Western Australia's Pilbara region. Last year Kuyu visited Roy Hill station several times, spending about 10 weeks there in September, before heading back through Lorna Glen for another walkabout. But by the end of October, it was back to Roy Hill again, and that is where she has remained ever since.

The above map shows the collection of GPS points (nearly 2000 of them) which we have obtained this year. The cluster to the south-east occurs across a large area of relatively flat spinifex plain, and this is where Kuyurnpa has spent most of her time (i.e. all of February and March this year). Finer detail shows her movements in this period have often been very short, sometimes only travelling 1 - 2 km between roosts, which appear to be random with no favoured roost site selected. But throughout April she has ventured to the north west much more, moving 55 km between roosts on occasion.

This is the longest period our immature eagle, who is now approaching 2 years old, has spent in one location. Although it is much larger than her natal home range, which lies about 430 km to the south, and that of neighbouring eagles on Lorna Glen, it is still interesting to note this more sedentary behaviour after an initial wandering journey which covered about a quarter of WA's area (as shown on the map below - click to enlarge). I am hoping to find out more about Kuyurnpa's behaviour, and hopefully see what she looks like, when I visit Roy Hill Mine in early June this year to screen 'Where Do Eagles Dare?'. More soon!

Kuyurnpa's dispersal path in 2014. Roy Hill is shown with a green arrow. (Note that the northernmost and southernmost fixes are GPS errors.)

Monday, 16 March 2015

Refurbished PTTs

Today I am pleased to have received two refurbished PTTs which I plan to deploy on more eagles later this year. These came from two previously tracked wedge-tails: Gidjee, our adult female who died after unexpectedly leaving home in mid 2014, and Jarrkanpa who was killed in a heat wave earlier this year. I also plan to obtain some more funding to purchase additional transmitters with the hope to increase the sample size of tagged juveniles whose dispersal behaviour I plan to track. Watch this space!

Tuesday, 27 January 2015

An Early Death

Yesterday I received the sad news that Jarrkanpa was unfortunately found dead. Recent tracking data downloaded on 20th January showed a lack of movement on the afternoon of 15th and for the whole of 16th January, but at the time of that download, no further data was available. As previous tracking data on a juvenile eagle (Kuyurnpa) had shown birds can remain stationary or show limited movement for more than a day, I made the decision to wait and see. But when the next set of data came in 3 days later, still no movement had been recorded. The Lorna Glen managers were away and out of contact but yesterday the caretaker managed to visit the location shown by Jarrkanpa's tracking data and confirm the outcome.

So what happened? A postmortem was unable to reveal the exact cause of death but it did conclude that the harness was still attached as normal and there were no injuries caused by the Teflon straps. What is most likely is Jarrkanpa died of heat exhaustion. Temperatures at Lorna Glen during the past fortnight have been exceptionally hot, with one daily maximum of 50.3˚C recorded at Lorna Glen during the week of 12th January. The table below shows the temperatures recorded at Lake Carnegie (~60 km east of Lorna Glen) for the week in which Jarrkanpa died.

Date in January
Min. Temp (˚C)
Max. Temp (˚C)
Young birds not used to such conditions may not yet have learned the behavioural or physiological adaptations which help older, more experienced birds survive. For example, it is thought that one of the reasons adult eagles soar so high (as shown by altitude readings recorded in this study) is to keep cool and conserve energy. Considering he was on the wing for less that 2 months, Jarrkanpa may not have known that if he gets too hot, he can simply 'go up' to cool off. Also, premature death in juvenile eagles during extended periods of hot weather has been recorded previously at Lorna Glen. Two eaglets aged 7-8 weeks both died on their nests in October 2012 when the recorded temperatures at Wiluna and Lake Carnegie exceeded 40˚C for more than 10 days in a row. 

Although it is never nice to have a study bird die unexpectedly, it is an accepted part of research on wild animals that this sort of thing will happen, especially for a species for which, like many other large eagles, the juveniles have a high natural mortality rate (as shown by extensive research by the CSIRO in the 1970's). This event only reiterates how precious life is, and how difficult it is for animals to survive in one of the harshest ecosystems in the world. It also makes me think how amazing it is that Kuyurnpa not only survived her post-fledging period, but that she is still being tracked after dispersing from Lorna Glen over 12 months ago.

Tuesday, 20 January 2015

Flying Higher

In our last checkup on Jarrkanpa, he had shown a great deal of confidence gain in his soaring ability, moving beyond the 1000 m altitude mark. Today I checked the latest set of fixes and thought I'd post a 'day in the life' to show how he progressed even more. At 5 am he made his first movement from a roost in the woodland, not far from his nest. By 10 am the young eagle was stationary, probably sitting in a tree and digesting his breakfast. But by 11 am he had taken to the sky and was RIGHT up there, reaching nearly 5000 m above the ground! (click the above map to enlarge and see the altitude reading). At midday Jarrkanpa had begun to drop from the heavens, and he spent the next few hours roosting in a tree, avoiding the baking temperatures (which had also been responsible for helping him soar). The remaining afternoon fixes all showed much lower altitudes, indicating a few short flights from perch to perch in the woodland north of the lake.

If you cast your mind back to this time last year, you might remember that Kuyurnpa took similar steps with her learning to fly. This is obviously part of a young eagle's progression to independence, learning to ride the air currents and move about the landscape in the easiest possible fashion, before they one day leave home and fend for themselves. Kuyu left home at the end of March... when will Jarrakanpa make his departure?

Saturday, 10 January 2015

To the South... then North

Jarrkanpa is flying high! Check out the GPS fix shown above on the left (click image to enlarge the map) - the altitude reading shows a very modest 2200m above sea level, which is about 1.7 kilometres high! Clearly this young male eagle is learning the ways of his wings, and after 6 weeks in the air is moving about the country with confidence. You can also notice how he has moved quite far away from the small cluster of points near his nest that we saw in the last update, roosting about 2.5km south-west on the second day of this New Year, then on 5th January, roosting ~3.5km north. The point far west into Wallu's home range can probably be explained by its altitude: when soaring on a thermal at such height, it is probably very easy to drift away on the wind and end up quite a distance off course!

It certainly has been a thrill to watch this young male eagle spread his wings with every week. It only seems like yesterday that Kuyurnpa was doing the same thing, branching out further and further from her days of nest confinement. What is she up to now?

Contrary to her normal behaviour of vast wanderings, Kuyurnpa has remained settled in a 'home range' since 31st October, when she sailed in after a fortnightly foray to Lake Carnegie. This small area north-east of the Pilbara town of Newman is about 100 km in diameter, and it's the second time Kuyu has spent more than a month here. The big question now is WHY? There are almost certainly other wedge-tails in this area, but it would seem too early for her to have paired up (previous research has shown most breeding wedgies are more than 5 years old). Perhaps the food supply is particularly good there... but we won't know for sure until I get out there for a look!

A map showing the location of Kuyurnpa's current 'home range', nearly 400 km from her natal nest.