Wednesday, 30 November 2016

Goonta's Going!

After fledging on 16th November and spending most of the following 10 days roosting in a patch of tall trees near her nest, Goonta has now started to make larger movements, with the latest exciting map (downloaded today - click to enlarge) showing her gradually carving a path eastwards. The most recent fix we received is nearly 1 km east of her nest, which is quite a good effort for a bird that hasn't been on the wing long! I am super excited to monitor this young desert eagle's progress over the coming weeks!

Monday, 28 November 2016

Close on Matuwa

It's been a while since we had an update from our two longest-tracked eagles, Wallu and Kuyurnpa, but I'm pleased to report all is well with both! Kuyurnpa has been spending the past few months wandering the Carnegie Lakes system and floating over Matuwa on occasion, and Wallu has remained 'at home' as normal. Today, Kuyurnpa flew in from the far east and roosted almost on Wallu's home range, as shown in the above map. This is the closest these birds have been since April this year, when Kuyu passed right over Wallu's nest. How long will she stay on Matuwa this time?!

Friday, 21 October 2016

Welcome Goonta!

This is the beautiful Goonta, the latest magnificent Wedge-tailed Eagle to join our family of satellite-tracked birds. Goonta was banded last week, and after receiving approval to commence the fieldwork component of my PhD a few days ago, we returned to her nest today to fit her with a harness-mounted PTT.

Bill Brown prepares to place Goonta in a handling bag after her PTT has been attached.

Using a new attachment procedure that I recently learned from my wonderful raptor-researching friends in Scotland, I fitted the transmitter to the eagle's back using a Teflon harness, which is stitched on at the front creating a 'weak link' that will eventually disintegrate. The transmitter is light (70 g) and makes up only a very small proportion  of the bird's total weight (2.5 kg). It was wonderful to be able to share this experience with Bill, and also with a good family friend David Ryder, who I have known since very early on in my ornithological career (about 27 years!), and who has also been volunteering to help with this year's research.

After snapping a few photos, Goonta was then placed back on her nest, and this time she stood and watched us carefully, probably wondering if we would be back to visit again. Other than to spy her from a distance and make sure it is behaving normally, we won't need to disturb her again - the monitoring will now be done via a remote satellite connection!

The PTT is just visible on Goonta's back.

It is hard to believe that 3 years has passed since we tagged the previous juvenile female wedgie Kuyurnpa, who has now travelled over 10 000 km each year since. Time - just like these amazing birds - flies fast! I can't wait to see where Goonta goes!

Goonta watches the sun set from her outback eyrie. It won't be long before she'll by flying towards it.

Tuesday, 18 October 2016

An Arid Year

Experiencing first hand the boom and bust cycles of desert life is one of the most appealing features of conducting research in these amazing ecosystems. While in some years decent rainfall is recorded and wildlife is able to flourish, in others it is quite normal for conditions to be dry for many months at a time. For me, one of the constant thrills of researching eagle ecology is the insight into the ecosystems it provides: eagles are a window into the environment. By examining their nesting efforts in one year, we are able to read the environment and determine what local conditions have been like for the previous year.

Having just completed assessing the Matuwa Wallu-wurru / Wedge-tailed Eagle population's breeding activity for 2016, it was evident that the past season had been a dry one indeed. Only three of the 35 breeding pairs (less than 10%) produced chicks, compared to five pairs last year, and five the year before. Such productivity is very low but probably quite normal in the arid zone where these top order predators only thrive in occasional productive years. It is also an indicator that ecosystem productivity was low, because only three territories had enough prey for the resident adults to nest, incubate, hatch and rear chicks. 

A typical Wallu-wurru nest from the 2016 breeding season, being partially lined but with no signs of breeding.
The majority of eagle territories contained one nest which had signs of preliminary nesting, being partially or fully lined, but there was no evidence of further breeding activity. Together with the tracking data from our breeding adults, these signs of continued visitation to nests show the long-term attachment to territory that Wedge-tails display, first suggested by CSIRO research in the 1970's. Incidentally we did observe adult pairs perching on their nest, or soaring nearby, and while assessing the 100 or so nests by helicopter, we were able to get some great views of these magnificent birds in flight.

An adult female Wedge-tailed Eagle banks in front of the chopper. Note the bird's barred primary feathers which suggest she has not yet reached full adult plumage.

Despite most nests being empty, one that we visited did have a large, healthy juvenile aged about 10 weeks. The discovery of this eaglet created an opportunity for what was a definite highlight of this recent trip. Martu Elders (who have kindly continued to endorse this ongoing eagle research on their land) and children from the local Wiluna Remote Community School were on country to take part in educational activities, so a small group visited the nest with us to learn about ringing/banding research.

After hand-catching the eagle on the nest, it was lowered to the floor in a handling bag for processing. I was very fortunate to have Bill Brown, a Wedge-tailed Eagle researcher and experienced raptor handler from Tasmania, volunteering with me to help. His skills in holding the bird and keeping it calm during processing were fantastic and allowed the procedure to go ahead quickly and smoothly. 

The Martu Elders, school teachers and children, and a group of bird-banding researchers led by my friend and colleague Neil Hamilton, all watched on as we explained the process of fitting metal and coloured leg-rings to allow identification of the birds, taking measurements, and the implications of this research overall.

Bill Brown removes the eagle from the handling bag.

Once banding and measuring was complete the eagle was returned to its nest, where it sat quietly and bobbed down to lay flat on the nest cavity. This behaviour is typical for nestlings that want to remain hidden in low, outback eyries. We then all gathered below the Wallu-wurru nest to take a group photograph, during which time the eagle remained quiet. This gave Rita Cutter (one of the Martu women elders) an idea of a name for the bird: Goonta, which is a Martu word meaning 'shy' or 'quiet'. A perfect fit for this female eagle. 

While walking back to the car, the whole experience began to sink in. It brought tears to my eyes to able to be on country with this land's (and the world's!) oldest indigenous culture, people who have for thousands of years lived in a sustainable relationship with the ecosystems out here. What an absolute privilege to have their permission to conduct ongoing work to find out more about these charismatic birds of prey, in what I hope can continue to be a collaborate venture to engage with this amazing landscape.

The Kalgoorlie Miner reported a great article on this event, which you can read here. Also, the school children have since created some wonderful videos documenting their experiences while on country. You can view these, as well as a selection of photos, at the school's Facebook page.

Sunday, 24 July 2016

Northern Loops

After spending the past 3 weeks at Roy Hill, Kuyurnpa has again drifted southwards back towards Matuwa, this time taking a slightly 'western' (compared with previous trips) route which took in parts of the Great Northern Highway. As you can see in the above map, there are three points at which her journey overlapped with WA's main artery north. Two of these were just 'crossings' where our eagle soared high over the thin strip of bitumen and kept flying, but the third and southern-most point shows Kuyurnpa spending several hours at ground level near the road, then roosting for the night 200 m west of it, about 100 km north of Meekatharra. A likely explanation is that she was attracted to feed on roadkill, a common activity for many young, nomadic eagles like Kuyurnpa. This behaviour occurred after a 420 km journey from Roy Hill. Most travellers I know don't even last half this distance before they are tempted to stop at the nearest roadhouse for some 'roo jerky'... then again, most travellers I know are not eagles!! 

Turning east again, Kuyurnpa spent the next two days completing her 640 km trip back to Matuwa. Her homeland was then the focus for two-and-a-half weeks, but on 22nd July she completed a huge northern loop by flying 430 km north to Roy Hill again, a total return distance of ~1500 kms! Here's a map showing those movements:

Although Matuwa only kept her attention for 17 days, and the above map shows a few concentrated GPS fixes which do not seem to indicate much movement, this initial glance is misleading. Let's zoom in a bit:

The green dots on the top left and top right corners of the above map show GPS points recorded on Kuyurnpa's inward (4th July) and outward (21st July) paths to the Matuwa area, respectively. It's really interesting to look closer and see the exploratory behaviour during her stay. The large cluster of points near the south-east corner of Matuwa, where Kuyurnpa spent several days at a time exploring a (possibly vacant) territory are actually broken up by a few flights back and forth to roosts in the north (on Kurra-Kurra, the Martu Aboriginal property adjoining Matuwa). Together with some loops to the east and west (including one flight over her natal territory, shown by the blue triangle), the distance our girl has travelled while 'not really moving much' is over 500 kms! This means the loop we saw above on the first map is actually 2000 km, a miraculous achievement by Kuyurnpa and a demonstration of the sheer ease with which this magnificent eagle species can cover ground!

Sunday, 26 June 2016

Kuyu Leaves Carnegie

Although I'm currently away in Scotland gaining experience in Golden Eagle research, which will be an enormous help for my future eagle studies in Australia, I've been closely monitoring the movements of our two sat-tagged 'wedgies' Wallu and Kuyurnpa. As you would've read recently, Kuyu spent much of late 2015 and the early part of 2016 in the vicinity of Matuwa, wandering the lakes of the Carnegie area and frequently 'ducking over' (or, more accurately, 'eagling' over!!) to visit habitats close to her natal territory. In the past month, however, she has headed northward again, embarking for her other favourite haunt at Roy Hill, making one overnight stop to complete the ~350 km journey there on 3rd June.

Zooming in on the above map, you can see more detail of Kuyurnpa's recent movement in relation to the major landforms (the pale grey sections are rocky ironstone 'plateau's' with Porcupine Grass (Triodia sp.), and the red 'sandy' looking areas are lowlands, with the large reddish section to the west being the well-known Fortescue Marsh):

We can now glance back to the same map and look at our young girl's movements between March and June 2015:

These datapoints indicate Kuyurnpa recently revisited many of the same areas she had been to before, perhaps even using the same roost sites, places she has probably stored inside her internal 'black box'!

Now to Wallu...

Compared with this juvenile female, our adult male has continued his much more sedentary behaviour, but of late we have seen him leave his home range on a number of occasions, something which in the last 3 years has only been recorded once before. After spending the nights of 9th & 11th June a kilometre or so outside of his home range (southern- and western-most GPS fixes in the above **map), Wallu then travelled way to the north-east and spent the night of 10th July about 50 km away, before heading 'home' to roost the next day. Then, on 20th July, he moved away east and again spent the night 50 km away:

At this stage I cannot offer any explanation for these unusual movements - perhaps food is short at home, or there is competition for mates? Sometimes I wish I was there on board the PTT to actually SEE what was going on! The main thing is, Wallu is alive and well, and continuing to generate very interesting findings.

Thanks for tuning in everyone! I'll post more updates from arid Western Australia (via not-so-arid Scotland!) soon :)

**(Just to keep you up to scratch with things, the black polygons shown on the above map are the approximate 'boundaries' (I use that term very loosely) to other adult breeding territories, something I've been working on lately. The blue triangle in the fenced enclosure, where our late Gidjee lived, and the green line denotes the boundary between the Murchison and Gascoyne IBRA regions.)

Wednesday, 18 May 2016

More of Matuwa

 Where are the eagles now!? If you checked in just over a month ago, you would have seen that Wallu was still at home, and Kuyurnpa was loitering around her well-known haunt to the north of Lake Carnegie. Not much has changed in the past 6 weeks, except to say that our young girl's homing behaviour has continued, with regular visits to Matuwa. She has spent 6 nights roosting on our study area, which averages one per week, a slight increase in regularity since the start of 2016. Spending so much time looking at Matuwa on a mapping system, which makes this huge area appear tiny, often makes me under-appreciate the scale of this immature eagle's regular movements! It still amazes me that one night she can roost on Matuwa, and the next she can be way out near Carnegie again, almost 100 km away. The joys of being able to fly!