THE URBAN CROWNED EAGLE
This blog follows experiences and events throughout the course of my research while based at the University of KwaZulu-Natal.
This MSc research is focusing on the ecology of urban Crowned Eagles. How do they survive, even thrive, amongst the urban environments of Durban and Pietermaritzburg, South Africa?
I’ve been busy with plenty of office work and life events which are difficult to express. So time for a different perspective. The year 2013 has been nothing if not interesting. I have had to face some gargantuan questions and challenges. While facing these challenges head on, I have had many moments both of ecstasy and of troubling wobbles. So while this kind of business doesn’t provide the most compelling blog posts, I thought a nature-oriented metaphor could
Metamorphosis
A wonderful transition that the sluggish, legged-worm creatures we call caterpillars take on their journey in life to being bright, expressive, often gaudy, creatures of flight. The ancient Greeks used the word Psyche, meaning soul (now mind)
To put it in context, let’s start with a little bit of homework. The first 20 years of my life, in New Zealand, was spent in great ignorance of butterflies and moths. Later, with a couple of years of entomology courses at Massey University, I learned that NZ’s Lepidoptera diversity bears such resemblance to other groups of animals on this long isolated, remote, south pacific land. The butterfly diversity is particularly embarrassing with only 13 native species, however the remaining 1800 species are of moths, with a very high endemism of about 90%. Moths though are mostly covert and camouflaged creatures of the night
South Africa in contrast, is a place of mind-blowing diversity for a humble Kiwi. There are 666 species of butterfly, and further, there are more than this number of brightly-colored day-flying moths alone, with a wild estimate of some total of 10,000 species of moths
So I have given them much appreciation and paid some glancing attention of the butterflies and moths while out at my eagle sites. Summer has been a wonderful spectacle of emergence
Having delved into my collection of photos from this year gone, I’ve found a few nice photos to share here. I’ve also added one or two of Glen McLean’s photos, who has helped identify some of these species, and is making a good start to developing a digital collection of the butterflies of South Africa. Maybe in coming years I’ll be seen wandering gardens with my butterfly net and camera
The ADU’s Virtual Museum is a depository and citizen science project of digital specimens of all types of wildlife. And submitting digital butterfly specimens will contribute to the SABCA, a joint project of Lepsoc, ADU and SANBI to revise the Atlas of SA butterflies distribution and conservation status
stunning and very large caterpillars of the emperor moth
unexpectedly touching hairy caterpillars is an uncomfortable experience
the metamorphosis is so extreme there is no way to tell what this will look like as an adult. photo G McLean
despite widespread and such obvious aposematism, cuckoo's thrive eating caterpillars. photo G McLean
this species is extremely toxic to touch, it looks as dangerous as a nudibranch! photo G McLean
one of the vivid day flying moths of the superb moth family
possible Black Pie
Brown-veined White
False Dotted Boarder (one of the Whites)
the boring underside of the beautiful Green-banded Swallowtail
a male Mocker Swallowtail. females have a variety of mimetic patterns of the monarch group, hence 'mocker'
Orange Tip. photo G McLean
Common Mother-of-Pearl. one of SA's showiest butterflies.
Brown Pansy
White-barred Acraea. a close muellerian mimic of the african monarch. this haggard one is 'mud-puddling'
either a Smokey Blue or Ant Blue species. Ant Blues so named because their larvae live in ants' nests
summer form of the Garden Commodore, also called Garden Inspector.
likely a Speckled Red Acraea. with the dark forewing veins either atypical form or another species
Recently back from a fourth trip to Mkambati. This was set to be a very important one for Morgans [link] research on the Cape Vulture breeding colony at Mkambati Nature Reserve. It was a fantastic achievement of coordination and collaboration as Morgan brought together twelve people to take part in this operation. A thorough range of experts and assistants came together, including the Endangered Wildlife Trust’s Vulture Working Group, EWT’s Wildlife & Energy Program, Ezemvelo KZN Wildlife’s Bearded Vulture Research, The African Bird of Prey Sanctuary, Eastern Cape Parks and Tourism Agency, and KZN bird ringers and University of KwaZulu-Natal researchers.
The goal was to achieve a successful ‘mass capture’ of vultures in a walk in trap. With four satellite GPS trackers, and forty wing tags to attach, we were aiming to capture as many as the two teams could safely process without undue stress to the vultures. A hide is placed near the trap to observe and close the trap when a number of birds are inside. There was just enough room for three people, who would set up before dawn and sit until the vultures were caught. The remaining team was to sit a few minutes drive away, at a viewpoint over the ‘superbowl’ lookout, and wait patiently by for the call of all hands on deck.
Our previous capture back in November went surprisingly quickly. With ten birds caught within the first half hour, and all done and dusted by 11am that day. So expectations were high… “no we wont need to pack lunch” was one memorable quote uttered on the night of our briefing. On the first morning while we all waited at the wonderful panoramic scene at the superbowl, Juan Morgan and Ben sat for almost ten hours in the hide without the least hint of enthusiasm from the vultures. It was a long and frustrating day. By 4pm the vultures are less keen to feed as they are to get home to the roosting cliffs, and our stomachs lead us back to the lodge for supper.
Things got even more frustrating on the second day when, although vultures were feeding on parts of the carcass nearby, they were obviously very skittish, and never settled for long enough to be caught. Long days at the superbowl were passed in various ways: I was reading… a lot, Meyrick had a near run-in with a magnificent specimen of a Black Mamba while out walking, Kerin found a stunning diversity of wildflowers to identify, and Eva went off hunting for the Mamba that Meyrick was all too happy to never see again – only to return from a foray down the cliff with a picture of a porcupine, and a rather smelly skull of a red hartebeest.
Another nine hour day on the third day and despondency was setting in, particularly because for most of the day several vultures sat perched on top of the trap! The wind has been gusting for several days. Some clear signs of cabin fever were becoming apparent and we had accumulated something to the order of 33 person days of effort and still not one vulture to show for it. Something had to change.
That evening another carcass was procured, and the vulture restaurant was baited with fresher more enticing food. Day four was my chance to be one of the three in the hide, and that night I packed books and entertainment to keep me occupied for a bum-numbing ten hour watch. Arriving at the hide at dawn, the weather had changed, and the wind was barely whispering. I was hopeful, but nonetheless settled into the camp chair as best I could.
The dawn lifted, the wind had died to a whisper, white-naped ravens started amassing, and then a fish-eagle arrived. Within 20 minutes the first vultures landed by the carcass and started feeding in and mobbing in their raucous manner. The fish-eagle was first to be pushed off as dozens and dozens of vultures frenzied. The first-eagle was the first to notice the other carcass and move off towards the trap, followed by the late coming vultures who couldn’t find a place at the table.
Twenty-five vultures and a fish-eagle were caught within the first 40 minutes of the forth day. By 11am all the vultures were processed. There are now an additional four GPS tagged birds, and 25 wing tagged birds. These tagged birds will be invaluable additions to research on foraging behaviour, and nesting colony behaviour respectively.
arriving at Mkimbati Gate on the evening of the 13th
pre-dawn and ready to head out from riverside lodge
beautiful ocean sunrises each morning as we set out to the capture site
high spirits at the superbowl
our perspective of the trap from the superbowl lookout
the highlight of the day... LUNCHTIME!!!
frustration watching several hundred vultures pass by
on the dawn of the forth morning the fish-eagle takes the lead
25 vultures penned
the vulture team
ready to work. Photo by Kerin Bowker
removing a vulture from the pen. Photo by Kerin Bowker
many hands make light work. Photo by Kerin Bowker
heading home on the 18th, we spotted this pre-migratory congregation of Amur Falcons
Burkhard Schlosser has been at the Victoria Country Club
Estate on almost a daily basis for the last few months. He has had his camera trained in one
particular direction from one particular spot at the Estate. Trained towards the Crowned Eagle nest that
has become somewhat famous in the area.
This nest is quite a special one for me. It is the first eagle pair to nest on an artificial
platform that I built for a raptor. I put this up for them after they failed to
build their own nest earlier last year. Once
the little eaglet reached 15 days of age I was able to put up a nest camera to
record all the behavior and especially, the food, of this nest since. Having being called Donna for months, a blood
test during the ringing process confirmed this eaglet was indeed a Don. The mum is named, appropriately, Victoria, a regal and hard willed girl, and by default dad is Albert.
It has been very nerve racking to work with this particular nest because, despite the carefully planned ethical considerations and cautions for
the study methods employed in my own research. There is great deal of passion, enthusiasm, caution and personal connection to these birds felt and expressed by the local residents and public
around the VCCE. So while being so
concerned with the welfare of the bird from my own perspective, I would also feel
that much worse by empathizing with the public followers of these birds should
anything happen to them. The stability and durability of the built nest site, the disturbance from monthly climbing to the nest to service the cameras, and the delicate operation of briefly removing Don from the nest to ring and record a bunch of morphometric data. A bunch of nests did fail this year, mostly seem due to bad weather during the hatching and newly hatched stage, but I am glad to say all of the five nests that I studied with cameras have successfully fledged.
Thankfully we have has a very good run with this pair and
that we have collected a remarkable set of prey data from the camera. 67,000 photos. This is mostly thanks to Ron Perks who was
the driving force behind securing the donations required to purchase the
equipment used for the study, with acknowledgements to all of the various
supporters for the Victoria Country Club Estate surveys. I have recently done the prey analysis for
the first four months of operation to date.
I am quietly holding onto that data for now, so that there will be great
revealing of the new data on the night that I make a presentation to be held at the Victoria
Country Club on the 9th of April.
So while there are quite a few example photos from the
camera to be seen on previously published blogs. The photos leading to fledgling won’t be
posted here yet. Maybe later in
April? So for now though, I am happy to
reproduce here a bunch of Burkhard’s photos, with his permission of
course. Burkhard has been getting his
photos spread far and wide, and some of these are on Africa Geographic, a
stunning photo of a Malachite Sunbird was on the cover of Wild Bird Trust
website, and there are plenty of followers to frequent updates on facebook.
All rights to these photos are copyright to Burkhard
Schlosser.
Victoria feeding little Don on the 28th of October. The camera (black bok to far left) has been in place since 21 October
After the meal Victoria likes to bring fresh gum sprigs to cover the remains of the food
Don at 47 days old. 23 November 2012
With still very undeveloped flight feather, Don exercises and develops muscles. 72 days old on 18 December 2012
Despite the look, Victoria is grateful for the food given by Albert. 22 Dec 2012. Don was ringed at 80 days old on 26 December 2012.
Lunch delivery 12 Jan 2013
Gentle motherly tenderness at feeding time. 12 Jan 2013
At 97 days old, Don's flight and tail feathers are still growing. 12 Jan 2013
At 99 days old the wings have an impressive spread and catch a lot of air. 14 Jan 2013
Branching', walking out and jumping back to the nest, three days before first free-flight. 17 Jan 2013
Freedom of flight. 21 January 2013
Out on a limb. 21 January 2013
Don has an urge to return to the nest regularly. He continues to be fed on the nest. 21 January 2013
Albert bringing in another morsel. 27 January 2013
Relaxed and windswept, at just under four month old, Don is a beautiful eagle. 2 February 2013.