The Cape Bird Club
Western Cape Raptor Research Programme – Argo the Black Eagle
By Lucia Rodrigues
I frequently walk in Silvermine Nature Reserve and noticed a pair of Black Eagles displaying particular interest in a nest situated on Noordhoek Peak.
At the beginning of May, when it became apparent incubation had started, I contacted Andrew Jenkins at Raptor Research, Fitzpatrick Institute UCT. I hoped there would be a compelling reason to save the second chick to hatch, from certain death. This unfortunately was not to be. The nest however, was good news because in recent years the only known successful breeding site for Black Eagles on the Cape Peninsula Mountain Chain was on Table Mountain.
As far as we are able to tell, Argo hatched on 2nd June 2004. I happened to be at the nest that day.
photograph by Anthony van Zyl
"Argo" on the 16th June 2004 in his nest.
The wind was strong and made it difficult to hold my binoculars still. One egg looked fuzzy and then it moved! Refocusing I saw a little head move feebly. The second egg was still intact.
Rob Simmons visited the nest on the 6th June and thought the chick to be about five days old.
By the 7th June it was sitting up, looking decidedly perky. It was quite endearing to see the adult gingerly stepping around its precious offspring, rearranging fine bits of greenery.
I avoided the nest for the next week, because images of siblicide would forever mar joyful memories of this experience.
On the 18th June, arrived at the nest to find Argo lying quietly by himself.
Soon after, both adults come flying by and Argo immediately started cheeping and kept this up as the adults swooped in and out of view. Just before the mist came down, Troy, (my German Shepherd) and I were sitting still as statues on the top of a rock, when one of the Black Eagles flew by at eye level. So close, I felt I could have reached out and touched it, although it was probably twenty feet away. Close enough to clearly see the different colours around its eyes and beak. As it flew abreast of us, it turned its head slightly and glared at us. A most magnificent moment.
A number of cold fronts swept in over Silvermine late June, but despite my worst fears, Argo's well being seemed unaffected by it.
Saturday 3rd July, another cold and stormy day. I have noticed Argo is generally left to himself on the nest. The adults although always in the vicinity, are not inclined to keep him company. Whenever they land on the nest to briefly check on him, he calls out in recognition. I regularly visit the nest, but never see evidence of food being plentiful. Argo however seems to have grown bigger at each successive visit.
The next day Sunday 4th July, was bright and sunny. I noticed for the first time Argo looked up at me as I arrived at the nest. He is just over a month old and as one of the adults flew in and onto the nest he stood up on two strong woolly legs!
Thursday 15th July. Lovely sunny, windless day. Argo is a lot taller than a week ago and dark feathers are beginning to appear on his back.
Tuesday 27th July. Another windstill, sunny day. Argo's wings are now completely covered with brown and black feathers and the crown of his head is covered with brown feathers. His feet have become more prominent, big strong yellow claws and Argo spent some time inspecting them.
photograph by Anthony van Zyl
Watching out for Black Eagles.
Sunday 1st August. Gusting wind, with light, streaming mist that comes and goes. Argo is lying still on the nest and both adults are in entertaining mode. Riding updrafts, circling, swooping down and then up again. Disappearing and then reappearing through the mist. Quite beautiful and exhilarating, I almost feel suspended between heaven and earth just watching them. Suddenly one adult breaks away and with great purpose swoops down and out of sight, only to reappear shortly afterwards with a small dassie hanging, seemingly lifeless, from its claws. The two adults fly around together for quite a while, before landing on the nest, just as the mist closed in and obscured the rest of the ritual from view.
photograph by Anthony van Zyl
Black Eagles soaring in the early spring sky.
Monday, 2nd August. Sunny and windless. Argo is two months old and today we are ringing him. Andrew Jenkins and Anthony van Zyl, abseil down to the nest. Soon after Andrew and Anthony arrive at the nest, so do both adults. They seem to fly very closely, past the nest several times, their wing tips almost touching the rock face. Argo reared up as Andrew arrived at the nest and he had to hold onto both legs until Anthony came down and assisted to subdue the bird. Argo settled down and allowed himself to be handled. He was adeptly weighed, measured and ringed. Argo weighed 3,9 kg, which was quite big for a Black Eagle his age. Other measurements taken were; wing chord 390 mm and tail 200mm. Evidence of food leftovers was surprisingly sparse for an eagle's nest at that stage. Andrew found the feathers of a feral pigeon, the keel of a small game bird, (possibly a young Cape Francolin), dassie fur pellets and the top of the skull of a small mammal, which could have belonged to the small dassie, I had seen the adult take onto the nest the day before. As soon as Andrew and Anthony left the nest, first one adult and then the second arrived. Both inspected Argo in turn and seemed satisfied nothing was amiss. All three eagles stayed on the nest, while the second adult busied itself with rearranging some twigs and other bits and pieces of nesting material. The ringing exercise did not seem to have an impact on the eagles and life continued with its normal routine.
photograph by Andrew Jenkins
"Argo" at 2 months after being ringed and his statistics taken.
One late afternoon I arrived at the nest to see one adult feeding Argo. the second adult arrived, but was not welcomed by the feeding adult who immediately mantled over the food item. This did not seem to faze the second adult at all, who then proceeded to show off his flying prowess with exhilarating skill. The wind was quite strong as he hovered dead still with wings completely outstretched. Slightly turning to one side, he suddenly lifted up very high at great speed, hung suspended for a minute then folded back his wings and plummeted down to earth, only to swoop back up and repeat the entire exercise. He seemed to be doing this for pure pleasure.
Argo left the nest on either Thursday the 26th or Friday the 27th August and I did not see him again until Sunday 5th September, when I caught a fleeting glimpse of him flying behind his parents.
My first long encounter with him flying was at Noordhoek Peak on Saturday the 18th September. He is magnificent. Twice he launched himself from the cliff into a strong wind in a curious and comical position with his tail up. Looking at him I was not sure whether he was just having some fun or having trouble launching himself. Once properly airborne however, he looked like a pro. Suddenly he cried in alarm as a Rock Kestrel dived at him. He disappeared to the left where he settled on a rock, seemingly to recover, but was soon flying again. Both the adults appeared suddenly and joined him. Argo immediately started calling and the three of them flew off to towards Constantiaberg.
photograph by Ann Koeslag
photograph by Ann Koeslag
"Argos" parents soaring in the summer sky 2005.
Monday 27th September, on my way up to Noordhoek Peak, first came across the two adults sitting cosily together on the tallest peak of the Amphitheatre. Arriving at the peak, Argo appeared with both his parents, flying and calling to his hearts content. The Rock Kestrel dived down on him again, but he took this in his stride and hardly faltered in his flight.
Soon Argo will have to start fending for himself and he will have to leave the Silvermine area. We're not sure where his life experience will take him.
If anyone sees him, please report it on the CapeBirdNet or Western Cape Raptor Research Programme, Fitzpatrick Institute, UCT or Lucia as below.
Lucia Rodrigues
cell 083 325 8881
email signet@webafrica.org.za
We would be most grateful.
