Black Eagle chicks in the midst of a Cain and Abel struggle

Two eggs were laid by the Walter Sisulu Botanical Garden’s resident Black Eagle pair during May 2012. The eggs hatched in early June after an incubation period of 44 to 45 days and two chicks emerged four to five days apart. 

The sad reality is that only a single chick will grow to adulthood. The reason for this being a phenomena called Cainism (or in other words a Cain and Abel struggle) whereby the stronger of the two chicks (usually the oldest (Cain), attacks and eventually kills and devours its sibling (Abel) after a 3 to 4 day struggle. The first chick, being the older and the stronger, will intercept the food offered by the female. The male provides most of the food while the chick is in the nest while the female feeds the young chick during the early stages and also defends the nest. The chick will grow into a handsome golden/brown juvenile eaglet. 

The gardens are situated in Roodepoort (Gauteng, South Africa) and fifteen eagle-generations have passed since the Black eagles (Verreaux’s eagles) were discovered in the Garden - I have been following the life of these two Black Eagles (Verreaux’s (Black) Eagles) for many years. Over the past 30 years Emoyeni, the female, has produced a chick every second year or even annually at times. In Nov 2011, Mbuso, their last juvenile Black Eagle chick, left the Garden to establish his own territory.

 Mbuso

The Black Eagles on their nest

The webcam focusing on the nest

The male circling the nest

For more interesting info visit the website or view the eagles via webcam or alternatively view them on TV at the Garden entrance.

PS : You can read all the Black Eagle articles in the menu on the left - they are all coloured RED

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Black Eagle Cam Project

This is the world of the ‘Black Eagles of Roodekrans’ at the Walter Sisulu Botanical Gardens in Roodepoort, Gauteng, South Africa. Weighing up to 4.8 kg this is one of Africa’s largest and most spectacular eagles. - These are certainly the masters of the sky!



The Black Eagle Cam is situated in the Walter Sisulu National Botanical Gardens, in Johannesburg, South Africa. The camera is a joint project supported by a number of sponsors including Africam. The projects aims are to create awareness and support for the Black Eagle Project. In 1998 the Black Eagle Project was set up as an affiliated to the Walter Sisulu National Botanical Garden and was registered as an independent, Section 21, non-profit organization.


Black Eagle Cam at the Walter Sisulu Botanical Gardens keeping an eye on the nest - Recently the web cam components were stolen and repairs are under way

The project consists of a 7 member committee and approximately 30 dedicated volunteer members. What is so significant about this project is that these eagles are the last of a once much larger population that inhabited the mountain ridges of Johannesburg.

The aims of the project at that stage were : -

• To educate and inform the public about the Black Eagles and raptors in general.
• To conserve and secure the Black Eagles in the Walter Sisulu (Witwatersrand) National Botanical Garden for future generations to enjoy.
• To monitor and obtain vital information on their breeding cycle.

In 1998, Black Eagle Monitoring Project (BEMP) broke away from Raptor Conservation Group and became affiliated to the Walter Sisulu (Witwatersrand) National Botanical Garden. The project was renamed the Black Eagle Project Roodekrans (BEPR) and was registered as a Section 21, non- profit organisation, with its own constitution, bank accounts and appointed auditor. The project consists of a 7-member committee and approximately 30 dedicated volunteer members.


The ringing process


Doing wing measurements

Due to the expansion of the city of Johannesburg their habitat and food source has come under threat. This specific nesting site has been documented as far back as the early 1940’s and it is estimated that the current mating pair are the third or fourth descendants from the first documented nesting pair.


Black Eagle pair, Emoyeni and Thulane


Black Eagle on his way to the nest with nesting material


The precious egg

It remains quite incredible how the Roodekrans pair have tolerated the rapid rate of urbanisation and development within their immediate hunting area. The influx of visitors to the Garden, noise, lack of prey and competing against the elements must surely challenge their existence. The interference within and around the territory has escalated with stray and domestic dogs and vagrants being largely responsible for the reduction of their principal prey base, the Dassie (Rock Hyrax). The eagles have had to adapt their prey base to include guinea fowl, francolin, red rock rabbit and in desperation the easiest prey – chickens, although this does not happen very often.



The recording of information on the Roodekrans eagles started on a very ad hoc basis by Dr. Gerhard Verdoorn of the Raptor Conservation Group, in 1988, which progressed to become a school study project by Albert Froneman. In 1992 Albert Froneman, Rob Harrison-White, Chris van Rooyen and Sally Panos, the latter serving on the committee at this time, initiated the Black Eagle Monitoring Project. The project was then a working group of Raptor Conservation Group.


The Black Eagles on their nest with the two eggs

Location and subject matter
The Walter Sisulu National Botanical Gardens, are nestled in the Crocodile River Valley that cuts through the Roodekrans mountain ridge. As a back drop to the gardens and a main geological feature along the ridge is a conspicuous red cliff face that forms the Witpoortjie waterfall. These cliffs are an ideal habitat for the Black Eagles and other animals in particular the rock Dassie or hyrax that can account for as much as 90% of their diet in some areas. It is estimated that a breeding pair can consume around 400 Dassies / year, so it is not hard to see how with the increase in urbanization, and habitat destruction how the whole food chain is put under threat.


Black Eagles form life long mating bonds. The current female estimated to be between 35 to 40 years old, known as Emoyeni, (upon the wind) was first sighted in the early 1970’s, and has successfully reared a number of offspring. Her current mate Thulane (The shy one) is much younger and replaced her last mate that vanished back in 1998. The pair have over the years built a number of nesting sites on the cliff face where a pan tilt zoom camera has been installed to document there progress and behaviour in an effort to better understand these animals.

Although, Black Eagles pair for life, they will replace their companion. In the Roodekrans scenario the female, Emoyeni replaced her mate 3 times after 2 of them disappeared. Eagle pairs spend approximately 95% of the daytime together, before nest refurbishment; this is a behavioural characteristic of black eagles. They will perch, fly and hunt together, should the female fly to the nest site the male will follow and usually hops onto the surrounding rocks. After eggs are laid and when there is a young chick on the nest paired black eagles spend very little time together. During nest building 77% of their time is spent together but this decreases dramatically to 6% during incubation. As the young eaglet grows the time spent together by black eagle pairs gradually increases again.

When to view
The eagles live permanently in the area throughout the year, but the best time to catch them on the camera is between mid March through to the end of September each year. Egg laying normally occurs in Mid May followed by a lengthy incubation period of 44 to 45 days. The cam runs during daylight hours only between 7am and 6pm Central African Time (times are subject to change due to change in sun rise and sun set), the images are normally refreshed at 30-second intervals. Visitors to the botanical gardens will be able to view live video from the nest in the visitors centre. For more information regarding these eagles please check out the following website: www.blackeagles.co.za


QUATELE
"THE CROSS ONE"

The previous male eagle was admired by all who watched him and his memory will remain with everyone who knew him for many years to come. Each individual eagle carries his own identity and their own distinct features – Quatele looked so fierce with his over-hanging eyebrow, hence the name “the cross one” any prey would dive for cover. Monitors and volunteers carried out an intensive search in the surrounding area, but no trace was found. We have no idea what happened to Quatele – we can only presume that he was either shot, poisoned, captured or died of natural causes, but wherever you may be,
"May you always soar on great wings of destiny!"


EMOYENI
"UPON THE WIND"

The grand old lady is probably over 40years old and is loved by many who have followed her life cycles with passionate interest. The first sightings of Emoyeni were in the early 1970's with her first mate; unfortunately we do not know anything about him. Quatele was her second mate and she scoured the ridges searching for him when he disappeared in 1998. Emoyeni patiently taught her third mate Thulane everything she knew, tolerating his initial shortcomings, but now appreciating his newfound expertise. Many a lesson could be learnt from this magnificent black eagle.
"May the wind always be beneath your wings!!"


THULANE
"THE SHY ONE "

The joyful outcome of 1998 was the arrival of the new male, just sexually mature, shy and inexperienced. Barely in his first year of adulthood, as he was small in length and wingspan, the “V” on his back was not quite developed and his inside leggings were still pale. He still had so much to learn, his insecurities with mating and nest building showed, but there again he had a patient teacher – Emoyeni. However, “the shy one” has proved to be a good pupil and has matured into a mighty species.
"He is Emoyeni's mate for life now."

HOW CAN YOU HELP?
Poisoning
There are many poisons used by man that affect raptors - the farmers use poison for "problem animals" such as the black-backed jackal, caracal, leopard or cheetah from ravishing their stocks, this causes major problems when scavenging raptors like Bateleurs and vultures eat the bait or poisoned animal. Organochlorine pesticides build up in a food chain and unfortunately many raptors being at the end of that chain, eat the poisoned prey and will most certainly face death.

In agricultural pest control Organophosphates have replaced Organochlorines, as they are believed to break down much faster, whereas the Organochlorines remain stable and are stored in the animals fat. Where humans are concerned the organophosphate can be lethal. Insecticides of today, such as parathyroid and carbonates are highly toxic to birds but not to mammals. Secondary poisoning in birds can occur, however, when carbonates are used in the control of termites, as the birds eat termites. Low levels of Organochlorines ingested by raptors over a period of time results in egg breakage, shell thinning and embryos dying in unbroken eggs, thus causing a decline in raptor population and extinction in certain areas. Always use an environmentally product like "Racumin" in the control of rodents.

Natural habitat
The basic requirements are a reliable food source and an undisturbed nesting site. Fortunately an increasing number of landowners now protect and preserve their eagles, as they have come to realise the benefits of eagles in their territory. Eagles have an exceptional ecotourism value, as bird watching is one of the fastest growing pastimes in South Africa. Diversity of habitat results in a rich and dense fauna. Mountain populations of black eagles have a higher nest density and breeding success compared to open area populations. At the present time, in this country, there are lengthening lists of endangered species and degraded ecosystems, which never heal.
The environment must be protected, to prevent extinction of animals and plants.

Power lines


All raptors are attracted to power lines, as they utilise them for hunting, nesting, roosting and feeding perches.

As they are so vulnerable to electrocution these power lines can be hazardous to eagles, if the phase conductors are separated by less then the wingspan of the eagle, the bird can be electrocuted while landing or taking off, or if the distance between an earth-wire and an energised conductor is less than the wingspan or the distance between tip of the bill to tail tip. The eagle's age, experience, the weather, or season may also affect the susceptibility of the eagle. Inexperienced eagles may also collide with the conductors in flight, but this risk is lower then electrocution. Landowners are requested to report eagles roosting on lines, plus dead eagles found under the power lines, to assist Eskom in taking steps to minimise electrocutions. Eskom, in association with EWT are world leaders in the development of various products to insulate conductors, thus reducing deaths to sustainable levels.

Hunting


Black eagles must be one of the most persecuted eagles in the world, due to the fact that some farmers feel justified that they kill small livestock. This is, in fact, very rare, and the South African public are now aware, due to various media articles, of the relentless killing of these eagles by stock farmers, for decades. Farmers are now encouraged to tolerate these raptors and accept their beneficial, ecological function in farming ecosystems, particularly in the control of Dassies, which compete with livestock for grazing. There is a huge ecological impact to the healthy ecosystem by the killing of raptors.

Removal of eggs and chicks
Eagles are not aggressive to humans unless they themselves or the contents of their nests are threatened. Hand reared eaglets are likely to be more aggressive to humans and
are more difficult to handle than wild ones. Chicks handled by humans are imprinted, which is a serious handicap to successful rearing and then they are unable to return to the wild. Severe damage can be done to a chick if fed on an incorrect diet - damage that is irreversible.

GO HERE http://www.blackeagles.co.za/google.htm> to get a bird's eye view of the nesting and surrounding area.

(Most of this information was compiled from the Black Eagle Cam Project Website )

Black Eagles

"When we open ourselves to the natural world, we escape the fast-paced bustle of our daily lives. That experience, not only reduces our stress, it also grounds us, reaffirming our connection to the Earth and all its creatures."


"Black Eagle" water colour - Maree©

I am utterly fascinated by birds, raptors in particular. To me they are the kings of the skies and their survival plight, as cities grow and multiply, is of on-going concern to everyone, or should be, at least.

The resident pair of Black Eagles in the Walter Sisulu Botanical Gardens in Roodepoort, Gauteng, South Africa, is under threat from urban spread.



Earlier nesting reports on the Black Eagle pair reads as follows :

Mating
Mating was first observed in March becoming frequent in April 2003. The day prior to laying the eagles were seen to mate five times. The mating observations were consistent with prior years.


Nest of the Black Eagles at Walter Sisulu botanical Gardens, Roodepoort. The nest is monitored by the Black Eagle Cam.

Nest building and laying
Nest building was first observed in February 2004, but increased significantly in March 2004 were on occasions that the black eagles would bring in excess of 10 branches on a daily basis. As Garget (1990) has noted in the Matopos study that after an unsuccessful breeding year there is a tendency for black eagles to move nesting site and use an alternate nest site. However, the Roodekrans black eagles spend most of there efforts building the bottom nest only. It was apparent that they were not going to change nest site. Building continued up to the day of egg laying. It was interesting to note that the male was seen to initiate building on a number of occasions.

Incubation and hatching
Incubation commenced with the laying of the first egg. The majority of the incubation being undertaken by the female, however the male would often relieve the female for periods. The first egg hatched on 2 June 2003, 45 days after laying which is normal. The second egg hatched on 6 June 2003, four days later.

Cain and Abel
The Cain and Abel struggle lasted for 3 days, young Abel died on 9 June 2003. This year the aggression from Cain was minimal and the project thought there might be a chance that Abel would survive. After two days Cain suddenly attacked Abel and did not let up for 24 hours, intervening the prey that was offered to them by the female eagle. On the morning of the 9 June 2003 Abel was dead when the female left the nest at 8.15am.



Fledging
We knew the Roodekrans black eagles were going to surprise us as they do every year. The juvenile eagle only fledged on the 22 September 2003. At 112 days this is the longest recorded fledging for the Black Eagle Project. The longest prior fledging recorded was 106 and 104 days in 1998 and 1993 respectively.

Newton (1979) highlighted that the male eagle chicks in most raptors tend to develop more quickly than females and are therefore more likely to fledge earlier. Observing the chick flying it was obvious from it size that it was a female which corresponds to the lengthy fledging period. It is generally believed that the male juvenile black eagles fledge from about 95 days, in 1993 the chick fledged at 93 days.

Gargett (1990) also notes that observations do not support statements that the young are deliberately starved by the parents in order to encourage them to fly nor that the parents bait the young off the nest with prey. This has not been observed in the Roodekrans black eagles either.
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However, after the juvenile eventually fledged, it was soon apparent that this was a very confident juvenile. This juvenile was very confident in its behaviour when compared to prior juveniles. Prior juveniles tended to hide away in the ravine on the eastern ridge. This juvenile black eagle spend most of it time on Butchers Block while prior chicks have hid in the ravine and were difficult to locate. Soon after fledging the juvenile black eagle was soaring with the adult eagles and would often follow the adults in flight. The juvenile would even sit in the three trees perching area near the public which was very uncommon.

We were however still surprised at how early the juvenile left the nesting area. There was not even the aggression from the parents as in the past. The young eaglet was seen in the last week of November 2003 and returned several times before leaving the territory mid December. The prior juveniles were often in the nesting area for 12 weeks, 17 weeks in 2001. This juvenile black eagle was only in the nesting area for 9 weeks. Little has been written about the Black Eagle post nesting period which makes it difficult to explain this unusually short period.

Urban Development
The development in the last year(2006/2007) has been immense and the eagles are certainly finding this very disturbing. The northern and southern borders of the Walter Sisulu National Botanical Garden have residential developments with no green belt available for migration paths for small mammals. With the future developments in the pipeline it will not be long before the Botanical Garden will be the only green space left in this immediate area. The project has observed adverse behavioural pattern for the latter part of 2003 and it is certainly man who is now the eagles main adversary. It is really surprising these tolerant birds stay in what has become a very unsuitable territory for eagles of their stature.


Waterfall with Black Eagles' nest to the left, identified by the white droppings left on the cliffs - Walter Sisulu Botanical Gardens, Roodepoort, Gauteng, South Africa