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 Post subject: Re: The Mystery behind the sable and roan decline in KNP
Unread postPosted: Fri Jul 16, 2010 9:26 pm 
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oddesy wrote:
The water points were later systematically closed and still there has been no recovery, so what is the problem? why can the population not recover. The one big factor is that not only is the northern population decreasing but so is the pretoriuskop population so water points are not solely to blame.


This was exactly the point I was trying to make, Imberbe, and please allow me to do so as you allow others to do. From the above it was clear that artificial waterholes were not the sole and perhaps not the major reason for the decline as was pointed out in another thread by EJ. I fully understand ecological balance, and the fine cups it balances on, and how difficult it is to find same again, if at all... ever. :thumbs_up:

Further, what I do not understand is that the most expensive solar power equipment [that was proudly donated by huge corporations to Kruger] were abandoned in the veld too? Why was it not 'recycled', auctioned, or better yet, donated to communities close to Kruger to enhance their lifestyles? I was saddened to see all these solar panels going to waste in Kruger. Or are these panels part of a backup plan? Ten years down the line? :hmz:


Sanparks this morning had a community drive, inter alia soup kitchens in Sunnyside. :dance: :clap: :clap: :dance: A proud moment to hear this on the radio. :clap: :clap:

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 Post subject: Re: The Mystery behind the sable and roan decline in KNP
Unread postPosted: Mon Jul 26, 2010 8:02 pm 
A few points:

1. I don't think one should ignore the parrallel decline in Tsessebe and Eland numbers over the same years...so vegetation/parasites etc. would seem to be precluded as a factor.

2. The one common denominator does seem to be predation linked to artificial water points, and especially up north. I always ONLY saw roan at or near these points, and still do! (And Liechtenstein's Hartebeest, for that matter)...never at a river.

This would lead one to believe that these species learned to avoid river pools and their attendant lion prides, and quickly latched on to the new windmills, as they are by and large less water-dependant, and could survive more easily around smaller supplies, as compared to large herds of buffalo and wildebeest, for example. (Not zebra)

3. Historically, there were a few roan around Pretoriuskop, and MANY Sable. The same area was not known for large predator numbers at all, but that changed slowly but surely. (Eland, Tsessebe and Liechtenstein's still occur there, but artificially so, and in barely surviving numbers, after being released from the "rare antelope" camp established there as a backwater against disease outbreaks in the North.)

4. Roan are apparently extremely susceptible to Anthrax, and during the 80's were subjected to annual immunisation carried out via darts fired from helicopters, a practice which was later questioned as being very stressful on the herds...rather understandably...and possibly contributed to their sudden decline soon after.?

5. Roan have always been regarded as surviving on the very edge of their natural African range in Northern Kruger.

6. There has been an unusually wet cycle regarding Kruger as a whole for the last decade or so, probably contributing to the rare antelope once again being able to "escape" to less watered areas, and slowly recuperate over the Summer months.





To sum up:

I think the rare antelope just never had quite a sufficient numerical basis IN CERTAIN AREAS to withstand any or all of the pressures mentioned in other posts, and all have historically been scarce, except for sable around PK, and eland in the Far North.

Their numbers should improve with the new water policy, but extinct populations should be slowly reintroduced in certain areas of the Park, subject to scientific confirmation, as they are simply too isolated to do it by themselves.


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 Post subject: Re: The Mystery behind the sable and roan decline in KNP
Unread postPosted: Mon Jul 26, 2010 8:27 pm 
During the 70's to end 80's Sable numbers were yearly judged to be around 1900, and eland 900.


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 Post subject: Re: The Mystery behind the sable and roan decline in KNP
Unread postPosted: Mon Jul 26, 2010 8:47 pm 
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Brilliant forum :clap:

I had often seen a small herd of about 6 Sable around the southern part of the Kruger. Near Skukuza. I was informed that it was part of a breeding programme. Does anyone know anything about this and if these guys are still around?

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 Post subject: Re: The Mystery behind the sable and roan decline in KNP
Unread postPosted: Mon Jul 26, 2010 9:14 pm 
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Richprins wrote:
4. Roan are apparently extremely susceptible to Anthrax, and during the 80's were subjected to annual immunisation carried out via darts fired from helicopters, a practice which was later questioned as being very stressful on the herds...rather understandably...and possibly contributed to their sudden decline soon after.?


Very interesting RP. My late father, a state vet, spoke about this a lot many years ago. My understanding about this is as follows.

During the immunisation process, carried out via darts fired from helicopters, animals like roan and sable were stressed to the limit and to such an extend that they suffer from Vlekspier or Capture Myopathy. What happens is that when these animals are chased around by helicopter the metabolism in their muscles changes from using oxygen to using stored energy which leads to the build up of lactic acid which in turn drops the ph in the body. The heart is affected and the muscle starts to die due to the releasing of myoglobin which is a breakdown product of muscle.

Myoglobin damages the kidney, liver and the lungs start to bleed. In short the kidneys and liver cannot process the toxins and this is fatal to the animal. They actually ran themselves to death.

I may be wrong with certain facts and it would be great to have a vet here to advice on this issue.

(Source: http://www.fourthcrossingwildlife.com/C ... Fowler.pdf" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false; )


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 Post subject: Re: The Mystery behind the sable and roan decline in KNP
Unread postPosted: Tue Jul 27, 2010 7:53 pm 
Your post is 100% correct, TheunsH, as far as I know! :thumbs_up:

Except only roan were immunised, not sable.

Welcome, Sable 2!

Don't know of sable programmes at Skukuza...probably just a normal herd, depending on the time period.

Sable were also kept at the rare antelope camp at Pretoriuskop, some of which were "reintroduced" to the far north in one project, which is under the "Sable" thread.

I must stress that I am not a scientist, rather someone who has been fortunate enough to visit Kruger many times over the period concerned! :)


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 Post subject: Re: The Mystery behind the sable and roan decline in KNP
Unread postPosted: Thu Aug 12, 2010 3:44 pm 
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I have read a artical (can't remember where) that stated the main reason for the decline in the numbers was due to the fact that the sable's babies are being born in the winter and they hide them until they are a bit stronger. Due to the fact that there were now waterholes in areas that are usually dry because they don't need a lot of water and more animals expecially lions there was a sharp drop in their growth rate.That was the main reason why they closed some waterpoints.


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 Post subject: Re: The Mystery behind the sable and roan decline in KNP
Unread postPosted: Thu Aug 12, 2010 7:23 pm 
Welcome, estellem! :clap:

That sounds about right, although the calving could possibly be late winter or later! :thumbs_up:


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 Post subject: Re: The Mystery behind the sable and roan decline in KNP
Unread postPosted: Fri Oct 15, 2010 12:02 pm 
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The sable In the Pretoriuskop Region:

Thought some forumites might find this interesting. I explained the rationale behind the decline in sable in the north but those ideas do not hold for the herds found within the south, so why have the number of herds of sable declined from a recorded >20 in 1977 to only 4 now??

Pretoriuskop receives over 700mm of rain every year and as such when artificial waterpoints were installed very, few were setup in this area because of the greater moisture availability, so the waterpoints could not be the reason for their decline in that area.

Between 2006 and 2009 the 4 herds in the pretoriuskop area were tracked and studied. They looked at food resources, as well as aspects of topography and vegetation that influence resources.

In 2008 the Carnegie Airborne Observatory conducted hyperspectral imaging and LiDAR (light detection and ranging) flights over the areas of the current home ranges and historicsal home ranges of the sable and provided this Raw data to the scientists. This data provided a 3-dimensional map projection and measured vegetation structure, composition and chemistry , really impressive technology!. other data collected included phenology, greeness, height, feeding vs non-feeding site etc.

It was found that sable show a significant preference for areas of intermediate to high tree canopy cover while they show some avoidance for areas dominated by shrub cover. They avoid bottomland areas (which basically means that they avoid river channels and the lower slopes of a catenal profile). The data also showed that there is a significant influnce of termite mounds (if you look at a large scale, large area) in the home ranges occupied by the herds.

BUT

There is also no significant difference between current home ranges and historical home ranges which suggests that more factors need to be considered before we can understand the decline of the sable population in southern kruger. Although ; the findings do show that the habitat is suitable for sable.

so not by any means a definitive answer but the centre for African Ecology seems intent on finding out the reasons for their decline :thumbs_up:

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