Rhino Numbers and Census

[Richprins]

Please read the paper before forming opinions and and making inflammatory statements.

The paper is based on previous population surveys dating back from 2010 and has nothing to do with the 2012 survey.

Which statements do you refer to, Dewi!?

[iNdlovu]

My statements or more questions are in response to the question raised in parliament whether a census had been carried out to which the minister replied "yes" which is clearly not true. i have no problem with Ferriera's document.

[Dewi]

Dr Ferreira is telling lies, IMO!

This one RP.

[Richprins]

If you are pertaining to the reasons for the 2012 census not happening, I blame Dr Ferreira as he was the head of the project as per the parliamentary comments above. I doubt the minister would have had better first hand info.

If you are pertaining to the validity of the "census" techniques used by Dr Ferreira and his team regarding WHITE rhino in Kruger, this subject was addressed briefly on the first page of this thread, and on the old AIKONA forums. To reiterate regarding that: The technique used since annual "total surveys" using fixed-wing aircraft and helicopters where necessary that covered the entire Kruger Park was replaced with a statistical analysis method monitoring large harbivores, imported from USA...a team from Texas I believe.

This technique uses a small percentage of the Park actually covered aerially in various biotypes, as indicated in the "paper". It was warned to be inaccurate when superimposed upon African conditions by the US team themselves, but was adopted after "total surveys" ended anyway.Whatever the reasons, it is no substitute for the real thing, and it is a travesty in my and many others' opinions that proper censussing was done away with in Kruger at that stage. The fact that the minister promised a proper census this year would support that argument, I believe, and also questions the validity of the latest method.

The lying comes about with the various estimates of white rhino numbers dished out over the last 24 months, and the linking of estimates to the validation of continuing white rhino sales from Kruger DESPITE the poaching scourge.

If you read back you will see conflicting "guesstimates" from various official sources over said period, a strong cause for concern and a justifiable reason for doubting the truthfulness of the main source, Dr Ferreira's department.

In fact the "paper" gives conflicting estimates of WR numbers in 2010 vs official pronouncements by Dr Mabunda and the Minister, and is in my opinion an attempt to confuse the differing impacts of poaching and sustainable selling of WR, justifying the latter, even though it may appear contrary in said "paper".

Also, the "paper" intimates that these WR surveys were done in November and February, months with enhanced plant growth, which also causes confusion regarding the one reason for the cancellation of the 2012 census!

That is my opinion, and not necessarily AW's...but rest assured I check up with contacts both old and new before making statements.

[Dewi]

This still does not justify calling someone a liar RP.

You have intimated that the paper is not worthy due to your use of inverted commas, when in fact it has been peer reviewed prior to publishing.

The methods of the survey are stated, and as I am well aware from carrying out population surveys elsewhere, figures can be manipulated using statistical analysis, but by stating which methods were used, studies can be carried out later using the same methods to establish a trend. When varying methods are used, discrepancies are inevitable. This does not make someone a liar.

We could both fly over the same area on different days, counting every single rhino we see, and the numbers will vary. That will not make either of us liars unless we deliberately fabricate the numbers.

There is a vast difference in estimating population surveys using say transects, and actually counting every single animal in the population. I'm sure that most scientists would love to be able to count every single individual, but it's just not possible due to practical & financial constraints. Scientists all over the World extrapolate from their data to arrive at figures'conclusions. They may not be accurate as to the exact numbers of individuals that are really there, but they will be accurate enought to provide trends to what is happening over time.

Anyway, I'm rambling. The main point I'm trying to make is that I don't agree to calling someone a liar on this forum, wether it's just an opinion or not, without solid justification or evidence. This will not help our cause. It may even, or already has, drive people away or stop others from joining.

Rant over.

[Richprins]

Point taken, Dewi!

Will change my grammar to "convenient bookkeeping"...

I know some are driven away, and I'm not generally abusive, but this sort of thing is at the coalface of our core principles on AW. There is clear evidence of conflicting intimations of numbers, and has been for years now! I firmly believe the rhino numbers are being dabbled about.

I agree it is not pleasant, and have more pleasant things to do, but enough is enough!

Dr Ferreira is being attacked by me because he is in charge. So too Dr Mabunda is being attacked by me/us because he is in charge.

As you say, figures may be manipulated in a statistical exercise, and if those figures had remained constant over the last year, so be it! But it's not!

Other opinions are welcome, but I feel one's own opinion is entitled on AW!?

[Richprins]

11. Annexure One –Notes on Rhino Counting
There has been some debate around the accuracy of rhino counts undertaken in the Kruger National Park. Estimating the number of rhino in such a large area presents some particular difficulties and it is not usually possible to be 100 per cent accurate.
Techniques used to minimise error are strip transects, block counts, distance sampling, dung counts, mark-recapture techniques, call-up surveys, registration studies and total counts (100% coverage of an area) (Ferreira, Botha & Emmett, 2012). A total aerial count (by helicopter) is the most accurate method.
Accuracy is assessed in terms of two measures, bias and precision and there are a number of possible sources of error. First, there may be some animals in the population who are not available to be counted at the time of counting (availability bias), second, the animals may be available but may not be seen to be counted (detectability bias) and thirdly, even if the animals are available and detected, different observers have different abilities to detect (observer bias). These affect the precision (the likely spread of estimates given the uncertainties introduce by the biases) of the count.
Accurate counts are critical for the management of rhino (and other large mammals) in the KNP and sufficient budget will need to be found to permit for an annual helicopter based count to be implemented – at least until the poaching threat abates. The budget per count, assuming that population profiles are included, will be approximately ZAR 3 million per count in 2012 Rands (Fereirra, 2012).

The largest population of white rhino in the world exists in the Kruger National Park (KNP). In 2010, estimates indicated the presence of 10,621 white rhino in the park (Ferreira, Botha & Emmett, 2012). Since the late 1990’s, white rhino have been translocated from the KNP for biodiversity and conservation reasons and sold to generate conservation revenue. By 2010, 1 402 had been removed, largely to other conservation areas, with no adverse effects on the population and numbers continued to increase in the park. However, the number of poached white rhino is now exceeding the number of white rhino that the SANParks white rhino management model – outlined below- requires (4.4% of the standing population at any given time). At these increasing rates of poaching the number of surplus rhinos available in the next few years will reduce, and the overall population is expected to decline in 2016 (Ferreira, Botha & Emmett, 2012).
These predictions depend on white rhino population data being precise and there are some concerns in this regard as a result of potential for bias and differences in survey methodologies deployed over time. However, surveying wildlife, especially species such as black rhino, is notoriously difficult. The current KNP survey results have been published in the peer reviewed literature as confirmation of scientific accuracy & reliability and are considered to be as accurate as scientifically possible (Ferreira et al 2011, Ferreira et al 2012).
If there is significant downward variation in the current trend which assumes a continued upward linear growth in poaching, then matters could be significantly worse than they are at present. Additionally, poachers tend to target adults resulting in changed population structure which could cause rapid population collapse once population thresholds are reached (Ueno, Kaji & Saito, 2012). Poaching has already impacted on the provision of live white rhino to other areas to extend the species range as well as on the funds earned which contribute towards conservation (Ferreira, Botha and Emmett, 2012).
Surveying rhino every two years offers the best option for detecting a 2 per cent change in population estimates, currently however this budget is not provided for by SANParks Surveys need to do more than just count rhino as information is needed on age, sex, fecundity, survival and landscape use to ensure optimal conservation of the species and provide alternative population information that can corroborate population estimates. Internationally accepted best practice in terms of population survey requires helicopter block count and distance sampling approaches as two reliable and precise methods (Emslie, 2012).


http://d2zmx6mlqh7g3a.cloudfront.net/cd ... 0rim_0.pdf




Mabunda and Mabasa said there was no need to worry, in 2010 and 2011 respectively, as the number of animals poached would not exceed the birthrate. We estimated the actual numbers to be far lower than the 15 000 in Kruger espoused officially back then.


Disaster is looming!

[mouseinthehouse]

Sorry I just skimmed through this thread and I might have missed some bits. I have been hammering SP for weeks on the census issue specifically can they clarify if the census was completed or curtailed before completion last year. Of course I have heard elsewhere that it wasn't completed due to weather and operational difficulties but I want info from the horse's mouth.

I read Dr Ferreira and colleague's Sept. 2012 paper and I find some of the results worrisome but entirely credible from a scientific standpoint. (I am a biologist so it helps a little when interpreting papers) The authors do point out the shortcomings of the survey methods as long with other noted concerns about impacts from offtake by poachers and management.

I sent an email query to Dr Ferreira - was handballed to Mr Mabasa. Two emails later to Mr Mabasa - not even a polite decline to provide anything. Just ignored.

About a dozen or more requests on the Poaching thread on SP have been ignored. Eventually Lesego said she would enquire for us. Of course.........nothing.

My next strategy is I am going to start phoning Mr Mabasa and Mr Thukuli and Mr Modise direct. Should be fun! -O

[Toko]

Do you think the RIM report would use data from 2010, if there was a more recent census?

[mouseinthehouse]

No of course not but I am just being cranky on purpose and want them to publicly state the status of the 2012 census and to provide info on when and how the next one will take place. Well one may as well ask for them to fly to the moon. But I do love a challenge.