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JamesP

New Hirola Population Surveys

24 posts in this topic

Hi all,

 

I've recently returned from Kenya where I was gathering data for my MSc thesis on the translocated hirola population in Tsavo East National Park.

 

As part of this research I conducted a survey of the population, gathering data on its size, distribution and demographics. Together with a population survey of hirola in their natural range conducted by Juliette King and the Northern Rangelands Trust(NRT) we now have a complete picture of the global hirola population.

 

Sadly, this picture isn't very hopeful. My research found 67 hirola in Tsavo. Whilst this shows a slight decline on previous estimates there has recently been a severe drought so this is not unexpected. The population there seems to be relatively stable.

The survey of the natural range found 245 hirola, indicating that the population continues to decline.

These two surveys indicate a global hirola population of around 312 individuals.

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Thank you James, bleak news indeed. I would be very interested in any other bits of information you gathered if and when you have time. Did you visit Ishaqbini?

 

There are various theories on why the Tsavo population isn't thriving and I wonder if you have any further research on the causes of this.

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I'm actually surprised there are that many in Tsavo East, and so few elsewhere. I've obviously picked up the wrong impression somewhere). However, either way, it is very few!

 

Just out of interest (no challenge to methods I probably wouldn't understand even if you explained them) how would you know with reasonable certainty that you have identified all of the exisiting groups in Tsavo East, which is quite a large area, much of which is not accessed because there is no (or little) offroad driving.

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I might be wrong (I will have to check), but 245 is the nember of hirolas which were actually counted in their current natural range (Ishaqbini - Arawale - edge of Boni forest) ina 2 or 3 days aerial count, but it is estimated that there are a bit more in the area.

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IMHO, it is a minor miracle that the translocated hirolas have survived thus far. My understanding is that the hirola and the hartebeest separated thousands of years ago -- and probably for good reason. It is noteworthy that the two do not naturally occur together as a result. In Tsavo East, Coke's hartebeest is a dominant herbivore. IMHO, it is only a matter of time before the hirolas are outcompeted away.

 

Pault, there is almost never a precise way of counting game. There have been aerial surveys done from time to time in Tsavo. But at the end of the day, you still have to estimate.

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Thanks, Safaridude.

 

And James, thank you for posting.... forgot my manners first time around.

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Thanks, Safaridude.

 

And James, thank you for posting.... forgot my manners first time around.

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Hi guys,

 

As far as methods go we conducted both an aerial survey and a ground survey. Originally the plan was to conduct an aerial survey and use that to inform the subsequent ground survey. As it happened there was a fuel shortage in Kenya just as I arrived so there was no fuel for the plane. Because of this the ground survey was conducted first and the aerial survey was conducted when fuel became available, which was after the ground survey had finished.

The ground survey was conducted using KWS monitoring data and information from safari guides and drivers on more recent sightings to target areas where hirola were likely to be. We spent 10 weeks driving round Tsavo and had KWS staff in the vehicle so we could drive offroad and leave the vehicle. We found all of the herds which KWS thought were in the area which in total was 45 hirola.

The aerial survey was then conducted independantly by KWS after our ground survey was complete. The plane flew 500m wide transects at 200ft and 400mph. It covered an area of over 4000km2 over a period of a week. The plane used a GPS to record the location of any hirola sightings and gave this to a ground team who then drove to the location and tried to confirm the sighting and record the age and sex of the hirola. The aerial survey found 47 hirola, 25 of which had been previously sighted during the ground survey. This gave a total population size of 67.

It is possible and even likely that this figure is wrong. Hirola are very difficult to identify individually and have quite a dynamic herd structure, that is they regularly change herds or wander off alone. Also, in recent years the accuracy of aerial surveys has been increasingly questioned. However, with the length of time we were surveying from the ground and the area covered by the aerial survey it is likely this is a fairly accurate population estimate. Hirola have only ever been found south of the Galana River in Tsavo but we don't know why. As with the Ishaqbini count of 245 it is likely that a few hirola will have been missed but not enough to suggest anything other than a decreasing or stagnant population.

 

There are lots of theories explaining why hirola numbers in Tsavo have never increased beyond 80ish: predation, competition, habitat etc.

The fact is no one knows despite a KWS PhD on exactly that topic a few years ago. My suspicion is that predation is a large part of it possibly with competition or a lack of suitable grazing as secondary factors. Disease may also play a role but we simply don't know.

Monitoring in Tsavo is poor because the KWS Research Station there is underfunded. They have only 1 vehicle to conduct all their research and monitoring activities. One of the recomendations of my thesis was to GPS collar male hirola and the provision of a dedicated vehicle for hirola monitoring.

 

Twaffle - I gathered data on everything I could whilst I was out there! In addition to the size of the population I looked at herd size, sex, age, distribution, the species hirola associated with, hirola behaviour, I made a habitat suitability map of Tsavo using the hirola distribution and GIS (geographic information system) layers of vegetation, soil, waterholes etc, I surveyed tourists and Kenyans to see how aware they were of hirola, I took photos of hirola prints and dung because there were none in any of the guides we had, I conducted searches of the media and scientific literature to see how prevelant the hirola was and I contacted all the zoos which had ever held hirola to find out more details of the populations held there.

Rather than me go through all that I'll attach my thesis to the bottom and you can have a look for yourself! Most of it should be fairly accessable but I'd stick to the results and maybe the discussion unless you're particularly keen!

Please feel free to distribute the thesis to as many people as you want. Anything to raise the profile of hirola conservation! The copyright is owned by my university so it shouldn't be replicated but its a password protected PDF so you shouldn't be able to copy or print screen anyway.

 

Its great to have so much interest! All questions are welcome!

 

James

The Tsavo Hirola.pdf

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Thank you so much James, I'll download the Hirola PDF when back on my computer and read with interest.

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Hey guys,

 

Safaridude mentioned that he is about to go back to Tsavo for the thrid time to see hirola.

 

For him and anyone else who goes to Tsavo the hirola there are almost all south of the Galana River and are concentrated in the area south of the Aruba Dam.

The attached map is of where I saw hirola in Tsavo (its in the results section of my thesis as well).

Basically the loop that runs from Satao Camp, past Satao Airstrip and then right to Aruba Dam and back to Satao Camp is where we saw them most. We particularly saw a herd of 7 on the road that runs past Satao Airstrip and a herd of 14 that we saw on the road from Aruba Dam to Satao Camp (that's nursery herds 1 and 2 on the map).

Hirola herds tend to move around alot but they do have key areas where they spend most of their time. Especially if you're in Tsavo from March to June I'd have a look in these areas. Hirola also often associate with Grant's gazelles and impala so make sure you have a really good look with a decent pair of binoculars because its very easy to miss them in a mixed herd!

 

Also have a look at the hirola ID guide I created (attached) although as Safaridude points out the picture of the kongoni/Coke's hartebeest is actually a Lichtenstein's hartebeest. It looks pretty similar to a kongoni apart from the horns. The white rump is the best distinguishing feature.

 

Good hunting all!

 

James

post-14769-0-42385100-1322134146_thumb.jpg

Hirola Identification Guide.pdf

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Very interesting info on this bizarre and charismatic antelope!

 

I was distressed to come across this image on Flickr: [http://www.flickr.com/photos/scirecordbook/3633279096/in/]

 

Hopefully the date this image was taken is wrong.

I really struggle to understand what goes on in the heads of these people!

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That looks like an image scanned from an old slide, though I might be wrong. Welcome to Safaritalk Rainbirder.

 

Matt

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Trophy hunting in Kenya stopped in 1977, so the picture must be quite old.

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That looks like an image scanned from an old slide, though I might be wrong. Welcome to Safaritalk Rainbirder.

 

Matt

Thanks for the welcome!

The image does look old and given what Paolo says it must pre-date 1977.

A sad end for such a fine-looking beast!

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Hi Rainbirder!

 

I've just had a look at your photo and I'm fairly sure that the man in it is a Kenya Wildlife Service employee.

Its possible that this was taken during one of the two translocations of hirola from the Kenya-Somali border to Tsavo East National Park. If so then the hirola is just darted not shot! Fingers crossed!

 

James

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Hi Rainbirder!

 

I've just had a look at your photo and I'm fairly sure that the man in it is a Kenya Wildlife Service employee.

Its possible that this was taken during one of the two translocations of hirola from the Kenya-Somali border to Tsavo East National Park. If so then the hirola is just darted not shot! Fingers crossed!

 

James

 

Hi James,

 

I don't think the guy in the image has any conservation credentials!

The image is on this page and keeps bad company!

 

Steve

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Posted (edited)

 

 

Hi James,

 

I don't think the guy in the image has any conservation credentials!

The image is on this page and keeps bad company!

 

Steve

 

Various trohies in that gallery must be quite old - not only the hirola, which, as said, must be pre -1977.

 

I refer in particular to the black rhino in the Luangwa Valley and the roan in Uganda. They should date as of the 1970s too.

Edited by Paolo

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Just had a look. Oh dear.

 

Lets just hope this sort of thing doesn't happen any more.

 

James

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Posted (edited)

 

 

Hi James,

 

I don't think the guy in the image has any conservation credentials!

The image is on this page and keeps bad company!

 

Steve

 

Various trohies in that gallery must be quite old - not only the hirola, which, as said, must be pre -1977.

 

I refer in particular to the black rhino in the Luangwa Valley and the roan in Uganda. They should date as of the 1970s too.

 

I agree Paolo, many of these trophies will be 30+ years old but this Flickr account was set up in 2009 and a quick search of Flickr revealed some recently active photo-streams of similar trophy hunting such as this: http://www.flickr.com/photos/theunis_botha_big_game_hounds/

 

 

 

and http://www.flickr.com/photos/realafricasafari/ -then click the "big seven" or "hunts" set tabs on the right.

 

 

 

and: http://www.flickr.com/photos/worldtoafrica/

 

No Black Rhino or Hirola in the recent images but all pretty sickening stuff nonetheless.

 

Unlike natural predators these guys don't pick off the stunted, the weak, diseased or small-horned/tusked; they pick large fit sexually-mature targets in their prime -a perversion of natural selection which favours survival of runts and the least obtrusive!

Sri Lanka is home to the type subspecies of Asian Elephant (Elephas maximus maximus) which was also the largest subspecies however the elephant populations in the National Parks of Sri Lanka are now of a smaller size on average with a clear reduction in stature when compared both with historical documentation and with the early photographs taken in the 19th century during the time of colonial British rule. This smaller size is thought to be the end result of a long-continued process of removing the physically best specimens from the potential breeding-stock through trophy-hunting (and to a lesser extent domestication). Only 7% of Sri Lankan elephants now have tusks.

 

Sorry for this rant which is perhaps not appropriate in a thread about Hirola!

Edited by Rainbirder

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Please remember the copyright rules about posting images up on Safaritalk. Rainbirder, I guess these are not yours?

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I had a look at that photo again rainbirder and on the right hand side on the flickr page it says that the photo was taken on November 21st 2008!

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Posted (edited)

Please remember the copyright rules about posting images up on Safaritalk. Rainbirder, I guess these are not yours?

Absolutely not (my images) Matt.

I simply included links to these Flickr accounts -all of which have their privacy settings set for full visibility. The second link was to a photo set but instead of a link tab it seems to have initiated a direct slideshow of the images in the set -this was completely unintentional on my part (but was quite a pleasing effect had the content not been so unpleasant).

 

Sorry, I hadn't set out to display these images directly on Safaritalk.

I've since edited it to create a link tab only.

Edited by Rainbirder

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Thanks mate, sorry to have to wear the moderator hat...

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If indeed the SCI score indicated of 69 is correct, then the animal was taken in March 1969 near the Tana River in Kenya. I happen to have the SCI record of trophy hirolas. The last legally hunted hirola was indeed taken in 1977 before the hunting ban in Kenya.

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