As with much of Southern Africa, and seemingly many other places in the world, Botswana is currently receiving some fairly heavy rainfall. Maun is getting rain nearly every day while the level of the floodwaters coming into the delta from Angola, as a result of rainfall there, is currently higher than previous records for this time of year. The Makgadikgadi is also receiving some good rains but these are often very localised heavy showers with only the occasional storm affecting the whole park. This means that the pans are getting progressively wetter and muddier making conditions a little tricky in places. So far I have avoided getting stuck but there have been times when it’s been touch and go!
Throughout January the zebra have been grazing on the grass islands along the edge of the pans. With the presence of fresh rainwater in the pans and waterholes these grass islands, where the grasses there have grown significantly in the last month, become easily accessible and the zebras are making the most of it.
Newborn zebra foals and wildebeest calves are thriving and it is interesting to observe the differences in their behaviour. Wildebeest calves of a similar age join together in large crèches and run around while their mothers graze. Foals on the other hand largely stay with their mothers within the family harem, only playing with other foals if they are from the same harem.
We have had a busy month of fieldwork with behavioural and grazing observations conducted, population counts done and water, faeces and grass sampled. With all of the zebra on the pans it makes them slightly easier to find with less time spent travelling between areas searching for the herds.
When water sampling we spotted a lone cheetah sitting on a ridge a few hundred metres away. We approached slowly as cheetah in the Makgadikgadi are often very nervous but unusually this one was incredibly relaxed and not fazed by the car at all. After taking a couple of photos we moved to carry on with the sampling when I realised that 15 zebra were about to walk straight past where the cheetah had laid down and so I moved back to a ridge a hundred metres or so away to watch what would happen. Through my binoculars I watched the cheetah scan along the line of zebra and settle on the smallest foal. When the foal was at its closest point the cheetah took off and rapidly caught up with the foal bringing it down. Within seconds of the cheetah getting the foal, the foal’s mother and father were on the scene defending the foal and trying to chase the cheetah away. At the second attempt they succeeded and the cheetah retreated to a nearby bush but the foal stayed down. Around a minute passed before the foal sprang back to its feet and trotted rapidly off in the opposite direction to rejoin the harem having only a slight scratch on its rump but a more serious cut on its face to show for its close brush with death.
It all happened so quickly that it is difficult to piece together the images of the event in my mind. I was torn between wanting the foal to survive the attack but also wanting the cheetah to complete its hunt successfully as predator hunts often fail with only around 1 in 4 hunts successful. It was, however, fascinating to watch the zebra come in to defend their foal without hesitation and I have no doubt that the cheetah, a big and healthy male, will be more successful in the future.
I am now into the last few months of fieldwork for the project and I am looking to complete the last few pieces of the jigsaw. As well as taking the remaining GPS collars off in early April, I am hoping to conduct an aerial population count of zebra within the Makgadikgadi. I have tried to plan this in the past but have had to postpone it due to a lack of funding. I am planning this now and, as with anything that involves flying, it is likely to cost a significant amount of money – around £1,000.
To understand more about the movement of zebra within the Makgadikgadi and the reasons behind this movement, I have been collecting grass and faeces samples for analysis. The influence of dietary protein and minerals is going to be very important in understanding more about the zebras’ movement and long-term requirements. These samples are sorted initially at the Okavango Research Institute in Maun but to be analysed in more detail it is likely that I will have to send them to South Africa. To get these samples analysed I will have to pay between £5 and £10 per sample depending on the analysis required and due to the number of samples I am expecting to have to pay £2,500 to £3,000 for this analysis.
If you feel that you would able to contribute towards meeting the costs of the aerial survey or the sample analysis then I would be very happy to hear from you and any assistance would be greatly appreciated. I should also remind you that all donations are tax deductible.
Best wishes to you all,
James
Sunday, 13 February 2011
Tuesday, 4 January 2011
Happy New Year
2011 has arrived leaving me wondering what happened to 2010 which just seemed to come and go in the blink of an eye. Maybe the Mayan prophecy for 2012 is correct after all!
December began with zebra spread out across the Makgadikgadi with some still drinking from the Boteti River and grazing nearby whilst others were grazing on the eastern boundary of the National Park. Rains had been quite light and sporadic with only a few of the surface waterholes containing water. This meant that many of the zebra chose to remain near to the Boteti River until there had been further heavy rainfall to ensure that there would be drinking water available to them before they headed east. Other zebra decided to take a risk and moved east in the knowledge that there should be some water available to them but they would have to search for it.
Unfortunately, one of the collared zebra which had remained near to the Boteti River had a very close encounter with the resident lions. They are two of the biggest female lions people have ever seen with both weighing over 200kgs and so it is no surprise that the collared zebra didn’t survive the encounter.
As December wore on everything began to dry out even more until a couple of big storms passed through just before Christmas. One storm caught me whilst we were grass sampling and instantly flooded the roads causing us to seek shelter and wait for the storm to pass – we were sat there for 3 hours! As always, the sun eventually reappeared and quickly began to dry everything out once more allowing us to carry on with our work.
With the recent storms it appears that the zebra herds have finally migrated east with large numbers being seen around Jacks Camp. I hope that this means that the wet season has now arrived in earnest which brings its own challenges. I’m sure it won’t be long before the mosquitoes are everywhere and I will have to be very careful not to get stuck in the wet mud of the pans!
With the arrival of the rains comes new life. In the last update I mentioned how one of the collared zebra had recently given birth, I can now add that a further collared zebra gave birth around the 10th December. There are more foals being born all of the time and it is quite incredible to see so many young foals within the herds.
I have recently posted some photos from the Makgadikgadi in 2010 to my website and if you click on the following link you can view these images - http://www.zebramigration.org/gallery/
I would like to thank you all for your support for the research during 2010 and I hope that this continues through 2011. I hope that you all have a very happy and prosperous 2011.
December began with zebra spread out across the Makgadikgadi with some still drinking from the Boteti River and grazing nearby whilst others were grazing on the eastern boundary of the National Park. Rains had been quite light and sporadic with only a few of the surface waterholes containing water. This meant that many of the zebra chose to remain near to the Boteti River until there had been further heavy rainfall to ensure that there would be drinking water available to them before they headed east. Other zebra decided to take a risk and moved east in the knowledge that there should be some water available to them but they would have to search for it.
Unfortunately, one of the collared zebra which had remained near to the Boteti River had a very close encounter with the resident lions. They are two of the biggest female lions people have ever seen with both weighing over 200kgs and so it is no surprise that the collared zebra didn’t survive the encounter.
As December wore on everything began to dry out even more until a couple of big storms passed through just before Christmas. One storm caught me whilst we were grass sampling and instantly flooded the roads causing us to seek shelter and wait for the storm to pass – we were sat there for 3 hours! As always, the sun eventually reappeared and quickly began to dry everything out once more allowing us to carry on with our work.
With the recent storms it appears that the zebra herds have finally migrated east with large numbers being seen around Jacks Camp. I hope that this means that the wet season has now arrived in earnest which brings its own challenges. I’m sure it won’t be long before the mosquitoes are everywhere and I will have to be very careful not to get stuck in the wet mud of the pans!
With the arrival of the rains comes new life. In the last update I mentioned how one of the collared zebra had recently given birth, I can now add that a further collared zebra gave birth around the 10th December. There are more foals being born all of the time and it is quite incredible to see so many young foals within the herds.
I have recently posted some photos from the Makgadikgadi in 2010 to my website and if you click on the following link you can view these images - http://www.zebramigration.org/gallery/
I would like to thank you all for your support for the research during 2010 and I hope that this continues through 2011. I hope that you all have a very happy and prosperous 2011.
Sunday, 28 November 2010
Pula!
After months with barely a cloud in the sky the first rains have arrived turning Botswana green once again. It is incredible to see the influence of rain and how even bare soil rapidly turns into a lush carpet of grass and herbs. Beetles, moths, butterflies, millipedes, frogs and scorpions have all returned en masse with the frogs feeding particularly well on flying termites.
Within the Makgadikgadi there was sufficient rain to encourage the zebra to migrate east to access the lush growth which has emerged following the fire with the grasslands looking like they have been especially cultivated to grow grass in order to feed the thousands of hungry mouths. However, the rains received so far have not been enough to really fill the waterholes and so they are now nearly all dry again until the next good rainfall. This has meant that the zebra have had to move from the grasslands back to the Boteti or head north west where there has so far been more rainfall. Botswana has been predicted to receive above average rainfall this year and so the zebras, as well as the researchers, will just have to patient!
Since the first rains the Makgadikgadi has begun to look like a large nursery with offspring of zebra, gemsbok, impala and springbok being born as each species maximises the positive effect of the rain. A collared zebra has been one of the many zebra to give birth so far and both foal and mother looked in very good condition when they were observed last week. Being born at the start of the wet season gives the foal a great chance to successfully negotiate the difficult first year of its life. I have named the foal ‘Pula’ which means ‘rain’ in Setswana. Rains are so important to life in Botswana that ‘Pula’ also means money and through the research I have certainly come to realise the importance of both!
Throughout the dry season zebra are reliant on the Boteti River as the only place where they can access drinking water. However, due to the need to find grazing of both sufficient quantity as well as quality, it was necessary for zebra to regularly be travelling 20-25 km away from the river and only drinking once every 3-4 days. By only drinking infrequently zebra are able to maximise the length of time which they spend in the grazing area. However, one collared zebra avoided this journey entirely by remaining on the western side of the river near to Leroo La Tau in an area 5km x 2km in size between the river and the fence for four months! She crossed the river into this area on June 20th and only crossed back again after the first rains in November.
Nearly 3 months have passed since the bush fire spread through the Makgadikgadi in early September. It was horrific to see the impact of the fire with such a large area comprehensively burnt but the ability of nature to respond to such extreme events is always amazing to see. Many of the burnt areas are now thick with fresh grass and the contrast between burnt and un-burnt areas is very noticeable with herbivores favouring the burnt areas. The long-term repercussions of the fire are still to be seen but may ultimately prove to be positive as the fire removed the old grass which forms dense, unpalatable tufts and allowed for new grass tufts to begin again with fresh growth which is more easily grazed by all herbivores.
I will continue to monitor the weather with interest as we wait for the rains to being in earnest. As ever if you have any questions or comments then please feel free to contact me. I look forward to hearing from you.
Within the Makgadikgadi there was sufficient rain to encourage the zebra to migrate east to access the lush growth which has emerged following the fire with the grasslands looking like they have been especially cultivated to grow grass in order to feed the thousands of hungry mouths. However, the rains received so far have not been enough to really fill the waterholes and so they are now nearly all dry again until the next good rainfall. This has meant that the zebra have had to move from the grasslands back to the Boteti or head north west where there has so far been more rainfall. Botswana has been predicted to receive above average rainfall this year and so the zebras, as well as the researchers, will just have to patient!
Since the first rains the Makgadikgadi has begun to look like a large nursery with offspring of zebra, gemsbok, impala and springbok being born as each species maximises the positive effect of the rain. A collared zebra has been one of the many zebra to give birth so far and both foal and mother looked in very good condition when they were observed last week. Being born at the start of the wet season gives the foal a great chance to successfully negotiate the difficult first year of its life. I have named the foal ‘Pula’ which means ‘rain’ in Setswana. Rains are so important to life in Botswana that ‘Pula’ also means money and through the research I have certainly come to realise the importance of both!
Throughout the dry season zebra are reliant on the Boteti River as the only place where they can access drinking water. However, due to the need to find grazing of both sufficient quantity as well as quality, it was necessary for zebra to regularly be travelling 20-25 km away from the river and only drinking once every 3-4 days. By only drinking infrequently zebra are able to maximise the length of time which they spend in the grazing area. However, one collared zebra avoided this journey entirely by remaining on the western side of the river near to Leroo La Tau in an area 5km x 2km in size between the river and the fence for four months! She crossed the river into this area on June 20th and only crossed back again after the first rains in November.
Nearly 3 months have passed since the bush fire spread through the Makgadikgadi in early September. It was horrific to see the impact of the fire with such a large area comprehensively burnt but the ability of nature to respond to such extreme events is always amazing to see. Many of the burnt areas are now thick with fresh grass and the contrast between burnt and un-burnt areas is very noticeable with herbivores favouring the burnt areas. The long-term repercussions of the fire are still to be seen but may ultimately prove to be positive as the fire removed the old grass which forms dense, unpalatable tufts and allowed for new grass tufts to begin again with fresh growth which is more easily grazed by all herbivores.
I will continue to monitor the weather with interest as we wait for the rains to being in earnest. As ever if you have any questions or comments then please feel free to contact me. I look forward to hearing from you.
Saturday, 6 November 2010
Fire!
September has been and gone with the temperatures steadily rising as we wait for the first rains of the year. By the start of September all of the collared zebra were found in the Boteti region of the Makgadikgadi in order to drink the fresh river water as all waterholes in the eastern Makgadikgadi had dried up.
It has been a long and tough month within the Makgadikgadi as massive bush fires gripped the park in early September. On 6th September the fire spread through the whole park from east to west having started outside the national Park in an area around some cattle posts. I think it was started by a farmer burning a field to promote new growth for his cattle and it spiralled horribly out of control due to the strength of the wind.
The morning after the fire started I was heading through the park to do grass sampling but got blocked by the fire which was burning across the road. After travelling off road to get around the fire, I rejoined a road where the fire was burning to the north, east and west of us without knowing how far the fire had spread. Driving through the burnt grassland with nothing but black ash left we saw Steenboks and Gemsboks looking very confused with their new surroundings as they tried to find shade and food.
On the drive into Khumaga and the Boteti we came across two groups of around 500 zebra huddled close together and clearly in a state of shock all standing around not knowing what to do. Other herds of zebra had fled from the fires and remained close to the Boteti in unburnt areas waiting to see what happened next. By this stage the fire was continuing to burn throughout the park and continued to head west towards Meno A Kwena and the tar road.
The fire burnt for a few more days as it back burnt through thick grassland. The fire even burnt through the trunks of some mature Leadwood trees causing the trees to topple. Driving through the burnt areas was horrifying as we saw the true scale of the devastation while trying to avoid areas that still smouldered even up to a week after the fire had passed through. A massive area of the park has been burnt which is visible if you look at the following two satellite images taken just before and just after the fire. Click on the links below and look for the white salt pans towards the centre of the image and then look to the area North and West of the pans before and after.
Pre-fire: http://rapidfire.sci.gsfc.nasa.gov/subsets/?subset=SERVIR_Africa_South_Central.2010248.aqua.1km This is at 1km resolution but by clicking on the 250m alternate pixel size link near the top of the page you can get a more detailed image
Post-fire: http://rapidfire.sci.gsfc.nasa.gov/subsets/?subset=SERVIR_Africa_South_Central.2010252.aqua.1km The same resolution applies for this image but unfortunately there is a bit of cloud around so is not quite so clear.
Within days of the fire passing through the Makgadikgadi, new green shoots were seen coming from the burnt tufts of grass. Despite there still being some fairly large areas which survived the fire, zebra and other herbivores were seen to be actively choosing to graze in the burnt areas on these lush green shoots. These shoots are high in nutrients and provide good grazing but as they are quite sparse the zebra need to constantly be on the move to find sufficient grazing resources. One collared zebra has been recorded 31km from the nearest point where it could access the water in the Boteti River as it searches for suitable grazing as well as going for up to 5 days between drinking bouts.
I am heading back down to the Boteti region this week in order to continue fieldwork. I will be particularly interested to see exactly where the zebra are grazing as well as assessing any changes in their body condition as a result of the fire. I am also interested to see whether the behaviour of the zebra has changed and whether they have adjusted their activity patterns in order to find sufficient nutrients.
Fires are often an ecological disaster but they have the potential to rejuvenate grass sward by removing the moribund grass and allowing for fresh growth. However, unless the rains are forthcoming and persistent, it may take sometime for the sward to restore itself. I will monitor with interest how the Makgadikgadi changes over the next few months and what effect this has on the zebra.
It has been a long and tough month within the Makgadikgadi as massive bush fires gripped the park in early September. On 6th September the fire spread through the whole park from east to west having started outside the national Park in an area around some cattle posts. I think it was started by a farmer burning a field to promote new growth for his cattle and it spiralled horribly out of control due to the strength of the wind.
The morning after the fire started I was heading through the park to do grass sampling but got blocked by the fire which was burning across the road. After travelling off road to get around the fire, I rejoined a road where the fire was burning to the north, east and west of us without knowing how far the fire had spread. Driving through the burnt grassland with nothing but black ash left we saw Steenboks and Gemsboks looking very confused with their new surroundings as they tried to find shade and food.
On the drive into Khumaga and the Boteti we came across two groups of around 500 zebra huddled close together and clearly in a state of shock all standing around not knowing what to do. Other herds of zebra had fled from the fires and remained close to the Boteti in unburnt areas waiting to see what happened next. By this stage the fire was continuing to burn throughout the park and continued to head west towards Meno A Kwena and the tar road.
The fire burnt for a few more days as it back burnt through thick grassland. The fire even burnt through the trunks of some mature Leadwood trees causing the trees to topple. Driving through the burnt areas was horrifying as we saw the true scale of the devastation while trying to avoid areas that still smouldered even up to a week after the fire had passed through. A massive area of the park has been burnt which is visible if you look at the following two satellite images taken just before and just after the fire. Click on the links below and look for the white salt pans towards the centre of the image and then look to the area North and West of the pans before and after.
Pre-fire: http://rapidfire.sci.gsfc.nasa.gov/subsets/?subset=SERVIR_Africa_South_Central.2010248.aqua.1km This is at 1km resolution but by clicking on the 250m alternate pixel size link near the top of the page you can get a more detailed image
Post-fire: http://rapidfire.sci.gsfc.nasa.gov/subsets/?subset=SERVIR_Africa_South_Central.2010252.aqua.1km The same resolution applies for this image but unfortunately there is a bit of cloud around so is not quite so clear.
Within days of the fire passing through the Makgadikgadi, new green shoots were seen coming from the burnt tufts of grass. Despite there still being some fairly large areas which survived the fire, zebra and other herbivores were seen to be actively choosing to graze in the burnt areas on these lush green shoots. These shoots are high in nutrients and provide good grazing but as they are quite sparse the zebra need to constantly be on the move to find sufficient grazing resources. One collared zebra has been recorded 31km from the nearest point where it could access the water in the Boteti River as it searches for suitable grazing as well as going for up to 5 days between drinking bouts.
I am heading back down to the Boteti region this week in order to continue fieldwork. I will be particularly interested to see exactly where the zebra are grazing as well as assessing any changes in their body condition as a result of the fire. I am also interested to see whether the behaviour of the zebra has changed and whether they have adjusted their activity patterns in order to find sufficient nutrients.
Fires are often an ecological disaster but they have the potential to rejuvenate grass sward by removing the moribund grass and allowing for fresh growth. However, unless the rains are forthcoming and persistent, it may take sometime for the sward to restore itself. I will monitor with interest how the Makgadikgadi changes over the next few months and what effect this has on the zebra.
Lions 1 - Zebras 0
August has been another busy month in the Makgadikgadi as the temperatures have steadily increased and I have recorded a high of 35oC while observing a collared zebra. There has also been a steady increase of Elephants in the eastern Makgadikgadi and while out one day I came across 14 male elephants feeding near to the research camp and merrily pushing down any tree they felt like.
With the increase in temperature the waterholes in the Jacks Camp area are rapidly drying up with only 2 major waterholes remaining. It won’t be long before these too are dry and the zebra are forced to migrate to find suitable water resources. There is currently only one collared zebra remaining in the east as every other collared zebra has migrated to the Boteti region.
It so far seems that the collars which were deployed at the end of July to replace broken GPS collars are working well and providing some interesting data. The zebra in the Boteti region have divided themselves into two distinct groups with those which migrated earlier in the year drinking from and grazing in the area surrounding Meno A Kwena while those which migrated later currently drinking from the river around Khumaga and Leroo La Tau. Despite being in different areas they are following similar drinking patterns as they come into drink every 2-3 days.
Unfortunately one GPS collar is no longer sending through GPS data after the zebra had an extremely close encounter with some Lions and came off second best. This was one of the few zebra which had retained her original collar from March. It’s a shame that the Lions chose the collared zebra but it goes to show that predation is a serious risk for zebra in the Makgadikgadi.
I would like to thank those of you who have generously provided additional funding to the project in the last couple of months. Fundraising is an ongoing process as I look to meet the running costs of the project as well as significant one-off costs. These include darting zebra to replace and remove collars, the chemical analysis of grass and faecal samples and an aerial population count of the zebra herd which I hope to conduct in early 2011. All donations can be tax-deductible and if you would like to support the project in anyway then please contact me.
With the increase in temperature the waterholes in the Jacks Camp area are rapidly drying up with only 2 major waterholes remaining. It won’t be long before these too are dry and the zebra are forced to migrate to find suitable water resources. There is currently only one collared zebra remaining in the east as every other collared zebra has migrated to the Boteti region.
It so far seems that the collars which were deployed at the end of July to replace broken GPS collars are working well and providing some interesting data. The zebra in the Boteti region have divided themselves into two distinct groups with those which migrated earlier in the year drinking from and grazing in the area surrounding Meno A Kwena while those which migrated later currently drinking from the river around Khumaga and Leroo La Tau. Despite being in different areas they are following similar drinking patterns as they come into drink every 2-3 days.
Unfortunately one GPS collar is no longer sending through GPS data after the zebra had an extremely close encounter with some Lions and came off second best. This was one of the few zebra which had retained her original collar from March. It’s a shame that the Lions chose the collared zebra but it goes to show that predation is a serious risk for zebra in the Makgadikgadi.
I would like to thank those of you who have generously provided additional funding to the project in the last couple of months. Fundraising is an ongoing process as I look to meet the running costs of the project as well as significant one-off costs. These include darting zebra to replace and remove collars, the chemical analysis of grass and faecal samples and an aerial population count of the zebra herd which I hope to conduct in early 2011. All donations can be tax-deductible and if you would like to support the project in anyway then please contact me.
Sunday, 15 August 2010
Beware of rivers!
Dear all,
July has come and gone in a flash as the dry season continues. The Boteti River has risen significantly and having recently passed Rakops is now closing on Mopipi and Lake Xau. The river was deeper than I expected and unfortunately caught me out as I got stuck trying to cross. Thanks to Leroo La Tau I was recovered from the river but with everything a little wetter. Upon later examination it turned out that there was an electrical immobiliser in the car which I was unaware of and which had been disabled previously but upon getting wet it became active once more and caused all of the electrics to cut out leaving me stranded. Needless to say the immobiliser has since been removed but I don’t intend to try and cross the Boteti again except by boat!
In the eastern Makgadikgadi the remaining surface waterholes are drying up but there is still enough water in some of the deeper waterholes to provide sufficient water for a few thousand zebra and wildebeest. The remainder of the zebra population has already migrated back to the Boteti and are making full use of the fresh Boteti river water.
The movement data provided by the GPS collars is very interesting and is raising many more questions. In the Boteti zebra are regularly choosing to graze 18km away from the nearest source of water while one zebra has been recorded 23.5km from the nearest source of water. The zebra are actively choosing to walk past areas which appear to have good quality grass in order to reach their current grazing areas. What is it about these areas which the zebra will walk such large distances for? How do the zebra know how to find these areas and return to them so regularly? Why have some zebra migrated back to the Boteti while others have remained in the Eastern Makgadikgadi? What triggers the zebras to migrate? These are just some of the many questions which I am looking to answer through this research.
During the last week of July I went with a veterinarian to try and replace the broken GPS collars with new replacement collars. We knew that it would be difficult as the last time we tried to remove collars it took us 8 days to remove 7 collars.
We headed to the pans of the eastern Makgadikgadi first to locate any collared zebra which had yet to migrate. I had tracked 3 collared zebra in this area less than one week before and so was hopeful that we would be able to find them now. During the course of two days and following lots of VHF tracking we located and replaced the collars on the only two collared zebra which we could find. This meant that all of the remaining collared zebra had (I hoped!) to be in the Boteti region to which we headed next.
After stopping countless times in order to scan the area using VHF tracking equipment and many kilometres of off-road driving the remaining 4 zebras with broken GPS collars were located and eventually darted. The thick acacia scrub around the Boteti made things both easier and more difficult at the same time. It was made easier in that we could get closer to the zebra than in the open grasslands where it is difficult to get 50 metres away from the collared zebra. It was more challenging because of the number of bushes and tall grasses which were often between us and the zebra and through which a dart can not travel. Patience, as ever, was the key and we were ultimately successful and were able to replace all of the broken collars.
After the successful darting there are 10 zebras collared in the Makgadikgadi once more and hopefully these collars will remain on the zebra until March 2011. I will keep checking on them each month to see where they are and to make sure that the collars are still working.
If anyone has any comments or queries about the research then please contact me.
Best wishes to you all and thank you for your continued support.
James
July has come and gone in a flash as the dry season continues. The Boteti River has risen significantly and having recently passed Rakops is now closing on Mopipi and Lake Xau. The river was deeper than I expected and unfortunately caught me out as I got stuck trying to cross. Thanks to Leroo La Tau I was recovered from the river but with everything a little wetter. Upon later examination it turned out that there was an electrical immobiliser in the car which I was unaware of and which had been disabled previously but upon getting wet it became active once more and caused all of the electrics to cut out leaving me stranded. Needless to say the immobiliser has since been removed but I don’t intend to try and cross the Boteti again except by boat!
In the eastern Makgadikgadi the remaining surface waterholes are drying up but there is still enough water in some of the deeper waterholes to provide sufficient water for a few thousand zebra and wildebeest. The remainder of the zebra population has already migrated back to the Boteti and are making full use of the fresh Boteti river water.
The movement data provided by the GPS collars is very interesting and is raising many more questions. In the Boteti zebra are regularly choosing to graze 18km away from the nearest source of water while one zebra has been recorded 23.5km from the nearest source of water. The zebra are actively choosing to walk past areas which appear to have good quality grass in order to reach their current grazing areas. What is it about these areas which the zebra will walk such large distances for? How do the zebra know how to find these areas and return to them so regularly? Why have some zebra migrated back to the Boteti while others have remained in the Eastern Makgadikgadi? What triggers the zebras to migrate? These are just some of the many questions which I am looking to answer through this research.
During the last week of July I went with a veterinarian to try and replace the broken GPS collars with new replacement collars. We knew that it would be difficult as the last time we tried to remove collars it took us 8 days to remove 7 collars.
We headed to the pans of the eastern Makgadikgadi first to locate any collared zebra which had yet to migrate. I had tracked 3 collared zebra in this area less than one week before and so was hopeful that we would be able to find them now. During the course of two days and following lots of VHF tracking we located and replaced the collars on the only two collared zebra which we could find. This meant that all of the remaining collared zebra had (I hoped!) to be in the Boteti region to which we headed next.
After stopping countless times in order to scan the area using VHF tracking equipment and many kilometres of off-road driving the remaining 4 zebras with broken GPS collars were located and eventually darted. The thick acacia scrub around the Boteti made things both easier and more difficult at the same time. It was made easier in that we could get closer to the zebra than in the open grasslands where it is difficult to get 50 metres away from the collared zebra. It was more challenging because of the number of bushes and tall grasses which were often between us and the zebra and through which a dart can not travel. Patience, as ever, was the key and we were ultimately successful and were able to replace all of the broken collars.
After the successful darting there are 10 zebras collared in the Makgadikgadi once more and hopefully these collars will remain on the zebra until March 2011. I will keep checking on them each month to see where they are and to make sure that the collars are still working.
If anyone has any comments or queries about the research then please contact me.
Best wishes to you all and thank you for your continued support.
James
Monday, 19 July 2010
Winter arrives!
June has come and gone and winter is officially here. I woke up one morning to find ice on my windscreen and an air temperature of 0.8oC. Getting out of the tent before dawn when it is this cold is not appealing but I know that by October I will be wishing for winter once more. The Boteti River is also rising significantly and it is now no longer possible to drive across the river at Leroo La Tau. Earlier this month the water level rose 7cm in 2 days.
Within the Makgadikgadi there are now two distinct populations of zebra. There are those which have remained around the seasonal waterholes in the east and those which have migrated back to the Boteti River. The fact that there are so many around the Boteti is quite confusing as there is still so much water available to the zebra in the east around the open grasslands. Perhaps the urge to migrate and follow traditional movement patterns is stronger than we think. Or maybe the grazing in the west around the Boteti is significantly better – although at first glance this doesn’t appear to be the case. It may even be linked to predation or the prevalence of mosquitoes in the east which has caused the zebra to migrate west.
I am now working hard to collect as much data as I can from both the eastern and western Makgadikgadi to try and understand what is currently occurring. Grass and faeces samples are being collected to compare the quantity and quality of the available grazing resources. The remaining waterholes are still being sampled in the east to record water quality changes and behavioural observations are being conducted to record activity patterns.
Towards the end of June I received the replacement GPS collars which I am hoping to deploy during July. Locating and darting collared zebra is always a challenge as they seem to know that they are being targeted and so the darting process is likely to take some time. There is also a significant cost involved with the darting which I had not expected and so I am now looking to raise funds to help cover these costs. If you feel that you might be able to help with these costs then please let me know and I would look forward to hearing from you.
If you have any questions or comments about anything to do with zebras and the research then please feel free to get in touch.
Best wishes to you all,
James
Within the Makgadikgadi there are now two distinct populations of zebra. There are those which have remained around the seasonal waterholes in the east and those which have migrated back to the Boteti River. The fact that there are so many around the Boteti is quite confusing as there is still so much water available to the zebra in the east around the open grasslands. Perhaps the urge to migrate and follow traditional movement patterns is stronger than we think. Or maybe the grazing in the west around the Boteti is significantly better – although at first glance this doesn’t appear to be the case. It may even be linked to predation or the prevalence of mosquitoes in the east which has caused the zebra to migrate west.
I am now working hard to collect as much data as I can from both the eastern and western Makgadikgadi to try and understand what is currently occurring. Grass and faeces samples are being collected to compare the quantity and quality of the available grazing resources. The remaining waterholes are still being sampled in the east to record water quality changes and behavioural observations are being conducted to record activity patterns.
Towards the end of June I received the replacement GPS collars which I am hoping to deploy during July. Locating and darting collared zebra is always a challenge as they seem to know that they are being targeted and so the darting process is likely to take some time. There is also a significant cost involved with the darting which I had not expected and so I am now looking to raise funds to help cover these costs. If you feel that you might be able to help with these costs then please let me know and I would look forward to hearing from you.
If you have any questions or comments about anything to do with zebras and the research then please feel free to get in touch.
Best wishes to you all,
James
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