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.
Sunday 28 November 2010
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
Thursday 27 May 2010
Migrating?
Dear all,
It has been another interesting month here in the Makgadikgadi. The first month since August 2009 where I can’t remember any rain falling and where the mosquitoes have been happy to bite anything repeatedly and regardless of whether repellent was applied or not! Fortunately, they now appear to be slowly diminishing as the weather starts to turn colder and the shallow pools are gradually drying up. The deep waterholes remain and will do so for a considerable time to come as evaporation rates slow down.
Of the 10 collars which were deployed in late March and early April, there are only 4 collars still working and only 2 of these working as they should. Unfortunately, this means that I have to replace all but the 2 working collars with replacement collars that are being provided by the collar company. Not only has this lost valuable fieldwork time as well as valuable GPS data which have not been collected, but I will also have the additional costs associated with darting zebra. I am hoping that I will be able to change the collars in June but this depends on when the replacement collars are available.
Fieldwork has continued during May with the assistance of Rob, Dutch and Matt who have been kind enough to brave the mosquitoes with me. I have visited over 200 known waterholes, as well as found quite a few more, in order to record water availability and quality. I have also sampled grazing sites, collected faecal samples and conducted behavioural observations. It’s amazing how quickly a month can disappear.
As a result of the collar problems, it has proven to be significantly more challenging to find the zebra. It is amazing how well herds of 1,000 or more zebra can seem to disappear in the Makgadikgadi. They tend to stay very close to each other and move slowly across the ecosystem to find fresh grazing each day. When you see them like this they appear to be like a shoal of Sardines or a flock of Quelea: constantly changing shape but always linked.
Starting in the east, where some remain, during May the zebra have moved across much of the Makgadikgadi towards the centre of the Park. Some, however, have gone a step further and have migrated west to the Boteti and there are now two collared zebra in the Boteti region.
This migration was unexpected as there is still so much rain water remaining in the surface waterholes of the eastern Makgadikgadi. Exactly how many are in the Boteti is unknown but I am hoping to fly this weekend which will allow me to look at the bigger picture. All of the remaining collared zebra are still grazing in the centre of the park and it will be interesting to see whether they choose to go east or west as there does not appear to be much surface water remaining in this area.
The migration of zebra back to the Boteti raises some interesting questions. Why have they migrated when there are still large quantities of water and grass in the eastern Makgadikgadi? What triggered this movement? Will the zebra remain in the Boteti region for the rest of the dry season? Will the remainder of the zebra in the Makgadikgadi migrate west as well or will there be two groups – 1 in the west and 1 in the east? How do the grazing resources differ between the two areas?
I will look to collect data to help answer these questions in the coming weeks as well as continuing to monitor the movements of the zebra.
If you have any comments or questions then please feel free to contact me at any time.
It has been another interesting month here in the Makgadikgadi. The first month since August 2009 where I can’t remember any rain falling and where the mosquitoes have been happy to bite anything repeatedly and regardless of whether repellent was applied or not! Fortunately, they now appear to be slowly diminishing as the weather starts to turn colder and the shallow pools are gradually drying up. The deep waterholes remain and will do so for a considerable time to come as evaporation rates slow down.
Of the 10 collars which were deployed in late March and early April, there are only 4 collars still working and only 2 of these working as they should. Unfortunately, this means that I have to replace all but the 2 working collars with replacement collars that are being provided by the collar company. Not only has this lost valuable fieldwork time as well as valuable GPS data which have not been collected, but I will also have the additional costs associated with darting zebra. I am hoping that I will be able to change the collars in June but this depends on when the replacement collars are available.
Fieldwork has continued during May with the assistance of Rob, Dutch and Matt who have been kind enough to brave the mosquitoes with me. I have visited over 200 known waterholes, as well as found quite a few more, in order to record water availability and quality. I have also sampled grazing sites, collected faecal samples and conducted behavioural observations. It’s amazing how quickly a month can disappear.
As a result of the collar problems, it has proven to be significantly more challenging to find the zebra. It is amazing how well herds of 1,000 or more zebra can seem to disappear in the Makgadikgadi. They tend to stay very close to each other and move slowly across the ecosystem to find fresh grazing each day. When you see them like this they appear to be like a shoal of Sardines or a flock of Quelea: constantly changing shape but always linked.
Starting in the east, where some remain, during May the zebra have moved across much of the Makgadikgadi towards the centre of the Park. Some, however, have gone a step further and have migrated west to the Boteti and there are now two collared zebra in the Boteti region.
This migration was unexpected as there is still so much rain water remaining in the surface waterholes of the eastern Makgadikgadi. Exactly how many are in the Boteti is unknown but I am hoping to fly this weekend which will allow me to look at the bigger picture. All of the remaining collared zebra are still grazing in the centre of the park and it will be interesting to see whether they choose to go east or west as there does not appear to be much surface water remaining in this area.
The migration of zebra back to the Boteti raises some interesting questions. Why have they migrated when there are still large quantities of water and grass in the eastern Makgadikgadi? What triggered this movement? Will the zebra remain in the Boteti region for the rest of the dry season? Will the remainder of the zebra in the Makgadikgadi migrate west as well or will there be two groups – 1 in the west and 1 in the east? How do the grazing resources differ between the two areas?
I will look to collect data to help answer these questions in the coming weeks as well as continuing to monitor the movements of the zebra.
If you have any comments or questions then please feel free to contact me at any time.
Friday 2 April 2010
Darting 2010: Part A
As we approach the supposed end of the wet season, Botswana continues to receive regular rains in what is proving to be another good wet season. I am told that Central Kalahari is receiving its heaviest rainfall of the year while the Makgadikgadi has been receiving intermittent storms. The continued rains will be a further boost to zebra in the Makgadikgadi as they are able to make the most of grazing on the nutritious grass islands in the salt pans. I will soon be spending much more time in the Makgadikgadi with the zebra as the latest field season gets underway. However, it is first necessary to collar 10 random adult mares with GPS collars.
After the collars were returned to Botswana from Germany, where they have been refurbished with new battery packs, we headed down to the pans on the 26th March to try and collar 5 zebra. Putting collars onto random zebra mares is theoretically a much easier task than locating and darting a collared zebra so as to remove the collar. However, we did learn in December when we were removing the collars that zebra are much more relaxed first thing in the morning and will let you drive closer to them. We were therefore still up long before dawn to give us time to find a herd of zebra as the sun was creeping up over the horizon.
After persistent drizzle through the night we could not have asked for a nicer day with clear skies and, more importantly, relaxed zebra. These zebra were in groups of between 50-100 individuals and were happily grazing quite close to the research camp so we did not have far to go. When we were able to get close enough to dart the first zebra after only 10-15 minutes of effort we knew things were looking good.
The major challenge was for me to identify an adult mare and then to explain to the vet which one I was looking at. This might not sound to be a challenge but when all zebra have black and white stripes, and are stood close to each other grazing, identifying a specific zebra and explaining to someone else which one it is can be quite a challenge. I usually try to find an identifying feature that makes the zebra more noticeable and this is often to do with the stripe pattern or the colouration.
While a zebra is sedated and we are working to fit the collar and take the relevant measurements, the rest of the herd stay nearby and continue to graze while watching us from a safe distance. Often the sedated mare’s stallion will stay much closer, observing us while we work and waiting for the safe return of his girl.
Once we had successfully darted and collared a zebra we then moved a little further away to find a different herd of zebra and to start the process all over again. We had 5 GPS collars to deploy during this first trip which we achieved this in less than a day and a half. I only hope that when we head back down to the pans in a week’s time things continue to go well for us.
If you have any questions about anything to do with the darting process then please feel free to get in touch.
James
After the collars were returned to Botswana from Germany, where they have been refurbished with new battery packs, we headed down to the pans on the 26th March to try and collar 5 zebra. Putting collars onto random zebra mares is theoretically a much easier task than locating and darting a collared zebra so as to remove the collar. However, we did learn in December when we were removing the collars that zebra are much more relaxed first thing in the morning and will let you drive closer to them. We were therefore still up long before dawn to give us time to find a herd of zebra as the sun was creeping up over the horizon.
After persistent drizzle through the night we could not have asked for a nicer day with clear skies and, more importantly, relaxed zebra. These zebra were in groups of between 50-100 individuals and were happily grazing quite close to the research camp so we did not have far to go. When we were able to get close enough to dart the first zebra after only 10-15 minutes of effort we knew things were looking good.
The major challenge was for me to identify an adult mare and then to explain to the vet which one I was looking at. This might not sound to be a challenge but when all zebra have black and white stripes, and are stood close to each other grazing, identifying a specific zebra and explaining to someone else which one it is can be quite a challenge. I usually try to find an identifying feature that makes the zebra more noticeable and this is often to do with the stripe pattern or the colouration.
While a zebra is sedated and we are working to fit the collar and take the relevant measurements, the rest of the herd stay nearby and continue to graze while watching us from a safe distance. Often the sedated mare’s stallion will stay much closer, observing us while we work and waiting for the safe return of his girl.
Once we had successfully darted and collared a zebra we then moved a little further away to find a different herd of zebra and to start the process all over again. We had 5 GPS collars to deploy during this first trip which we achieved this in less than a day and a half. I only hope that when we head back down to the pans in a week’s time things continue to go well for us.
If you have any questions about anything to do with the darting process then please feel free to get in touch.
James
Wednesday 3 March 2010
The Wet Season
While Maun and the Okavango Delta have been receiving both good and consistent rainfall since early November, much of the rest of Botswana has so far received intermittent rains. Recently the Makgadikgadi had been very dry for the time of year and it was possible to drive across the pans from the south without the worry of getting stuck. However, this all changed last week with over 200mm falling within a few days. With further rainfall to be expected before the end of March it looks likely that the zebra will remain in the eastern Makgadikgadi for the foreseeable future. In 2009, 180 mm of rain in June provided sufficient water to allow zebra’s to graze for more than 3 months in the eastern grasslands. I wait to see how long this most recent rain will keep them in the east for.
Over the next few weeks I will be based in Maun, finalising my plans for the upcoming field season as well as continuing with my fundraising in order to ensure a successful year. The first major step will be to redeploy the GPS collars now that they have had new batteries fitted to them. This will take place towards the end of March while the zebra are in the east and will involve the identification and darting of 10 random adult zebra mares.
I hope that you are all having a good 2010 and, as ever, if you have any questions or comments then I would like to hear from you.
Best wishes,
James
Over the next few weeks I will be based in Maun, finalising my plans for the upcoming field season as well as continuing with my fundraising in order to ensure a successful year. The first major step will be to redeploy the GPS collars now that they have had new batteries fitted to them. This will take place towards the end of March while the zebra are in the east and will involve the identification and darting of 10 random adult zebra mares.
I hope that you are all having a good 2010 and, as ever, if you have any questions or comments then I would like to hear from you.
Best wishes,
James
Monday 1 February 2010
2009 - A summary
In early April 2009 I collared 10 zebra mares within the Makgadikgadi Pans National Park so that I would be able to follow the movements of these zebra throughout the year. Due to regular rainfall throughout the year, 2009 has been an eventful and prosperous year for the Makgadikgadi zebra. The zebra have been able to remain in the open grasslands of the Makgadikgadi to feed on grass which has not stopped growing all year. All of this has meant that the zebra foals born during the 2008-09 wet season have had a great chance to survive their first year of life – typically the hardest for any animal.
During the 8 months since the collars were deployed, 1 collared zebra was killed and eaten by lions in July and 2 of the remaining 9 GPS collars failed due to technical problems. Despite the problems I have been able to collect over 150,000 GPS positions from the 10 collared zebra thus allowing me to view up-to-date movements in response to rainfall, the drying up of waterholes and grass availability.
The fieldwork I have conducted during 2009 has been an incredible learning experience for me with a lot of valuable data collected. Since deploying the collars I have studied the grass that the zebra choose to eat and the waterholes where they prefer to drink. I have also observed the behaviour of zebra by conducting sunrise to sunset observations with additional observations of their grazing behaviour. Samples of grass, water and faeces have been collected for more detailed analysis later so that I can study how the zebra are making the most of limited water availability. During 2010 I will look to build on the data collected in 2009 as well as collecting other types of data to help answer my questions.
When you use GPS collars to track wildlife one of the most important decisions is to decide how long you want to collect data for. There are two main options – a long collar life with less GPS fixes taken daily or a short collar life with a high-intensity of GPS fixes taken daily. Both options have their merits depending on the data that you are looking to collect. I chose the latter knowing that I would have to remove the collars before the end of 2009 to refurbish them with new batteries. Therefore, at the beginning of December, with the assistance of a qualified veterinarian, I set about trying to remove the GPS collars.
Usually when you are darting wild animals, particularly to remove or replace collars, the hardest part is finding your target animal. However, in this instance, finding the collared zebra was the easy part, the hard part was getting close enough so that we could dart them. After a couple of frustrating days when we were unable to get close to any of the collared zebra we realised that our best chance would be in the hours immediately after sunrise when the temperatures were still bearable and the zebra were more relaxed. This meant we needed to be up by 4am so that we could be with a collared zebra before sunrise. Our new strategy paid off immediately as on the third morning we were able to remove the collars of 2 zebra before 8am.
Over a period of 8 days we were able to successfully remove the 7 working GPS collars. I removed 1 of the faulty collars in July and this means that the one collar which remains is one which failed in September. I will try again to remove this collar in March 2010. During the darting we were also able to collect some important information on the weights and physical condition of the collared zebra that were all heavily pregnant and due to give birth imminently.
The data provided by the GPS collars is vital in helping me to understand how zebra are able to survive and thrive in the challenging Makgadikgadi environment. Not only do the collars provide detailed movement data, they also allow me to track the zebra so that I can study behaviour as well as identify and sample the grazing and water resources which they are utilising. It is for this reason that in March 2010, once my collars have been refurbished, I will collar a further 10 zebra mares so that I can follow their movements within the Makgadikgadi throughout 2010.
During the darting period, whilst tracking a collared zebra, we were lucky enough to come across a mare just about to give birth so we stopped to observe this special event. Within 15 minutes the foal was up on its feet before its mother, looking a little wobbly at first but soon gaining confidence in how to use all 4 limbs in unison. The rest of the harem were not far away and soon came to greet the new arrival, a yearling was particularly interested, before they all moved off to rejoin the safety of the herd. The first few days of this foal’s life will be the toughest but if it can stay close to its mother then it will have a great chance of reaching adulthood due to the abundance of water and grass available this year.
If you have any questions or comments then please feel free to email me, zebra@zebramigration.org or visit the project website www.zebramigration.org where there will be additional photos and blogs added shortly.
Best wishes for a healthy and prosperous 2010.
During the 8 months since the collars were deployed, 1 collared zebra was killed and eaten by lions in July and 2 of the remaining 9 GPS collars failed due to technical problems. Despite the problems I have been able to collect over 150,000 GPS positions from the 10 collared zebra thus allowing me to view up-to-date movements in response to rainfall, the drying up of waterholes and grass availability.
The fieldwork I have conducted during 2009 has been an incredible learning experience for me with a lot of valuable data collected. Since deploying the collars I have studied the grass that the zebra choose to eat and the waterholes where they prefer to drink. I have also observed the behaviour of zebra by conducting sunrise to sunset observations with additional observations of their grazing behaviour. Samples of grass, water and faeces have been collected for more detailed analysis later so that I can study how the zebra are making the most of limited water availability. During 2010 I will look to build on the data collected in 2009 as well as collecting other types of data to help answer my questions.
When you use GPS collars to track wildlife one of the most important decisions is to decide how long you want to collect data for. There are two main options – a long collar life with less GPS fixes taken daily or a short collar life with a high-intensity of GPS fixes taken daily. Both options have their merits depending on the data that you are looking to collect. I chose the latter knowing that I would have to remove the collars before the end of 2009 to refurbish them with new batteries. Therefore, at the beginning of December, with the assistance of a qualified veterinarian, I set about trying to remove the GPS collars.
Usually when you are darting wild animals, particularly to remove or replace collars, the hardest part is finding your target animal. However, in this instance, finding the collared zebra was the easy part, the hard part was getting close enough so that we could dart them. After a couple of frustrating days when we were unable to get close to any of the collared zebra we realised that our best chance would be in the hours immediately after sunrise when the temperatures were still bearable and the zebra were more relaxed. This meant we needed to be up by 4am so that we could be with a collared zebra before sunrise. Our new strategy paid off immediately as on the third morning we were able to remove the collars of 2 zebra before 8am.
Over a period of 8 days we were able to successfully remove the 7 working GPS collars. I removed 1 of the faulty collars in July and this means that the one collar which remains is one which failed in September. I will try again to remove this collar in March 2010. During the darting we were also able to collect some important information on the weights and physical condition of the collared zebra that were all heavily pregnant and due to give birth imminently.
The data provided by the GPS collars is vital in helping me to understand how zebra are able to survive and thrive in the challenging Makgadikgadi environment. Not only do the collars provide detailed movement data, they also allow me to track the zebra so that I can study behaviour as well as identify and sample the grazing and water resources which they are utilising. It is for this reason that in March 2010, once my collars have been refurbished, I will collar a further 10 zebra mares so that I can follow their movements within the Makgadikgadi throughout 2010.
During the darting period, whilst tracking a collared zebra, we were lucky enough to come across a mare just about to give birth so we stopped to observe this special event. Within 15 minutes the foal was up on its feet before its mother, looking a little wobbly at first but soon gaining confidence in how to use all 4 limbs in unison. The rest of the harem were not far away and soon came to greet the new arrival, a yearling was particularly interested, before they all moved off to rejoin the safety of the herd. The first few days of this foal’s life will be the toughest but if it can stay close to its mother then it will have a great chance of reaching adulthood due to the abundance of water and grass available this year.
If you have any questions or comments then please feel free to email me, zebra@zebramigration.org or visit the project website www.zebramigration.org where there will be additional photos and blogs added shortly.
Best wishes for a healthy and prosperous 2010.
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