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.
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