Tuli Elephant Count

Sep 13, 2010

MISSION  33 of  2010

Name of Mission: Tuli Elephant Count     
Date of Mission: 10th to 13th September 2010             
Beneficiary: Jeanetta Selier
Aircraft used: Cesna 182
Pilot: Avroy Shlain, Timothy Webster & Tamiko Sher

Objective of the Flight

To assist with an aerial count of elephants in the tuli block

Pilot’s story of the mission: By TAMIKO SHER, a Bateleurs member, writing on behalf of Bateleurs pilots Avroy Shlain and Timothy Webster

It is a cool morning on 10 September, Friday, at 0830 when Avroy Shlain and I took off in ZS-COM, his Cessna 182 in immaculate condition. In his early seventies, Avroy is a marvel as a pilot; careful, accurate and highly disciplined. As members of The Bateleurs, volunteer pilots who fly for environmental missions, we are off to the Tuli Block to assist with an aerial elephant count.

The visibility is poor that morning, but we make it in just over two hours to Limpopo Valley Airfield, a comfortable tar strip just inside the border of Botswana where Zimbabwe and South Africa meet. En route we hear the others; a Cessna 206, piloted by Raymond Steyn, and another Cessna 182 flown by Tim Webster. Ray and Tim own the Pilatus agency at Rand Airport, with Ray having spent more the 300 flying hours in aerial surveys throughout Southern Africa.

An aerial elephant survey is a marvel in precision planning, similar to a military sortie. Permission must be gained from the three different countries to allow planes to fly over the designated Tuli Block area at heights of 300 – 1000 feet, well below normal required heights for park areas. The area must be geographically mapped, the Cybertrackers prepared and in place, the transect scientifically planned to allow for accurate counting. Fuel must be trucked in, meals, accommodation and transportation for a large group planned.

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It requires tremendous skill on the part of a crew of pilots, ground crew, scientists who download the data, experienced counters and others who assist with the process. The pilots must contribute long days of flying on a precise grid, known as transects, which are spaced between 800 – 1000m apart, making clean turns and at all times, regardless of winds, keep the plane steady and level for the counters. When an elephant herd is spotted, they must make a tight circle around the herd to allow for accurate counting.

Jeanetta Selier, the mastermind and coordinator behind the aerial elephant surveys, says:  “We can only work with highly skilled pilots as the flying requires a high level of precision and experience.” With 10 years at Tuli under her belt, Jeanetta is also known as the ‘Elephant Lady’ and is working towards a PhD at the School of Biological Science and Conservation at the University of Kwazulu Natal.

Aerial surveys are critical to creating a body of research that, over time, becomes the basis of measuring the elephant populations in this area for the three countries. Critical decisions, such as the number of hunting licenses, and handling of claims of elephant damage, are made by looking at this data.

“Without the Bateleurs,” says Jeanetta, “we would have never been able to do this work. Aerials surveys allow us to move quickly over the area and develop of a sense of how many herds are there.”

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This year’s count is 200 elephants up on the previous year, but it seems the number of bull elephants has come down. One plane counted more then 230 elephants in one morning!

Each morning starts early and we look forward to another cool morning of counting, the light winds of morning later giving way to hard, bumpy air. After several hours, each plane returns to refuel. The crew unloads, the truck backs up to the plane and reloads with avgas, the crew grabs a quick bite to eat and drink under the shade of the thatched Limpopo Valley field customs and immigration rondavaal.  Raymond covers the Tuli block north of the camp, Tim does the section over Zimbabwe, and Avroy covers the land to the west of the camp, plus the rivers.

The data from this survey will add to a growing database of scientifically collected information that will help maintain, protect and keep the legacy of the Tuli elephants for years to come. I am thrilled, and humbled, at the opportunity to be a tiny cog in this working machine, and will keep the memory of the scratching of the elephant relatives, the dassies, above my head at night, the stars waking us before the winds in the morning, and the promise of seeing elephant from the air.

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Beneficiary’s story of the mission: By JEANETTA SELIER

This report comprises extracts from a much longer, more detailed and scientific version compiled by Jeanetta Selier.  Her comprehensive report is available on request, by email to info@bateleurs.org

Objective of the Flight

To determine the distribution and population total of the Central Limpopo River Valley elephant population in the previously identified range.

The Tuli elephant population occurs in three different countries namely Botswana, South Africa, and Zimbabwe, and is one of the important cross border populations on which very little intensive scientific data pertaining to numbers and movements has been collected. This is a more or less free ranging population, in that there are only a few fences and human settlements that influence movement. But this is changing rapidly. In light of the proposed Greater Mapungubwe Trans-Frontier Conservation Area, and the developing agriculture, mining, dam construction and other settlement in the region, information on the numbers, distribution, movements and dynamics is essential for proper management to avoid human-elephant conflicts and habitat destruction and loss of biodiversity. Aerial surveys provide information on numbers, group structure and distribution that are important baseline data pertinent to basic ecological questions and conservation planning and management.

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Land use by people is different in different parts of the elephant range and different agencies manage the elephant population in different parts of the range. In Botswana the area along the Limpopo consists of a number of adjoining farms, which form an area known as the Tuli Block (Fig. 1). The Northern Tuli Game Reserve in Botswana consists of a number of privately owned farms bounded by the Limpopo, Motloutse and Shashe rivers. It comprises about half of the area of a conserved ecosystem which consists of the Tuli Circle Safari Area and the Mlala Reserve in Zimbabwe, and the Mapungubwe National Park in South Africa.

A total aerial count of the Central Limpopo Valley elephant population was conducted over a two-day period (11 -12 September 2010). The methodology was similar to those of previous years. Three fixed wing aeroplanes (Cessna 206; two C182T) were used to count the study area simultaneously. A team consisting of a pilot, navigator and two observers were used. The two observers, one positioned on each side of the aircraft recorded counted elephants on either side of the aircraft and relayed the information via an intercom to the navigator, who also recorded the position of the aircraft. Data and flight paths for the Northern Tuli Game Reserve and Mapungubwe National Park were recorded on a Cybertracker and combined with photographs taken of the various elephant groups encountered.

Flight lines ran roughly parallel to the Shashe River in a north-south direction for the entire study area. Transects were 1 km wide (500m each side of the aeroplane) and flying height 100 m to 150 m with a flight speed of 90-100 knots. The transect width was set at 1 km due to the openness of the area (Plate 1). Flight times were restricted to early mornings 07h00 – 1100 for the duration of the count.

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The area was divided so that the start and end of transects flown by different aeroplanes and on successive flights by the same aeroplane would ensure that double counting did not occur. On day one the Northern Tuli Game Reserve (Botswana), Mapungubwe National Park (South Africa), the Tuli Block from the Motloutse River to Zanzibar and Sentinel Ranch, Nottingham Estate, River Ranch (Zimbabwe) were counted. On day two the Tuli Circle in Zimbabwe and the major rivers (Motloutse and Thune) in Botswana, the Shashe River from the Tuli Circle to the confluence of the Ramokgwabane and the Shashe River as well as Letsibogo Dam were counted. Within the communal areas of Botswana a 1km transect were flown along the Shashe River towards the confluence of the Shashe and Ramokgwabane River. From the confluence a transect south towards Letsibogo Dam was flown. A 4 km area in the vicinity of Letsibogo Dam were surveyed comprising of approximately eight transects. From the dam a 1 km transect was flown along the Motloutse River to the confluence of the Thune and Motloutse rivers. A 1 km transect was flown up along the Thune River and back down one of the tributaries to the Thune towards the Motloutse River. On transects along the rivers, visible elephant impact were recorded.

The highest density of elephants occurred within the Botswana section of the study area (Table 2). The highest concentration, as expected, was found in protected and semi protected areas (NTGR; MNP; BDMRF), which also have the highest number of water points in the region, which may account for the distribution.

The total number of elephants counted in 2010 was 1237 compared to 1262, 1294, 1240, 1080 and 1229 in 2000, 2001, 2004, 2007 and 2008 respectively (Table 1). This figure is similar to the 2004 and 2008 count but slightly lower to the counts of 2000 and 2001 and higher than the count of 2007.

Elephant numbers counted within the Central Limpopo Valley during the six total aerial counts appear to be stable at between 1100-1300 elephants. No estimate of the accuracy of these counts is possible.

The distribution of the elephant population is mainly determined by the presence of humans and human activity, fences and large river systems. At least four distinct core areas can be identified for the mid to late winter period within the study areas suggestion the possibility of different clans or bond groups.

Group size distribution was different between the different aerial counts and can be correlated to the rainfall within the area. Higher rainfall seasons resulted in fewer but bigger groups while low rainfall seasons resulted in more but smaller group sizes.

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Data from the six aerial counts suggest that the population within the Central Limpopo Valley at least for the winter months is stable. Movement of elephants between the NTGR, MNP, BDMRF, TSA and SNRC occurs. Movement of elephants from the NTGR and BDNRF to Letsibogo Dam is possible but unlikely. Elephants however do move into the communal areas within the Bobirwa sub district in Botswana. It is more likely that the elephant population utilising the Letsibogo Dam area is a separate subpopulation travelling to and from the Ramokgwabane River. The movements of this sub population are still unknown and it is suggested that two satellite collars be fitted to a herd and a single mature bull in order to track their movements. Movement out of the current study area following the Limpopo River in a westerly direction is likely. According to  reports from farmers on the BDMRF elephant numbers have been steady increasing along the Limpopo riverine in this region and moving south to as far as Zanzibar. The sections between Baines Drift and Zanzibar have not been previously counted.

The following organisations sponsored the 2010 elephant count – The Bateleurs, the Peace Park Foundation, the Northern Tuli Game Farmers Association, the Mashatu Game Reserve, Tuli Lodge and the South African National Parks Board. A word of thanks to Tuli Lodge for accommodating participants in the aerial count, Pete le Roux for sourcing and collecting AVGAS for the aerial count, Nick Hiltermann for his organisation of events, Dennis Summers and his airfield team for always being ready and waiting to help with the refuelling of the planes. A special word of thanks to Raymond Steyn, Tim Webster and Avroy Shlain (all Bateleurs pilots) for their superb flying, Cathy Greaver (SANParks) for assisting with the computer program and navigating, Bruce Page for all his help, all the counters for their assistance and time,  and Nick Hiltermann for being able to use his photographs.

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