IN THE FIELD zebra surprise A herd of zebras – or any other large herbivore – may be here one day, gone the next. Where do they go? With the aid of satellite tracking, researchers are begin- ning to find out and, reports John Hanks, the animals’ movements are bolstering the case for TFCAs. Kelly Landen
ifty years ago on a cold encroached upon and the land adjacent to The satellite tracking of zebras in Botswana’s and miserable winter’s day in them being irreversibly transformed, options Chobe region and Namibia is turning up a few revelations for researchers. FEngland I was enthralled by a book for dispersal to take place or migration that had just been published: Serengeti routes to be restored are fast disappearing. Shall Not Die. Bernhard and Michael This makes a strong argument in favour Grzimek’s account of the extraordinary of accelerating the development of TFCAs floodplains and moved 15 kilometres annual migrations of a million or more wil- before it is too late. north into Namibia’s Caprivi Strip before debeest accompanied by 200 000 zebras One of the best examples of the very returning south to Chobe National Park at became a classic, firmly establishing the real potential of TFCAs to make a major the start of the rains. Two of the collared Serengeti as the flagship of Tanzania’s tour- difference to both dispersal and migration animals then travelled south-eastward to ism industry. It also pointed me in the direc- is the 444 000-square-kilometre Kavango– the Seloko Plains region while the third tion of a career in conservation in Africa. Zambezi TFCA, which links parts of Angola, trekked an astonishing 240 kilometres in I have subsequently retained an inter- Namibia, Botswana, Zambia and Zimbabwe. a straight line south to Botswana’s Nxai est in the migration of large mammals In pioneering research, Elephants Without Pan National Park. and when I first started working on the ‘This new cross-border zebra route has establishment of Transfrontier Conservation This new cross-border zebra route [is] never been mapped,’ says EWB’s Michael Areas (TFCAs) in 1997, the ‘restoration of a major conservation finding at a time Chase. ‘It’s a major conservation finding at large mammal migration routes’ between when long-distance movements are a time when long-distance movements are neighbouring countries was used as one being lost around the world being lost around the world.’ of the biological reasons for setting them A researcher working in Namibia, Robin up. The objective sounds simple, but it has Borders (EWB; www.elephantswithout Naidoo, has also recently collared zebras resulted in a certain amount of confusion borders.org) has recorded and mapped the and recorded the same straight-line move- because, surprisingly, there is no universally dispersal of elephants from Botswana north ment to Nxai Pan. If these animals do accepted definition of the word ‘migration’, into Zambia across Namibia’s Caprivi Strip indeed return from the south to Namibia particularly when it is applied to large mam- and even into Angola. The team has recently on a regular seasonal basis, they could be mals. Strictly speaking, migration occurs expanded its projects to include other large completing one of Africa’s longest trans- in response to changing seasons and is herbivores (see ‘View from the top’ in Africa boundary mammal migrations. This is an predictable and repeated each year, with Geographic August 2011), initially looking exciting discovery at a time when some of the animals returning to where they came at the zebra population on the western the initial euphoria linked to TFCAs and their from – as happens in the Serengeti. floodplains of Botswana’s Chobe River potential to make a difference has started An equally important reason for estab- which, according to EWB’s dry-season aerial to diminish. lishing TFCAs is to allow for unhindered surveys, numbers close to 3 000 animals Says Chase, ‘It’s astounding that we dispersal, or the movement of animals out and is increasing. are still discovering phenomenal biolo- of an area and into a new range. This may Although conservation staff have worked gical events that we knew nothing about. take place for a variety of reasons, and the in and around this area for many years, the It goes to show how vital systems require animals may not necessarily return to where seasonal movements of its zebras were ongoing monitoring, as wildlife is diverse and they came from; if they do, the movement is unknown. To remedy this, three zebras were adapts to habitats that are continually trans- neither predictable nor seasonal. fitted with satellite collars in August 2012. forming as a result of human disturbance, With Africa’s human population still The EWB team observed that during the climate change and other environmental on the increase, protected areas being dry season the herds were on the Chobe conditions.’
10 africa geographic • march 2013