Okavango-Makgadikgadi Zebra Migration Research

The Zebra Migration Research Project started in 2008 and is ongoing. The project aims to increase our understanding of the second longest zebra migration in Africa.

The zebra migration was discovered unexpectedly during field work for Okavango Herbivore Research. A proportion of the GPS collared zebra migrated from the Okavango Delta at the onset of the rains. They travelled 290km to the Makgadikgadi grasslands to the south-east, joining the large herds of resident Makgadikgadi zebra and wildebeest. At the end of the wet season, once the last of the seasonal water holes dried up they walked back to the Okavango Delta. At a 580km round-trip this is the second longest intact zebra migration in Africa.

The migration is interesting for both its biology, terrestrial migrations are increasingly rare due to habitat fragmentation, and its implications for conservation biology across Africa, the migration could only recently have restarted due to its route being blocked by a veterinary cordon fence and is thus of interest in relation to wildlife corridor and Transfrontier parks.

The project has 4 specific aims.

1. Determine how the migratory route varies annually.

2. Estimate of the size of the migratory population.

3. Investigate what drives the migration, resources or predation and how energetic strategies vary between migratory and Okavango/Makgadikgadi resident zebra

4. Investigate the genetic independence of the three populations

Research is focussed on the Moremi Game Reserve, Makgadikgadi National Park and intermediary Wildlife Management Areas, the areas through which the migration passes

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Methodology

A number of methods are being used in this study.

  • High-quality GPS collars to record movement
  • Camera traps and aerial surveys to assess population structure
  • Sampling forage quality and quantity in both the Okavango Delta and Makgadikgadi
  • Utilising satellite data on vegetation (NDVI) and rainfall (TRMM)variability along the migratory route and in the two home ranges

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Findings to date

This project is ongoing. To date, the major findings include:

  • Zebra follow a highly directed route during the migration. They move quickly in an orientated fashion and can cover over 40km/day.
  • It is the only published incidence of a terrestrial mammal migration restarting after a break of more than one generation.
  • The zebra's use the weather to time their migratory movements; leaving the Delta soon after the first rains and varying their speed along the migratory route according to the amount of rain and quality of forage on route.

Outputs
Bartlam-Brooks, H.L.A., Bonyongo, M.C. & Harris, S. (2011) Will reconnecting ecosystems allow long-distance mammal migrations to resume? A case study of a zebra, Equus burchelli, migration in Botswana. Oryx, 45 (2), 210-216.
Hattie L. A. Bartlam-Brooks, Pieter S. A. Beck, Gil Bohrer and Stephen Harris. (2013) In search of greener pastures: Using satellite images to predict the effects of environmental change on zebra migration. Journal of Geophysical Research: Biogeosciences, 118 (4), 1427-1437. DOI: 10.1002/jgrg.20096 (Research Highlight in Nature - Travelling zebra forecast the weather. Nature, 500, 124. DOI:10.1038/500124a)

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