Spreading Mimosa, Declining Lechwe – Is There a Link?

The Trust is concerned about the rapid spread of the alien, invasive shrub Mimosa pigra on the Kafue Flats and the recent steep decline in numbers of the endemic Kafue lechwe, Kobus leche kafuensis. We believe these two trends may be related and at the end of 2016 we launched a new project to investigate a possible link.

The background to the project is provided in our briefing: ‘Mimosa Invasion of the Kafue Flats and Decline of the Kafue Lechwe’

Our first priorities are:

  1. To map the recent and historic extent of Mimosa on the Flats using satellite imagery and ground truthing.
  2. To review the literature on lechwe numbers, range, movements, behaviour and diet.
  3. Once Mimosa thickets are mapped accurately, to overlay lechwe survey data to explore any relationships between seasonal distribution patterns and the present distribution of Mimosa.

Good progress has been made in mapping the probable extent of Mimosa on the floodplain. We are delighted to have secured the help of Chris Legg, a recently retired geologist and remote sensing specialist. Chris worked for the Geological Survey of Zambia for a number of years and wrote the recently republished ‘Tourist Guide to the Hot Springs of Lochinvar National Park’.

Chris has recently produced a draft vegetation map for the Kafue Flats. The accuracy of this interpretation is now awaiting ground truthing by volunteers in May this year.

A start has also been made on reviewing the literature on lechwe. A few omissions and errors in previous lechwe survey reports and status reviews have been identified, but our study is at an early stage.

The project is unfunded and we are dependent upon the inputs of volunteers working pro bono. We would welcome donations to enable us to complete and expand the investigations.

KBT_map_2013_region revised key draft_opt

Vegetation Map of the central Kafue Flats, based on Landsat imagery from 2013