Hirola Conservation Programme:

saving the world's most endangered antelope

Promotes the conservation of the hirola antelope and its fragile habitat in partnership with communities in eastern Kenya.

Monday, 16 October 2017 08:57

hirola habitat restoration project updates

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Our habitat restoration project includes nine experimental plots across three distinct soil where we are determining the ideal conditions necessary to increase grass growth. Using these plots we are testing the response of four native grass species (Cenchrus ciliaris, Enteropogon macrostachyus, Eragrostis superba, and Chloris roxbhurgiana) to four different restoration approaches (tilling, manure application + seeding, seeding, no treatment). In each of three soil types, we located three 50m x 20m treatment blocks. Our preliminary results from two soil types suggest total grass cover was higher in the seeded treatment than the seeding + manure treatment. Both tilling and no treatment did not result in any significant above ground biomass suggesting that lack of seeds rather than soil capping or water availability might be the key mechanism limiting grass growth. Overall, planted grass species performed better in loam soils (median 45% cover) than in high clay (black cotton) soils (median =40% cover). Similarly planted grasses performed better than other grass species and forbs in both loam and black cotton soils. These experiments are aimed at informing landscape level grassland restoration for hirola, where tree encroachment has suppressed their recovery for nearly three decades.

In addition, we rolled out larger restoration plots in core areas of hirola to test the effeteness of applied nucleation in restoring grasslands for hirola. Nucleation plantings is a concept that entails dense plantings of small areas with several species (grass etc), usually with the several species distributed like stepping stones of varying sizes. From these experiments, we observed less erosion in the areas where we have cut down tree branches and then placed on the ground as carpets. We also recorded more above ground biomass, forbs and perennial grasses including the planted grasses in the cleared patches compared to the control plots (cleared only and no seeding). Grasses were found to grow beneath the cut tree branches, with fallen trees forming litter under the tree branches.
Most importantly, hirola and other grazers (e.g. zebra) were attracted by these restored sites. As such, we quantified the relationship between grass species and two components of hirola habitat use: (i) relative probability of encountering hirola in improved vs not improved habitat types, (ii) Actual time hirola spent in each of these sites. Surprisingly, hirola is responding very well to restored habitat and spending approximately 10 times more in improved habitat compared to control sites. Equally seeding alone improved vegetation density by more than three times. While our restoration effort is long-term, manual removal of trees at a larger scale is expected to improve the availability of grass by 50% in the next two years. This means in the short and long term, hirola and livestock will have sufficient forage and improved habitat translating to productive and increased numbers. These habitat improvement efforts will coincide with the release of the first sanctuary bred hirola into restored areas hence high chance of survival.


Read 1939 times Last modified on Tuesday, 17 October 2017 11:16