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INFLUENCE OF CATTLE MANAGEMENT ON HABITAT SELECTION BY IMPALA ON CENTRAL KENYAN RANGELAND
Author(s) -
AUGUSTINE DAVID J.
Publication year - 2004
Publication title -
the journal of wildlife management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.94
H-Index - 111
eISSN - 1937-2817
pISSN - 0022-541X
DOI - 10.2193/0022-541x(2004)068[0916:iocmoh]2.0.co;2
Subject(s) - rangeland , dry season , habitat , acacia , livestock , nutrient , grazing , ecology , wet season , forage , shrub , biology , geography
In sub‐Saharan Africa, the widespread practice of corralling livestock overnight in thorn‐scrub “bomas” creates nutrient‐enriched patches within rangelands that can subsequently support unique plant communities for decades to centuries after boma abandonment. These nutrient‐rich patches (glades) may be preferentially used by native ungulates that coexist with livestock. To evaluate the potential link between cattle management via bomas and habitat for impala ( Aepyceros melampus ), I examined seasonal patterns of habitat selection by impala and landscape variation in grass nutrient content on a commercial cattle ranch in central Laikipia, Kenya. Studies using automated, infrared camera monitors showed that impala selected nutrient‐rich glades 2.6 times more frequently than surrounding Acacia bushland habitat during dry seasons, and 9.6 times more frequently during wet seasons. Significantly greater impala presence in glade versus bushland habitat during dry seasons suggests that impala presence may be related to reduced predation risk in shrub‐free glades. The large, significant increase in impala presence in glades from dry to wet seasons suggests that impala distribution also is linked to the availability of nutrient‐rich forage. In particular, grass nutrient analyses showed that wet‐season phosphorus (P) concentrations in grasses throughout the bushland landscape ( x̄ = 2,125 mg P/kg dry matter, varying from 1,789 to 2,922 mg P/kg across topographic positions and from 1,508 to 3,215 mg P/kg among grass species) were below recommended levels for pregnant and lactating ruminants, while mean P concentrations in glade grasses ( x̄ ± SE = 5,346 ± 2.92 mg P/kg) exceeded recommended levels. Results suggest that management to increase the relocation rate and distribution of current cattle bomas can have a positive, long‐term effect on the local distribution and abundance of impala.