Rainfall pattern and nutrient content influences on African elephants’ debarking behaviour in Samburu and Buffalo Springs National Reserves, Kenya
Date
2011Author
Ihwagi, Festus Wanderi
Chira, Robert Mutugi
Kironchi, Geoffrey
Vollrath, Fritz
Douglas-Hamilton, Iain
Type
ArticleLanguage
enMetadata
Show full item recordAbstract
The magnitude of debarking by elephants was investigated
in Samburu and Buffalo Springs National Reserves. About
1617 plants were monitored for debarking intensities for
6 months spanning through dry and wet seasons.
Debarking indices ranged from no debarking at all during
the wet months to complete stem girding at the height of
the dry season. A negative correlation was found between
rainfall and debarking indices. It was hypothesized that
nutrient content of the bark influenced the magnitude to
which trees were debarked. Bark samples were collected
from least, moderate and intensely debarked plants
throughout the 6 months. These were analysed for calcium
(Ca), sodium (Na), phosphorus (P), magnesium (Mg),
potassium (K), nitrogen (N), iron (Fe), copper (Cu), manganese
(Mn) and zinc (Zn). Significant positive correlations
were found between debarking intensity and each of the
nutrients N [crude protein (CP)], P, K and Zn. Bark was
found to be richest in CP and Calcium. Neutral detergent
fibre content was on average 67%. Monthly variations in
nutrient composition were minimal. Acacia elatior, the
most preferred species had significantly higher quantities of
each of the four elements N, P, K and Zn than Acacia
tortilis, the second most preferred woody species.
Citation
African Journal of EcologyPublisher
2011 Blackwell Publishing Ltd, Afr. J. Ecol School of biological sciences