|Journal||Ph.D. thesis in Ecology for L'Universite Claude Bernard-Lyon|
One of the main challenges for endangered species protection in Africa is to find a sustainable way of integrating objectives of nature conservation with the economic development needs of the local human population. Last West African giraffe population, Giraffa camelopardalis peralta, lives in Niger. These giraffe are unique for several reasons: (i) they represent the only population of peralta sub-species, and (ii) they live in an area densely populated by humans, (iii) which is unprotected and (iv) without predators. In 1996, this giraffe population was almost extinct, with only 50 individuals remaining. Despite signs of population recovery, the sub-species has been classified as “endangered” according to the IUCN Red List assessment criteria. What are the limiting factors for the maximum annual growth rate that has been recorded over the last years in the population? Are favorable conjunctures to this population increasing sustainable?
Assessing population conservation requires knowledge of demographic parameters and understanding of the environmental factors driving its spatial distribution. Census data from 1996 to 2009 were analyzed and then demographic parameters through a capture-mark-recapture method were determined. A multi-scale spatial analysis allowed me to determine giraffe distribution at both population and herd level (through observations), and to measure habitat selection at the individual level (through GPS satellite collars).
Census results, almost exhaustive from 2005 to 2008 highlighted an annual growth rate of 12%. This is the maximum growth rate for a giraffe population, and fits with the theoretical maximum growth rate for the species.
At the population and herd level, giraffe distribution patterns are driven by food availability. These food resources are seasonally distributed and impacted by human activities. Habitat selection shows that during dry season, giraffe avoid village proximity, where disturbance is high. However, at night giraffe move closer to villages where food resource quantity and quality are higher (tree density, granaries). The use of bean field crop suggests that some cultivated crops gain in attraction and even become favourable to giraffe. This might explain the increase of human-giraffe conflicts. My results clearly show the importance of taking human activities and perception into account, when assessing wildlife conservation strategies.
Key words: giraffe, demography, habitat selection, home range, human-wildlife conflicts
Author: Jean-Patrick Suraud
Journal: Ph.D. thesis in Ecology for L'Universite Claude Bernard-Lyon
|Suraud - 2006 - Identifier les contraintes pour la conservation de.pdf||Download|