Expanding human populations have appropriated land that used to be available to wildlife. Such land was either converted to another land use that was: more economically viable, not protected for wildlife in any way, minimally protected, lost effective protection status by lack of enforcement, or was abandoned by wildlife authorities unable to operate during times of civil strife or other factor leading to a lack of resources. The lions’ prey species are also attractive for human consumption, and utilization of game species is rife throughout Africa. Such utilization is largely illegal, but has assumed commercial proportions; whilst prosecution is practically non-existent.
As habitat is lost lion populations are becoming increasingly fragmented within insular reserves closed to natural immigration [1-2]. Whereas previously natural re-colonization had been possible the opportunities for such events today are greatly reduced or non-existent. This trend increasingly applies even within countries with previously substantial lion populations outside protected areas. Natural re-colonization increasingly requires emigration from an occupied area through an inhospitable habitat matrix [3}.
Kenya, Tanzania, Botswana, Mozambique and possibly other lion range states still maintain many lion populations living outside strictly protected areas. As individual lions in protected areas naturally disperse, such movements often mean those lions move into surrounding areas that have no connectivity to other habitat patches and/or into marginally suitable habitat, bringing them into conflict with human populations in those areas.
In reality, local communities are often against the maintenance of any predator or other species that threatens human lives and livestock, crops and agriculture.
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 Packer C, Pusey AE, Rowley H, Gilbert DA, Martenson J, O’Brien SJ (1991) Case study of a population bottleneck: lions of the Ngorongoro crater. Conservation Biology 5: 219–230 (pdf)
[3} Ebenhard T (1991) Colonization in metapopulations: a review of theory and observations. Biological Journal of the Linnean Society 42: 105–121. (pdf – purchase required)
Isolation of African protected areas (pdf)
Newmark WD (2008) Front Ecol Environ 6(6): 3210-0328
Wildlife and food security in Africa (html)
Ntiamoa-Baidu Y (1997) Food and Agriculture Organization of the United Nations, Rome 1997
Relative densities of mammals in response to different levels of bushmeat hunting in the Udzungwa Mounatins, Tanzania (pdf)
Topp-Jorgensen E, Reinhardt Nielson M, Marshall AR, Pederson U (2009). Tropical Conservation Science 2 (1) 70-87
Determinants of attitudes towards predators in central Kenya and suggestions for increasing tolerance in livestock dominated landscapes (pdf)
Romanach SS, Lindsey PA, Woodroffe R (2007) Oryx 41 (2): 185-195