Management Of Large Mammals In African Conservation Areas PDF Download

This dissertation assesses aspects of biodiversity conservation in East Africa from three angles: 1) protected area representation and effectiveness, 2) wildlife corridors, and 3) large mammal sensitivity to humans in savanna ecosystems. I first consider protected area representation and effectiveness across East Africa (Burundi, Kenya, Rwanda, Tanzania and Uganda – 1,722,114 km2) (Riggio et al. under review; Chapter 1). Protected areas are the cornerstone of in situ conservation and their effective management is critical for maintaining biodiversity in the long term. East Africa contains a network of 1,776 protected areas (including 186 protected areas with IUCN management categories I through IV) covering more than 27% of its terrestrial area. However, many of these protected areas were established before the advent of modern conservation biology, and several are now threatened by land conversion fueled by rapid human population growth. Here I document the extent to which East African protected areas encompass ecoregions and endemic terrestrial vertebrate taxa and, using new land conversion data derived from high spatial resolution satellite images, I assess how they have been encroached upon by agriculture and other land use. I find that East African protected areas cover most ecoregions well (>10% threshold of ecoregion representativeness set by the Convention on Biological Diversity’s Aichi Target 11), some very well (>90% - Rwenzori-Virunga montane moorlands and East African montane moorlands), but Masai xeric grasslands and shrublands, Somali Acacia-Commiphora bushlands and thickets, and Southern Swahili coastal forests and woodlands are poorly represented. While protected areas cover the geographic distribution of most East African endemic and near-endemic terrestrial vertebrate species, they cover less than 10% of the distribution of 47 endemic species (16% of the 303 endemic species). Encouragingly, East African protected areas are largely unconverted to human use, with only 6.8% of their total area experiencing land conversion (1.6% for strict protected areas). I then aim to assess the current state of wildlife corridors across Tanzania (Riggio & Caro 2017; Chapter 3) using Wami-Mbiki Wildlife Management Area as a test case (Riggio et al. 2018; Chapter 2). Wildlife corridors can help maintain landscape connectivity but novel methods must be developed to assess regional structural connectivity quickly and cheaply so as to determine where expensive and time-consuming surveys of functional connectivity should occur. I use least-cost methods, the most accurate and up-to-date land conversion dataset for East Africa, and interview data on wildlife corridors, to develop a single, consistent methodology to systematically assess wildlife corridors at a national scale using Tanzania as a case study. My research aims to answer the following questions; (i) which corridors may still remain open (i.e. structurally connected) at a national scale, (ii) which have been potentially severed by anthropogenic land conversion (e.g., agriculture and settlements), (iii) where are other remaining potential wildlife corridors located, and (iv) which protected areas with lower forms of protection (e.g., Forest Reserves and Wildlife Management Areas) may act as stepping-stones linking more than one National Park and/or Game Reserve. I identify a total of 52 structural connections between protected areas that are potentially open to wildlife movement, and in so doing add 23 to those initially identified by other methods in Tanzanian Government reports. I find that the vast majority of corridors noted in earlier reports as “likely to be severed” have actually not been cut structurally (21 of 24). Nonetheless, nearly a sixth of all the wildlife corridors identified in Tanzania in 2009 have potentially been separated by land conversion, and a third now pass across lands likely to be converted to human use in the near future. My study uncovers two reserves with lower forms of protection (Uvinza Forest Reserve in the west and Wami-Mbiki Wildlife Management Area in the east) that act as apparently crucial stepping-stones between National Parks and/or Game Reserves and therefore require far more serious conservation support. Methods used in this study are readily applicable to other nations lacking detailed data on wildlife movements and plagued by inaccurate land cover datasets. My results are the first step in identifying wildlife corridors at a regional scale and provide a springboard for ground-based follow-up conservation. Finally, I evaluate the sensitivity of the larger mammals of savanna Africa to humans (Riggio et al. 2018b; Chapter 4). Habitat loss and overexploitation are driving differential declines in vertebrate taxa but variation in responses means it is often difficult to determine where to place conservation effort. Here I present an easy-to-use method to rank the relative sensitivities of the larger mammals of savanna Africa to human activities in order to prioritize conservation activities. I first make coarse predictions about susceptibility based on species’ intrinsic ecological traits. Next I determine actual presence of these species using transect surveys within the heavily impacted Wami-Mbiki Wildlife Management Area in Tanzania, by conducting interviews outside this protected area, and monitoring changes in populations within both of these zones. Finally I use these combined data to derive a sensitivity measure than we compared to prior predictions about the susceptibility. My empirical measure of sensitivity to humans is positively correlated with species’ body mass, and home range size. The empirical data allow me to categorize these species into those that are very sensitive to humans (species in danger), sensitive to humans (human avoiders), moderately common species (human adapters), and those that are positively impacted by people (human exploiters). Conservation efforts aimed at human avoiders and species in danger are likely to have disproportionate payoffs in protecting larger mammal assemblages in Africa as these more sensitive species likely act as focal species (sensu Lambeck 1997) for management efforts. My measures combine easy-to-conduct transect data with interview data, and evaluate temporal changes to reach conclusions about how sensitive large mammals are to humans. These methods can be applied in other regions where studies are beginning to examine wildlife declines outside protected areas. Literature Cited: Riggio, J., Hijmans, R., Jacobson, A., and Caro, T. (under review). The protected areas of East Africa.Riggio, J. and Caro, T. (2017). Structural connectivity at a national scale: wildlife corridors in Tanzania. PLoS ONE. 12:e0187407Riggio, J., Mbwilo, F., Van de Perre, F., and Caro, T. (2018). The forgotten link between northern and southern Tanzania. African Journal of Ecology. DOI: 10.1111/aje/12533 Riggio, J., Kija, H., Masenga, E., Mbwilo, F., Van de Perre, F., and Caro, T. (2018). Sensitivity of Africa’s larger mammals to humans. Journal for Nature Conservation. 43:136-145.