Despite heightened awareness of the need to find additional resources for tropical biodiversity conservation, and recognition that the benefits to populations in developed countries may be significant, very few empirical studies have been conducted to estimate these values. In this article, we report the results of a choice experiment survey that investigated the preferences of UK residents for the conservation of threatened wildlife in the Eastern Arc Mountains in Tanzania, part of the Eastern Afromontane “biodiversity hotspot”. We examine the sensitivity of values to species types, the number of species, the number of conservation sites and, more unusually, to potential substitutes/complements. Critically we find some evidence of coherency in preferences. Respondents are willing to pay significant, positive amounts to conserve charismatic and/or endemic species and are scope sensitive to the number of endemic species. In contrast, species which are neither endemic nor charismatic, and the number of conservation sites, do not contribute significantly to utility. Further, changing the overall scope of the ‘good’ is found to have a significant and differential impact on respondent's choices depending on the species type: as the availability of wildlife increases, we observe substitution effects for non-endemic charismatic species, and complementarity for endemic (non-charismatic) species.