Landscapes of Coexistence for terrestrial carnivores: the ecological consequences of being downgraded from ultimate to penultimate predator by humans

Fear of predation can have major impacts on the behaviour of prey species. Recently the concept of the ecology of fear has been defined and formalised; yet there has been relatively little focus on how these ideas apply to large carnivore species which, although not prey sensu stricto, also experience fear as a result of threats from humans. Large carnivores are likely also subject to a Landscape of Fear similar to that described for prey species. We argue that although fear is generic, ‘human‐caused mortality’ represents a distinct and very important cause of fear for large carnivores, particularly terrestrial large carnivores as their activities overlap with those of humans to a greater degree. We introduce the idea of a ‘Landscape of Coexistence’ for large carnivores to denote a subset of the Landscape of Fear where sufficient areas of low human‐caused mortality risk are present in the landscape for long term coexistence of large carnivores and humans. We then explore aspects of terrestrial large carnivore behavioural ecology that may be best explained by risk of human‐caused mortality, and how the nature of a Landscape of Coexistence for these large carnivores is likely to be shaped by specific factors such as habitat structure, wild and domestic prey base, and human distribution and behaviour. The human characteristics of this Landscape of Coexistence may be as important in determining large carnivore distribution and behavioural ecology as the distribution of resources. Understanding the Landscape of Coexistence for terrestrial large carnivores is therefore important for their biology and conservation throughout large parts of their remaining ranges. Synthesis The Landscape of Fear concept describing the relationship between predator and prey also applies to the relationship between humans and top carnivores. We synthesise current research to introduce the Landscape of Coexistence concept, arguing that top predators respond to the risks of human‐caused mortality through spatiotemporal partitioning of activities to reduce contact with people. The character of the Landscape of Coexistence may be more important than the distribution of resources in determining large carnivore distribution and behavioural ecology in human dominated landscapes. Understanding their behavioural responses to human threats is crucial to successful conservation of large carnivores.     

Stochastic acquisition of Qa1 receptors during the development of fetal NK cells in vitro accounts in part but not in whole for the ability of these cells to distinguish between class I-sufficient and class I-deficient targets.

Fetal mouse NK cells are grossly deficient in the expression of Ly49 molecules yet show a limited ability to distinguish between wild-type and MHC class I-deficient target cells. In this paper we report that during their development in vitro from immature thymic progenitors, a proportion of C57BL/6 fetal NK cells acquires receptors for a soluble form of the nonclassical class I molecule Qa1b associated with the Qdm peptide, but not for soluble forms of the classical class I molecules Kb and Db. The acquisition of these Qa1 receptors occurs in a stochastic manner that is strictly controlled by cytokines, and in particular is strongly inhibited by IL-4. All fetal NK clones tested, including those that lack detectable Qa1 receptors, express mRNA for CD94 and for both inhibitory and noninhibitory members of the NKG2 family. Fetal NK cells lacking receptors for Qa1 (and also for classical class I molecules) cannot distinguish between wild-type and class I-deficient blasts but, surprisingly, distinguish efficiently between certain wild-type and class I-deficient tumor cells. A variant line that lacks several members of the NKG2 family kills both types of tumor cell equally well, suggesting the existence of NKG2-containing inhibitory receptors that recognize as yet undefined nonclassical class I molecules of restricted distribution.     

Postmodernism and African conservation science

In Africa, the movement away from traditional protectionist conservation to community-based approaches is partially related to postmodernist influences. Proposed transfrontier conservation areas will incorporate local communities, and a clearer understanding of the limitations of community-based conservation is thus needed. The sustainability of community-based conservation projects is questioned on economic and other grounds, and many African countries lack the prerequisites (ecological, demographic and sociological) for successful programmes. The romanticisation of pre-colonial societies gives undue weight to traditional systems of resource management, and we challenge the postmodernist notion that traditional peoples practised sustainable harvesting of natural resources. It is suggested that this will occur only under unlikely conditions of low human population density, lack of access to modern technology, and limited exposure to consumerism. In agriculture, postmodernists interpret the overstocking of livestock as a rational socioeconomic response, thus giving the practice unjustified legitimacy. The allied proposition that peasants enjoy a rich diversity of farming practices is largely unfounded, at least in some parts of Africa. We conclude that postmodernist thinking has had a significant negative impact on conservation science in Africa, largely by marginalising the central issue of human population pressure. Towards more effective African conservation, we suggest roles for the ecologist, for the social scientist, and for the donor community.     

Molecular and morphological evidence for a Pleistocene radiation of laminate‐toothed rats (Otomys: Rodentia) across a volcanic archipelago in equatorial Africa

West African Mountains of the Cameroon Volcanic Line harbour two montane‐endemic species of laminated‐toothed rats (Otomys), which represent the most westerly occurrence of the genus. We explore here through mtDNA sequencing and cranial morphometrics the taxonomic status and phylogenetic relationships of O. burtoni (Mt Cameroon) and O. occidentalis (Mts Oku and Gotel). We conclude that both species are valid and can be discriminated by molecular data, as well as quantitative and qualitative cranial characters. From molecular data, O. occidentalis and O. burtoni are closest neighbours (p‐distance = 7.5–8.5%) and weakly associated sister species (suggesting a single West African radiation) and both are sister clades to a well supported clade of central, East and northeast African members of the O. typus s.l. and O. tropicalis s.l. species complexes from mountain ranges comprising the East African ‘Montane Circle’ and Ethiopian Highlands. Re‐evaluation of the evolutionary origins of the allopatric Otomys populations in equatorial Africa is undertaken in light of fossil evidence of a southern African origin of the genus. We can conclude that Otomys reached the Cameroon Volcanic Line via corridors of temperate grasslands during the Late Pliocene. Our data support the hypothesis that, following major peripatric speciation events at around 2.3 to 2.03 Ma (from East Africa into West and North Africa respectively), further speciation occurred across neighbouring mountain ranges in West, Central‐East and North‐East Africa. Estimated molecular dates of speciation events in Otomys reveal close congruence with well‐constrained geochronological estimates, pertinently the uplift of the Albertine Rift in the Early Pleistocene. These regional analyses reveal how peripatric speciation events established narrow‐range endemics of Otomys on principal stratovolcanoes across the East African plateau and Cameroon. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 113 , 320–344.