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The biological traits of different species usually predispose them to dissimilar levels of extinction risk. Accordingly, we analysed genetic variation and population genetic structure of two endangered forest monkeys to determine how they were influenced by habitat change. The Tana River red colobus and mangabey are of similar body size, are sympatric and endemic to forests in Kenya. The mangabey is frugivorous, terrestrial and exhibits female philopatry but the colobus is folivorous, arboreal and both sexes exhibit natal dispersal. We predicted that both species would have low genetic variation due to high genetic drift, and possible inbreeding, because their populations are relatively small and subdivided in forest fragments. Nevertheless, we expected the mangabeys to have a higher genetic variation because they have a larger population, and their higher vagility would enhance gene flow. Thus, we expected a stronger population genetic structure in the colobus because lower vagility would constrain dispersal and increase genetic differentiation. Finally, we expected both species to exhibit isolation by distance due to greater gene flow among populations in close geographic proximity. We genotyped 146 colobus and 76 mangabeys with nine microsatellite markers and found that both species had relatively high heterozygosities but low allelic richness. Furthermore, allelic richness, heterozygosity and genetic differentiation were all higher in the mangabey and only the mangabey exhibited isolation by distance. Taken together, our results suggest that species with divergent behavioral ecologies may exhibit differential vulnerabilities to genetic erosion due to habitat change. [ABSTRACT FROM AUTHOR]

Institutional innovation in providing inputs and services is a central element for smallholder development. Agroforestry is an important income generating activity for millions of smallholders in the tropics, yet access to quality planting material-germplasm-of valuable tree species remains a major hurdle for improving farm productivity. We discuss requirements and possibilities for institutional innovation in developing more efficient delivery systems for tree germplasm as one aspect of improved input supply. We describe a simple model for delivery to farmers that identifies the major types of germplasm sources and discuss how this model can be used to identify relevant interventions to address bottlenecks in current systems. Our analysis leads to eight input supply configurations for smallholder agroforestry, typified by three major models. Lessons from the evolution of smallholder crop seed delivery systems can be applied to tree germplasm supply and indicate that a commercial, decentralised model holds most promise for sustainability. However, current emphasis in agroforestry on government and NGO models of delivery hinder the development of this approach. The application of prevailing classification approaches may also create a barrier to the development of appropriate supply systems that effectively service smallholders. An important implication of our analysis is that current actors in agroforestry input supply systems must redefine their roles in order for effective delivery to take place. We chose a case study from Kenya to illustrate our points. [ABSTRACT FROM AUTHOR]

We used mtDNA sequence data from the Tana River red colobus and mangabey to determine how their population genetic structure was influenced by dispersal and habitat fragmentation. The colobus and mangabey are critically endangered primates endemic to gallery forests in eastern Kenya. The forests are a Pliocene-Pleistocene refugium that has recently undergone significant habitat loss and fragmentation due to human activities. We expected both primates to exhibit low levels of genetic diversity due to elevated genetic drift in their small populations, and to show a strong correspondence between genetic and geographic distance due to disruption of gene flow between forests by habitat fragmentation. Additionally, because mangabey females are philopatric, we expected their mtDNA variation to be homogeneous within forest patches but to be heterogeneous between patches. In contrast, colobus have a female-biased dispersal and so we expected their mtDNA variation to be homogeneous within and between forest patches. We found high levels of haplotype and nucleotide diversity as well as high levels of sequence divergence between haplotype groups in both species. The red colobus had significantly higher genetic variation than the mangabey did. Most of the genetic variation in both primates was found within forest fragments. Although both species showed strong inter-forest patch genetic structure we found no correspondence between genetic and geographic distances for the two primates. We attributed the high genetic diversity to recent high effective population size, and high sequence divergence and strong genetic structures to long-term habitat changes in the landscape. [ABSTRACT FROM AUTHOR]