Foreword One of the curiosities of eastern Nepal is a little-known will enable information about insectivores and tree shrews . insectivore known locally as or “water to contribute to such public information programmes. rat”. Knowing that its occurrence in the mountains to the Several of these projects have research components, and east of Mt. Everest, on the border with Tibet, was still these could be modified to incorporate appropriate only suspected, I spent several weeks in 1973 seeking to research into tree shrews and insectivores. confirm its occurrence there. With teams of local Sherpas, Other important research questions for which answers we trudged through many mountain torrents, turning might be sought could include: over rocks, searching for evidence, and setting live traps. Our efforts were finally rewarded by capturing one What role do insectivores play in maintaining the individual of this elegant little water shrew, with diversity of insect faunas? amazingly silky fur, webbed feet with fringes, and a paddle-like tail. The local people were well aware of the What role do moles and fossorial shrews play in the existence of this animal, though they paid little attention cycling of nutrients and water in forested ecosystems? to it because it was so innocuous and seemed to have so little to do with their affairs. How do tree shrews affect forest regeneration? Do In this sense, the Nepalese were no different than most they play any role in seed dispersal? Control insects other people in the world: insectivores are basically which prey on seedlings? unknown, unnoticed, and unloved. Yet as this Action Plan shows, these inconspicuous members of virtually Given that some populations of widespread species of all ecosystems throughout Eurasia are an important part shrews are becoming isolated, can these populations of the ecological fabric of the region. be used for the study of speciation? How, then, can greater public interest be aroused? Or at least, how can the conservation needs of these species What are the habitat requirements of key species, and be better incorporated in conservation plans? A useful what ar.e the management implications of these first step might be to identify which on-going or planned requirements ? If some species of tree shrews, for projects are taking place in important habitats of key example, prefer early successional habitats, how insectivores and tree shrews. For example, the Kerinci should protected areas be managed to maintain such region of West Sumatra is the site of a major project habitats? receiving funding by the Global Environment Facility (GEF). This region supports populations of the The kinds of research implied by such questions will endangered Sumatran water shrew, the the lead to an expanded appreciation of tree shrews and lesser gymnure, and no less than four species of tree insectivores, demonstrating that they have an ecological shrew as well. Thus insectivores and tree shrews can help importance far greater than is generally appreciated. I to enhance the importance of the Kerinci project for hope very much that this Action Plan leads quickly to global biodiversity, thereby contributing to an important new avenues of research that extend beyond basic international effort. taxonomy and distribution, and begin to investigate why Those interested in insectivores and tree shrews might insectivores and tree shrews are deserving of a significant then ask how projects already planned or under way investment by people in their conservation. might be modified to better address the needs of insectivores and tree shrews. Many of these projects Jeffrey A. include public information components, so those Chief Biodiversity Officer interested in these animals should devise approaches that IUCN, Gland, Switzerland iv This Action Plan addresses the conservation needs of The most important single threat to insectivores and two unrelated groups of small mammals: the tree shrews is habitat destruction. This takes many forms: (non-volant mammalian insectivores) and Scandentia in western Europe, for example, removal of hedgerows, (tree shrews) of Eurasia. It provides a review of what is expanding road networks, intensive cultivation with currently known about the taxonomy, distribution, widespread use of fertilizers and pesticides, and drainage conservation status and requirements of almost 200 of wetlands is having a noticeable impact on the numbers species. In assessing and evaluating these criteria, this and distribution of many species. Water pollution, Action Plan constitutes a first attempt to identify and combined with the construction of hydro-electric dams prioritise species in terms of the degree of threat and need and canals, threatens aquatic species throughout the for conservation action. In addition, and through a series region. Wetland drainage is also a major problem in of specific recommendations, it seeks to stimulate further south-east Asia. Of greater consequence in this region, activities in order to promote a greater awareness of the however, is the level of human encroachment into tropical extent of the threats facing certain species and the need forests; slash-and-burn cultivation and logging are for conservation action. destroying vast areas of prime habitat for many species. Insectivores are among the most numerous and Although little evidence is available on the effects such widespread small mammals of the Eurasian region. For clearance may have on insectivore and tree shrew the purpose of this review, 180 species have been populations, it is highly likely that the combined effect of considered. The tree shrews form a separate, cohesive these processes could, in the long-term, lead to serious group of 19 species and are confined entirely to South habitat fragmentation and isolation of small, vulnerable and south-east Asia. Although unrelated, insectivores populations. Species at particular risk are those with and tree shrews have a number of physical and behavioural already restricted distributions as well as the many features in common: both groups exhibit a monospecific genera covered in this Action Plan. primitive features, such as simplified dentition; all are Perhaps the greatest problem in formulating predominantly insect-eating animals; and forests (both conservation recommendations for insectivores and tree tropical and temperate) are one of the most important shrews is the current lack of data on the ecology, distribution habitats of both groups. Insectivores, however, are not and conservation status of the vast majority of species. only confined to forests: many are fossorial, aquatic or The secretive nature of a great many of these animals has terrestrial, living under a wide range of climatic and meant that vital information such as the extent of a altitudinal conditions. They therefore face a much broader species’ range or population size is often lacking, or that range of potential threats than tree shrews. few details exist on their natural history, ecology or In spite of their ecological and evolutionary conservation status. Using the most recent guidelines importance, insectivores and tree shrews remain some of prepared by IUCN on how to identify threatened species, the least well-known mammals. The majority of species this report demonstrates that many species are endangered are relatively unimportant to humans in economic terms; or threatened: 13 species have even been classified as a limited number have been trapped for their fur or as a “Critically Endangered” (Table 1). The current lack of source of food, and only a few are considered pests. As reliable field data almost certainly prevents the most species are nocturnal, or secretive in other ways, identification of other potentially threatened species. It many people are often unaware of the existence of these also impedes the formulation of definite conservation species. Tree shrews, perhaps the most obvious and actions. On occasion, this problem is further compounded visible of the two groups, are an exception but until by uncertainties regarding taxonomic status. Such recently have been almost totally ignored by field limitations hinder action that might help identify impending ecologists. In terms of their biomass, however, all of threats to a given species and its habitat, and enable these species fill a major ecological role as predatory remedial action to be taken. For these reasons, threats to small mammals. Many also fill a range of unique niches. insectivores and tree shrews often go unnoticed until it is Yet, because these are not high profile animals, they are too late to act. Future emphasis should be given to conducting often overlooked in surveys when conservation or additional field surveys to prepare and implement specific development plans are being drawn up for a region. For conservation programmes of these species and their habitats. these reasons it is essential that the ecological Despite the limitations imposed by the current lack requirements of these species be determined and a greater of information on many species, this Action Plan still awareness generated of their conservation needs. has an important role to fulfil in highlighting the need V Acknowledgements The compilation of this Action Plan could not have been those of many other experts, have helped to clarify the achieved without the assistance of the members of ITSES mystery of small mammal taxonomy and has meant that the Insectivore, Tree Shrew and Elephant Shrew this work could become a reality and not