There are four known species of Isoetes (Family Isoetaceae) from China: I. hypsophila, I. sinensis and I. yunguiensis on the mainland, and I. taiwanensis on Taiwan. In a 4-year study we documented the distribution and habitat characteristics of all four species and evaluated their conservation status using IUCN criteria. All four species are facing a high risk of extinction and should be categorized as Critically Endangered on the IUCN Red List. Habitat degradation and loss, water pollution and eutrophication, competitive exclusion, and human disturbance are the main factors causing the decline and extirpation of Isoetes. Only I. taiwanensis is protected in situ in Yangmingshan National Park on Taiwan. None of the species or habitats of Isoetes on mainland China are presently protected, although all species have been designated by the government as State Key Protected Wild Plants. Our results suggest that conservation strategies should be implemented urgently, particularly on the mainland.

The Vulnerable endemic Kloss's gibbon was surveyed throughout the Mentawai Islands, Sumatra, Indonesia, using a call-based method. Populations were estimated by extrapolating from local densities using recent assessments of remaining forest cover. About 20,000–25,000 Kloss's gibbons remain in nearly 3,000 km2 of forest (about 40% of the islands' total area). This number is markedly lower than a 1980 estimate of 36,000 on the northernmost island of Siberut. Conservation action to preserve the remaining populations should focus on strengthening the enforcement of regulations in Siberut National Park, formally protecting the Peleonan forest in north Siberut, and cooperating with a logging company in North and South Pagai to protect the populations in the company's self-established conservation and buffer areas.

The unique primates of south-eastern Madagascar face threats from growing human populations. The country's extant primates already represent only a subset of the taxonomic and ecological diversity existing a few thousand years ago. To prevent further losses remaining taxa must be subjected to effective monitoring programmes that directly inform conservation efforts. We offer a necessary first step: revision of geographic ranges and quantification of habitat area and population size for diurnal and cathemeral (active during both day and night) lemurs. Recent satellite images are used to develop a forest cover geographical information system, and censuses are used to establish range boundaries and develop estimates of population density and size. These assessments are used to identify regions and taxa at risk, and will be a useful baseline for future monitoring of habitat and populations. Precise estimates are impossible for patchily-distributed taxa (especially Hapalemur aureus, H. simus and Varecia variegata variegata); these taxa require more sophisticated modelling.

The European population of Dupont's lark Chersophilus duponti, restricted to Spanish steppe, was estimated to be 13,000 pairs in c. 50 populations in 1988. There is, however, recent evidence that this number was overestimated because of the previous use of line transects for estimating population sizes. In 2002–2004 we surveyed 34 previously known local populations in patches of variable size across half of its Spanish distribution. We found 13 (38%) local populations to be extinct, and a total of only 283–339 territories in 17 of the extant populations, seven of which held <5 territories. This census contrasts dramatically with the estimate of c. 3,000 pairs in the same populations in the 1980s. We estimate that the present Spanish population is c. 1,300 pairs. The discrepancy between this and earlier estimates is partly but not entirely due to previous overestimations. Habitat loss due to ploughing, and possibly habitat degradation and the resulting stochastic extinction of small and isolated populations, have contributed to the species' decline. Urgent research is needed to design and manage an adequate network of steppe patches that will ensure the long-term existence of this species. We recommend that Dupont's lark be categorized on the IUCN Red List as Endangered, both globally and nationally within Spain.

Morangaya pensilis is an endemic monotypic cactus genus from the southern part of the Baja California Peninsula, Mexico. Previously known only as scattered individuals occurring at a very low density in the highest areas of Sierra de La Laguna, the occurrence of a relatively more dense population (4–7 plants per 250 m2) is reported on Sierra Cacachilas, c. 40 km to the north. Disturbance to the species' habitat includes fragmentation, illegal collection and trade, and land use changes, especially to farming and cattle ranching. Seeds collected from Sierra Cacachilas had a relatively high viability (92%) but recruitment (of 2-month old seedlings) in the area was relatively low, despite above average rainfall in the year of measurement. M. pensilis is eligible for inclusion in Mexico's list of threatened species and fulfils the requirements for categorization as Vulnerable on the IUCN Red List. Management activities that are already taking place in this area include restrictions on cattle and goat grazing and consideration of areas suitable for translocation of the species.

The recently revised IUCN Technical Guidelines on the Management of Ex Situ Populations for Conservation represent an attempt to synthesize current thinking on the strategic application of ex situ conservation for the maximum benefit of both threatened species and habitats. We review this document as a means of assessing major changes in the application of ex situ conservation. We identify a number of major themes. These include the need for the integrated management of wild and captive populations, expansion of ex situ capacity in terms of institutional facilities and breadth of taxonomic experience, an important emphasis to be given to the need for in-country conservation initiatives, and the need to comply with national and international legal structures, most notably the Convention on Biological Diversity.

We report on seven new localities for Mantella bernhardi, a Malagasy poison frog that was previously known only from a single site. This species has been considered threatened with extinction because of ongoing habitat destruction and collection for the pet trade (up to c. 3,000 specimens per year). The new localities considerably extend the known range of this species, which has now been documented from c. 21.00° to 24.15°S and 47.00° to 48.00°E, and over 60–629 m altitude. Two of the sites are within protected areas (Ranomafana National Park and Manombo Special Reserve). An overlap analysis of the potential distribution area of the species, based on the extent of remaining primary vegetation, indicates that the habitat of M. bernhardi in south-eastern Madagascar is fragmented and populations may be relatively small and isolated. We support the IUCN Red List category of Endangered for this species and highlight the need for detailed studies of its populations.

Populations of harlequin frogs Atelopus are declining throughout their geographical range. In Peru six of the 11 nominally described species are Critically Endangered, and there are at least 17 undescribed additional forms (all representing apparently distinct species), the conservation status of which is unknown. Most Atelopus taxa in Peru have relatively small geographical ranges, some known only from single populations, and have only a limited chance of survival. Conservation will require: (1) improvement of the faunistic and taxonomic knowledge of the genus, (2) field surveys, including in remote areas, (3) assessment of all species and populations for chytridiomycosis and research on the agent's biology, (4) ex situ conservation measures to facilitate later reintroduction, and (5) involvement of national and international conservationists and local people.

I present data on the decline of Hose's langur Presbytis hosei over a 7-year period in the Kayan Mentarang National Park in the remote northern part of East Kalimantan, Indonesia. In 1996 Hose's langurs were among the most common primates in the Nggeng Bio valley, occurring at densities of over two groups km−2, and could be observed almost daily. A repeat census of the same area in 2003 indicated that these densities had dropped by 50–80%, and observation of the species in the valley had become a rare occurrence. During the 7-year period the forest remained in a relatively pristine condition but, despite being part of a National Park, active protection of the valley was lacking and hunting was common. From interviews with local hunters and Park staff it appeared that hunting for bezoar stones (visceral excretions found in langurs and used in traditional medicine) was the primary reason for the observed decline in Hose's langur. In 1998 a merchant calling at a nearby village had expressed an interest in the stones and guaranteed to purchase them, and this sparked excessive hunting of Hose's langur in the area, to such an extent that 3 years later this hunting was no longer economically viable. This study demonstrates that, with increasing access to markets, hunting large vertebrates for medicinal purposes, even for short periods only, can have a dramatic impact on population numbers. In such cases, habitat protection alone does not guarantee preservation, and more active protection of wildlife is required.

Using the species-area correlation I predicted the percentage of endemic Amazonian mammals committed to extinction by 2020 as an outcome of deforestation resulting from the implementation of mega-infrastructure projects in the Brazilian Amazon. Simulations based on optimistic and non-optimistic deforestation scenarios showed a 2-fold and a 3-fold increase, respectively, in Amazonian mammals committed to extinction. The predicted number of threatened species by 2020 was 5–18% of the total number of endemic mammal species, depending on the scenario and equation used. This increase in extinction rates could be catastrophic for ecosystem stability in the Amazon because the loss of functional groups may produce a cascade effect of species extinctions.