Conservation science is born of an inherent conflict. On one hand it is based in science, an objective, value-free search for truth that leads to general laws, with no a priori desire for particular outcomes. On the other hand it is clearly driven by value–laden goals related to making the human–nature relationship an enduring one. In contrast to an objective science, particular outcomes – such as preservation of biodiversity and protection or restoration of functioning ecosystems – are clearly pursued in conservation. The result is a sometimes uncomfortable merging of two human endeavours – one objective and one value-laden – that are inherently antagonistic and can result in tension. To make this tension creative, rather than destructive, we need to understand how both components are necessary and synergistic in forming a complete conservation science.

By the early 1990s only 90 individuals of the endangered Arctic fox subspecies Alopex lagopus semenovi, remained. These few survivors are confined to Mednyi Island, part of the Commander Islands chain. The formerly abundant population crashed in the mid-1970s and has never recovered from only 10–15 per cent of its former numbers. In 1983 the Mednyi Island foxes were listed in the Russian Red Data Book. Their demise coincided with the arrival of mange, introduced by seafaring trappers and caused by the mite Otodectes cynotis, which was associated with devastating cub mortality. In 1994, in a unique intervention, we sought to save the population by treating cubs with antiparasitic drugs. That summer, mortality was reduced. A census in 1995 suggested that over-winter survival was at least no worse, although it is too soon to judge whether this intervention can be a route to population recovery.

The ring-tailed lemur Lemur catta is generally considered to be a species of dry deciduous forest, gallery forest and spiny thorn scrub at relatively low altitudes. During a survey of the summit zone of the Andringitra Massif, one of the most climatically extreme areas on Madagascar, we recorded this species above the tree-line at 2520 m in an area composed mostly of exposed rock, low ericoid bush and subalpine vegetation. Information was collected on food plants consumed by this species. This pelage coloration of the local population of L. catta differed from museum specimens and photographs taken from other areas of this species's range. The taxonomic status of the Andringitra population is in need of further study.

Reports of the Tibet red deer, a subspecies of Cervus elaphus, have been so few in recent years that there were fears that the animal was extinct. A survey in a mountainous region of south-east Tibet in October 1995 found evidence that a few deer survive in one small area and possibly two others in high-altitude valleys of the tributaries of the Subansiri River. The most exciting finding of the survey, however, was an estimated 200-strong population of this deer in high rolling hills near the village of Zhenqi, north of the Yarlung Tsangpo River. This is the only known viable population of the deer and, although some hunting occurs, including by professional poachers from outside Tibet, the fact that it survives is an indication of the tolerance of the local people. The Tibet Forest Bureau has agreed to fund guards and to establish a reserve for the deer in co-operation with local people.

Brazilian crocodiles are threatened by gold mining and related mercury- and lead-contamination of animals and their habitat, deforestation, increasing use of land for agriculture and destructive forestry, increased human incursions, and commercial and subsistence hunting for skins and meat. Contaminated meat is consumed by local people and miners, and meat and skins are exported to global markets. Already depleted black caiman Melanosuchus niger populations are seriously affected.

This paper presents the results of surveys conducted in 1994 to establish the population size and density, and conservation status of red howler monkeys Alouatta seniculus insulanus and white-fronted capuchin monkeys Cebus albifrons trinitatis in the Trinity Hills, Bush-Bush and Central Range Wildlife Sanctuaries of the Republic of Trinidad and Tobago, West Indies. Populations of the red howler and capuchin monkey have declined by about 25 per cent in Bush-Bush Wildlife Sanctuary over the past 25 years. This decrease was attributed to intensive hunting pressure and habitat destruction. These factors have also caused monkey population declines in the Trinity Hills and Central Range Wildlife Sanctuaries. Recommendations are presented for the local government to enhance the protection of wild monkeys and their habitats in Trinidad.