Surveys of river birds were made in north-west Argentina in October 1993 and in southern Bolivia in December 1994. Data were collected on foraging behaviour, breeding biology and breeding abundances of the Rufous-throated Dipper Cinclus schulzi (a threatened species) on three river systems in Tucumán and Jujuy provinces in Argentina and on two river systems in Tarija department in Bolivia. Rufous-throated Dippers foraged from wetted rocks and when standing in water in riffles and on the edges of cascades and waterfalls; swimming or diving was not observed. Five nests were found in Argentina, two of which were incomplete. One had a clutch of two eggs and another contained two well-grown, feathered nestlings; the fifth was inaccessible. These records indicate that breeding starts early in the Argentinian spring. Nests of adjacent pairs of Rufous-throated Dippers were from c.650–1,200 m apart. Juvenile plumage resembles that of the adult. Some information is provided on the biometrics of seven birds caught in mist-nets, and on vocalizations and on the relative abundance of dippers, Torrent Ducks Merganetta armata and two species of Cinclodes. Possible threats to rivers within the range of the Rufous-throated Dipper include reservoir construction, hydroelectric and irrigation schemes, eutrophication, deforestation and stock-grazing. Pollution, reduced flows and river channel modification are more prevalent at lower altitudes below the breeding range of the Rufous-throated Dipper.

Twenty-eight predominantly tropical bird species have ranges that only just extend into the north-eastern part of South Africa, mainly within the Kruger National Park (KNP). These species are listed as “rare” (200 breeding pairs) in the South African Red Data Book (Brooke 1984). This study assesses the extent to which six of these rare bird species represent viable populations in the KNP. Grid squares in the KNP (2.5 × 2.5 miles) were visually assessed according to several bird habitat parameters. Bird records were also plotted on this grid system and habitat associations were identified for each species. This allowed for the measurement of total suitable habitat within the KNP for each species. Bird densities within known habitat were determined using spot-mapping and fixed-distance strip-transect techniques. Estimated population sizes for each species were obtained by extrapolating density estimates to total suitable habitat. Of the six study species, Arnot's Chat, Rudd's Apalis, Wattle-eyed Flycatcher and Tropical Boubou are likely to occur in sufficient numbers to constitute viable populations within the KNP, with estimated population sizes of 1,394, 4/758/ 2,070 and 10,450 birds respectively. The populations of White-crowned Plover and Long-tailed Starling are probably too small to be viable in the long term, with estimated population sizes of 305 and 382 birds respectively. The results presented here are testable and can be used as a baseline for future monitoring.

The avifauna of the environs of North-western Peru Biosphere Reserve (NPBR) is herein catalogued. This reserve embraces the largest example of protected Neotropical Pacific xeric forests, a habitat complex much scarcer than rainforests. NPBR is very important conservationally because much of the adjoining dry-forest region of south-western Ecuador has been denuded. Exact locality records and their specific literature sources are furnished for North American migrants and those species which have inhabited the vicinity of NPBR but have not been reported there by the authors of reference books that address avian geography. For each tabulated avian species, the earliest attribution or one of the earliest attributions for a specific record of that taxon in the environs of NPBR is provided. Also, 16 species that are threatened, or are endemic to a short strip of extreme south-western Ecuador and north-western Peru, are noted.

The rainforest avifauna of south-eastern Cameroon is poorly known. In one of the first surveys of birds from this region, we report on bird species netted and observed in the Lac Lobeke Reserve. We document 11 minor range extensions, including that of the extremely rare Zenker's Honeyguide Melignomon zenkeri. The abundance of several rare species of birds and mammals in the area, in addition to low human densities and relative inaccessibility, should make the Lac Lobeke region a priority in conservation efforts. Currently, large logging operations and the commercial exploitation of wildlife threaten the fauna of the region.

The montane forests of the Darién highlands in eastern Panama and adjacent Colombia embrace the entire ranges of 11 species of bird. By calculating the area which each of these species occupies, a reassessment of their status (using the new IUCN criteria) shows that four should be added to the globally threatened list, on the basis of their ranges being less than 100 km. Although the area which these birds occupy is protected within national parks, a number of threats appear to be compromising their long-term survival, and thus the Darien region urgently requires further conservation attention.

When formulating conservation priorities, conservation biologists often rely on published lists of species-level taxa. This paper discusses the nature and taxonomic status of “species” and “subspecies” and different ways of defining “species”. Species are here taken to be terminal and evolutionarily independent units which are qualitatively diagnosable and reproductively cohesive; genealogical biodiversity is thus taken for what it is in the first place, namely the observable result of evolutionary history, an approach which has become known as the phylogenetic species concept (PSC). In contrast to the widely applied Mayrian or “biological” species concept (BSC), no inferences are made about how the degree of morphological differentiation of allopatric but seemingly closely related taxa translates in the absence or presence of reproductive isolation. Many diagnosably distinct endemic island taxa have traditionally been treated as “subspecies” of widespread “polytypic biological” species. At the same time, the “subspecies” category is also used to name arbitrarily delimited sections of intraspecific clinal variation. Thus, the “subspecies” category subjects entirely different evolutionary phenomena to the same hierarchical level through the use of trinomials. Nevertheless, and despite the discrepancy in ontological status among its contents, “subspecies” are usually considered to be of lower evolutionary and/or conservation status than “species” and this has resulted in low conservation priorities allotted to diagnosably distinct island endemics, many of which have traditionally been considered to be “merely Mayrian subspecies”. This has been recognized by some authorities who, because of the threatened status of certain island taxa, advocated treating them binomially in order to generate appropriate conservation measures to save them from extinction, without however justifying their action by any sort of phylogenetic reasoning. Although well intended and sometimes quite successful as regards the follow-up by conservationists, this demonstrates the arbitrary manner in which “species” can be defined under the BSC. Some examples of endemic taxa from eastern Atlantic islands are discussed, demonstrating the way “list thinking” and the lack of phylogenetic reasoning among conservationists translates into the presence or absence of conservation actions. Some of the criticisms of the PSC by adherents of the BSC are discussed. It is advocated that conservationists replace “list thinking” with “lineage thinking”.

Whether they are “mere subspecies” or “phylogenetic species”, the omission of such forms from the ICBP (now BirdLife International) Red Data Book (RDB) was my personal decision, and I have long been sensitive to the type of charge contained in Hazevoet's paper (preceding pages). This decision, taken back in 1982, was based on the time, space and cost that would have been involved in the systematic review and inclusion of subspecies (RDBs being much fuller treatments than those in Birds to watch 2, the work criticized for the omission by Hazevoet), and on the fact that the future of the many “full” species needing urgent documentation and action consequently stood to be compromised.