The Laysan Duck Anas laysanensis is a threatened species endemic to Laysan Island, Hawaü U.S.A., with a population that appears subject to severe fluctuation, although this may be attributable to different census methods. The most effective method used so far has been one that notes the ratio of marked to unmarked birds seen on censuses conducted at dusk around the central lake. In 1986 and 1987, weekly censuses were made from which population estimates were derived with the Lincoln—Petersen Index: the current population is approximately 500. The ducks were least visible during the nesting and moulting periods of spring and summer, and population estimates were significantly lower during that period in both 1986 and 1987. This phenomenon calls in doubt other estimates and probably accounts for the fluctuations noted in previous years. Thus careful attention should be given to potential problems in monitoring threatened species populations, because without a clear understanding of the ecology of the threatened species, population estimates could suggest inappropriate management measures.

Studies of records of the Black-bodied Woodpecker Dryocopus schulzi through literature searches, communications with ornithologists, personal observations and data from museum specimens show that the distribution of the species is basically limited to xero-phytic chaco woodlands in western Paraguay, northern and central Argentina, and southern Bolivia. Its western limit is defined by the transition zone between the chaco and the semi-humid montane forest on the east Andean slopes of southern Bolivia and north-west Argentina; in the extreme south it extends into the dry deciduous woodlands n i the sierras of Córdoba and north-eastern San Luis. The taxonomic history of the species has been chequered; we present morphological and vocal differences from its closest relative that reaffirm its specific validity. It appears to have suffered an alarming decline over much of its former range in Argentina, and appears to survive only in two isolated population centres of significant importance, in Córdoba and adjacent San Luis and in the central part of the Paraguayan chaco. The main cause of its rarity is destruction of habitat for timber extraction and expansion of agriculture and cattle-raising.

El estudio de registros del Carpintero Negro Dryocopus schulzi mediante revision biblio-gráfica, comunicaciones de ornitólogos, observaciones personales e información adjunta a especímenes en museos, muestra que la distribución de la especie básicamente se circunscribe al bosque chaqueño de carácter xerófilo del oeste de Paraguay, norte y centro de Argentina y sur de Bolivia. Su extremo occidental alcanza la zona de transición entre el chaco y los bosques semihúmedos montanos en las sierras orientales andinas del sur de Bolivia y del noroeste argentino; en el extremo sur se extiende hasta los bosques secos decíduos de las sierras cordobesas y del noreste de San Luis. La historia taxonómica de l a especie ha sido confusa; las diferencias morfológicas y vocales que aquí se presentan y comparan con su pariente más próximo reafirman su validez específica. Parece haber sufrido una disminución preocupante en la mayor parte de su distribución original en Argentina, y quedan aparentemente tan solo un par de núcleos poblacionales aislados de cierta importancia, en Córdoba y zona adyacente de San Luis y en la zona central del chaco paraguayo. La principal causa responsable de su rarefacción se debe a la destrucción del hábitat por la explotación de los recursos madereros y a la creciente expansión de la frontera agrícola y ganadera.

Ornithological surveys were carried out in the remnant forests of the island of Negros, in the central Philippines, over five weeks in the summer of 1991. From this work it is concluded that, without the implementation of immediate conservation measures, the global extinction of four bird species is likely to occur in the near future. These are Negros Fruit-dove Ptilinopus arcanus, Negros Bleeding-heart Gallicolumba keayi, Writhed-billed Hornbill Aceros waldeni and White-throated Jungle-flycatcher Khinomyias albi-gularis. Another four species restricted to the lowlands of Negros and the adjacent island of Panay, Visayan Tarictic Hornbill Penelopides panini, White-winged Cuckoo-shrike Cora-cina ostenta, Flame-templed Babbler Stachyris speciosa and Visayan Flowerpecker Dicaeum (australe) haematostictum, must be considered under extreme threat, and the endemic Negros Striped-babbler Stachyris nigrorum is under considerable pressure. A further twelve species listed as globally threatened are also in serious danger of extinction on Negros. This paper details the results of fieldwork and presents our conclusions and suggestions for conservation, which must include the direct preservation of the last fragments of lowland forest on the island.

Four weeks of fieldwork in the forests of Mindoro, Philippines, in 1991 has elucidated the status of the six bird species endemic to the island. Of these, Ducula mindorensis and Otus mindorensis are high-altitude species with restricted ranges and in need of active conservation in the medium term. Three of the four lowland species, Gallicolumba platenae, Centropus steerü and Penelopides mindorensis are under immediate threat of extinction through forest clearance and fragmentation, while the fourth, Dicaeum retrocinctum, s i not under immediate threat but is certainly at risk of extinction in the long term. Whilst deforestation is an enormous problem across the entire Philippines, Mindoro is the smallest centre of endemism with the least forest cover after the Sulu Islands. Extinctions are believed inevitable within the next 10 years unless concerted action is urgently taken. The Halcon range must receive attention in order to conserve the montane species, but more urgent by far is the preservation of lowland forest remnants, concentrating on central-west Mindoro.

The White-breasted Parakeet Pyrrhura albipectus, a threatened parrot known from three general areas of south-east Ecuador, was investigated in the only one of these areas to receive any protection, Podocarpus National Park, in 1990 and 1992. Its habitat there is upper tropical and subtropical forest, with some evidence that it can tolerate disturbed areas; six food-plants were added to the one (liana) already known, two euphorbs, another liana, a Miconia, a Ficus and Mollia gracilis (on which feeding was regular in August and September). Food-passing to one possible and another evident juvenile at this time suggested local breeding. Three adult and one juvenile call were distinguished. The species was found at nine sites in or immediately adjacent to the park, but mining concessions, currently suspended, may soon be granted and the park thereby seriously affected.

Pyrrhura albipectus es un psitácido amenazado conocido exclusivamente en tres zonas del sudeste de Ecuador; en 1990 y 1992 se estudió en el Parque Nacional Podocarpus (única zona donde recibe algun tipo de protectión). El hábitat en el área está constituido por bosque tropical y subtropical de las cotas mas elevadas, con cierta evidencia de que la especie puede tolerar hábitats alterados; seis tipos de plantas se añaden a la dieta hasta ahora conocida para la especie (una liana), éstas incluyen: dos euforbias, otra liana, una Miconia, un Ficus y Mollia gracilis (de la que se alimentaba de forma regular en agosto y septiembre). Se detectó transferencia de alimentos de un adulto a un juvenil y a un segundo posible juvenil, lo que sugiere reproductión local. Se identificó el reclamo de tres adultos y un juvenil. La especie fue localizada en nueve zonas del parque o en su inmediata proximidad, pero concesiones mineras, detenidas en la actualidad, pueden ser subvencionadas con el consiguiente impacto a la integridad del parque.