During 1942–1983, the average survival rate of Ospreys in Sweden (as derived from ringing data) was 53% during the first year, and for older birds it varied between 72% and 86% (below the level recorded in North America). The annual survival rate decreased significantly among young birds (1st-3rd years of life) but not among older age classes. A weak relationship between annual survival and rainfall in wintering areas in West Africa may exist for some year-classes.

Breeding success was 2.1 young per successful breeding attempt over the period 1961-1987, which is lower than during 1938-1946. The long-term annual growth rate of the population declined from 7% around 1940 to 5% around 1990.

A local decline in breeding success occurred during the 1960s and 1970s in areas heavily affected by acid precipitation in south-west Sweden, but this trend halted during the 1980s as liming programmes restored the fish stocks in acidified lakes. There was a significant relationship between lake productivity, measured as concentrations of total phosphorus, and breeding success: at 16 lakes breeding success ranged between 1.6 and 2.3 young per nest per year, and at the most oligotrophic lakes breeding success was close to the minimum required to balance mortality.

The Swedish population of the Osprey is not in acute danger, but the decline in the potential for population growth should be noted.

This double issue of Bird Conservation International is a milestone volume in Neotropical bird migration studies that will stand independently on the shelves of many research biologists. We were very pleased to be asked, toward the end of 1993, to become the publication forum for these symposium proceedings, although this has naturally necessitated the journal taking the unusual step of publishing combined issues. There are no current plans to produce symposium volumes of this size on a regular basis, but the journal will continue to publish selected papers from BirdLife (and other important international) symposia. The journal has indeed already carried several papers presented at specialist group meetings in South America (on cracids, parrots) and several further contributions based on these meetings are expected.

A total of 390 bird species are known to occur in the Korup National Park (KNP) and the surrounding Korup Project Area (KPA). Although the avifauna of KNP is incompletely known, it is already among the most ornithologically diverse lowland forest sites i n Africa. The avian diversity of the KPA is increased by the montane forest bird species of the Rumpi Hills Forest Reserve (RHFR) and the Nta Ali Forest Reserve (NAFR). The lowland and montane forests of the KNP/KPA are very important to the conservation of African forest birds. Four species found in the Korup area are considered globally threatened, and four are considered near-threatened. In addition, 40 species were considered for threatened status, some of which are likely future additions to the threatened list. Twelve of Korup's 36 montane forest bird species are endemic to the montane areas of western Cameroon, eastern Nigeria, and Bioko (Fernando Po). The RHFR is especially important as a refuge for montane birds because much of the montane forest elsewhere in western Cameroon has been cleared for agriculture. Breeding phenology data are provided for many lowland forest species. Additionally, this report provides information on many rarely recorded species for western Cameroon, including several species not previously documented in the region. Kemp's Longbill Macrosphenus ketnpi was recorded for the first time in Cameroon. Because it is sympatric with the Yellow Longbill M. flavicans in Korup, additional evidence now exists for the contention that M. ketnpi and M.flavicans are separate species. The Yellow-chested Apalis Apalisflavidawas also documented for the first time in Cameroon.

Millions of birds migrate every year from breeding grounds in North America to wintering grounds in tropical America. Some 50% of the species which breed in North America spend the winter in the Neotropics. Although these migrations have been studied quite extensively, austral, altitudinal and local movements of birds are also very important but poorly documented to date.

Three different methods (visual detection on transects, call-playback and territory mapping) were used to estimate the densities of the White-breasted Mesite Mesitornis variegata in western Malagasy deciduous forest. The species is threatened and belongs o t an endemic family of uncertain affinities. The population in the Menabe region, central-west Madagascar, surveyed using call-playback (the most efficient survey method), is estimated at 3,000-19,000 individuals; that of Ankarafantsika, north-west Madagascar, 6,000-26,000 individuals. Other western populations may be relicts. The White-breasted Mesite occurs at highest densities and with highest productivity in logged forest near rivers in the south of its range and in undisturbed sand-forest in the north, and is present at low density or absent from some areas of apparently suitable habitat, as well as forest that is secondary or has been severely damaged by burning. It is probably not immediately at risk from rats, dogs or selective exploitation, but hunting and forest burning through accidental bushfires or clearance for agriculture are locally important threats.

Trois méthodes différentes (détection visuelle sur transect, réémission de chant, et délimitation du territoire) ont été utilisées pour faire des estimations de la densité de la Mésite Variée Mesitornis variegata dans la forêt sèche de l'ouest de Madagascar. L'espèce est considérée comme menacée et appartient à une famille endémique de relations obscures. La population dans la region du Menabe, centre-ouest Madagascar, estime avec la réémission de chant (la méthode la plus efficace) est entre 3,000-19,000; celle de l'Ankarafantsika, nord-ouest Madagascar, est entre 6,000-26,000. Les autres populations occidentales sont probablement des vestiges. L'habitat ou l'espece se trouve le plus commune est à côté des rivières dans la foret exploitée, dans la partie méridionale de son aire de distribution, et dans forêt intacte sur sable dans le partie septentrionale. L'espece parait etre absente dans d'autres régions, meme où l'habitat est similaire. Elle existe rarement ou pas du tout dans les forêts sécondaires ou brulees. Les rongeurs introduits et Sexploitation forestiere selective ne posent pas probablement un grand problème pour l'espece, mais la chasse et le defrîchement pour l'agriculture sont localement importante.

The Madagascar Red Owl, known from the eastern rainforest of central Madagascar by a few specimens collected in the nineteenth and early twentieth century and one sight record in 1973, was rediscovered in late July 1993 in north-eastern Madagascar. An adult bird, held in captivity for approximately one year, was located in the town of Andapa. According to the owner, the owl had been obtained south-west of Andapa, near the village of Antanamangotroka, in a forested area connected to the Réserve Spéciale d'Anjanaharibe-Sud, and at about 800 m above sea-level. This record expands the known geographic range of this species and provides the first documentation of its continued existence in over 20 years.

La Chouette de Soumagne, connue de la forêt pluviale orientale du Domaine du Centre de Madagascar à travers quelques spécimens collectés au 19ème siècle et début du 20ème siècle et d'aprés une observation en 1973, a été redécouverte à la fin du mois de juillet 1993 au nord-est de Madagascar. Un individu adulte, qui venait de passer plus d'un an en captivité, a été découvert dans la ville d'Andapa. D'après la personne qui détenait l'animal, la chouette avait été capturee au sud-ouest d'Andapa, pres du village d'Antanamangotroka, au sein d'une zone forestière connectée avec la Réserve Spéciale d'Anjanaharibe-Sud, à une altitude d'environ 800 m au-dessus du niveau de la mer. Cette nouvelle donnée constitue une expansion significative de l'aire de distribution de cette espèce et apporte la preuve de la survie de cette espèce endémique qui n'avait pas été observee depuis plus de 20 ans.

In the course of a 13-year study of fall migration of Nearctic-breeding landbirds through a site in the Valle Central of Costa Rica, 5,549 migrant birds of 63 species, and 782 local residents of 28 species, were banded. Arrival dates of migrant species were fairly constant from year to year with passage migrants tending to arrive earlier than winter resident species. Differences in numbers and timing of first-year vs. older birds were noted in some species. Passage migrants showed higher fat deposits than did winter resident species and were virtually never recaptured in succeeding years, indicating a lack of fidelity to specific stopover sites. Winter resident species were recaptured in years following banding at frequencies approaching those for many resident species. Among winter resident species, individuals arriving early had higher fat deposits and were recaptured less frequently than those arriving later; apparently the latter were most likely to remain for the winter in or near the study area. This arrangement probably reduces intraspecific competition between transient and resident individuals of these species. Both at regional and local levels, migrant and local resident species differed in size distributions and to some extent in diet; these differences may reduce competition between these groups. Resident species had generally ceased to nest by the time the migrants arrivedin large numbers, but usually were feeding fledglings and/or moulting, suggesting that the presence of the migrants does not result in a scarcity of resources. The long-term but low-intensity, low-budget nature of this study may make it feasible to duplicate in many areas of the Neotropics, where information is needed regarding effects of land-use changes on resident and migrant avifaunas.

Twenty-eight species of parrot have been recorded in Argentina. Most of them inhabit forests in the northern part of the country. The conservation status of Argentine parrotsis serious, especially as regards the large species. Of the 11 species of macaws and amazons that formerly existed there, only four now occur for certain. Today, it is still possible to find flocks of many of the remaining species, but several of them have declined. The main problems affecting these species are habitat destruction, primarily of the Misiones forest, and international trade. The large number of species without authorized export quotas for 1993 indicates a very good level of protection for these species, but the authorized quotas for the remaining species are generally high.

Veintiocho especies de loros han sido registradas en Argentina, la mayoría de las cuales habitan selvas en el norte del país. El status de conservatión de los loros argentinos es serio, especialmente el de las grandes especies. De las 11 especies de guacamayos y amazonas que existieron antiguamente, sólo cuatro ocurren con seguridad en la actualidad. Aunque todavía es posible encontrar bandadas de muchas de las especies restantes, muchas de ellas han declinado. Los principales problemas que afectan a estas especies son la destruction del habitat, printipalmente las selvas de Misiones, y el comercio international. El gran número de espeties sin cuotas de exportatión autorizadas para 1993 indica un muy buen nivel de protectión para estas espeties, pero las cuotas autorizadas para el resto de las especies son en general altas.

Austral migrants are species that breed in temperate areas of South America and migrate north, towards or into Amazonia, for the southern winter. Migrations among these species are the most extensive of Southern Hemisphere migrations, and the austral system represents a third major migration system, in the sense that the term has been applied to Northern Hemisphere temperate-tropical migration. The geography of South America greatly influences the austral system. Lack of east-west geographical barriers and the shape of the continent promote a pattern of partially overlapping breeding and wintering ranges. The suboscine family Tyrannidae, the tyrant-flycatchers, is the largest group of austral migrants, with other major families including Emberizidae, Anatidae, Furnariidae, Accipitridae and Hirundinidae. Tyrant-flycatchers constitute more than one-half of the passerine austral migrants and roughly one-third of total austral migrants, a taxonomic domination seen in no other global migration system. Parallels exist, however, between austral migration and the Nearctic and Palearctic systems. Many of the same families, including Hirundinidae, Anatidae and Charadriidae, exhibit similarly high degrees of migratory behavi-our in each system. Passerine migration in the austral system is similar in numbers to that of the Nearctic-Neotropical system, but species migrate shorter distances and breed in more open and scrubby habitats. Possible differences in year-round resource availability between South American and North American temperate forests, in addition to differing availability of these habitats, may contribute to the low numbers of forest-dwelling austral migrants.

Authors' note At the time this paper was presented at the Quito symposium, it was already accepted for publication in American Naturalist, and consequently it has not been possible to reproduce it in full here. To retain it in some form for this volume, at the request of the editors F.G.S. drafted the version below, which represents an extended Spanish summary; however, for the full text, data and complete analysis it is necessary to consult the original article (Levey and Stiles 1992).

The Bristle-thighed Curlew Numenius tahitiensis is a rare shorebird that breeds in western Alaska and winters on oceanic islands in the tropical and subtropical Pacific Ocean. Before human colonization, the islands on which curlews winter were devoid of terrestrial predators, allowing curlews to evolve a rapid moult during which about 50% of adults become flightless. Especially when flightless, these birds are vulnerable to harvest by humans and to predation by introduced mammals such as dogs and cats. On atolls where they are harvested by humans, curlews tend to occur only on uninhabited islets. Consequently, human encroachment in Oceania has probably reduced Bristle-thighed Curlew numbers and altered winter distribution of the species. Future studies should (1) identify concentrations of wintering curlews, focusing in the Tuamotu Archipelago; (2) determine whether migratory stopover sites exist in the central Pacific between Hawaii and the southern end of the wintering grounds; and (3) establish a monitoring programme to assess population trends in several parts of the winter range. A comprehensive plan is needed to provide for the existence of predator-free islands throughout key portions of the winter range.

Competition between closely related species of migratory birds is thought to be important in determining their winter distributions, habitat and resource use. However, the role of active dominance interactions has generally been downplayed. In this paper we review the occurrence of interspecific feeding territories among certain Neotropical migrants. Aggressive dominants have been reported primarily at flowering plants, but also at the honeydew from scale insect infestations, the canopy of insect-rich pioneer trees and, occasionally, fruiting trees. Although the phenomenon is uncommon, aggressively dominant species may be important in certain habitats. The presence of such interspecific territorial systems argues for the poverty of resources in the habitat as a whole. Studying aggressive interactions among migrants is a way of using bird behaviour to define critical resources for conservation management.

During June and July 1994, five sites in the Annamese Lowlands Endemic Bird Area weresurveyed for restricted-range and globally threatened birds, with the ultimate aim of identifying a suitable area for protected area establishment to safeguard populations of endemic Lophura pheasants. Vietnamese Pheasant L. hatinhensis was found at twosites situated less than 10 km apart, although only regularly encountered in one area, the Net River watershed, Quang Binh province. No conclusive evidence was found of the existence of Imperial Pheasant L. imperialis at any site, although it almost certainly also occurs in the Net River watershed or close by. Where they occur, logging and hunting pose the most serious threats to the long-term survival of these endemic pheasants. Although previously believed to be largely confined to forest in flatter areas, evidence collected during the surveys suggests that L. hatinhensis is commonest on ridgetops and slopes in areas with relatively undisturbed, closed-canopy forest. Hence, a major recommendation of this study is that conservation areas for this species should include the maximum extent possible of closed-canopy or lightly logged forest that includes hilly terrain as well as lower-lying, flat areas. The most appropriate area for designation as a protected area was identified as forest in the Net River watershed. It is recommended that a full feasibility study for the establishment of such an area be undertaken as a priority, and that meanwhile a moratorium on legal logging activities and efforts to curtail illegal logging and hunting be implemented by Vietnam's Ministry of Forestry.

The Maleo Conservation Project Phase II surveyed the distribution and status of Maleonesting grounds in and around Dumoga-Bone National Park in North Sulawesi, Indonesia, in 1990–1991. The number of known nesting grounds is now 83, 35 inland and 48 coastal, while 18 sites require confirmation. Most sites along this coast are now abandoned or severely threatened (many now being cut off from adjacent forest), and the population there is estimated at only 335–740 pairs. The region's inland nesting grounds, used by putatively 2,000 pairs, are also increasingly threatened, notably through egg exploitation. An average of 5·45 birds per day visited one inland nesting ground, Tambun, over a 10-month period, indicating usage by 160 pairs altogether.

In this study I present data suggesting altitudinal movements of some species of foliage-gleaning insectivorous birds and related species of an oak-pine woodland of western Mexico. These movements can be regarded as short-distance or local migrations because the species involved breed in the woodlands and forests of the Sierra Madre Occidental highlands and winter in the tropical forests of the Pacific lowlands. Nine species of insectivorous birds out of 17 breed at the study site in the mountains of southern Durango and move to the lowlands in the winter; these can be regarded as short-distance or local migrants. In Mexico tropical deciduous and semi-deciduous forests are distributed mostly in the Pacific lowlands in the states of Sinaloa, Durango, Nayarit and Jalisco. Tropical forests of the Pacific lowlands are very important as wintering grounds for both North American and local west-Mexican migrants; however, there is only one protected area in western Mexico which to some degree includes these two types of tropical forests, and it is not located in the Sierra Madre Occidental, the most important mountain range in Mexico in terms of length and area covered. In addition, these tropical forests are the northern limit of the range for many tropical species. At present, these habitats are not threatened seriously by human activities (mainly forestry and cattle-raising) but this might change at any moment. At the study site the temperate highlands of southern Durango are already under the protection of “La Michilía” Biosphere Reserve, but a proposal to enlarge the area of the reserve to include the valley of the Río Mezquital and the western slope of the valley will increase the diversity of habitats, both temperate and tropical. As a consequence more bird species, as well as other taxa, will be protected in their natural environments. Such a proposal must be supported by field evidence on actual habitat use both during the breeding and wintering season, by local and long-distance migrants, in order to assess accurately the importance of this area as a representative place of western Mexico.

Frugivorous White-ruffed Manakins Corapipo leucorrhoa (Pipridae) showed pro nounced seasonal emigration from a pre-montane wet forest site (550 m) on the Atlantic slope of Costa Rica. “Resident” breeders left the area between August and October, and returned between February and April, at the onset of the breeding season. Female patterns differed from those of males primarily in later departure (October) and later return (April). I documented 57 fruit species in the diet at this locality and monitored phenology for 43 of those species, many of which were understorey members of the Melastomataceae. The emigration did not coincide with a period of local fruit shortage (relative to abundance at the same locality in other months), but the relative abundance and species composition of fruit resources in the areas to which the manakins migrated remains unknown. However, peak resources did coincide with the period in which recent fledglings would be commonest and the period during which most individuals were moulting prior ot emigration. Resources were lowest from November, when residents were absent, untilJune, well into the breeding season. Tentative evidence suggests considerable annual variation, possibly owing to differences in the timing of the rainy season. Individuals captured during the period when almost all “resident” breeders were absent (November) appeared to be transients, and were rarely recaptured. Weights differed between sexes, with females (χ = 12.5 ± 1.0) significantly heavier than males (χ = 11.1 ± 0.8). Males were lightest during the breeding season, intermediate in weight during the moulting period, and both sexes were heaviest during the migration period, when they accumulated subcutaneous fat. Females were lightest during the moult period, at which time many may also have dependent fledglings. Many other frugivores and nectarivores may engage in similar altitudinal migrations. Even where altitudinal migration is not possible, birds might migrate to other habitats with different fruit resources or phenologies. The design of nature reserves should accommodate the possibility of significant altitudinal (or cross-habitat) migration for many species of frugivores and nectarivores.

We documented habitat use by the Resplendent Quetzal Pharomacrus mocinno, a large frugivorous bird that breeds in cloud-forests in the highlands of Central America, to assess the adequacy of protection afforded to regional biodiversity by the Monteverde reserve complex, a protected natural area that includes most of the highland forests of the Tilarán mountain range in western Costa Rica. Our results demonstrated that this relatively large (20,000 ha) protected natural area does not adequately protect the area's biodiversity. Through the use of radio-telemetry, we identified the areas on the Pacific slopes that are most critical to altirudinally migrating Quetzals. These forest patches are subject to deforestation and degradation and are rapidly becoming further isolated from other remaining forest. The possibility of the local extirpation of the Quetzal, through continued habitat loss on the Pacific slopes, presents an unusual dilemma for the region because the species is the major attraction for the Ideal tourist industry which now includes over 80 businesses and annually generates over US$5 million in local revenue. Therefore, its extirpation would seriously affect regional economic stability. In order to protect the Monteverde Quetzal population, we propose a regional conservation plan that depends on participation of local landowners to protect their remaining forest fragments and allows for the development of corridors to connect critical habitats as the focus of a regional conservation effort. While the ecological significance of the structure of corridors per se, versus other possible formats, is still being debated, we have selected the corridor format primarily because it is relatively easy for landowners to grasp the concept and the necessity for continuity of the corridor network. This recognition provides an important incentive for participation across property boundaries, promoting cooperation in a group effort rather than as isolated actions. Success of this cooperative plan will provide an example for grass-roots participation in buffer-zone management strategies elsewhere in the Neotropics.