The Little Bustard Tetrax tetrax is a Near Threatened grassland bird that is fully migratory within its eastern population, wintering in large numbers across the south Caucasus and northern parts of Iran. The species’ habitat selection has been comprehensively studied in its western European range, but very limited information is available for its eastern population. Surveys carried out between 2010 and 2015 show a considerable population increase and probable range expansion in the region. We modelled the suitability of potential winter habitat for the species and found that distance to country border, land cover and altitude were the most important variables in predicting habitat suitability. There is still considerable hunting pressure in Iran and distance to border is likely to be related to strict hunting prohibition along the border belt imposed for military purposes. This represents an opportunity for the conservation of the species, where management efforts should aim at ensuring the maintenance of suitable land cover.

Modelling the distribution of species of conservation concern is an important issue in population ecology. Classically, logistic regression analyses are conducted to estimate species’ distributions from detection/non-detection data in a sample of sites and to test for the significance of several environmental variables in predicting the probability of occurrence. These modelling approaches assume that species detection probability is constant and equals one in all sampled sites, which is critical, notably in the case of rare, shy and cryptic species. The capture-recapture-like approach developed by Mackenzie et al. (2002, 2003) provides a reliable tool that accounts for imperfect detection when estimating species occurrence, as well as for assessing the relevance of site features as predictors of species occurrence probability. The aim of this study was to explore the possibility of using this approach in the context of Houbara Bustard Chlamydotis undulata in southern Tunisia. Our results show once more the low detectability of this emblematic species and stress the need to take this factor into account when estimating Houbara spatial distribution. The distribution of Houbara in southern Tunisia is more likely to be shaped by human-related than by habitat factors. In particular, Houbara occurrence was positively associated with site remoteness and camel numbers. Houbara seemed to avoid areas with high human presence and shared the most remote and agriculture-free zones with free-ranging camels.

Cercomacra carbonaria and Synallaxis kollari are passerine birds endemic to the gallery forests of Roraima state in northernmost Brazil and adjacent Guyana. The IUCN Red List of Threatened Species lists both as Vulnerable but they have been removed from Brazil's list of threatened species because of data deficiency. They are poorly known, reflecting both Roraima state's distance from Brazil's main population centres and the inaccessibility of their habitat. In 2004 and 2005, we conducted bird surveys along the major rivers that provided previous sightings, and expanded records from only a handful to several dozens. We found C. carbonaria at 29% of the points surveyed, and estimated its local population density at approximately 80 individuals km−2 and total population size to exceed 15,000 individuals. The species has 723 km2 of available habitat, 8% of which is inside conservation units. We found S. kollari at 44% of the points surveyed, and estimated its local population density as approximately 60 individuals km−2, with an estimated total population size exceeding 5,000 individuals. It has 206 km2 of available habitat, none of which is inside conservation units. We recommend that C. carbonaria be down-listed on the IUCN Red List to the Near Threatened category, and that S. kollari be listed as Endangered. Both species live in areas vulnerable to habitat loss. We also recommend that both species re-enter the Brazilian list of threatened species and highlight the importance of indigenous reserves to their conservation.

Resumo

Cercomacra carbonaria e Synallaxis kollari são aves passeriformes das matas de galeria do Estado de Roraima em sua parte mais ao norte do Brasil e da Guiana adjacente. Ambas as espécies são catalogadas como “Vulneráveis” pela lista vermelha de espécies ameaçadas da IUCN, mas foram excluídas da lista de espécies ameaçadas do Brasil devido è insuficiência de dados. Estas espécies são pouco conhecidas, refletindo tanto a distância do Estado de Roraima dos principais centros urbanos quanto a inacessibilidade do seu hábitat. Em 2004 e 2005, realizamos censos de aves anteriormente avistadas ao longo de rios maiores, aumentando assim os registros de apenas alguns poucos números para diversas dezenas. Encontramos C. carbonaria em 29% dos pontos amostrados e estimamos sua densidade local em ∼80 indivíduos km−2 e o tamanho populacional total em mais de 15.000 indivíduos. A espécie possui 723 km2 de habitat disponível, 8% do qual está incluído em unidades de conservação. Encontramos S. kollari em 44% dos pontos amostrados e estimamos sua densidade populacional local em ∼60 indivíduos km−2, com uma estimativa de tamanho populacional total em mais de 5,000 indivíduos. Esta espécie tem 206 km2 de habitat disponível, nenhum dos quais incluído em unidades de conservação. Recomendamos que C. carbonaria seja rebaixada para a categoria ‘Quase Ameaçada’ e S. kollari categorizada como ‘Ameaçada’ na lista vermelha da IUCN. Ambas as espécies vivem em áreas vulneráveis em relação è perda de seu hábitat. Recomendamos, também, que ambas as espécies sejam re-incluídas na lista de espécies ameaçadas do Brasil, destacando a importância das reservas indígenas para a sua conservação.

Around 80% of the world population of Northern Rockhopper Penguin Eudyptes moseleyi is found at Tristan da Cunha and Gough Island in the South Atlantic Ocean, where populations appear to be declining. However, numbers of birds at Middle Island, a small satellite island of Nightingale Island at Tristan Cunha, have not been counted since 1973 when an estimated 100,000 pairs were recorded. Updated population counts were obtained for all four islands at Tristan da Cunha (Tristan, Inaccessible, Nightingale and Middle islands) in 2009 providing a census of the whole island group and the first repeat count of Middle Island. Estimated breeding numbers at these four islands were Tristan 6,700 pairs, Inaccessible 54,000 pairs, Nightingale 25,000 pairs and 83,000 pairs at Middle Island. These counts confirm that Tristan da Cunha is a vitally important site for this ?Endangered? species holding over 65% of the global population and that breeding number have been relatively stable over the last 30 years.

Safeguarding threatened species in captivity is a promising management approach, but evaluating the performance of captive programmes is essential to assess reintroduction potential. The eastern population of the Northern Bald Ibis, Geronticus eremita, used to be a locally common migratory bird species, but catastrophic population declines throughout the past century have resulted in a single population in southern Turkey that forages freely during summer but only survives in captivity during winter. We examined whether breeding success of this semi-wild colony was comparable to breeding success of previous wild populations, and to what extent breeding success was influenced by supplementary feeding and wild foraging in habitats near the breeding station. Average productivity from 2009 to 2015 was 1.12 fledglings per nesting pair (range 0.96–1.19). In 2013 and 2014, there was no correlation between attendance at supplementary feeding events and productivity, and breeding birds attended on average only 35% of supplementary feeding events. Birds that were frequently observed at a local tree nursery raised fewer offspring, while birds observed more frequently in poldered cultivation, and in particular in mint crops or in fields covered with manure, raised on average more offspring. Foraging success was highest in meadows and cropland, particularly in mint crops and fields covered in manure, and lowest at the tree nursery. We speculate that selection of highly suitable wild foraging habitat such as mint crops or fields covered in manure allows the Northern Bald Ibis to raise more fledglings than exclusive reliance on supplementary food provided at the breeding station. Establishing a second breeding colony of this species in Turkey will therefore require a careful assessment of the suitability of wild foraging habitat in the vicinity of suitable nesting opportunities.

Effective shorebird conservation requires a greater understanding of use and availability of high-tide roosts in coastal non-breeding areas. In this paper, we explore 1) variation in use of roosts; 2) landscape and environmental correlates of roost use; and 3) responses to predators and humans at roosts, to evaluate roost availability for a wintering population of Dunlin Calidris alpina pacifica at Humboldt Bay, CA, USA. For four winters (2002–2005), Dunlin use of particular roosts was highly variable at the population and individual level, even at the most-used roosts. In any given day, week, or month, most Dunlin roosts were unused, and we continued to record new roosts even in the fourth year of study. Although roost use was influenced by landscape attributes, time of day, and environmental conditions, these variables left most variation in roost use unexplained. Dunlin departures from roosts were associated with the presence of avian predators, but not with human activity. Collectively, these observations revealed no strong evidence that roost availability was limited. This contrasts with findings of other studies, even after considering differences in methodology and spatial scale of analysis. We discuss implications for the interpretation of movement data, protection and/or creation of roosting habitat, and assessment of roost quality.

The translocation of species to a new site plays an important role in the conservation of many threatened birds; however, the problems and processes involved in planning and implementing such translocations are rarely reported. In order to establish a second secure ‘insurance’ population of the endangered Rarotonga Monarch Pomarea dimidiata, or Kakerori, 30 young birds were moved from the Takitumu Conservation Area on Rarotonga to the 2,700 ha island of Atiu between 2001 and 2003. The translocation of this single-island endemic was to a site outside the historical range of the species, because the small, but rapidly growing, population on Rarotonga was considered to be highly vulnerable to a catastrophe, such as a cyclone, or the arrival of a new bird disease or predator. The translocation followed consultation with local communities, an assessment of the suitability of islands in the southern Cook Islands, and an assessment of the disease risk posed by the translocation. The translocation appears to have been successful because Rarotonga Monarchs have bred well in a variety of forest habitats on Atiu.

We investigated the impact of introduced predators on the productivity of the St Helena Plover Charadrius sanctaehelenae, a shorebird endemic to the South Atlantic island of St Helena. The nest predator species identified have all been introduced to St Helena in the last 510 years, and all are species that are known to be invasive on other islands. The species responsible for taking the largest proportion of eggs was the domestic cat Felis catus, with rats (Rattus rattus or R. norvegicus) and Common Myna Acridotheres tristis taking smaller proportions. Nest survival varied spatially and was correlated with an index of cat density. No relationship was observed between the number of nesting attempts per pair in a year and predator density. The resulting estimates of productivity were insufficient in some areas to allow stable populations to persist locally. Future work should focus on assessing the population level impacts of current and reduced predator densities to St Helena Plovers, and understanding the influence of resource availability and habitat structure on the densities and impacts of predators.

Tracking studies of seabirds have generally focused in identifying areas used for foraging, in the hope of highlighting regions of energy transfer which may be important for seabird and general ecosystem conservation and special management. However, some sea areas may serve functions other than providing nutritional resources, which may be equally relevant, particularly if used by large numbers of individuals. In this paper, based on a study of 4 breeding colonies in the Falkland Islands and on 314 individuals tracked, we show that virtually all (97.8%) black-browed albatrosses Thalassarche melanophris (BBA) bathe in the close vicinity of the colony, remaining in the area for nearly an hour, before departing on a foraging trip. This compares with only 20 to 40% of the individuals landing close to the colony at the end of a foraging trip. The observed utilization of marine areas by BBA in a radius of 1 to 5 km around the nesting colony is one order of magnitude higher than elsewhere, including foraging hotspots. Clearly, even long-range flying birds such as albatrosses can make an intensive use of the sea-surface in the immediate vicinity of the colonies, and therefore any threats to seabirds in these areas (disturbance, pollutants, collision with artificial structures and light attraction) can potentially have a major impact at the population level. As such, the close neighbourhood of seabird colonies are potentially highly sensitive areas, and this needs to be taken into account when carrying out risk assessments or during marine spatial planning exercises.

Red-legged Cormorant Phalacrocorax gaimardi, considered Near Threatened, is one of the most conspicuous seabirds on the south Pacific coast, although its current status is unknown. During spring and summer of 1998, 1999 and 2000 we surveyed Red-legged Cormorants along the Chilean coast. Survey portions of the coast were chosen based on published information, and discussions with local people. Nesting sites were distributed from Arica (18°30′S) to the Peninsula de Taitao (46°25′S). We found 40 breeding areas with at least 54 colonies, ranging from two to 964 nests. Colony size (as number of breeding birds) was larger in the south than in the north. Isolated pairs or small colonies were found in the northern and central part of Chile. The southern coast (Xth Region) held most colonies, including the largest one with approximately 1,000 breeding pairs, suggesting it is a critical area for the species. We estimated the Red-legged Cormorant population in Chile to be between 5,018 and 5,218 breeding pairs. The Xth Region holds approximately 80% of the whole Chilean population. Factors affecting the breeding distribution of this bird in Chile include coastal development, nesting habitat availability and the occurrence of El Niño (ENSO) events. Human consumption may be important locally, mainly in the south. Chile holds more than 70% of the world breeding population, estimated at fewer than 15,000 individuals. The Peruvian population has declined during recent decades, and the Argentinean population seems to be small and stable. Thus the Chilean coast, particularly the Xth Region, is a critical area for the conservation of this species.

Historical and anecdotal data indicate that out of 14 original species of resident diurnal raptors, six have become extinct and two more are considered endangered in the middle Cauca Valley, Colombia. While the decline of several species is related to a drastic reduction of original habitats such as forests and wetlands, three open-habitat species have also suffered population declines. Possible causes include the recent expansion of intensive agriculture (at the expense of cattle-ranching areas), agrochemical pollution, hunting, and factors such as body size, the proximity of the valley to the upper altitudinal limit of most of the affected species, and the relative isolation of the valley from the Caribbean region and the savannas east of the Andes. The need for monitoring projects s i stressed for the vertebrate fauna, including those species considered common in open and disturbed habitats.

Informaciones históricas y anecdóticas indican que de una fauna original de 14 especies de aves rapaces diurnas residentes en el valle medio del rio Cauca, Colombia, se han extinguido seis especies y dos mas se consideran amenazadas. Mientras que la disminucion de algunas especies se relaciona con la drástica reductión de hábitats originales tales como bosques y humedales, tres especies propias de hábitats abiertos también se han visto afectadas. Se identifican como probables factores la expansión de la agricultura intensiva (a expensas de las areas previamente dedicadas a la ganaderia), la contaminatión por agroquimicos, los conflictos con los intereses humanos y ciertos factores como el tamano corporal, la proximidad del valle medio del Cauca al limite superior de distributión altitudinal de estas especies y el relativo aislamiento del valle con respecto de la región del Caribe y de las sabanas al oriente de los Andes. Se relieva la necesidad de establecer programas de monitoreo de las faunas de vertebrados, inclufdas las especies consideradas como comunes en hábitats abiertos y perturbados.

Fieldwork on the distribution, habitat preferences and status of birds was conducted in the Bikin River basin, northern Ussuriland, south-east Russia, during May–July 1992,1993,1995,1996 and 1997. The results of this survey combined with data collected during 1960–1990, show the area to be of high conservation priority and one of the most important for the conservation of Blakiston's Fish Owl Ketupa blakistoni, Chinese Merganser Mergus squamatus, Mandarin Duck Aix galericulata and Hooded Crane Grus monacha. This paper reports on all of the 13 threatened and near-threatened breeding species of northern Ussuriland, with special emphasis on their occurrence and status in the Bikin area. Three more species, included in the Red Data Book of Russia, are also briefly discussed. Maps show the distribution of the breeding sites of the species discussed. The establishment of a nature reserve in the lower Bikin area is suggested as the only way to conserve the virgin Manchurian-type habitats (wetlands and forests), and all 10 species of special conservation concern. Monitoring of the local populations of Blakiston's Fish Owl, Chinese Merganser and Mandarin Duck in the middle Bikin is required.

Cosmoledo Atoll, in the Aldabra Group, western Indian Ocean, has rarely been visited by scientists. This paper reports the first visit by ornithologists during the south-east monsoon when many seabirds breed. The breeding populations of three species of booby (Sula spp.) and of Sooty Tern Sterna fuscata were censused and all other species of bird seen were recorded. The atoll proved to have globally significant populations of Masked Booby Sula dactylatra of the subspecies melanops, Red-footed Booby S. sula of the subspecies rubripes, and Sooty Tern of the subspecies nubilosa. Cosmoledo also supports populations of landbirds that have forms endemic to the Aldabra group, but whose taxonomy requires examination using molecular techniques. The atoll, although currently uninhabited, suffers the impacts of exotic fauna and flora, including cats and rats, introduced by previous inhabitants. The isolation of Cosmoledo confers some protection, but its value as a centre of biodiversity, and designation as an Important Bird Area by BirdLife International, indicate that formal protection is needed. Political mechanisms for this are suggested, the implementation of which would help to procure funding to enable practical conservation of the atoll's biota.

Chu Yang Sin Nature Reserve, Dak Lak Province, Vietnam, is within an area of high bird endemism and supports a number of globally threatened and restricted-range species. Data were collected on the bird communities of the Reserve and their habitat in 1995, to ascertain habitat associations of some of the endemic and threatened taxa. Birds were surveyed in circular plots around a recording point. Habitat associations were investigated using Discriminant Function analysis, and populations estimated using DISTANCE.

Seven restricted-range species and 38 restricted-range subspecies were recorded in the survey. The number of contacts with some of the endemic species was low, which limited the statistical investigation of the habitat require ments of these species. When analysis was possible, altitude was the most important of the factors measured determining species distributions, while measures of forest architecture seemed less important. The area appears to support important populations of several restricted-range taxa and, provided that protection and management of the protected area can be enhanced, it remains one of the most important areas for bird conservation in southern Vietnam. Some drawbacks of the techniques used in the survey are discussed.

This paper summarizes current knowledge and outlines future work on the breeding biology of Southern Ground Hornbill Bucorvus leadbeateri in Zimbabwe. All available records since 1900 were analysed, including casual reports by members of BirdLife Zimbabwe and published records. Estimates were made for the start and end of the breeding season, group sizes, clutch size and productivity levels, together with an assessment of preferred habitats and nest-tree species. There is a need for intensive fieldwork to determine aspects of breeding biology such as incubation and nestling periods. Particularly important for sound management and conservation strategies is relative breeding success in different land-tenure systems. The author has started work in a communal area 40 km south of Bulawayo city; land-use systems such as new resettlement areas, commercial farms and protected areas remain to be studied.

The Javan Hawk-eagle Spizaetus bartelsi is endemic to the island of Java. Severe habitat fragmentation and small population size, aggravated by illegal hunting have put this rainforest species on the list of threatened bird species. Intensive searching since 1986 resulted in the discovery of a large number of localities additional to the historic ones. All known locality records of Javan Hawk-eagle have been scrutinized and are listed in the present paper. Confirmed post-1980 records are from 24 forest fragments of varying sizes: 10 (including 28 discrete localities) in west, seven (including 14 discrete localities) in central and seven (including 20 discrete localities) in east Java. The configuration of available habitat in forest clusters is evaluated. The co-existence with other threatened bird taxa, and the need for further field surveys and studies of the Javan Hawk-eagle are discussed.

Developing a standardized survey methodology to census and estimate the size of wintering populations is a main conservation priority for the endangered Little Bustard. We present a standard and repeatable methodology to census wintering Little Bustard populations at a regional scale, and the first statistically reliable population estimate of a Little Bustard wintering population in Spain. We carried out two surveys, in 2003 and 2004, using UTM 10 km × 10 km squares as census units, which were subjected to stratified sampling over the species' potential distribution range in the region of Madrid (Central Spain). Only the areas of potentially suitable habitat within squares of known winter presence of the species were considered. The species' winter distribution in Madrid was fairly constant between years, showing a fragmented pattern in three main nuclei. The number of Little Bustards observed was consistent between surveys (752 and 786 birds, respectively), with birds grouped in an average of 32 flocks (1 to 350 birds, mean = 27.9 birds). No between-winter differences in flock size were observed, although differences between sectors were significant. The highest densities were observed in the Tagus valley (mean density = 2.9 birds km−2, 293 birds), followed by north-eastern farmland (mean density = 0.6 bird km−2, 269 birds). The estimated size of the Little Bustard population wintering in the Madrid region was 1,051 (95% CI = 1,043–1,231). This calculation was based on recorded population density, measured as the number of birds per square kilometre, and considers the potential habitats available in each sector. We propose this methodology as adequate for surveying any Little Bustard wintering area, at both regional and smaller spatial scales. Survey results are consistent with previous tentative estimates for the region of Madrid, and with available information on Little Bustard movements. Sixty-five per cent of squares with Little Bustard presence were outside any protected area, which makes the wintering Little Bustard population of Madrid highly vulnerable to habitat disappearance and may affect the viability of breeding nuclei whose individuals winter in the region.

Translocations of threatened species play an increasingly important role in conservation management. However, few studies have examined what effects, if any, the translocation process itself (i.e. catching, handling, confining, transferring and releasing an animal into an unfamiliar environment) has on subsequent breeding success. Takahe Porphyrio hochstetteri living on offshore “predator-free” islands in New Zealand are a model system for examining such effects because pre-breeding birds have been frequently translocated between established island populations before they pair up and breed at 2-3 years of age. We postulated that “translocated” breeders (i.e. breeders that had been raised on another island) would delay first breeding attempts and/or have lower reproductive success compared with “resident” birds (i.e. bred on the same island that they were raised). The results indicated that translocated birds did not delay breeding and had similar mean hatching and fledging success as resident pairs in their first breeding season and subsequent seasons combined. The results suggest that at least for large or long-lived birds such as Takahe, the effects of any stress from the translocation itself, or the release into an unfamiliar environment, might be either short-lived or not significant enough to hinder subsequent breeding success. We recommend that further research be carried out on other species to determine the baseline effects, if any, of translocations, so that they can be taken into account when considering other determinants of translocation success such as habitat suitability, number of individuals and timing of releases.

Bwindi Impenetrable Forest, south-west Uganda, supports 24 of 37 restricted-range bird species of the Albertine Rift Mountains Endemic Bird Area (EBA). In common with other montane forest fragments in the EBA, Bwindi's structure and ecology have been substantially modified by human activities, the impact of which on its birds is difficult to gauge in the absence of quantitative information on their habitat use and abundance. During October 1999, habitat associations of nine restricted-range species and of 12 species with which they were commonly associated, were measured at Ruhija, Bwindi Impenetrable Forest. Logistic regression analysis was used to determine the relationship between habitat, topography, altitude and species occurrence. Population densities of 19 species were estimated using distance sampling, at survey points visited between dawn and midday. Although the detection rate declined during the morning, observations made towards midday helped to improve precision, without lowering density estimates. Eight habitat and topographical features significantly associated with restricted-range species are described. Few of the features measured were significantly associated with more than one species, underlining the importance of maintaining a diverse forest structure. Two restricted-range species were among the commonest birds in the study area, while a further four species were at least as abundant as their more widespread congeners.

The Olrog’s Gull Larus atlanticus is an endemic and threatened species of the south-western Atlantic. Little is known about its movements during the non-breeding period. The objective of this study was to analyse the migration of the species by tracking adults from Bahía San Blas (Buenos Aires province, Argentina) with geolocators and using information of sightings of ringed gulls. Differences between males and females were evaluated using tracking data and ringed data were used to determine age differences. A single core area (kernel 50%) from 21 tracked birds was identified. This area included the study colony and also other breeding colonies located up to 300 km to the north. The range area (kernel 95%) included coastal areas up to 1,000 km from the colony. All sightings of ringed gulls (n = 41) occurred north of the breeding colony, however 12 adult individuals were sighted during the winter in its breeding grounds. Our results suggest the occurrence of partial migration behavior in Olrog’s Gull. The migration pattern reported here implies than during the non-breeding season, breeding and wintering areas away from the nesting grounds should be considered as one system in the design of conservation strategies for this regionally threatened gull.