Bird Conservation International

Published by Cambridge University Press (CUP)
Online ISSN: 1474-0001
Publications
Breeding success of Pale-headed Brush-finch during the 2002 season in Yunguilla valley, 
Microhabitat use of Pale-headed Brush-finch pairs successfully raising offspring versus pairs that failed to raise offspring in the 2002 breeding season in Yunguilla valley, Ecuador. Samples are sightings of individuals (point observations); results are given as mean ± SD, z and P values from 
Article
Pale-headed Brush-finch Atlapetes pallidiceps is a restricted-range species that is threatened with extinction due to habitat loss. The total population of 60-80 individuals achieved a reproductive output of only 0.74 young per breeding pair in 2002. Brood parasitism by Shiny Cowbird Molothrus bonariensis was a major factor reducing breeding success, affecting 38.5% of broods. Parasitism rates reached 50% in an ungrazed reserve, but only 14% on an adjacent grazed plot. The resulting difference in breeding success was not, however, attributable to vegetation parameters used to describe microhabitat use. Cowbird parasitism rates therefore seem to be influenced largely by factors operating at the landscape level. These may include grazing scheme, topography, humidity and host availability. It is suggested that lower species diversity and bird abundance rendered the grazed site less attractive to cowbirds. Current parasitism rates are of great conservation concern due to the low population size of Pale-headed Brush-finch, and the initiation of controlling measures is pressing. Management options described from intensive cowbird control programmes in North America are reviewed and evaluated for their applicability here. To. combine the possibility of further data collection with commencement of immediate conservation action, we consider two alternative approaches. Nest monitoring and cowbird egg removal would enable the study of the distribution of parasitism in relation to landscape and vegetation variables, whereas cowbird shooting and nest monitoring might provide a larger short-term benefit to reproductive output. Habitat management, resumption of some grazing in the reserve and cowbird removal should be considered for the intermediate future.
 
Article
The distribution of Tahitian landbirds in the early twentieth century and at presented here together with maps. Three categories may be recognized: (1) species with a declining distribution owing to changes in habitats (Green-backed Heron), (2) stable or increased species, including local and earlier introduced species, and (3) newly introduced species (Zebra Dove, Red-vented Bulbul, Silvereye and Crimson-backed Tanager). Moreover, owing to their low population numbers, two species, the Pacific Pigeon and the Tahiti Monarch, are on the verge of extinction even if their distribution has not changed notably during this century. Les repartitions des oiseaux terrestres reproducteurs de Tahiti, au début et à la fin du 20e siècle, sont présentées sous forme de cartes. Trois catégories d'espèces sont dis-tinguées: (1) espèce dont la répartition est en déclin a la suite des modifications d'habitats (Héron vert), (2) espèces stable ou en légère augmentation, chez qui on trouve des oiseaux locaux et des oiseaux introduits, et enfin (3) les espèces introduites durant le 20e siècle (Tourterelle striée, Bulbul à ventre rouge, Zosterops à poitrine grise et Tangara cramoisi). II apparaît que deux espèces, le Carpophage du Pacifique et le Monarque de Tahiti, sont aujourd'hui très menacées, même si leur répartition n'a pas régressé d'une façon significative.
 
Trends in Mexican Duck counts. Only those sites with significant changes (P < 0.05) and average counts larger than 300, or those showing significant declines are included in the table
Annual population indices and numbers of Mexican Ducks counted in Mexico. Indices express the relationship to the base year 2000
Numbers of Mexican Ducks counted in 15 priority sites in Mexico during midwinter surveys. The percentage these represent of midwinter count totals and the estimated population size of 55,500 birds are shown. See text for details on prioritization procedure.
Article
Little is known about Mexican Duck Anas diazi biology and populations. We analyse long-term (1960–2000) trends of Mexican Duck numbers in Mexico and employ contemporary count data (1991–2000) from the U.S. Fish and Wildlife Service midwinter surveys to identify key sites for conservation using a complementarity approach. The overall Mexican Duck population showed a significant long-term increase of 2.5% per year, with large fluctuations throughout the study period. The Northern highlands population increased at an annual rate of 7.7%, while the Central highlands population showed no significant long-term trend. During the last decade, counts in both the Northern and Central highlands exhibited no significant change. At the site level, significant long-term increases occurred in four localities in the Northern highlands (Laguna Babícora +13.9% annually, Laguna Bustillos +25.9%, Laguna Mexicanos +20.4% and Laguna Santiaguillo +16.9%) and in three localities in the Central highlands (Languillo +15.3% annually, Presa Solís +8.9%, Zacapu +13.4%). Two sites in the Central highlands showed significant declines, in the long term (Lago de Chapala, -5.2% per year) and during the last decade (Lerma, -11.8% per year). The Northern highlands held 16% and the Central highlands 84% of the Mexican Duck population in the period 1960–2000; during the last decade, these figures were 31% and 69%, respectively. A set of priority sites for conservation of the Mexican Duck was identified, consisting of 15 sites holding more than 70% of the midwinter Mexican Duck counts in Mexico. Ten sites from the priority set also qualify for designation as wetlands of international importance under the Ramsar Convention on Wetlands, by holding [greater-than-or-equal] 1% of the estimated population. Four of the priority sites are in the Northern highlands and 11 in the Central highlands, of which eight are distributed along the Rio Lerma drainage. The most urgent actions that need to be undertaken are to estimate the current minimum population size in Mexico; to establish a programme for monitoring populations in the priority sites, especially those located within the highly degraded Rio Lerma drainage; and to determine the most feasible management actions for the species, concentrating efforts around the priority sites.
 
Responses to the question "Have you seen these birds?".
Initial knowledge of bird species in the survey.
Article
This case study concentrates on the extent of knowledge among the Australian public of Australia's tropical bird species, and their willingness to support their conservation. In order to place this issue in context, we provide background information on the status of Australian bird species, focusing attention on species that occur in tropical Australia. Then, using questionnaire survey results, we consider the hypothesis that the public's support for the conservation of different bird species depends on their understanding of the species' existence and status. Based on results from a sample of residents in Brisbane, Queensland, we found that knowledge of bird species that occur exclusively in the Australian tropics (including tropical Queensland) was very poor compared with that of those occurring in the Brisbane area that are relatively common. Experimental results indicated that when respondents in the sample had an option to allocate A$1,000 between 10 bird species listed in the survey, they allocated more funds to the better-known and more common species, unless they were provided with balanced information about all the selected species. With balanced information, the average allocation to bird species confined mostly to the Australian tropics, particularly those threatened, increased. This demonstrates the conservation implications of information provision about bird species. The results showed that public education can play a crucial role in attempts to conserve bird species that are poorly known and threatened.
 
Forest areas containing Javan Hawk-eagles 
Article
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.
 
Classification tree describing the pattern of habitat preferences of the Black-bellied Sandgrouse in Fuerteventura (Eastern Canary Islands). The probability of presence of the species is expressed below each box as a percentage. Bold-lined boxes indicate final environmental conditions. The number of transects meeting the previous set of conditions is shown inside each box. The splitting variables and threshold values selected refer to left branches of the tree, so that right branches met opposite conditions. See Table 1 for the acronyms of the variables.  
Article
We estimated the breeding population size and assess the habitat relationships of Black-bellied Sandgrouse in the Eastern Canary Islands (Fuerteventura, Lanzarote and La Graciosa, Spain) by means of a survey based on 1,787 0.5-km line transects and distance sampling done in 2005 and 2006. The population comprised 2,906 individuals (90% CI: 2,363-3,562), which is much higher than the numbers estimated in previous reports based on partial surveys, and constitutes 20% of the total Spanish population. Sandgrouse in the Canaries are currently restricted to Fuerteventura, where 70% of the population gathers in four areas that encompass just 16.7 % of the island and are largely within Special Protection Areas classified under the EU Birds Directive (except the area of Tefia-Ampuyenta, first in absolute number of individuals). The environmental characteristics that maximize the probability of occurrence of the sandgrouse in Fuerteventura (probability = 0.196) are: treeless non-cultivated areas of sandy soils without bare bedrock, with a rock cover less than 44%, located in non-coastal areas with an average terrain slope less than 27.5%, at more than 400 m from the nearest urban area, with less than 795 m of dirt roads per 20 ha, with at least 0.9% of shrub cover and a NDVI index higher than 53. Sandgrouse were closer to human settlements in midsummer than in March, perhaps being attracted to artificial pools surrounding villages. Similar habitat characteristics exist in nearby Lanzarote, where the species could hypothetically reach densities as high as 4-5 birds km-2. Possible reasons for the absence of sandgrouse in this island are discussed.
 
Article
Bird Conservation International (1995), 5:251-277 Cambridge University Press Copyright © Birdlife International 1995 doi:10.1017/S0959270900001039 The distribution of 335 species of birds in 33 islands of humid montane forest in Mesoamerica is summarized, and patterns of distribution, diversity and endemism are analysed. The montane forests of Costa Rica and western Panama far exceed other habitat islands considered for species-richness, richness of species endemic to Mesoamerica, and richness of species ecologically restricted to humid montane forests. Other regions, such as the Sierra Madre del Sur of Guerrero and Oaxaca, the Los Tuxtlas region of southern Veracruz and the mountains of Chiapas and Guatemala, also hold rich and endemic avifaunas. Based on patterns of similarity of avifaunas, the region can be divided into seven regions holding distinctive avifaunas (Costa Rica and western Panama; northern Central America and northern Chiapas; southern Chiapas; eastern Mexico north of the Isthmus of Tehuantepec; Sierra Madre del Sur; interior Oaxaca; and Transvolcanic Belt and Sierra Madre Occidental), which serve as useful guides for the setting of priorities for conservation action. Se resumen las distribuciones de 335 especies de aves en 33 islas de bosque humedo de montana en Mesoamerica, y se analizan patrones de distribution, diversidad y endemismo. Los bosques montanos de Costa Rica y del oeste de Panama tienen la mas alta riqueza de especies, riqueza de especies endemicas a Mesoamerica, y riqueza de especies ecologicamente restringidas a bosque humedo de montana. Otras regiones, tales como la Sierra Madre del Sur de Guerrero y Oaxaca, la region de Los Tuxtlas y las montanas de Chiapas y Guatemala, tambien tienen avifaunas ricas en especies y en endemicas. Basado en patrones de similitud de avifaunas, se puede dividir Mesoamerica en siete regiones que tienen avifaunas distintas (Costa Rica y el oeste de Panama; el norte de Centroamerica y el norte de Chiapas; el sur de Chiapas; el este de Mexico; la Sierra Madre del Sur; el interior de Oaxaca; y el Eje Neovolcanico y la Sierra Madre Occidental), las cuales pueden servir como guias en el establecimiento de prioridades para la conservation.
 
Article
Bird Conservation International (2000), 10:2:149-167 Cambridge University Press Copyright © Copyright 2000 Cambridge University Presshttp://journals.cambridge.org/action/displayAbstract?aid=57213 The Philippine islands hold a concentration of species diversity and endemism of global importance, yet few studies have analyzed biogeographic patterns or attempted to prioritize areas for conservation within the archipelago. We analyzed distributions of 386 species on 28 Philippine islands and island groups, documenting intense concentration of species richness, especially of endemic species, on the two largest islands, Mindanao and Luzon. Factors identified as influencing species richness included island area, maximum elevation, and Pleistocene patterns of connection and isolation. Reserve systems were developed based on heuristic complementarity algorithms, and compared with the existing Integrated Protected Areas (IPAS) system in the country, showing that IPAS is an impressive first step towards protecting avian diversity in the country. Addition of presently proposed reserves on Palawan and Mindoro would make IPAS a near-optimal reserve design, at least at the level of island representation. Important challenges remain, however, with regard to design of reserve systems within islands to represent complete island avifaunas.
 
Distribution of Pink-headed Fruit-dove on Sumatra, Java, and Bali, Indonesia. 
Occurrence of Pink-headed Fruit-dove on Sumatra, Java, and Bali, Indonesia
Logistic regression of the presence (1) or absence (0) of Pink-headed Fruit-dove, in relation to the altitude of 32 isolated mountain complexes.
Article
Pink-headed Fruit-dove Ptilinopus porphyreus is a little-known, restricted-range species, endemic to the mountains of the Indonesian islands of Sumatra, Java and Bali. In the period 1981¿2002 we conducted surveys throughout its range and compiled data on its presence and absence on 32 isolated mountain complexes. The fruit-dove appeared to be restricted to < 12,000 km2 of forest, scattered over 20 major mountain complexes on the three islands, i.e. three on Sumatra, 16 on Java and one on Bali. It occurred exclusively on mountains of > 2,000 m in altitude, where, depending on the size of the mountain, it reached its lower altitudinal limit between 500 and 1,000 m. The species was found mostly in singles or as pairs but occasionally in flocks of up to 17 individuals. It occurred almost exclusively in forest, feeding on figs and small berries in the upper-canopy. We documented three cases of breeding in the wild. From captive birds it is known that a single egg is laid which is incubated for 20 days, with fledging occurring after another 15¿16 days. Based on a study of 104 skins, the breeding season peak in West Java is at the beginning of the dry season. Although Pink-headed Fruit-dove is found in scattered, ever-shrinking forest blocks of mostly < 200 km2, the scarcity of recent field records is more than likely due to its inconspicuous behaviour, and a threatened status is unwarranted as yet
 
Vegetation types in the Selva Zoque priority region of the Chimalapas, Mexico. Data from http://www.conabio.gob.mx.  
Article
Bird Conservation International (2003) 13:227–253.  BirdLife International 2003 DOI: 10.1017/S0959270903003186 Printed in the United Kingdom The Chimalapas region, in eastern Oaxaca, Mexico, holds lowland rainforests, tropical dry forests, and cloud forests typical of the Neotropics, as well as montane pine and pine-oak forests more typical of the Nearctic. Totaling more than 600,000 ha, much of the region is forested, and in a good state of preservation. The Chimalapas avifauna is by far the most diverse for any region of comparable size in the country, totalling at least 464 species in the region as a whole (with more than 300 species in the lowland rainforest) representing 44% of the bird species known from Mexico. Within the region, the humid Atlantic lowlands hold 317 species, the montane regions 113 species, and the southern dry forested lowlands 216 species. Important species present in the region include Harpy Eagle Harpia harpyja and several other large eagles, Black Penelopina nigra and probably Horned Oreophasis derbianus Guans, Scarlet Macaw Ara macao, Cinnamon-tailed Sparrow Aimophila sumichrasti, Rose-bellied Bunting Passerina rositae, and Resplendent Quetzal Pharomachrus mocinno. The area holds immense lowland rainforests and cloud forests that rank among the largest and best preserved in all of Mesoamerica, including a complete lowland-to-highland continuum, with entire watersheds preserved more or less intact.
 
Example distributional models developed in this study for 15 species.  
Prioritizations of existing reserves, with numbers corresponding to order of conservation priority: (A) for existing reserves, based on range-centre assumption; and (B) for existing reserves, based on any-occurrence assumption. Dotted circles indicate reserves not included in the priorization based on inability to add species to the system.
Accumulation of species in area selection analyses of existing reserves and of pixels (i.e. without regard to existing reserves) across China.  
Richness map for the 90 species and selected pixel-based areas. White indicates species richness of 1–5, light grey 6–10, medium grey 11–15, and dark grey > 16. Dark lines indicate pixel-based potential protected areas, and numbers correspond to order of conservation priority.  
Potential additions to the existing reserve network, based on analysis of 55 species not included in existing reserves, based on the range-centre assumption. Priority areas are indicated in order by numbers, and the six species that do not co-occur with other species are also shown.
Article
Bird Conservation International (2002) 12:197–209. © BirdLife International 2002 DOI: 10.1017/S0959270902002125 Printed in the United Kingdom We developed distributional models for 90 threatened bird species in China, and used heuristic complementarity algorithms to prioritize areas for conservation. The pixel-based area selection prioritized 20 areas for protection, which covered all species analysed. Area selecting for endangered species based on the existing biosphere reserve system included only 37–62 species in eleven reserves, leaving 28–53 species unprotected. We employed algorithms for area selection based on species richness and rarity and obtained two views of a most efficient reserve network. We used the distributional hypotheses to identify additions to the reserve system that would improve its effectiveness substantially. The pixel-based area selection approach includes species much more efficiently on a per-area basis, and thus offers exciting perspectives for improved protection of the country’s endangered avifauna.
 
The study area. 
Land use (percentage cover) in the desert valleys of Northern Chile.
Frequency distribution of matches between simulated Chilean Woodstar sampling results and the real sampling for Azapa (September 2003) in relation to different population sizes. The grey line represents the results for a uniform random distribution of birds in the valley, while the black line represents the random distribution of birds but using tree cover as a covariate. For each population size, a total of 10,000 simulations were performed. 
Hypothetical movement pathways for Chilean Woodstars throughout their known distributional range. 
Population estimates for hummingbirds in the Azapa and Vitor valleys, northern Chile, in September 2003 and April 2004.
Article
Publicación ISI Email : cestades@uchile.cl We assessed the conservation status of the Chilean Woodstar Eulidia yarrellii, a small hummingbird endemic to a few desert valleys of northern Chile and southern Peru. Although no population studies had been conducted, this rare species was presumed to have undergone a severe population decline during the past decades. Fieldwork in Chile produced a population estimate for September 2003 of 1,539 individuals (929-2,287; 90% CI), located in just two valleys: Azapa and Vitor. There was no evidence of stable populations elsewhere. Our observations tend to confirm the hypothesis of a past decline and evidence points to three main factors driving that trend: (1) Most natural habitat has disappeared and the species relies mostly on artificial resources for feeding and nesting. (2) The start of heavy use of pesticides in the Azapa valley in the 1960s in order to control the Mediterranean fruit fly and other crop pests coincides with the last reports describing the species as abundant. (3) The irruption in the last two decades of the Peruvian Sheartail Thaumastura cora has apparently exerted serious competition pressure on the species. These findings support the classification of the species as globally Endangered. We describe the main lines of action of the recently approved Recovery Plan for the Chilean Woodstar.
 
Article
Bird Conservation International (1998), 8:387-394 Cambridge University Press Copyright © Birdlife International 1998 doi:10.1017/S0959270900002148 Domestic chickens were derived from the wild Red Junglefowl Gallus gallus. A survey of 745 museum specimens of Red Junglefowl suggests that most wild populations have been contaminated genetically by introgression of genes from domestic or feral chickens. A male eclipse plumage, which appears to be an indicator of pure wild genotypes, was found in populations in the western and central portions of the species's range, but not in the easternmost populations. Eclipse plumages probably disappeared from extreme south-eastern Asia and the Philippines prior to the advent of intensive scientific collecting (about i860) and have not been observed in Malaysia and neighbouring countries since the 1920s. Populations exhibiting eclipse plumages were found in north-eastern India as late as the 1960s, but the dense human populations there make their continuing genetic integrity uncertain. These data suggest that surveys of wild and captive populations should be undertaken to assess the genetic integrity of this species. A re-evaluation of the conservation status of Red Junglefowl might then follow.
 
Summary of sets of coincident boundaries found among the differentiated populations summarized herein. Apart from well-known breaks between Pleistocene islands, the following additional zones of turnover of species were noted: (1) the Sulu Archipelago versus the remainder of the Philippines; (2) northern versus southern Luzon; (3) the Batanes and Babuyan islands versus the remainder of the Philippines; (4) Camiguin Sur versus Mindanao; (5) Tablas, Romblon and Sibuyan versus the remainder of the Philippines; (6) northern islands versus southern islands within Greater Mindanao; (7) subdivisions within Mindanao proper; and (8) Basilan versus Mindanao.  
Summary of biological species concept (BSC) and evolutionary species concept (ESC) perspectives on distribution of bird species endemic to single islands and single Pleistocene islands in the Philippine archipelago.
Article
Bird Conservation International (2006) 16:155–173. © BirdLife International 2006 doi:10.1017/S0959270906000256 Printed in the United Kingdom Alpha taxonomy involves delineation of the basic unit of biology: the species. The concepts by which we define species, however, have been controversial, with several alternatives competing at present, some creating fewer and some more species units, depending on interpretation of species limits. Although it is tempting to assume that species concepts would have little interaction with the geographic foci of species richness and endemism — and some have so argued — this assumption does not withstand careful analysis. In this paper, I develop a first-pass assessment of Philippine bird taxonomy under an alternative species concept, and compare the results with the traditional biological species concept lists. Differences between the two lists were dramatic, but not just in numbers of species; rather, new, previously unrecognized or previously underappreciated foci of endemism were noted. A thorough understanding of the taxonomic basis of species lists is therefore critical to conservation planning.
 
Article
Eleonora’s Falcon is a long-distance migrant of the Palearctic region. In recent years, the advent of satellite telemetry has enabled a more detailed investigation of the species’s migratory and wintering periods. In this study, we model the distribution pattern of four Eleonora’s Falcons originating from Greece within their wintering grounds in Madagascar with the use of satellite telemetry data and a niche-based technique, Maxent. The model predicted few highly suitable areas for the occurrence of the species, restricted to elevated areas receiving large amounts of precipitation during the wintering period, containing patches of primary and degraded humid submontane forests as well as cultivation. Most of these areas occurred within the previously estimated home ranges of the four falcons, as well as of three falcons from another independent study. Taking into account the ongoing alterations in landscape structure that occur within the eastern rainforest region of Madagascar, we believe that it is imperative to better understand the ecological requirements of Eleonora’s Falcon. To this end, we recommend the application of Maxent in the study of habitat selection of the species that could be further refined with the inclusion of biotic interactions and seasonal resource availability.
 
Article
White-bellied Heron Ardea insignis (WBH) is critically endangered, but we lack data on many aspects of its basic ecology and threats to the species are not clearly understood. The goal of this study was to analyse WBH foraging microhabitat selection, foraging behaviour, and prey preferences in two river basins (Punatsangchhu and Mangdechhu) in Bhutan which are likely home to one of the largest remaining populations of WBH. We also explored the relationship between the relative abundance of the WBH and prey biomass catch per unit effort within four foraging river microhabitats (pool, pond, riffle and run). Prey species were sampled in 13 different 100-m thalweg lengths of the rivers using cast nets and electrofishing gear. Riffles and pools were the most commonly used microhabitats; relative abundance was the highest in riffles. The relative abundance of WBH and prey biomass catch per unit effort (CPUE) also showed a weak but significant positive correlation (r s = 0.22). The highest biomass CPUE was observed in riffles while the lowest was found in the ponds. From the 97 prey items caught by the WBH, 95% of the prey were fish. The WBH mainly exploited three genera of fish ( Garra , Salmo , and Schizothorax ) of which Schizothorax (64%) was the most frequently consumed. This study provides evidence in support of further protection of critical riverine habitat and fish resources for this heron. Regular monitoring of sand and gravel mining, curbing illegal fishing, habitat restoration/mitigation, and developing sustainable alternatives for local people should be urgently implemented by the government and other relevant agencies. Further study is also required for understanding the seasonal variation and abundance of its prey species in their prime habitats along the Punatsangchhu and Mangdechhu basins.
 
Breeding colonies of the NBI Geronticus eremita known since 1900 in Morocco (see Appendix S1 for numbers). The southern part of the Kingdom of Morocco without breeding sites is not shown.
Quarterly precipitation for the period 1994-2016 at Tamri (30°41' N, 9°49' W). Precipitation data (meteoblue.com 2017). The spatial resolution of the weather model simulation is 30 km for the years 1994-2007 and 12 km for the years 2008-2016 (meteoblue.com 2017).
Quarterly precipitation for the period 1994-2016 at Oulad Noumer (29°53' N, 9°42' W). Precipitation data (meteoblue.com 2017). The spatial resolution of the weather model simulation is 30 km for the years 1994-2007 and 12 km for the years 2008-2016 (meteoblue.com 2017).
Parameters analysed for known breeding sites from 1900 to 2016 (*) and from 1977 to 2016, with corresponding references.
Site characteristics of the 28 breeding colonies of the NBI remaining since 1977. Available water bodies during the breeding season. Multiple mentions are possible.
Article
The Northern Bald Ibis (NBI) Geronticus eremita , is an ‘Endangered’ bird species of which only very few wild breeding colonies have survived along the Atlantic coast of south-west Morocco. This paper analyses ecological conditions of the 72 breeding sites of the NBI that have been known since 1900 in Morocco. Characterisation of breeding sites is based on physical criteria (elevation above sea level, geomorphology, mean annual precipitation and types of landscape) as well as land use, vegetation cover, infrastructure and types of settlement within three perimeters (0–1 km, > 1–5 km and > 5–10(20) km) using Google Earth satellite images. Statistical analyses of the number of breeding pairs, fledglings and rainfall during different quarters of the year from 1994 to 2016 in the two remaining breeding sites in Souss-Massa National Park and Tamri showed expected patterns as well as unexpected differences between the two localities. Based on our findings and indications in the literature, we suggest general and specific recommendations for potential future translocation projects of the NBI. Based on the analysis of the 28 breeding colonies existing after 1977, two elements emerge as the most important prerequisites: a low level of disturbances at the breeding sites and adequate feeding areas at a reasonable distance of 5–15 km.
 
Map of Parc National du Banc d'Arguin, Mauritania, with dark grey representing intertidal flats, light grey depicting the sea, and white colour showing the land. The dashed line represents the Park boundary. The division into 12 sections (A to L) is based on Zwarts et al. (1998a). The underlying map is based on publicly available Landsat imagery. The Iwik region is defined as the combined sections C and D.
Waterbird dynamics, expressed as mean relative growth rate, in Banc d'Arguin between 1980 and 2017. The red bars represent Southern breeding intertidal foraging species, orange Northern breeding intertidal foragers, dark blue Southern breeding subtidal foragers, and turquoise bars represent Northern breeding subtidal foragers. Spoonbill includes the Mauritanian subspecies Platalea leucorodia balsaci with Eurasian Spoonbill P. l. leucorodia. Grey Heron includes the Mauritanian Grey Heron Ardea cinerea monicae with European Grey Heron A. c. cinerea. Small herons include Western Reef Heron Egretta gularis and Little Egret E. garzetta.
Correlative trends in population growth per species compared between the total Banc d'Arguin (x-axis) and the Iwik region (y-axis). Each point is one species. The red/orange points are intertidal foraging species and the blue/turquoise points are subtidal foragers. The two rates show a positive correlation (Spearman rank correlation, r s = 0.55, P = 0.001, dashed line). Banc d'Arguin growth rates are measured from 1980 to 2017, and Iwik growth rates from 2003 to 2017.
Article
The Parc National du Banc d’Arguin in Mauritania hosts the largest concentrations of coastal waterbirds along the East Atlantic Flyway. In spite of this importance, a review of the changes in the numbers of waterbirds in the area is lacking since the first complete count in 1980. Here we analysed the seven complete waterbird counts made since then, and the additional yearly counts made in one subunit (Iwik region) since 2003. We present evidence for changes in the community composition of waterbirds over the past four decades. Total waterbird numbers showed a decrease between 1980 and 2017, with only Great White Pelican Pelecanus onocrotalus showing a significant increase in numbers. Five species showed significant declines: Long-tailed Cormorant Phalacrocorax africanus , Red Knot Calidris canutus , Bar-tailed Godwit Limosa lapponica , Eurasian Curlew Numenius arquata , and Western Marsh Harrier Circus aeruginosus. In the remaining species, the variation in numbers between counts was too large, and the number of complete counts too small, for trends to be detected. The yearly counts at Iwik region also showed sharp decreases in the numbers of Red Knot, Bar-tailed Godwit, and Marsh Harrier, but not of Long-tailed Cormorant and Eurasian Curlew. A multivariate analysis revealed a significant change in species composition over time, which was caused mainly by changes in the species depending on the intertidal mudflats for feeding (generally in decline) vs. the species depending on fish and crustaceans in the sublittoral and offshore zones (often showing increases).
 
Article
The 2020 EU biodiversity strategy aims to halt the loss of biodiversity and ecosystem services, but this requires effective monitoring to determine whether these aims are achieved. Common bird monitoring continuously assesses changes in the avian community, providing a powerful tool for monitoring temporal changes in the abundance and distribution of these upper trophic level consumers. Two-thirds of Denmark’s land area is intensively farmed, so agricultural habitats make a major contribution to Danish biodiversity. We looked for changes in abundance amongst farmland birds in Denmark during 1987–2014 to test for reductions in declines and to predict whether the 2020-target can be expected to be achieved. Sixteen specialist farmland species were those showing the most rapid declines amongst 102 common breeding species in Denmark. Of these, those species nesting on the ground showed significant long-term declines, which was not the case for those that nest elsewhere, i.e. in hedgerows, trees and buildings. There was no evidence to suggest that these trends were attributable to widespread declines in long-distance migrant species (as reported elsewhere), which may be affected by conditions at other times in the annual cycle. We therefore conclude that continued declines in specialist farmland breeding bird species are due to contemporary agricultural changes within Denmark and urge habitat- and species-specific analysis to identify the core causes of these changes and halt the declines.
 
Article
Four of China’s six wintering populations of “grey” geese Anser spp. declined during the last decade. In contrast, the Bar-headed Goose A. indicus wintering population in China’s Tibet Autonomous Region more than doubled. During six surveys in Tibet over a 27-year period (1991/92 to 2017/18 winters) we documented an annual growth rate of 6.8% in the Bar-headed Goose population – an increase from approximately 10,100 to 68,100 birds. We propose that in addition to the cessation of hunting, the population growth of Bar-headed Goose is being driven by changes in agricultural land use patterns in Tibet, the establishment of protected areas on the wintering and breeding grounds, and the impacts of climate change across the Tibetan Plateau. Consistent with this hypothesis, the sown area of winter wheat in Tibet has increased and geese have shifted from primarily feeding in crop stubble to planted winter wheat fields. We also found that the most rapid population growth coincided with a 1998 climate regime shift across the Tibetan Plateau resulting in warmer temperatures, an increase in net precipitation, the appearance of new lakes and changes in the water levels and surface area of historical lakes. We suggest that warmer temperatures and high-quality forage on the south-central Tibet wintering grounds may be enhancing over-winter survival, while on the breeding grounds the expansion of lakes and wet meadows is augmenting breeding and brood-rearing habitat.
 
Article
The Black Woodpecker Dryocopus martius is the largest woodpecker of the Palearctic Region and it has been recognised as a keystone species whose presence provides critical resources to secondary cavity-users in European forest ecosystems. Here we investigate cavity tree and foraging-habitat selection of Black Woodpecker in three natural parks located in the central and eastern Italian Alps and included in the Natura 2000 network. A total of 94 cavity trees were identified, showing a minimum diameter of 35 cm and a mean diameter of 51 cm. We counted 30 active nests, but only 40% were newly excavated. Silver fir Abies alba and larch Larix decidua were preferred as cavity trees, with silver fir also associated with habitat surrounding the cavity trees. Norway spruce Picea abies and Silver fir were found to be positively associated with the surroundings of feeding sites. Logistic regression models identified the average diameter at breast height and the average tree crown height as significant predictors, positively associated with both cavity trees (AUC: 0.988) and cavity tree plots (AUC: 0.866). Also, the total volume of dead logs and the percentage of understorey cover turned out to be significant predictors of feeding sites, showing a positive and a negative association, respectively (AUC: 0.708). Cross validation of logistic regression models indicated that only cavity tree models can be considered useful tools in conservation practice. Overall, our results indicated that the Black Woodpecker behaves like an opportunist when choosing feeding sites. On the other hand, our results also indicate that the Black Woodpecker clearly behaves as a demanding species when it selects cavity trees, showing a hierarchical pattern in habitat selection and a marked preference for large trees with high crown height. We discuss the implications of our results for the conservation of the Black Woodpecker in Natura 2000 alpine sites.
 
Article
The Natura 2000 network, the pillar of biodiversity conservation in Europe, still shows some knowledge gaps after almost 30 years since its implementation. As birds are a taxonomic group that is underrepresented in the literature related to Natura 2000 compared to their importance in the EU Directives, this review investigated the characteristics of the scientific research dedicated to birds in relation to Natura 2000. This review focused on 169 peer-reviewed articles covering a period of 25 years (1995–2019). Most studies were set within single Natura 2000 site or regions within countries, and concerned terrestrial habitats, particularly wetlands. The terrestrial Mediterranean biogeographical region and marine Atlantic region had the greatest number of publications, while Spain, Italy, and France were the countries with the highest number of reviewed articles. The number of publications was correlated to Natura 2000 coverage at both country and biogeographical region level. Bird species were studied mainly at a community or single-species level and most publications studied distribution and occurrence of the bird species of interest, while very few assessed the conservation status of the species. Only a few articles set within Natura 2000 sites addressed the issues of habitat suitability for birds or the effectiveness of conservation efforts. Both Annex I and non-Annex I bird species were examined in the literature, with most species having decreasing population trends at the European scale. Future research on bird conservation and Natura 2000 should focus on marine ecosystems as well as habitats that have received less attention despite their important role in a changing future (alpine and urban types). Moreover, future studies should encompass larger spatial scales and those species for which status and trends are still not thoroughly investigated. Finally, it would be important to enhance research efforts on the conservation status and effectiveness in relation to the network.
 
Article
In developing countries, land sparing' may be more effective than land sharing' in partially mitigating the impacts of farming on bird species diversity. We examined the pattern of change in the global and local distribution of Hinde's Babbler Turdoides hindei, a Vulnerable' Kenyan endemic whose local abundance is dependent on a passive form of land sharing, in which farmland is left fallow or abandoned, enabling Lantana scrub to colonise. In 2011 we assessed the species' global range and resurveyed three IBAs, surveyed previously in 2000-2001, to determine whether fine-scale changes in abundance reflected temporal changes in habitat quality. Although the babbler's known range increased between 1900-1970 and 1991-2011, we suggest that this apparent expansion largely reflects an improved knowledge base, and that several recently discovered sites are likely to have been overlooked in the past. In combination, the three IBAs surveyed in 2000-2001 and 2011 showed little net change in the number of individuals (+1.3%) or groups (-3.8%) encountered, despite a 68% decline in the number individuals recorded at one site. Within 1-km transect sections there was a positive correlation between change in Hinde's Babbler abundance and change in the amount of scrub cover available, such that a reduction in scrub cover of 22 and 6 percentage points, respectively, was associated with the loss of one group or one individual. The availability of scrub cover was dependent mainly on the amount land left uncultivated, perhaps in response to changes in the value of coffee and other crops. Since the babbler's abundance thus currently depends mainly on land sharing by default, rather than by design, we suggest that a more proactive approach, involving land purchase or payments for land set aside, might help to secure its future.
 
Article
Floreana Island has the highest proportion of local land bird extinctions on the Galápagos Archipelago, and is home to the range-restricted and critically endangered Medium Tree Finch Camarhynchus pauper . We used acoustic surveys during 2004, 2008 and 2013 to compare the estimated population size of C. pauper and other land bird species in a remnant patch of Scalesia forest. First, we compared song in C. pauper and C. parvulus and the recently discovered Camarhynchus hybrid group to justify our use of acoustic surveys to detect population trends given contemporary hybridisation between C. pauper and C. parvulus . Song differed significantly between C. pauper versus C. parvulus and hybrid birds, but not between C. parvulus versus hybrid birds. Second, we compared population size estimates. Camarhynchus pauper declined by 52% between 2004 and 2013 (with a 10% increase since 2008); C. parvulus /hybrid increased by 45% between 2004 and 2013 (with 28% decrease since 2008). In 2013, there were ∼ 419 C. pauper males in the Scalesia forest (estimate for Scalesia habitat only) and ∼ 2,537 males on Floreana Island (estimate for the entire available highland habitat). Not all species showed a pattern of decline in the highland Scalesia habitat between 2004 and 2013: Dendroica petechia (+256%), Crotophaga ani (+254%) Geospiza fuliginosa (+23%), and Myiarchus magnirostris (+11%) increased, while the ground finch G. fortis (-76%) decreased. Understanding why C. pauper is declining while other land bird species are increasing in the same habitat requires continued inquiry and monitoring efforts.
 
Map of western Madagascar showing the extent of Madagascar Fish Eagle surveys during 2005 and 2006.  
Map of Madagascar showing the sites mentioned in the text.  
Map of breeding pairs, territorial pairs and individuals of Madagascar Fish Eagles during 2005 and 2006. Circled areas show the higher concentration sites.  
Summary of Madagascar Fish Eagle numbers showing the number of breeding pairs, breeding trios and single birds recorded at lakes and marshes, rivers, coasts, and marine islands during the 2005 and 2006 surveys.
Article
Coastal and inland surveys for the endemic and “Critically Endangered” Madagascar Fish Eagle Haliaeetus vociferoides were conducted in western Madagascar from Antsiranana in the north to Manja in the south during the 2005 and 2006 breeding seasons (May–October). Surveys covered typical Madagascar Fish Eagle habitat: lakes, rivers, mangroves, estuaries, and marine islands within their known distribution. In total, 287 individuals were encountered, including 98 breeding pairs (196 individuals), 23 breeding trios (69 individuals), 15 single adults and seven immature birds. Of these 287 birds, 128 individuals (44.6%) were observed on lakes; 116 (40.4%) in coastal areas, consisting of 103 (35.9%) in mangroves and 13 (4.5%) in estuaries; 32 (11.2%) on marine islands and 11 (3.8%) on rivers. There was an increase between surveys in 1995 and this study in the number of Madagascar Fish Eagles counted, from 222 to 287, and in the number of pairs from 99 to 121. This study confirms that the Madagascar Fish Eagle population is still low due to human persecution (hunting, collection of eggs and nestlings), overfishing and habitat destruction. We recommend monitoring fish eagles annually at the higher concentration sites to evaluate human activities and conducting a population survey every five years throughout western and northern Madagascar.
 
Population index values for Egyptian Vulture surveyed in 18 protected areas in India between 1992 and 2011. Indices are population densities relative to that in 1992, estimated by a zero-inflated Poisson model with only the intercept in the binary component (see Methods for more detail). Vertical lines show estimated 95% confidence limits.  
Population index values for Red-headed Vulture surveyed in 18 protected areas in India between 1992 and 2011. Indices are population densities relative to that in the 1992, estimated by a zero-inflated Poisson model with the year effect in the binary component (see Methods for more detail). Vertical lines show estimated 95% confidence limits.  
The rate of population change (% per year) of Egyptian Vulture. Circles show average annual rates between each pair of consecutive surveys with their 95% bootstrap confidence intervals (vertical lines). Note that the upper confidence limits for 2002–2003 (130.05) go beyond the range of the figure.  
The rate of population change (% per year) of Red-headed Vulture. Circles show average annual rates between each pair of consecutive surveys with their 95% bootstrap confidence intervals (vertical lines). Note that the upper confidence limits for 2002–2003 (5.66·10 9 ) goes beyond the range of the figure.  
Article
Populations of three vulture species of the genus Gyps, the Egyptian Vulture Neophron percnopterus and Red-headed Vulture Sarcogyps calvus have declined markedly on the Indian subcontinent since the mid-1990s and all are now Critically Endangered or Endangered. Gyps vultures have been killed by the widely used non-steroidal anti-inflammatory drug diclofenac, ingested when they feed on carcasses of domesticated ungulates treated with the drug shortly before death. However, it is not known whether Egyptian Vulture and Red-headed Vulture are also sensitive to diclofenac. Veterinary use of diclofenac was banned in India in 2006. Since then, the prevalence and concentration of diclofenac in domesticated ungulates carcasses has decreased and population declines of Gyps vultures have slowed or reversed. Here, we examine counts of Egyptian and Red-headed Vultures obtained on road transects in and near protected areas between 1992 and 2011. We found indications that the declines in both species appear to have slowed and possibly increased after the ban was introduced, though the small numbers of birds counted make this conclusion less robust than that for the Gyps species. These results suggest that both species may have been adversely impacted by diclofenac and that government bans on this drug, which are beginning to take effect, may benefit a wider range of vulture species in the Indian subcontinent than was previously thought.
 
Article
The critically endangered Mariana Crow now exists in a single population on the island of Rota, Northern Mariana Islands. Targeted management requires an accurate measure of the population status of this species. In Mariana Crows the breeding population is both the easiest cohort to accurately survey and the most important segment of the population in terms of population recovery. The total number of Mariana Crow territorial pairs was estimated on the island of Rota using a direct count method, and total population size was calculated using a Chapman estimate. From September 2013 to April 2014, 46 crow pairs were found and up to an additional eight pairs were estimated in unsearched areas. The total population was estimated to be 178 individuals. This represents a 10–23% decline in pairs in the six years since 2007 and a 46–53% decline since 1998. This number is also considerably lower than the minimum 75 pairs recommended to maintain a viable population on Rota.
 
Article
We studied the habitat preferences of breeding Yellow Buntings Emberiza sulphurata, taking into account the effects of paddyfield abandonment in hilly rural areas within the heavy snow region of northern Japan. Across 30 transects located in valley bottoms, we investigated the relationship between Yellow Bunting abundance and landscape characteristics. The results of generalized linear mixed models showed that forest edge density and landslide sites positively affected Yellow Bunting abundance. These habitats were associated with bush vegetation (forest edge, shrub land, and tall grassland) and were adjacent to the forest. Paddyfield abandonment showed a hump-shaped effect with a peak at the middle succession stage, which was covered primarily with tall grass and some shrubs, but the effect on Yellow Bunting abundance was not statistically significant. To conserve Yellow Bunting habitats in hilly rural areas, it is necessary to protect the forest edge and landslide sites from urbanisation and exploitation. It is also necessary to continue crop cultivation in such areas, to maintain the edges between open land and forest. If cultivation can no longer be continued, the abandoned paddyfields should be kept bushy, using reed beds and shrubs, by active management.
 
Location of Socotra Cormorant breeding colonies in Abu Dhabi Emirate showing the mean nesting population at active colonies during 2006-2007 to 2016-2017 (* restricted access areas).
List of Socotra Cormorant breeding sites in Abu Dhabi Emirate and their status in 2016-17, 2006-07 and 1996 (numbers indicate breeding pairs).
Number of Socotra Cormorant breeding pairs and breeding colonies recorded during 2006-2007 to 2016-2017 in Abu Dhabi Emirate.
Article
United Arab Emirates is an important range country for the ‘Vulnerable’ Socotra Cormorant Phalacrocorax nigrogularis and Abu Dhabi Emirate holds most of the remaining breeding colonies. Emirate-wide monitoring of all breeding colonies was undertaken annually for 11 breeding seasons from 2006–2007 to 2016–2017 to monitor the status of breeding colonies and estimate the nesting population. Breeding was recorded in 10 colonies that were used intermittently with an average of four (± 1.3 SD) colonies active each year. The highest number of eight active colonies was recorded in 2016–2017. Establishment of two new breeding colonies on Butinah and Digala in 2016–2017 and recolonisation of three previously inactive colonies during the monitoring period emphasised the ability of the species to relocate and colonise suitable sites. Continued threats at some breeding colonies caused abandonment and subsequent relocation, resulting in a gradual shift of breeding colonies to safer areas. Presently, most of the breeding sites (62%) with an increased number of breeding birds are found in colonies with restricted access. The Emirate-wide nesting population witnessed a 10-fold increase in the last decade; after an initial decline in 2006–2007 it increased from about 5,000 pairs in 2007–2008 to nearly 52,000 nesting pairs in 2016–2017. Combined with the nesting population from the Siniya colony, the overall UAE nesting population is estimated at 60,000 to 70,000 pairs, nearly half of the global breeding population. Further augmentation of the current breeding numbers is possible if breeding colonies remain safe from human disturbance and invasive predators. For long-term conservation of Socotra Cormorant, protection of all remaining colony sites, including inactive ones, is important in addition to minimising disturbance along with widespread public awareness to change the people’s perception of the species as a competitor to commercial fisheries.
 
Survey route and study areas of Hakalau Forest Unit of the Hakalau Forest National Wildlife Refuge (HFNWR), Hawai'i. 
Differences in assessed trends between ordinary log-linear and state-space models for uncorrected counts (top panel) and detection-corrected abundances (middle panel). Differences in trends between uncorrected counts and detection-corrected abundances using state-space models (bottom panel). Posterior probabilities of a meaningful trend in open and closed forest. Lines originate at log-linear model probabilities and dots indicate state-space partitioned probabilities. Vertices represent 100% of posterior probability with that trend; shade gradations represent the thresholds of moderate (0.5 ≤ P ≤ 0.7; light gray), strong (0.7 ≤ P ≤ 0.9; medium gray), and very strong ( P ≥ 0.9; dark gray) evidence of trends. Species codes are HAEL = Hawai'i 'Elepaio, OMAO = ' Ō ma'o, HAAM = Hawai'i 'Amakihi, AKIP = 'Akiap ō l ā 'au, HCRE = Hawai'i Creeper, HAAK = Hawai'i ' Ā kepa, IIWI = 'I'iwi, APAP = 'Apapane, RBLE = Red-billed Leiothrix, and JAWE = Japanese White-eye. 
Article
Estimating population abundances and patterns of change over time are important in both ecology and conservation. Trend assessment typically entails fitting a regression to a time series of abundances to estimate population trajectory. However, changes in abundance estimates from year-to-year across time are due to both true variation in population size (process variation) and variation due to imperfect sampling and model fit. State-space models are a relatively new method that can be used to partition the error components and quantify trends based only on process variation. We compare a state-space modelling approach with a more traditional linear regression approach to assess trends in uncorrected raw counts and detection-corrected abundance estimates of forest birds at Hakalau Forest National Wildlife Refuge, Hawai‘i. Most species demonstrated similar trends using either method. In general, evidence for trends using state-space models was less strong than for linear regression, as measured by estimates of precision. However, while the state-space models may sacrifice precision, the expectation is that these estimates provide a better representation of the real world biological processes of interest because they are partitioning process variation (environmental and demographic variation) and observation variation (sampling and model variation). The state-space approach also provides annual estimates of abundance which can be used by managers to set conservation strategies, and can be linked to factors that vary by year, such as climate, to better understand processes that drive population trends.
 
Article
The little studied Mount Cameroon Francolin Pternistis camerunensis is endangered and strictly endemic to the undergrowth of Mount Cameroon’s primary forest. We surveyed the species in the Mount Cameroon National Park in July–August 2016 using call playback at 86 plots systematically placed along 17 transects in an attempt to assess the occupancy and conservation threats to the species. The study’s three main results are as follows. Firstly, Mount Cameroon Francolin occurred in the stratified vegetation types across the altitudinal range of 1,023–2,186 m. Secondly, the response rates of francolin were 15% in submontane forest (800–1,600 m altitude range); 80.8% in montane forest (1,600–1,800 m); 3.9% in montane scrub (1,800–2,400 m); and nil in the lowland forest (0–800 m). Thirdly, bird abundance significantly increased with latitude, ground vegetation height, presence of Prunus africana and tall grass cover but decreased with the density of small trees and disturbance caused by heavy Prunus exploitation, and also, based on indirect evidence, hunting. We recommend: (1) systematic use of call playback in monitoring the population status of francolins; (2) an increase in patrolling and law enforcement to control illegal hunting, land clearance and burning of the upper slopes; (3) promotion of sustainable harvesting of Prunus and agroforestry practices aimed at curbing land clearance in the park surroundings. Further research priorities and conservation strategies have been suggested based on this study’s emerging results.
 
Article
The Endangered Scaly-sided Merganser Mergus squamatus is amongst the most threatened of sea ducks (Mergini), with an estimated population of c.4,600 individuals based on a recent population estimate on the breeding areas in Primorye, Far East Russia, China and DPR Korea. For the first time, we present published and unpublished data on the wintering distribution in China and smaller numbers in Korea. We report 156 sightings during 2000-2011, together with 11 records of wintering sites using geolocation devices, from 16 provinces in China, with greatest concentrations in Jiangxi Province (97 reports from 18 sites). Both sources of data suggest some degree of winter site fidelity to fast-flowing clear water rivers 50-350 m wide, with riffles, islands or sand banks in hilly/mountainous areas with low levels of human disturbance. Surveys located a maximum of 370-770 birds, 8-17% of the estimated total population, confirming our poor knowledge of the species' wintering distribution. There is an urgent need to define the wintering range of this species which is widely dispersed and nowhere abundant, but is threatened everywhere by dam construction, sand and gravel extraction, industrial and domestic pollution and fishing that threaten the integrity of the winter habitat. This also raises important conservation questions about how to protect such a species that is not highly concentrated and may require catchment scale nature conservation actions to effectively safeguard its current distribution.
 
Article
Lake Junín is famous for the abundance and diversity of breeding, staging and wintering waterbirds. The lake supports the entire world population of three species or subspecies: Junín Grebe Podiceps taczanowskii, Junín Rail Laterallus tuerosi and the endemic subspecies of the White-tufted Grebe Rollandia rolland morrisoni . Surveys undertaken in the 1930s, 1960s, 1970s and 1980s confirmed the lake’s importance in the Andes, however there has been no recent assessment of its waterbird community. We undertook waterbird counts between 6 and 20 February 2014 from the lakeshore and by boat. Despite using differing survey methods, we nevertheless conclude that the relative abundance of waterbird species has changed dramatically compared to earlier counts. Most notably, the Junín Grebe has experienced a major decline since the 1930s when the species was considered extremely abundant and another native fish-eating species the White-tufted Grebe also appears to have declined. In contrast the Northern Silvery Grebe Podiceps juninensis , classified as ‘Near Threatened’, has apparently become more abundant. Numbers of Puna Teal Spatula puna and Common Gallinule Gallinula galeata seem to have crashed, presumably reflecting the general loss of submerged vegetation. In spite of a major decline in waterbirds overall, the Junín area holds numbers of migratory shorebirds, perhaps as a consequence of local hunting restrictions and awareness campaigns. Lake Junín is a candidate for listing on the Montreux Record under the Ramsar Convention as a wetland showing serious change in ecological character. Management planning should proceed to balance conflicting interests at the lake. Actions to re-establish a clear water column by reducing eutrophication (from settlements in the catchment) as well as sedimentation and heavy metals (from upstream mining) will contribute to improving ecological functions and to secure waterbirds including the endemics.
 
Orís landfill location (triangle) and distribution of Griffon Vulture Gyps fulvus nesting sites (white circles) in Catalonia. The distribution of nesting sites is based on data of 10x10 km UTM squares (data provided by Servei de Fauna i Flora, Generalitat de Catalunya 2018). Olive green gradient represent altitude from 0 m (light green) to >3,300 m (dark green). Map was developed in ArcMap 10.3 (ESRI 2014).
Relation between the estimated POPAN model abundance of vultures attending the landfill (N-POPAN) and number of breeding pairs in Catalonia (N-Census). The relationship trend line between the two variables is shown and the shadowed area represents the 95% CI.
Linear regression models constructed with estimated abundance of POPAN model as response variable and N-Census (number of breeding pairs census) and organic matter available (OMA) in Orís Landfill as predictive variables.
Article
Globally, vultures are one of the most threatened of all groups of birds. European vulture populations are benefited by several anthropogenic food sources such as landfills. Current European Union directives aim to decrease the amount of organic matter dumped in landfills, reducing this important food source for some vulture species. In this context, we assessed the effect of the reduction of organic waste available and accessible for scavengers in a landfill on the visitation probability and abundance of a local Eurasian Griffon Vulture Gyps fulvus population in Central Catalonia (NE Iberian Peninsula), using a long-term dataset of captured-marked-recaptured individuals in the period 2012–2018. Our results indicated a decrease in the visitation probability due to a significant reduction of organic matter dumped into the landfill after a waste treatment centre was built (0.82 to 0.76) that may cause a permanent emigration of vultures in response to food reduction. However, the estimated annual abundance of vultures tended to grow over time due to the positive trend that regional vulture populations have experienced in recent decades. These results suggest that population processes occurring at regional scales are more relevant to vulture populations than local waste management measures. A reduction in locally available food can make a site less attractive, but species with high dispersal capacity such as vultures may overcome this issue by moving to other suitable sites. Although Griffon Vultures obtain most of the food from domestic and wild ungulates, a regional application of European directives could threaten an important alternative feeding source, especially in food shortage seasons where landfills could be supporting the energetic requirements of the species. Conservation strategies should be planned to counteract the possible negative effects of new European directives on scavenger populations.
 
Results from conventional distance sampling from line transects in 2010, 2011, 2013, and 2014.
Seima Protection Forest (2927 km 2 ) comprising the Core Zone (1879 km 2 ) and the Buffer Zone (1048 km 2 ).  
Article
The catastrophic decline of the endangered Green peafowl Pavo muticus across its former range is well known, yet there are only a handful of reliable population estimates for this species from its remaining range, making global assessment challenging. We present the first rigorous population estimates for this species from Cambodia, and model the distribution and the relationships between this species and several environmental covariates from the Core Zone (187,900 ha) of Seima Protection Forest (SPF), eastern Cambodia. Using distance sampling the abundance of Green Peafowl in SPF in 2014 is estimated to be 541 (95% CI [252, 1160]). Density surface modelling was used to predict distribution and relative abundance within the study area, and there was some evidence that the species prefers areas of deciduous forest, non-forest, and to a lesser extent semi-evergreen forest. These results highlight the importance of the central and northern sections of SPF for this species. Furthermore, the analysis suggested that Green Peafowl abundance is higher in closer proximity to water, yet decreases in closer proximity to human settlement.
 
Article
Pelagic seabird populations have declined strongly worldwide. In the North Atlantic there was a huge reduction in seabird populations following the European colonization of the Azores, Madeira and Canary archipelagos but information on seabird status and distribution for the subtropical region of Cabo Verde is scarce, unavailable or dispersed in grey literature. We compiled and compared the historical and current distribution of all seabird species breeding in the Cabo Verde archipelago, updated their relative abundance, investigated their inland habitat preferences, and reviewed their threats. Currently, the breeding seabird community in Cabo Verde is composed of Bulwer’s Petrel Bulweria bulwerii , White-faced Storm-petrel Pelagodroma marina aedesorum , Cape Verde Shearwater Calonectris edwardsii , Cape Verde Storm-petrel Hydrobates jabejabe , Cape Verde Petrel Pterodroma feae , Boyd's Shearwater Puffinus lherminieri boydi , Brown Booby Sula leucogaster , and Red-billed Tropicbird Phaethon aethereus. One breeding species is currently extinct, the Magnificent Frigatebird Fregata magnificens. The relative abundance of Cape Verde Shearwater, Boyd’s Shearwater, Cape Verde Petrel, and Cape Verde Storm-petrel was determined from counts of their nocturnal calls in Santo Antão, São Vicente, Santa Luzia, Branco, Raso and São Nicolau. Cape Verde Petrel occurred only on mountainous islands (Santo Antão, São Nicolau, Santiago, and Fogo) from mid-to high elevations. Larger species such as the Cape Verde Shearwater and Boyd’s Shearwater exhibited a wider distribution in the archipelago, occurring close to the coastline but at lower densities on populated islands. Small procellariforms such as the Cape Verde Storm-petrel occurred at high densities only on rat-free islets and in steep areas of main islands where introduced cats and rats are unlikely to occur. The main threats to seabird populations in Cabo Verde range from predation by introduced predators, habitat alteration or destruction, and some residual human persecution.
 
Article
The middle and lower Yangtze River floodplain is a globally important wintering area for waterbirds in the East Asian-Australasian Flyway. Ornithologists have reported on wintering waterbirds in the floodplain since the 1950s. However, an integrated analysis of the long-term changes in waterbird diversity is not available. Here, we synthesise existing information on changes in wintering waterbird abundance and distribution in the floodplain, summarise possible influencing factors and propose some priorities for further research. Waterbird richness and abundance have declined over the past 60 years. Declining trends have been observed in a number of areas and species. Nevertheless, a few areas and species showed different trends. In addition, waterbirds have become more concentrated in a few suitable areas such as Poyang Lake and Dongting Lake. Land reclamation, hunting, dam operation and extensive aquaculture are probably the four major threats to wintering waterbirds, while establishment of nature reserves is beneficial to waterbird conservation. Our study suggests that waterbirds in the floodplain are vulnerable, and that effective conservation measures are needed to protect and restore the waterbird diversity of this area.
 
Article
As island ecosystems are among the most critical breeding habitats for seabirds, their protection should enhance population viability for many species. The Peruvian Diving-petrel Pelecanoides garnotii breeds only in Chile and Perú, is an endangered seabird with historically large populations of over 100,000 breeding pairs, but fewer than 1,000 remained in the 1980s and it became the first endangered seabird of the Humboldt Current System. In Chile, they breed on five islands, three of which are legally protected, but only two have a management plan. Between 2010 and 2014, we evaluated the density of nests, burrow occupancy, and colony patch sizes on the islands to estimate the breeding population. The population trend was assessed by compiling historical data available in the literature and several unpublished technical reports. The current breeding population size in Chile was ∼12,500 breeding pairs (95% CI: 10,613–14,676 pairs) that is ∼34% of the breeding pairs reported for Peru (∼36,450 pairs). Choros Island, the only island with adequate protection, accounted for ∼95% of the total breeding population of the Peruvian Diving-petrel in Chile. Historical population trends showed a significant increase in breeding pairs during recent years on Choros Island. It seems that the adequate legal protection of Choros Island is leading to the recovery of Peruvian Diving-petrels, demonstrating that protection of breeding colonies remains an essential strategy for the conservation of endemic seabirds.
 
Article
The Gran Canaria Blue Chaffinch Fringilla polatzeki is a threatened, endemic, forest‐dwelling bird species of the Canary Islands, whose core population at the end of the 20th century was restricted to the pine forests of Inagua Nature Reserve (38 km ² ). A translocation programme released birds from a breeding centre into the nearby (<3 km) pine forests of La Cumbre in the years following 2010. From 2015 to 2019 the La Cumbre population was reinforced by translocation of wild juveniles from the source population of Inagua. We estimate the population size, the spatial variation of abundance, and recent temporal changes in density of the species in Inagua and La Cumbre by means of line transects, distance sampling, and habitat suitability modelling using random forests. The average density of the Blue Chaffinch in Inagua Nature Reserve was 10.2 birds/km ² in spring 2019, with a population estimated at 362 birds (95% CI: 257–489). The most important variables affecting the distribution of the Blue Chaffinch in Inagua were the amount of precipitation during the summer (July–September), the solar radiation in June, and the northern position in the reserve, highlighting the importance of abiotic factors related to thermal and hydric stress during the breeding season. The density was considerably lower in the translocated population inhabiting 21 km ² of pine forests in La Cumbre (3.3 birds/km ² ), with an estimate of 68 Blue Chaffinches (35–141) breeding freely in the wild. The translocation programme successfully contributed to the establishment of a second viable nucleus, accounting for 16% of the total population within a time span of 10 years. This result reinforces the role of translocations in preventing extinctions of endangered species with very low population sizes restricted to only one isolated area.
 
Survey route of 2-m wide transect recording tern nests on the Wrangel Islands. Circles indicate Aleutian and Common Tern nests observed on 25 June 2018.
Aleutian Tern colonies surveyed in 2018-2019. Yellow dots indicate aerial photograph sample locations, and bar charts show numbers of nests detected in photographs.
Comparison of survey methods used for Aleutian Terns.
Article
Aleutian Tern Onychoprion aleuticus numbers have been in steep decline at known Alaskan breeding colonies in recent decades (IUCN recently uplisted to ‘Vulnerable’). Available data suggest that most of the species may currently breed in Russia. Efforts to document global abundance and trends have been hampered by remoteness of colonies, lack of a formal monitoring programme, and the absence of reproducible population estimates with quantifiable errors, especially for large colonies. We surveyed four historically large colonies in Russia (2018) and Alaska (2019), which together may comprise 30–50% of the global breeding population. At each colony we obtained high resolution aerial photographs using a small Unmanned Aircraft System (sUAS). The large size of the colonies and the minimum altitude required to identify terns made it impractical to collect imagery of the entire colony. Instead, we employed a sampling approach, with sample locations selected based on spatially balanced acceptance sampling. Statistically sampled, low altitude sUAS images provided a fast, reproducible, and rigorous count of abundance for geographically large colonies, with low disturbance, and were generally consistent with concurrent ground-based observations. Concurrence among observers in photo counts indicated high precision in counts of attending birds and unattended nests, although species attribution in mixed tern colonies remains a source of significant uncertainty. Our results indicate that the four colonies surveyed here together supported <2,500 pairs of Aleutian Terns in the survey years. None of the colonies approached their peak size reported previously, likely due to recent predation, long-term decline, cold early season weather, or other factors. If these reduced colony sizes are representative of the current conditions, the implications for the global population would be dire.
 
Article
The Western Tragopan Tragopan melanocephalus is endemic to the Western Himalayas and currently listed as ‘Vulnerable’ on the IUCN Red List which also emphasizes a data deficiency regarding its distribution and population size. With this study we provide new data from the Palas Valley, northern Pakistan and deliver a range wide estimate of the species current, past, and future potential distribution as derived from environmental niche models. In the Palas Valley, Western Tragopans occupied different summer habitats on north-facing slopes and winter habitats on south-facing slopes. A quantitative estimate of local populations in six side valleys was inferred from individual call-count surveys during two breeding seasons (April and May 2017, 2018) and disturbance factors were evaluated from information of local people provided in questionnaires. Generalized-linear models (GLMs) showed a significant effect of disturbance factors on Western Tragopans, i.e. local abundances decreased with increasing disturbance from livestock, collectors and hunters visiting the area. This effect was visible across survey years and at both, south- as well as north-facing slopes. While the known distributional range of the Western Tragopan is small and fragmented, our niche models inferred climatically suitable space between Himachal Pradesh and northwestern Pakistan to be more continuous. Given the species sensitivity to disturbance, these findings indicate that the observed fragmentation of the current range might also be attributed to habitat transformation or anthropogenic disturbance rather than climatic suitability. During the Last Glacial Maximum (LGM) T. melanocephalus was probably restricted to small forest refugia, whereas projections onto eleven future climate simulations were inconclusive with the majority suggesting that climatically suitable space for T. melanocephalus will likely expand in response to anthropogenic climate change. In conclusion, we recommend that future conservation measures should be planned with regard to the species’ sensitivity to anthropogenic disturbances.
 
Location of source (Boundary Stream Mainland Island/BSMI) and recipient (Cape Kidnappers Preserve/CKOBWP) sites of the Rifleman translocation.
Life cycle modelling diagram for the female-only population model used for North Island Rifleman reintroduced to CKOBWP. S 1 and S 2 are the annual survival probabilities of a first-year adult and older adult respectively, R is the mean number of young fledged per female, and S j is the probability of a fledgling surviving to the next breeding season.
Comparison of translocation strategies/methods used for the Ulva Island Rifleman translocation compared to the CKOBWP translocation. Data for Ulva Island are given in Leech et al. 2007
Number of mortalities (% in parentheses) at different stages of the translocation process for the Ulva Island and CKOBWP Rifleman translocations. Data for Ulva Island are given in Leech et al. 2007. CKOBWP results are separated according to translocation date on the bottom line (2008/2010).
Article
Despite many notable successes, the failure rate of animal translocations remains high. Conservation practitioners and reintroduction specialists have emphasised the need for ongoing documentation of translocation attempts, whether successful or not, including detailed methodologies and monitoring approaches. This study reports on the first translocation of the North Island subspecies of New Zealand’s smallest bird, the endemic Rifleman Acanthisitta chloris granti . We describe an improved transfer methodology following recommendations arising from a previous translocation of South Island Rifleman Acanthisitta chloris chloris . Key modifications included a reduced capture window, shorter holding times, lack of extended aviary housing, and separation of territorial individuals during holding. Survival from capture to release increased from 52% to 97% using this new methodology. However, only 22% of 83 released birds were found in the reserve the next breeding season, resulting in an initial breeding population of only six males and five females. An integrated Bayesian analysis of three years of subsequent population data, including a population boost from a second translocation, projected a median decrease to 0–5 females over 10 years, but with 95% prediction intervals ranging from 0 to 33. These projections explicitly account for parameter uncertainty, as well as demographic stochasticity, and illustrate the need to do so when making inferences for small reintroduced populations.
 
Article
Plastic pollution affects marine ecosystems worldwide and poses risks for seabirds. Most recorded impacts on organisms are negative but, in some cases, the constructive use of plastic fragments or objects by birds has also been recorded. Small blue and green plastic fragments are found scattered among nests in a large (c.500,000 pairs) Sooty Tern Onychoprion fuscatus nesting colony on Bird Island, Seychelles. We investigated whether the fragments were being imported by the birds, and if so whether import was accidental or intentional. We found that Sooty Terns were the only seabird species to have plastic fragments in their nesting area and import of fragments varied seasonally and spatially. Throughout the colony, plastic fragments were imported during egg-laying, incubation, and chick-rearing, but import declined as chicks began to fledge. A part of the colony where all eggs were harvested for human consumption received more fragments than among undisturbed nests. We failed to find evidence of ingestion and excretion of fragments and suggest other avenues for investigation.
 
Article
The Área de Conservación Osa (ACOSA) contains the largest population of Scarlet Macaws Ara macao in Costa Rica. Despite their influence on ecosystem dynamics and status as a flagship species, empirical data on the foraging patterns of this population is lacking. This information is crucial in implementing effective conservation strategies, particularly reintroduction attempts. Observations of feeding behaviour were made systematically over a 12-month period to provide the first direct examination of Scarlet Macaw diet within the ACOSA region. Scarlet Macaws feed on various items including seeds, flowers, bark, and leaf-gall larvae. Key findings included a demonstration of a smaller dietary niche breadth than that recorded for other Central American populations, use of button mangrove Conocarpus erectus , a species not previously recognised as a food source for Scarlet Macaws, and a heavy reliance on an exotic non-native species, Terminalia catappa. We argue that whilst human-modified coastal locations may present viable habitat for Scarlet Macaws, anthropogenic influences including the removal of native food sources and proliferation of exotic and cultivated species have left the Scarlet Macaws of the ACOSA particularly dependent on a small number of species. A full, read-only version is available at: https://www.cambridge.org/core/journals/bird-conservation-international/article/reduced-diet-breadth-in-the-scarlet-macaw-ara-macao-of-the-area-de-conservacion-osa-acosa-costa-rica-implications-for-conservation-and-ecotourism/DD759215CBD6FF1CB4CE6253F56267B9/share/a50d65eff9f7f435aa023a849899744139a6c976?fbclid=IwAR2P19a2JeJLKrdWKkzXzOokcwq_abp6Rh6PaO455iUH_HWTlXhZHfh4mlo
 
Number of identified species (grey bars) and average number of species per hour for each twilight and night phase (black line). Autumn 2011 covers 63 recorded nights and spring 2012 covers 67 nights. Abbreviations: ev.civ = evening civil twilight, ev.nau = evening nautical twilight, ev.ast = evening astronomical twilight, night.q1 = first night quarter, night.q2 = second night quarter, night.q3 = third night quarter, night.q4 = forth night quarter, mo.ast = morning astronomical twilight, mo.nau = morning nautical twilight, mo.civ = morning civil twilight. For details see Appendix S2.
Level of disturbance from various background noise sources liable to disrupt the sound analysis.
Article
Bird migration studies are sparse in the Caucasus region, but have received more interest in recent years. To date, these studies have focused on diurnal migration and no information about nocturnal bird migration is available from this region. Therefore, nocturnal bird migration in the Besh Barmag bottleneck (Azerbaijan) was acoustically analysed on the basis of 1,464 h 44 min of sound recordings cost-efficiently obtained with an autonomously operating recorder and an omnidirectional microphone between sunset and sunrise on 63 nights in autumn 2011 and 67 nights in spring 2012. In total, 88,455 calls of 106 migrating species were detected. Of these, 2,172 calls could not be identified due to recording deficiencies or imperfect familiarity with some of the vocalisations and may involve as many as 20 species. The calls and songs of another 13 non-migratory species were not counted. Due to organisational or technical constraints some nights in the study periods could not be analysed and so the ensuing data gaps were repaired by interpolation, resulting in an estimated total of 108,986 calls in autumn 2011 and 33,348 calls in spring 2012. In both seasons the most vocally productive and species-rich phase was civil morning twilight, containing as it does the onset of diurnal migration. In autumn 2011, 54.7% of the recorded calls occurred in civil evening and morning twilight and 68.8% in spring 2012. But species and call numbers were also high in the darkest twilight and night phases. The interpretation of the data is, however, partly conjectural and any future access to truly reliable information on migration densities is conceivable only through radar studies.
 
Major sub-Saharan staging sites (rectangles) of six tracked Aquatic Warblers (EN, HK, OY, PO, OX, RR). Grey circles indicate short-term staging sites en route. The locations are plotted on a map showing year-round water availability downloaded and scaled to lower resolution (0.125×0.125degrees) from https://global-surface-water.appspot.com (Pekel et al. 2016).
Article
Birds that are long-distance migrants partition their annual cycle among a number of locations over a large spatial range. The conservation of these species is particularly complex because it requires attention to a number of different and distant habitats based on knowledge of migratory phenology, routes and staging areas. In the case of the globally threatened Aquatic Warbler Acrocephalus paludicola , a habitat specialist that breeds in Europe and spends the boreal winter in sub-Saharan Africa, non-breeding staging areas were widely unknown until recently. We applied light-level geolocators to adult male Aquatic Warblers at breeding sites in Belarus and Ukraine. Data from eight retrieved geolocators confirmed a south-west and then westward migration route through Europe via the northern Mediterranean with staging sites on the Iberian Peninsula and occasionally France and north-west Africa. In sub-Saharan Africa, final staging areas were in Mali, either in the Inner Niger Delta or at (presumably) small water bodies in the desert, with one bird most likely staying in the north of Ivory Coast south of the previously assumed range. The birds probably stayed in the final staging areas for most of the non-breeding season, but the logger on only one bird provided data throughout the entire migration cycle. Pre-nuptial migration of the latter was by a more easterly route than the southward migration. Our study suggests that conservation strategies for Aquatic Warbler north of the Sahara should include consideration of unknown staging sites in the northern Mediterranean as well as on the Iberian Peninsula and in north-west Africa. South of the Sahara, our study demonstrates the importance of the Sahel for the conservation of the Aquatic Warbler, including both the major floodplains of the Niger River and small Sahelian wetlands that are under pressure from human development.
 
Geographic distribution of responses to Hen Harrier (top) and Short-eared Owl (bottom) questionnaires. Circle sizes indicate the number of pairs covered by each questionnaire (range: 1-1,375 pairs), circle colour indicates the trend reported by each questionnaire. Where two or more questionnaires covered overlapping or nested geographical areas, these are vertically aligned (e.g. six responses on Hen Harrier from the UK covered the entire UK and subpopulations; as a comparison, the two responses from Spain covered separate areas and so are horizontally aligned). Where populations are marked as extinct, the population size shown corresponds to the population size 10 years prior to extinction.
Perceived impact of conservation threats to breeding Hen Harrier and Short-eared Owl assessed by European experts through questionnaires (n = 23 responses from nine countries for Hen Harrier; n = 12 responses from six countries for Short-eared Owl). Dots indicate mean values for each threat across all countries, lines indicate standard deviation. See Table S1 for mean and standard deviation values.
Conservation threats to breeding Hen Harrier (a) and Short-eared Owl (b) assessed by European experts through questionnaires. Circle section size and colours indicate the estimated impact of the different threat categories (see legend). Lists indicate specific threats perceived to be most important in each country (i.e. in the upper quartile based on threat scores for each country). See Tables S2 and S3 for full list of threats and perceived impact values in each country. Breeding distribution maps based on BirdLife International and HBW (2018).
Article
Hen Harrier Circus cyaneus and Short-eared Owl Asio flammeus are open-country birds of prey with overlapping distributions. Although both species face similar conservation threats across their ranges, work to date has largely been undertaken at a national scale with few attempts to collate and assess factors relevant to their conservation at an international scale. Here we use an expert knowledge approach to evaluate the impact of conservation threats and the effectiveness of conservation strategies for each species across Europe. We report results of responses to a questionnaire from 23 Hen Harrier experts from nine countries and 12 Short-eared Owl experts from six countries. The majority of responses for both species reported declines in breeding numbers. The perceived impact of threats was broadly similar for both species: ecological factors (predation, extreme weather and prey availability), changes in land use (habitat loss and agricultural intensification) and indirect persecution (accidental nest destruction) were considered to be the greatest threats to breeding Hen Harrier and Short-eared Owl. Short-eared Owl experts also highlighted lack of knowledge and difficulties associated with monitoring as a major conservation challenge. Despite broad-scale similarities, geographical variation was also apparent in the perceived importance of conservation threats, with some threats (such as direct persecution, large-scale afforestation or habitat degradation) requiring country-specific actions. Implementation of different conservation strategies also varied between countries, with the designation of protected areas reported as the most widespread conservation strategy adopted, followed by species and habitat management. However, protected areas (including species-specific protected areas) were perceived to be less effective than active management of species and habitats. These findings highlight the overlap between the conservation requirements of these two species, and the need for collaborative international research and conservation approaches that prioritise pro-active conservation strategies subject to continued assessment and with specific conservation goals.
 
Migration paths followed by raptors and other large soaring birds in the coastal plain of the Isthmus of Tehuantepec, Mexico, obtained from eight years of spring and fall observations. Solid lines depict the most heavily used flyways, thick dotted lines less heavily used, and finely dotted the least used.  
Spring and fall counts (2007-2014) of raptors and other large soaring migrants observed from La Venta II at the Isthmus of Tehuantepec, Mexico.
Migration phenology of the most abundant raptors and other large soaring birds at the Isthmus of Tehuantepec, Mexico, based on records from our La Venta II observation site. Data were collected during eight spring and eight fall seasons (2007–2014). Solid line = mean proportion of the total seasonal migration observed per four-day period; dashed lines = 95% confidence intervals.  
Article
We present the first study of the spatial and temporal dynamics of raptors and large soaring birds from the Isthmus of Tehuantepec, Mexico. Using systematic migration counts from multiple localities in the southern states of Oaxaca and Chiapas, as well as observations of their flight trajectories during eight consecutive years (2007–2014), we describe the magnitude of these movements, their geographic extent, and the phenology of the most abundant species in both spring and fall seasons. The most abundant species were Turkey Vulture Cathartes aura , Swainson’s Hawk Buteo swainsoni , Broad-winged Hawk Buteo platypterus , Wood Stork Mycteria americana , American White Pelican Pelecanus erythrothynchos , Franklin’s Gull Leucophaeus pipixcan , and American Kestrel Falco sparverius . In spring, the seasonal average magnitude of migration was over 28,000 birds, while in autumn the average was over one million. The aggregated seasonal phenologies recorded illustrate a variety of migration patterns. The inter-annual variation is lower in autumn than in spring. Migrating raptors and other soaring birds did not seem to use any topographical feature as a leading line for their movements in spring, while in autumn they did. We estimated the main axis of spring flights to run along a SE–NW vector, while autumn migration follows a WNW–ESE general trajectory. Our results place the isthmus as one of the five most important sites in the world for raptors and soaring migrants. Sustaining annual migration counts at these sites is of high importance to track substantial portions (> 90%) of the global population of Turkey Vulture and Swainson’s Hawk, as well as over 10% of the global population of Broad-winged Hawk. Autumn migration counts have the potential for long-term population monitoring.
 
Coverage of the global IBA network by protected areas ( n = 10,708 IBAs). The solid line shows the mean percentage of each IBA covered by protected areas; the dashed line shows the percentage of IBAs that are completely covered (i.e. > 98% of their area) by protected areas.
Article
BirdLife International´s Important Bird and Biodiversity Areas (IBA) Programme has identified, documented and mapped over 13,000 sites of international importance for birds. IBAs have been influential with governments, multilateral agreements, businesses and others in: (1) informing governments’ efforts to expand protected area networks (in particular to meet their commitments through the Convention on Biological Diversity); (2) supporting the identification of Ecologically or Biologically Significant Areas (EBSAs) in the marine realm, (3) identifying Wetlands of International Importance under the Ramsar Convention; (4) identifying sites of importance for species under the Convention on Migratory Species and its sister agreements; (5) identifying Special Protected Areas under the EU Birds Directive; (6) applying the environmental safeguards of international finance institutions such as the International Finance Corporation; (7) supporting the private sector to manage environmental risk in its operations; and (8) helping donor organisations like the Critical Ecosystems Partnership Fund (CEPF) to prioritise investment in site-based conservation. The identification of IBAs (and IBAs in Danger: the most threatened of these) has also triggered conservation and management actions at site level, most notably by civil society organisations and local conservation groups. IBA data have therefore been widely used by stakeholders at different levels to help conserve a network of sites essential to maintaining the populations and habitats of birds as well as other biodiversity. The experience of IBA identification and conservation is shaping the design and implementation of the recently launched Key Biodiversity Areas (KBA) Partnership and programme, as IBAs form a core part of the KBA network.
 
Top-cited authors
John Croxall
Andy Symes
  • BirdLife International
Ben Lascelles
  • Harewood Estate, Leeds, United Kingdom
Ben Sullivan
  • Fishtek Marine
Richard Cuthbert
  • World Land Trust