Bird Conservation International - Current Issue

Volume 18 Issue 01

Sat, 01 Mar 2008 00:00:00 GMT

Bird Conservation International, Volume 18 Issue 01

Bird Conservation International is a quarterly peer-reviewed journal focusing on the conservation of birds and their habitats. The official journal of BirdLife International, it provides stimulating, international and up-to-date coverage of a broad range of conservation topics, using birds to illuminate wider issues of biodiversity conservation and sustainable resource use. Bird Conservation International publishes original papers and reviews, including specifically-targeted articles and recommendations by leading experts. It seeks to promote world-wide research and action for the conservation of birds and the habitats upon which they depend. Bird Conservation International has a special online subscription rate for individuals in developing countries. Please contact Journals Customer Services at journals@cambridge.org for more information.

Sources of variation in mortality of the Bearded Vulture Gypaetus barbatus in Europe

Research Articles
Antoni Margalida, Rafael Heredia, Martine Razin, Mauro Hernández,
Bird Conservation International, Volume 18 Issue 01 , pp 1-10

Abstract
We analyse the causes of mortality for the Bearded Vulture in Europe. Shooting (31%), intentional poisoning (26%), collision (18%) and unintentional poisoning (12%) were the most important causes of mortality. No differences were found between sexes or age classes (non-adults and adults) for any of the causes of death. When the four main categories of mortality were grouped in periods of 3 years from 1986 (coinciding with the species' reintroduction to the Alps) to 2006, mortality showed significant temporal variation. The results suggest that while the number of collision/electrocution deaths has remained stable or increased slightly, the number of cases of shooting has declined during the last 6 years, while at the same time intentional and unintentional poisonings have increased. We found substantial differences between causes of mortality recorded for birds located by chance (75% related to shootings and collisions with powerlines) and radio-tagged birds (86% related to intentional and unintentional poisoning), suggesting biases in methodology for monitoring mortality. The results suggest that human persecution continues to be the main factor contributing to unnatural mortality for European Bearded Vultures. Future management actions should concentrate on the creation of protocols for the collection of carcasses and detailed analyses to determine and mitigate anthropogenic sources of mortality.

Implications of deforestation for the abundance of restricted-range bird species in a Costa Rican cloud-forest

Research Articles
Vicencio Oostra, Laurens G. L. Gomes, Vincent Nijman,
Bird Conservation International, Volume 18 Issue 01 , pp 11-19

Abstract
Central America is a region of great avian diversity, and the highlands of Costa Rica and Panama are particularly rich in endemic bird species. Continuing deforestation has destroyed large parts of the birds' natural habitats in this region. The ability of birds to use non-forest habitats will ultimately determine their vulnerability to further deforestation, and knowledge of their habitat use is therefore essential in planning conservation strategies. We examined the effects of deforestation on the abundance of restricted-range bird species in the southern Costa Rican part of the Talamanca mountain range. We used line-transect distance sampling to obtain densities in forest and non-forest habitats. Most (22/28) restricted-range species were recorded in forest and non-forest. Of 28 restricted-range species, 13 species showed a clear preference for forest and 8 for non-forest, and total numbers were one-and-a-half times higher as high in forest compared with non-forest. Of the 10 most common species, one was more abundant in non-forest and seven were more abundant in forest. We conclude that forest is the primary habitat for the majority of the restricted-range avifauna, and their dependence on forest makes them particularly vulnerable to deforestation. Adequate protection of the forests in these mountains is therefore the best assurance of the long-term survival of these birds.

Taxonomic and conservation implications of ecological speciation in Nesospiza buntings on Tristan da Cunha

Research Articles
Peter G. Ryan,
Bird Conservation International, Volume 18 Issue 01 , pp 20-29

Abstract
In addition to protecting species, conservation also includes the maintenance of evolutionary processes, but this aspect is often overlooked. Nesospiza buntings provide a good case study of the need to conserve evolutionary processes. They are endemic to the South Atlantic Tristan da Cunha archipelago, and traditionally have been treated as two species, with each having different subspecies on Nightingale and Inaccessible Islands. Both species are listed as Vulnerable because of their small ranges ( 20 km2) and the threat posed by the possible introduction of alien organisms such as mice or rats. The two species differ markedly in size, especially bill size, related to dietary differences. However, recent research suggests that morphological diversity evolved independently on Nightingale and Inaccessible Islands, necessitating a revision of the taxonomy within the genus. I recommend that five taxa be recognized, with two endemic to Nightingale and three to Inaccessible Island. N. wilkinsi and N. questi on Nightingale are well-defined species, but there is considerable hybridization between taxa on Inaccessible Island. These three taxa may be incipient species, but are perhaps best treated as subspecies: N. acunhae acunhae, N. a. dunnei and N. a. fraseri (nom. nov.). All three species qualify as threatened, with N. acunhae and N. questi Vulnerable and N. wilkinsi Endangered. With fewer than 200 individuals, N. wilkinsi has one of the smallest natural populations of any bird. A reassessment of its population size is a conservation priority, following the 2001 storm that damaged many Phylica trees on Nightingale Island. Improved biosecurity quarantine measures are also needed for Nightingale Island. Care should be taken not to disrupt the natural processes occurring among bunting taxa on Inaccessible Island.

Camera trapping rare and threatened avifauna in west-central Sumatra

Research Articles
Yoan Dinata, Agung Nugroho, Iding Achmad Haidir, Matthew Linkie,
Bird Conservation International, Volume 18 Issue 01 , pp 30-37

Abstract
Tropical forests are becoming increasingly degraded and fragmented by logging, which can affect the survival of forest bird species in different ways. In this study, we present avifauna data collected from a monitoring programme in west-central Sumatra that set camera traps in three study areas with different habitat types, levels of degradation and protection status. From 5,990 camera trap-nights, 248 independent bird photographs were recorded, comprising four orders and nine species, including three endemic species. The Great Argus Pheasant (Argusianus argus) was recorded in all study areas and most frequently (n = 202 photographs), followed by the threatened Salvadori's Pheasant (Lophura inornata). The greatest diversity of bird species (five) and abundance index (1.44 bird photographs/100 trap-nights) was recorded from a primary hill-submontane forest site located inside Kerinci Seblat National Park (KSNP) bordering degraded forest in a former logging concession recently repatriated into KSNP. However, inside a primary-selectively logged hill-submontane forest site spread over KSNP and an ex-logging concession, a Sumatran Ground Cuckoo (Carpococcyx viridis) was photographed. This species is noteworthy because prior to this study it had only been documented once since 1916. It is therefore crucial to use the camera trap results to increase the protection status for the ground cuckoo area. This has already happened in the other two study areas, where camera trap data have been used to reclassify the areas as Core Zones, the highest level of protection inside KSNP. This study illustrates how routine monitoring can have wider benefits through recording, and conserving, threatened and endemic non-target species in unexpected habitats that might not otherwise have been surveyed.

The historical and current status of Pink-headed Duck Rhodonessa caryophyllacea in Myanmar

Research Articles
Andrew W. Tordoff, Tim Appleton, Jonathan C. Eames, Karin Eberhardt, Htin Hla, Khin Ma Ma Thwin, Sao Myo Zaw, Saw Moses, Sein Myo Aung,
Bird Conservation International, Volume 18 Issue 01 , pp 38-52

Abstract
Pink-headed Duck Rhodonessa caryophyllacea is a Critically Endangered species that has not been confirmed in the wild since 1948 1949. Historical records of the species are concentrated in India, although there are also a few from Myanmar. Between 2003 and 2005, BirdLife International and the Biodiversity and Nature Conservation Association (BANCA) conducted a series of field surveys of wetland habitats in the lowlands of Kachin state, an area with a cluster of historical records of the species. These were the first targeted efforts to assess the status of the species in Myanmar. These surveys were complemented by reviews of museum specimens and literature relating to the species in Myanmar. Two specimen records represent very strong evidence that the species occurred in Myanmar historically, although they shed little light on its seasonal status in the country. The surveys conducted by BirdLife International and BANCA were unable to confirm the continued occurrence of Pink-headed Duck in Myanmar. However, they did generate a limited amount of equivocal direct evidence, most notably two possible but unconfirmed sightings. There are several reasons for believing that the species may still persist in the lowlands of Kachin state and, perhaps, elsewhere in Myanmar. Shyness, combined with rarity, possible nocturnal habits and the impenetrability of its habitats, means that the species tended to be under-recorded historically, and may continue to be so currently. Further surveys are required to confirm this.

Geographic distribution, habitat association, and conservation status of the Critically Endangered Minas Gerais Tyrannulet Phylloscartes roquettei

Research Articles
Leonardo Esteves Lopes, Diego Hoffmann, Marcos Maldonado-Coelho, Edson Ribeiro Luiz, Santos D'angelo Neto,
Bird Conservation International, Volume 18 Issue 01 , pp 53-62

Abstract
Summary The Minas Gerais Tyrannulet Phylloscartes roquettei is currently classified as a Critically Endangered species, and is one of the most poorly known Neotropical birds. Here we report seven new localities for the species in the S o Francisco river basin, raising to 17 the number of localities where this species is known to occur. The range of this species was estimated at 33,500 km2, covering a wider habitat spectrum than previously thought, including, in addition to dry forests, riparian and semi-deciduous forests. We believe this species is overlooked because its voice is generally unknown and available plates in field guides are inaccurate.

Abundance and spatial distribution of Greater Rhea Rhea americana in two sites on the pampas grasslands with different land use

Research Articles
Paola F. Giordano, Laura M. Bellis, Joaquín L. Navarro, Mónica B. Martella,
Bird Conservation International, Volume 18 Issue 01 , pp 63-70

Abstract
Summary In Argentina the original landscape structure of the pampas grasslands has changed rapidly due to intensified and specialized agricultural practices. The conversion of grasslands into croplands has been suggested as a threat to Greater Rhea Rhea americana populations. The main goals of this study were to estimate the abundance of Greater Rheas and to analyse the species' spatial distribution at two sites of the pampas region with different land use: agro-ecosystem and grassland. The former was mainly devoted to crop production whereas the latter was mostly used for livestock grazing. Data were collected through 14 aerial surveys from 1998 to 2001, and in 2004. Each survey consisted of six strip-transects per site, spaced at regular intervals. The total area surveyed represented 4% of each study site (113 km2 in the grassland and 95 km2 in the agro-ecosystem). Greater Rhea density ( 0.11 to 0.86 2) than in the agro-ecosystem (from 0.05 0.08 ind. km 2). Greater Rheas occupied 51% of the study area in the grassland but less than 5% in the agro-ecosystem. They showed a wide and uniform spatial distribution in the former area, whereas in the latter individuals occurred in small and isolated clusters. These results raise concern about the future of the species because, over recent years, land has been increasingly used for crop production. Hence, if the current rate of change in land use continues, the conservation status of this species will be seriously affected.

Waterbird population estimates for a key staging site in Kazakhstan: a contribution to wetland conservation on the Central Asian flyway

Research Articles
Holger Schielzeth, Götz Eichhorn, Thomas Heinicke, Johannes Kamp, Maxim A. Koshkin, Alexej V. Koshkin, Lars Lachmann,
Bird Conservation International, Volume 18 Issue 01 , pp 71-86

Abstract
Realistic population size estimates for waterbirds are crucial for the application of wetland conservation strategies, since the identification of internationally important wetlands is based on local numbers relative to the population size of the respective species. Central Asia is a poorly surveyed region that is situated at the intersection of migration routes that lead waterbirds from Western Siberia to the south-west (South-West Asia, East Africa) and to the south-east (South Asia, India). We calculated waterbird population estimates for the Tengiz Korgalzhyn region, a large wetland complex in the steppe zone of Central Kazakhstan, based on waterbird surveys conducted between 1999 and 2004. For 20 of 43 species analysed the region supported more than 5% of the relevant flyway populations. Five species occurred with more than 40% of the flyway totals, including the Endangered White-headed Duck Oxyura leucocephala and the Vulnerable Dalmatian Pelican Pelecanus crispus. Peak numbers were recorded in summer and autumn and for most species numbers were more than an order of magnitude lower on spring migration compared with autumn migration. We identified 72 individual sites that held more than 20,000 waterbirds or more than 1% of a particular flyway population at least once. These sites are likely to constitute priorities for conservation. The general conservation status of the region is favourable, since many of the important sites are located within a strict nature reserve. However, outside the reserve hunting, fishing and powerline casualties represent conservation issues that should be monitored more carefully in the future.