The Central Pacific Conservation Area contains one of Costa Rica's two viable, but threatened Scarlet Macaw Ara macao populations. For 14 years (1990–2003), we monitored the size of this population. Non-linear models fitted to 1990–1994 observations revealed seasonal and long-term changes in population size. The peak of annual population size occurred in August, with a cyclic range of about 90 birds between the lowest and highest points of the annual cycle. The best model also revealed a decline in population size of approximately eight birds counted per year or 4% of the total population per year (1990–1994). Young-to-adult ratios calculated for the month of August during this study fluctuated around a baseline that averaged 6.1% a year (1990–2003). These ratios exceeded 8% for three different years (1995, 1996 and 2000). All three of these “good” recruitment years occurred after management began, and two of them were associated with zealous anti-poaching efforts that ultimately could not be sustained. After intensive management practices began in 1995, the August counts increased by about 37 individuals in two years (1995–1996) to an average 243 individuals, which remained almost constant up to 2003. Management practices included creation of a local conservation organization that coordinated environmental education, artificial nest construction, networking among stakeholders and with governmental authorities, and artificial and natural nest protection. Although Scarlet Macaw conservation efforts have been inconsistent since 1997, our study demonstrates that collaborative conservation by local stakeholders increased the population of this threatened species in 1995–1996, and from 1996 to present the population has sustained itself.

Powerlines may pose severe threats to bird populations. We assessed the significance of powerlines as a source of avian mortality within the Italian electric transmission and distribution system. We reviewed data from 11 mortality censuses and compiled a list of species that were found among powerline victims in Italy, based on over 1,300 reported individual casualties. Overall, 95 species of birds were reported among powerline victims (19% of Italy's total species). The number of recorded species was compared with the number of species in the Italian list, after grouping species based on morphology and ecology. Some groups (e.g. raptors, herons, storks and allies) were highly affected, while others (e.g. passerines and allies) appeared to be poorly represented among species involved in powerline accidents. Furthermore, we evaluated the validity of a published discriminant model for the classification of bird species as collision or electrocution victims according to body measurements. The application of the available model classified 54.7–73.5% of Italian species correctly (depending on the species included), compared with 88.6% of the original dataset. Two new discriminant models based on Italian powerline casualties classified 80.9–81.1% of species correctly. This approach can be a useful tool in assessing collision and electrocution risk for species in different geographical areas. While we recognize the need for a general preventive approach for reducing the bird–powerline conflict, our review highlights once more the importance of local situations, where powerlines may have a strong impact on avian communities.

The transition to the use of non-toxic shot and fishing weights has been slow at the international level despite the Bern Convention and the African Eurasian Migratory Waterbird Agreement (AEWA) having called for a ban on lead shot use by the year 2000. Adopting lead substitutes is also consistent with the habitat goals of the Ramsar Convention and the Biodiversity Convention. In countries where non-toxic shot and sinkers are required by law, published studies show a marked reduction in lead toxicosis and large savings of birds. A renewed commitment from the AEWA, the Bern Convention, and especially the Ramsar Convention is needed to encourage their parties to regulate the use of non-toxic materials. Eleven different non-toxic substitutes for shot now exist, and some of these can also serve as substitutes for lead sinkers. While previous regulatory emphasis has been placed on wetland habitats, any new initiatives could also propose a phasing out of lead shot in upland habitats to reduce the prevalence of secondary lead poisoning of migratory raptors.

Herewith the UNEP/AEWA Secretariat gives a response to the paper by Vernon G. Thomas and Raimon Guitart entitled “Role of international conventions in promoting avian conservation through lead toxicosis: progression towards a non-toxic agenda”.

The global population of the Critically Endangered Raso Lark Alauda razae was estimated in January 2003 at 93–103 birds and in November 2003 at 76–87 birds. Of these, only 25–35% were females. Counts were based on observations of individually colour-ringed and measured birds. Birds were not breeding during the January visit, and were concentrated in two small areas at opposite ends of the island of Raso. This distribution differed substantially from that recorded previously during the breeding season. Three different feeding strategies were apparent: flocking, aggregating around key resources and feeding singly or in pairs. Birds moving to new feeding areas immediately adopted the feeding strategy of other birds present. Birds were seen drinking seawater on several occasions. In November 2003, birds were breeding but nest survival was extremely low due to high rates of egg predation. No evidence was detected of introduced predators on Raso. However, a population of feral cats was found on nearby Santa Luzia, prohibiting natural colonization or deliberate introduction of Raso Lark to the island, despite much apparently suitable habitat there. Faecal analyses showed that these cats feed largely on skinks. Increased tourism development on neighbouring islands is identified as a potential threat to the species.

In 2001 and 2002, we assessed avian richness in Linggoasri (central Java) where almost all lowland rainforest had been cleared 3 years previously. Bird surveys were carried out in a selectively-logged forest, two regenerating forests and one pine Pinus merkusii plantation. A comparison with a bird list complied at least 3 years prior to logging in Linggoasri showed that 10 lowland bird species may have been extirpated from this area following logging. However, further surveys will be needed to validate these extirpations. A comparison with a list of lowland forest birds of Java shows that only 37% of these occurred in Linggoasri. From the lowland avifauna of Java, sole frugivores and insectivores were less likely to be present in Linggoasri. Smaller, generalist-feeding lowland species, endemic to Java, were more likely to be present in this area. Persisting lowland bird species, however, did not appear to be seriously affected physiologically by habitat degradation, showing no significant loss of body condition or reduction in survival and reproduction. There is an urgent need to preserve the few remaining lowland forest patches of Java and, given the alarming rate of deforestation throughout Southeast Asia, it is critical to conserve adequately large primary lowland forests (e.g. >5,000 ha) if we are to preserve existing lowland avifauna.

We examined the causes and consequences of disturbance to the chicks of Hooded Plover Thinornis rubricollis in central southern Victoria, Australia. Humans were the most frequent source of encounters, and response rates to a variety of stimuli were high. Three possible mechanisms by which disturbance could reduce chick survival were evaluated. (1) Disturbance might cause thermal stress to chicks. An encounter with a human often caused brooding to cease, but it is not clear whether overall levels of brooding were compromised. Chicks found themselves un-brooded due to disturbance for up to 290 min, and in ambient temperatures of 10–46°C. (2) Disturbance might cause energetic stress to chicks. Encounters with humans usually caused chick foraging to stop. Higher levels of disturbance were associated with less chick foraging. There was a tendency for broods to forage in lower and potentially more profitable levels of the habitat in less-disturbed conditions. However, the overall pattern of habitat use was similar during disturbed and less-disturbed conditions. (3) Adult defence of broods could be compromised by disturbance. However, no brood predation occurred in disturbed circumstances, and adults stayed close to their broods even in disturbed conditions. These data suggest that defence of chicks was not compromised by disturbance.

Endemic to the islands of Guam and Rota in the Mariana Islands, Mariana Crow Corvus kubaryi is the only corvid in Micronesia. Currently, it survives on Guam only because of translocation of individuals from Rota (1999–2003). Island-wide surveys in 1982 and 1995 on Rota yielded population estimates of 1,348 and 592 respectively, indicating a 56% decrease in only 13 years. A sharp decline in the only viable Mariana Crow population has serious implications for conservation efforts on Rota and for efforts to re-establish the Guam population. However, the validity of the apparent decline has been debated among scientists and government management agencies. We augmented the 1982 and 1995 island-wide VCP surveys with (1) an additional island-wide survey conducted in 1998, and (2) roadside surveys conducted during 1991–1993 and again during 1999–2002. We also outline historical changes in Rota's limestone forest based on aerial photographs and historical information. Data from all surveys indicate a significant decline in the Mariana Crow population. Declines occurred especially along the north-central coast and in the area east of the airport known as As Dudo in the 1990s, but the data indicate an island-wide decline over the entire span of the surveys. Introduced predators, human persecution, and habitat loss and degradation by anthropogenic and natural causes have all contributed to the decline. Long-term preservation of this species will require effective brown treesnake Boiga irregularis control, habitat protection, continued monitoring and research, and increased public education and awareness of Rota's rare and endangered species.