秦岭南坡常见雀形目鸟类密度调查

通过对秦岭南坡凤县、太白、留坝,洋县、略阳、佛坪、城固县境内21样方118条样线雀形目鸟类调查,观察到雀形目鸟类13科28种。记录数量少于10只的鸟类有7种,占观察记录鸟类数的25.00%;大于10只小于100只的鸟类有6种,占观察记录鸟类总数的21.43%;大于100只的鸟类有15种,占观察记录鸟类总数的53.57%。黄腹山雀、绿背山雀、红头长尾山雀和紫啸鸫观测到的数量最少,各为1只,而且各种仅出现在1个样方和1条样线中。大山雀、麻雀和喜鹊观察到数量最多,分别为657、621和568只。出现在样线最多的为喜鹊(78条)、大山雀(59条)和绿鹦嘴鹎(58)。平均密度最小的包括黄腹山雀(2.222 2)、紫啸鸫(2.222 2)和绿背山雀(3.268),均仅出现1条样线。平均密度最大的包括山麻雀(50.101 0±13.987 0)、棕头鸦雀(48.074 9±16.927 0)、金腰燕(45.432 5±39.364 9)和沼泽山雀(40.791 1±15.318 0),但这些数量并非最多。     

What makes an effective restoration planting for woodland birds?

Large-scale vegetation clearing accompanying agricultural development has been a major driver of biodiversity loss. Efforts to reverse this problem have often included revegetation, but the value of revegetated areas for biodiversity is poorly known. We addressed aspects of this knowledge gap using a case study in south-eastern Australia. We quantified relationships between bird species richness and the probability of detection for eight individual bird species and: (i) the context of a planting, i.e. the types of the vegetation cover in the neighborhood of a planting, (ii) the configuration of a planting, i.e. the location and geometry of a planting, and, (iii) the content of planting, i.e. the vegetation features of a planting.The presence and nature of the effects of these explanatory variables varied with each of our response variables. A combination of context, configuration and content variables were needed to explain the variability in species richness and the presence of individual species. Context effects were highly significant, particularly the amount of planted and remnant native vegetation surrounding plantings. We speculate that when the area surrounding a planting was potentially suitable, recognition of planting “patch” boundaries disappeared and, correspondingly, configuration effects such as planting size were limited. Our results suggest that maximizing the value of planted areas for bird biota requires consideration not only of the features of the vegetation within a planting, but also where a planting is placed.     

The disproportionate value of scattered trees

Scattered trees are declining in agricultural landscapes worldwide. They are considered keystone structures because their effect on ecosystem functioning is believed to be disproportionate relative to the small area occupied by any individual tree. We empirically demonstrate the disproportionate value of scattered trees for birds and bats in an Australian livestock grazing landscape. We surveyed birds at 108 sites and bats at 63 sites. Sites spanned the full range of tree densities in the study area, from zero to over 100 trees per hectare. The marginal value of individual trees was highest when trees occurred at low densities. Compared to treeless sites, bird richness doubled with the presence of the first tree; bat richness tripled with the presence of 3-5 trees; and bat activity increased by a factor of 100 with the presence of 3-5 trees. Thereafter, the marginal effect of additional trees on birds and bats diminished rapidly. Although specialist species were restricted to large areas of dense tree cover, scattered trees effectively maintained moderate levels of bird and bat activity throughout largely cleared parts of the landscape. Future management activities should recognize the disproportionate value of scattered trees.     

Microbiological survey of birds of prey pellets

A microbiological survey of 73 pellets collected from different birds of prey species housed at the Wildlife Rescue and Rehabilitation Center of Napoli (southern Italy) was performed. Pellets were analyzed by culture and biochemical methods as well as by serotyping and polymerase chain reaction. We isolated a wide range of bacteria some of them also pathogens for humans (i.e. Salmonella enterica serotype Typhimurium, Campylobacter coli, Escherichia coli O serogroups). This study highlights the potential role of birds of prey as asymptomatic carriers of pathogenic bacteria which could be disseminated in the environment not only through the birds of prey feces but also through their pellets.     

陕西省鸟类新纪录——斑鱼狗

2019年3月11日,在西安市浐灞国家湿地公园观鸟时,发现了1只斑鱼狗。这是该种鸟第一次在陕西省被记录。陕西斑鱼狗的居留型还有待进一步确定。     

Impact of cork extraction on birds: Relevance for conservation of Mediterranean biodiversity

Montados are Mediterranean agro-forestry-pastoral systems recognized as an excellent example of balance between socio-economic development and biodiversity conservation. The economic viability of montados dominated by cork oak Quercus suber depends on the extraction of cork (the bark of trees), usually in 9 year cycles, which is mostly used for production of bottle stoppers. This study evaluated the impact of cork extraction on biodiversity, using birds as indicators.Comparing bird assemblages of areas with recently extracted cork and older cork revealed that only two species of bark gleaners and two of bark-foliage gleaners had lower densities in recently debarked areas. Arthropod sampling revealed that, in the first years after cork extraction, the bark has less prey, suggesting that the reduction in bark gleaners densities is a result of the decreased food availability. Focal observations confirmed that the affected species were those that foraged mostly on cork. However, our data demonstrated that bird richness and the density of the majority of species were unaffected by debarking, and that at the landscape level even bark gleaners had potentially stable populations.Pressure from the synthetic bottle stopper industry threatens to render montados economically unviable, and consequently be replaced by land uses much less valuable for biodiversity. Showing that cork extraction is compatible with the maintenance of the great ornithological value of montados, our results confirm that it is an economic activity that should be promoted for the benefit of biodiversity.     

Population trends of birds across the iron curtain: Brain matters

One approach to assess human impact on species’ population dynamics is to correlate ecological traits of species with their long-term population trends. Yet, few studies investigated population trends in multiple regions that differ in human impact to reveal which traits explain population trends over larger geographic areas and which only regionally. We examined the relationship between various species traits and long-term population trends of 57 common passerine bird species from 1991 to 2007 in three adjacent regions in central Europe that experienced differences in socioeconomic history: North-Western Germany, Eastern Germany and the Czech Republic. We tested effects of habitat, dietary and climatic niche, migratory strategy and cognitive ability, measured as relative brain size. We predicted that traits reflecting socioeconomic and land-use change had stronger effects in former communist countries than in North-Western Germany due to marked changes in these countries after 1990. We found that climatic niche and migratory strategy affected bird abundances similarly in all regions suggesting their influence is invariant across central Europe. In contrast, brain size showed regionally varying effects. The effects were negligible in North-Western Germany, slightly positive in Eastern Germany and strongly positive in the Czech Republic. Increases of species with large brains suggest that species with good cognitive abilities might have been better able to adapt to rapid socioeconomic change and make use of novel opportunities after the end of communism. Regional differences in population trends among species thus appear to be driven by an interaction between cognitive abilities and socioeconomic change.