Bird Conservation: The Science and the Action Report on the BOU Joint Conference, 6–10 April 1994

• 1 Birds are hugely popular and the public demands their conservation.
• 2 Ornithology has made a major contribution to nature conservation by virtue of this popular support. The value of birds as environmental indicators has been greatly enhanced by voluntary data collection on a wide scale over many years.
• 3 Habitat loss and degradation are the main causes of species decline, even though other factors may contribute to extinction. More research should address the causes of decline at an early stage, while the chance of recovery is highest.
• 4 The geographical ranges of native bird species should be maintained, both to avoid the risk of local or wider extinction and to enable people to enjoy them as part of their normal experience.
• 5 To maintain species ranges. conservation must be incorporated in policies affecting the wider countryside and the sea. This is as important as managing protected areas.
• 6 The management of protected areas can only be successful in the context of sympathetic management of the surrounding countryside.
• 7 The Biodiversity Convention requires countries to produce national conservation plans and strategies. This offers ornithologists an unprecedented opportunity to contribute to conservation by developing explicit objectives and specific targets for the maintenance (or restoration) of numbers and distributions of species, and of extent and quality of habitats. Targets should be ambitious but realistic and be sufficiently precise as to be testable.
• 8 Predictive models have the potential to support conservation advice, but traditional natural history studies have proved vital in the past and theory could not replace them.
• 9 Detailed ecological research with long data runs is the ideal basis for conservation action. But urgency demands shorter studies, informed by ecological intuition and knowledge, and reaching specific recommendations for action.
• 10 Conservation actions should be treated as experiments so that techniques can be improved progressively. This applies both to the management of nature reserves and to habitat management stemming from broader policy measures, for example in Environmentally Sensitive Areas.
• 11 Monitoring across a wide species base is essential because the threats to wildlife are unpredictable. Birds have proven to be successful indicators because they are highly visible: are enthusiastically counted by volunteers: and respond to a wide variety of environmental impacts.
• 12 Threshold levels, indicating the normal upper and lower levels of variation (for instance in numbers or breeding success), are needed in order to trigger prompt remedial action.
• 13 Monitoring, research and consenration action must be taken forward internationally. Integrated and common approaches enable exchange of data and inforniation. and reinforce national actions across the range.
• 14 Fxisting data need to be made more accessible by greater collaboration and openness, and by the use of computerization.
• 15 Ornithologists need to build stronger partnerships, both with other biologists and with decision-makers across the range of land-use and economic policy. This will be helped by better communication built on clear but simple messages for non-biologists.
• 16 The training of future ecologists should take account of the wide range of skills required by the expanding discipline of conservation.

     

Bird Tracks at the Hot Springs Mammoth Site,South Dakota,USA

The Hot Springs Mammoth Site, South Dakota, USA, has been excavated for over three decades, during which time numerous body fossils have been recorded. The site is particularly well known for the skeletal remains of mammalian megafauna. Bedding plane surfaces were studied that displayed the first record of small vertebrate (avian) and invertebrate traces. While large vertebrate tracks, often observed in cross-section, are well known at the site, the new traces form a hitherto unstudied assemblage.

The presence of distinct didactyl and tridactyl avian tracks from the site are described here for the first time. The small (～20 mm long) tracks and associated invertebrate traces suggest relatively high moisture content in the substrate on surfaces that experienced aerial or subaerial exposure. This is consistent with the interpretation that the upper layers of the site represent the latter stages of a sinkhole setting with a pond undergoing cyclical drying out.     

On the distribution of terrestrial invertebrates at Cape Bird, Ross Island, Antarctica

Terrestrial invertebrate distribution was surveyed over 12 km² of the ice-free area at Cape Bird, Ross Island, Antarctica. Gomphiocephalus hodgsoni (Collembola: Hypogastruridae), Stereotydeus mollis and Nanorchestes antarcticus (Acari: Prostigmata), Panagrolaimus davidi, Plectus sp. and Scottnema lindsayae (Nematoda), Tardigrada, Rotifera and Protozoa were all recorded. Invertebrates were found at 47 of 103 locations sampled. Logistic regression analysis suggested that the presence of mites and Collembola was strongly related to chlorophyll-a content of soil; but only Stereotydeus mollis and N. antarcticus were related to the presence of macroscopic vegetation, suggesting that current methods of assessing areas for protection may not adequately allow for invertebrate communities. Invertebrate communities were not dependent on ornithogenic carbon input. A better understanding of dispersal mechanisms is necessary to understand distributions of invertebrates in ice-free areas, particularly in light of potential habitat changes as a result of climate change.     

四川老君山自然保护区不同生境鸟类多样性研究

2006年4~5月采用"点样带法"(point transects)对四川老君山自然保护区的鸟类物种组成和种群数量进行了调查,共记录到85种鸟类,分属7目22科。其中,国家级保护鸟类5种,我国特有种13种,优势种4种。把调查区域划分为3种生境:原始林、次生林和人工林,并对各生境鸟类群落的鸟类数量级、鸟类群落的物种多样性、鸟类群落间的相似性进行了比较分析,其结果表明:1)国家级保护鸟类在原始林中最多,次生林中最少;我国特有种则是次生林中最多,人工林中最少。2)鸟类群落Shannon-Wiener物种多样性指数原始林最高,人工林最低。3)原始林和次生林之间的B ray-Curtis相似性指数最高,原始林和人工林之间相似性指数最低。     

Bird collisions at an offshore platform in the North Sea

Capsule Collisions with offshore structures in the North Sea could account for the mortality of hundreds of thousands of nocturnally migrating birds.

Aims To assess, for the first time, the circumstances of mass fatalities at an offshore structure, including the species involved, their numbers, ages, body conditions and injuries.

Methods At an unmanned tall offshore research platform in the southeastern North Sea, bird corpses were collected on 160 visiting days from October 2003 to December 2007. Corpses were identified to species and kinds of injury, ages, and fat and muscle scores were determined. Nocturnal bird calls were recorded, identified to species and quantified. Local and large-scale weather parameters were also considered.

Results A total of 767 birds of 34 species, mainly thrushes, European Starlings and other passerines, were found at 45 visits. Most carcasses were in good body condition and young birds were not more affected than adults. Three quarters of 563 examined individuals had collision induced injuries. Birds in poor body condition were less likely to be collision victims than those in good condition. Mass collision events at the illuminated offshore structure coincided with increasingly adverse weather conditions and an increasing call intensity of nocturnal birds.

Conclusions Assuming an average of 150 dead birds per year at this single offshore structure and additionally assuming that a considerable proportion of the corpses were not found, we estimate that mortality at the 1000?+?human structures in the North Sea could reach hundreds of thousands of birds. Since offshore industrialization will progress and collision numbers at offshore turbines will consequently increase considerably, we recommend reinforced measures to reduce bird strikes at offshore structures, especially in the light of substantial declines in some migrant species.     

Diet of the south polar skua Catharacta maccormicki at Cape Bird,Ross Island,Antarctica

Regurgitated pellets and fecal samples from south polar skuas Catharacta maccormicki breeding on Ross Island were analyzed for diet items. Adult penguin feathers were found in 79% of all the pellets and 42% of the fecal samples. Evidence of fish was found in 26% of the pellets and 39% of the fecal samples. The amount of refuse in the diet of skuas on Ross Island was directly related to the distance from McMurdo Station.     

Annual variation in the timing of reproduction in Antarctic fur seals, Arctocephalus gazella, at Bird Island, South Georgia

The arrival of Antarctic fur seals at a breeding beach on Bird Island, South Georgia, was studied over five consecutive breeding seasons, 1983 to 1987. Experienced bulls arrived first and established breeding territories on the beaches in anticipation of the arrival of the cows. Male arrival, which is less synchronous within years than female arrival, was significantly later in 1987 than in any other year. Female arrival, estimated by pup birth date where necessary, was highly synchronous; it usually started when 80% or more of potential territory sites were occupied by males. Cows arrived significantly later in 1984 and 1987 than in 1983, 1985 or 1986. The late arrival of both males and females in 1987 is attributed to unusually severe climatic conditions during the preceding winter. The late arrival and reduced fecundity of females in 1984 is attributed to markedly reduced food availability during the austral winter and summer of 1983. Males were not affected in 1984 because they could move away from the area of reduced food availability earlier than females and because they have a more varied diet. Factors influencing the winter distribution, the timing and pattern of arrival and the breeding of male and female Antarctic fur seals are discussed.