Mid-Holocene vegetation diversity in eastern Cumbria

The concept of biodiversity can operate at several different ecological levels from that of the Global ecosystem to the genetic diversity of a single species. This paper focuses on the beta-type diversity of vegetation communities at the intra and inter-regional scale, using five mid-Holocene (Neolithic) pollen diagrams from eastern Cumbria (c. 500 km² centred on the Eden valley). The sites were selected in order to include the variation in both soil/rock type and altitude within the study area, ranging from the Eden valley and southern limestone plateau to the foothills and summits of the western edge of the Pennines. The local pollen component which is dominant in these small sites, is used to determine intra-regional vegetation diversity for a time-slice in the Neolithic. Simple statistical methods are used to compare sites and as a measure of intra-regional vegetation-type diversity. This is compared with estimates of the community diversity for the British Isles during the same period. The results suggest that the intra-regional vegetation diversity is comparable to that of Northern England, and it is related to variation in both altitude and soil type. There are some differences, for example the steepness of the western face of the Pennines is probably responsible for a lack of the pine dominated zone, and pedological constraints probably prevented the full development of woodland on the limestone plateau at the south of the study area. The open landscape of the limestone plateau acted as a refuge for late glacial herbaceous taxa prior to their re-expansion into the wider landscape after widespread deforestation and arable cultivation. The results have implications for both the mapping of past vegetation at the national scale and for landscape archaeology.     

6种猛禽消化系统的比较研究

对6种猛禽(普通鵟Buteo buteo、毛脚鵟B.lagopus、红隼Falco tinnunculus、长耳鸮Asio otus、短耳鸮A.flammeus和鸮Bubo bubo)的消化系统形态结构进行了解剖测量和比较,以了解鸟类消化系统形态结构与食性的关系.结果显示,长耳鸮的消化管最长,是体长的2.08倍;鸮的消...     

Use of surrogate parental models and age periods in a successful release of hand-reared sandhill cranes

Ten sandhill crane chicks were reared in isolation from humans to prepare them for an experimental wild release. They were imprinted on realistic models using crane brooding calls and were fed by crane-like puppets. Six of the chicks were simultaneously imprinted on a human in a crane costume. The other four chicks were introduced to this surrogate parent at 5–7 days of age. The chicks were fed natural foods by the parent at two wild sites, one of which, the release site, was a staging area for migratory cranes. Observations were made on their behavioral development, including the time spent close to the model or costumed parent and the percentage of time spent foraging. The chicks spent the initial month close to the surrogate parent but moved away more to forage during the second month. The chicks regressed to again spend a great deal of time near the parent during the third and fourth months. They were released during this regressive period by removing the surrogate parent. All five of the released chicks showed increased interest in wild cranes within days of the release and formed a continuous association with wild cranes within 30 days. Four of the five were relocated by telemetry the following spring back in Wisconsin. These young juvenile cranes were excellent candidates for release due to their adaptable nature and their level of social development. The artificial stimuli of the surrogate parent helped the chicks to generalize their attachment to wild cranes. Once with wild cranes they quickly learned additional survival skills.     

Artificial incubation,hand-rearing,behavior, and release of common 'Amakihi (Hemignathus virens virens): Surrogate research for restoration of endangered Hawaiian forest birds

In order to test the effectiveness of captive-rearing and release strategies for future restoration of birds in Hawai'i, this pilot study was conducted in forests where introduced avian disease and mammalian predators were present. Methodology used resulted in the first successful hatching of Drepanidinae eggs in an incubator and subsequent hand-rearing of chicks from hatch. Sixteen Common 'Amakihi (Hemignathus virens virens) (mean hatch weight = 1.4 g) were hand-reared. Two different reintroduction strategies were evaluated for small honeycreepers. Known mortality in the wild after release was due to mosquito-transmitted disease (avian malaria and pox). This pilot study shows that the techniques necessary to hatch, rear, and release endangered Hawaiian honeycreepers are available. However, restoration efforts will probably not succeed unless mosquito-free, predator-controlled reintroduction sites are available or strategies are developed to decrease mortality in naive honeycreepers exposed to disease after release. © 1996 Wiley-Liss, Inc.     

被捕食动物对捕食者的识别研究及在放归中的应用

对捕食者的认知能力是当前生态学研究的一个热点。一些物种具有对捕食者先天的识别能力,而一些物种必须通过后天学习才能获得对捕食者的认知能力,还有许多动物通过社会学习和文化传播获得对捕食者的识别能力。本文就国外被捕食动物对捕食者的识别的研究进展进行综述,并讨论了该项研究对野外放归工作提供的重要理论意义和应用价值。     

Advances in the reintroduction of rare and endangered wild plant species

Human disturbance and climate change have increased the risk of extinction for rare and endangered wild plant species.One effective way to conserve these rare and endangered species is through reintroduction.In this review,we summarize the advances in wild plant reintroduction from five perspectives:the establishment of reintroduction biology as an important tool for biodiversity conservation;the importance of genetic diversity in reintroduction;reintroduction under global climate change;recruitment limitation in reintroduction;and reintroduction and ecological restoration.In addition,we consider the future of plant reintroduction strategies.     

Socialization of a Single Hand-Reared Tiger Cub

Given the drawbacks of hand-rearing nonhuman animals in captivity, the practice is generally avoided, but it is sometimes necessary. A few scientific publications are available to guide managers toward best practices in hand-rearing, but the majority of articles focus on hand-rearing captive primates. Less is known about hand-rearing carnivores, but early socialization appears to be critical for adult social behavior. This article documents the successful hand-rearing and reintroduction of a single female Sumatran tiger cub at Zoo Atlanta. Reintroduction included a systematic procedure that used scent trials and introduction sessions through a barrier to gauge interest and determine whether or not aggression was a problem. Based on signs of interest, reduced stress-related behaviors, and a lack of aggression, animal managers decided to proceed with reintroduction. During the introductions, the animals were not aggressive and did occasionally interact, although typical mother–infant interactions were rare. The cub has since bred naturally and successfully delivered and reared two litters of cubs. These data suggest limited exposure to an adult tiger may be adequate socialization for normal reproduction even if it is provided relatively late in the cub's development.     

Migration patterns of the Osprey Pandion haliaetus on the Eastern European–East African flyway

We analysed migration strategies of the Osprey Pandion haliaetus on the poorly studied Eastern European–East African flyway. Four adult birds were equipped with GPS-based satellite-transmitters or data-loggers in their breeding sites in Estonia (north-eastern Europe) and tracked to their wintering grounds in Africa and back, during up to six migration cycles. Departure times, migration routes, as well as wintering and stopover sites varied remarkably between individuals but not much between years. Stopovers (2–30 days) were made mostly in Europe and less in the Middle East (Turkey) and north-eastern Africa (Egypt). The Ospreys did not avoid flying long distances over the sea, and the sea was crossed four times during the night. The current study adds to current knowledge on Osprey migration and should help to concentrate actions on protecting important flyways and stopover locations.     

Human impact on mid- and late Holocene vegetation in south Cumbria, UK

The use of 9 pollen sampling sites and 56 14C dates has identified hitherto unsuspected or poorly-defined sequences of mid- to late Holocene (late Neolithic to post-Medieval) anthropogenic vegetation changes in south Cumbria, U.K. A series of small-scale, but significant woodland clearance episodes are recorded throughout the Bronze Age, followed by a marked recession in activity during the early Iron Age. The late Iron Age-Roman periods witnessed the first major clearance of woodland in the region which was succeeded by woodland regeneration in the post-Roman/early Medieval period. Woodland clearance intensified in the later Medieval period culminating in large areas of permanently open landscape. The results show that high-resolution, independently date pollen analysis is necessary to reveal regional evidence of small, temporary Bronze Age clearances. A well-documented prehistoric wooden trackway from Foulshaw Moss is shown to be significantly older than previously thought, dating to the mid-Bronze Age, ca. 1550–1250 cal B.C. Pre-Roman cereal cultivation in the area is also confirmed.The Department of Earth Sciences