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31.
A polymorphism in the sixth complement component (C6) has been investigated by isoelectric focusing. The results indicate that C6 is coded by genes at a single autosomal locus. Six structural alleles have been identified, a null allele is also postulated. Five island colonies of Shearwater were investigated, two alleles C6 A and C6 B predominate in all sites.
The ability of rabbit C5 and C7 to combine successfully with avian C6 indicates the functional sites of these molecules are highly conserved.  相似文献   
32.
Abstract

Two advantages could be gained by developing multi-species control by aerial baiting. It should assist pest managers to achieve sustainable resource management by improving the efficiency of operations; and it should reduce the likelihood of unwanted ecological side-effects (such as prey-switching) that sometimes follow when pest species are controlled individually. The technology to achieve efficient multi-species control is already well advanced, aided particularly by the refinement of aerial control of possums and by the development of baits for individual species. More effort will, however, be required to develop predictive models for planning the integration of multi-species control with conventional single-species control, and for predicting the ecological effects of such intervention.  相似文献   
33.
34.
Sooty Shearwater (Puffinus griseus) is the most common Procellariiform seabird along the south-eastern South American coast. In recent years the wintering population off California has declined noticeably. This decline has been confirmed on the breeding grounds in New Zealand. In Chile, knowledge of the population is limited. Investigations on Isla Guafo were carried out during two seasons (03/04 and 04/05), beginning an ongoing monitoring and evaluation of the breeding population of this species in southern South America. On Isla Guafo we estimate a population of about 4 million birds that nest above 150 m above sea level (m.a.s.l.) under a forest without understory. Sooty Shearwaters on Isla Guafo prefer north and western slopes that we hypothesise protect them from the predominantly southerly winds. Population of the species from New Zealand and Australia are compared with the Isla Guafo population and the state of its conservation is discussed.  相似文献   
35.
ABSTRACT Incidental seabird mortality associated with bycatch during longline commercial fishing is a conservation concern. An initial step to estimating likelihood of seabird bycatch and conceiving conservation strategies is determining amount of overlap between foraging birds and commercial fishing effort, identifying oceanographic features associated with foraging birds, and quantifying dive characteristics. We tracked 24 adult flesh-footed shearwaters (Puffinus carneipes) breeding on Lord Howe Island located east of Australia during incubation and early and late chick-rearing periods from 6 January to 17 April 2005. At-sea foraging distribution of flesh-footed shearwaters was primarily confined within the jurisdictional Australian Fishing Zone. Foraging was strongly associated with sea-surface temperature >24°C. Spatial and temporal overlap of longline fishing with foraging shearwaters varied throughout the breeding season, but was greatest (63% overlap) during early chick-rearing. Mean maximum distance reached from the breeding colony during a foraging event was 804 km (SD = 280) from Lord Howe Island. Foraging behavior was strongly diurnal, with 91% of dives occurring during daylight, and most dives (77%) were <5 m. Given that longline fishing and flesh-footed shearwaters overlap substantially, the Australian Fisheries Management Authority should consider implementing additional regulations to further reduce bycatch. Conservation strategies such as setting longlines at nights may reduce flesh-footed shearwater bycatch.  相似文献   
36.
We present morphometric data for the pink-footed shearwater (Puffinus creatopus) from both Chilean breeding colonies on Isla Mocha and Juan Fernández: weight, total length, wing length, tail length, head length, three bill and three tarsus size measurements and length of middle toe. Significant differences were found for most measurements between males and females as well as between birds from the two different breeding localities. In general, males were bigger than females, and birds from Juan Fernández were bigger than those from Isla Mocha. Geographic differences most likely reflect some kind of ecomorphological adaptation. Some variables, especially the total length of head, seem to be useful for sex determination in the field.  相似文献   
37.
Abstract

Adaptive co‐management and Participatory Action Research (PAR) promotes social ecological resilience by simultaneously protecting wildlife and its habitat and promoting capacity and motivation for sustainable harvest management by communities. We report here on a case study of learning through a partnership (1994–2009) between science and Traditional Ecological Knowledge (TEK) to determine the sustainability of titi (sooty shearwater, Puffinus griseus) harvests by Rakiura Maori in southern New Zealand. Testimony of Maori elders and titi harvesters (birders), members of the Rakiura Titi Islands Administering Body, researchers and participants in workshops and meetings were recorded throughout the 14‐year research project to identify critical determinants of success of the partnership. A large majority of participants supported the research, mainly because it expanded their knowledge by investigating the reasons for declining bird numbers and the means of ensuring the continuation of their muttonbirding heritage. Initial concerns about the research included fear that prohibition or quota would be imposed through political pressure from external groups; the intrusion of strangers on the islands; the misconception that the research was being promulgated by government regulatory agencies; and scepticism about research findings. Research also precipitated conflict and division within the Rakiura community, and some birders feared that science might displace matauranga Maori (TEK) of the Rakiura people for guiding harvest management. Core conditions for community engagement included trust between parties, effective communication of the science, equitable decision‐making responsibility, and building scientific capability and monetary support to enable meaningful participation. The most fundamental requirement is mutual respect for each party's knowledge. Attention to this inclusive, equitable, slow and prolonged process makes it more likely that the community will uptake results to improve sustainability of harvesting. The research has heightened awareness within the harvesting community of conservation issues facing the titi and of potential options to mitigate them. Eradication or control of weka (Gallirallus australis), and reducing titi harvest levels from around a quarter of the manu (family birding territories), are the main practical ways of increasing sustainability, but the magnitude and direction of climate change impacts on the shearwater population remains uncertain.  相似文献   
38.
ABSTRACT

With the development and implementation of tracking technology, we are now able to monitor the foraging behaviour of seabirds while at sea. Time-Depth Recorders (TDRs) were fitted to Hutton's shearwaters (Puffinus huttoni), an endangered endemic New Zealand species, to measure how diving behaviour varies over the breeding cycle. Hutton's shearwaters (~350?g) dive up to 339 times per day (average 68.8) at depths to 35?m (average 5.6?m), and for periods up to 60?s (average 19.2?s). Incubating birds dived deeper than birds feeding chicks, and a significant difference in diving depth and dive duration were detected at different times of the day. Neither dive frequency nor dive duration differed significantly between years, but there was some annual variation in dive depths. The temporal variation we observed in the diving behaviour of Hutton's shearwaters suggests they are likely to exploit different types of pelagic prey at different stages in their breeding cycle. With on-going changes in the marine environment, monitoring changes in feeding behaviour using TDRs may provide a way to assess environmental change and improve the conservation of this species.  相似文献   
39.
The first solitary migration of juvenile birds is difficult to study because of a low juvenile survival rates and sometimes long delays in return to the breeding grounds. Consequently, little is known about this crucial life event for many bird species, in particular the sensory guidance mechanisms facilitating the first migratory journey. Initial orientation during the first migration is a key measure to investigate these mechanisms. Here, we developed an assay to measure initial orientation as flight direction upon first take‐off in nocturnally fledging juvenile seabirds. We dorsally deployed a coloured LED on juvenile birds to allow researchers to observe the vanishing bearings of individuals as they flew out to sea. Additionally, we co‐deployed either a small Neodymium magnet or glass bead (control) on top of the bird's head to investigate the use of magnetoreception, previously unexplored in this early life stage. We used this assay to observe the first flight of Manx shearwaters Puffinus puffinus and found that they did not orient towards their wintering ground straight after taking off. Further, we did not find an effect of the magnetic treatment on juveniles' flight direction, though whether this is due to the birds not using magnetoreception, other salient cues being available or a lack of motivation to orient to the migratory beeline is unclear. We were, however, able to identify wind direction and topography as drivers of first flight direction in Manx shearwaters, which fledged with wind component between a crosswind and a tailwind and directed their maiden flight towards the sea and away from the land. This novel assay will facilitate the study of the maiden flight of nocturnally fledging birds and will help advance the study of sensory guidance mechanisms underpinning migratory orientation in a wide range of taxa, including species which are traditionally challenging to study.  相似文献   
40.
In 1997/98 a census was made of the Manx Shearwater populations on three Welsh Islands: Skomer, Skokholm and Middleholm. The census was made by counting all the burrows in the winter, playing a tape-recording of a male call (to which only males respond) down a sample of the burrows during the incubation period and applying a correction for the response rate (the proportion of males which respond). The response rate was determined by playing the tape-recordings down a set of burrows in which eggs had been laid and where the incubating birds could be examined. Knowing the total number of burrows, the number of burrows sampled, the number of responses and the response rate enabled us to make an estimate of the population size on each island. Skomer, with an estimated population of some 102000 breeding pairs is probably the largest colony of Manx Shearwaters in the world; the estimates for Skokholm and Middleholm were 46000 and 3000 respectively. These figures are compared with earlier censuses undertaken using traditional methods.  相似文献   
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