Dispersal and dormancy strategies among insect species competing for a pulsed resource

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Relationships between bird morphology and prey selection in two sympatric Great Cormorant Phalacrocorax carbo subspecies during winter

Variation in bird morphology (notably sex size dimorphism) has been suggested to contribute to differences in food use between individuals. We explore the hypothesis of food partitioning (diet overlap and prey size selection) in two sympatric subspecies of the Great Cormorant Phalacrocorax carbo with respect to bird morphology (subspecies and sex) in inland French waters. These areas represent a recent and increasing contact zone used as a common non-territorial winter feeding area by the continental P. c. sinensis and the marine P. c. carbo subspecies. A high dietary overlap between subspecies and sexes was found at the major sites studied. Prey size selection was found to be site-specific and generally related to a gradient of structural size and body mass (male P. c. carbo  > male P. c. sinensis  > female P. c. carbo  > female P. c. sinensis ). With respect to bird morphology, differences in prey size consumed by Great Cormorants were more pronounced between sexes in freshwater habitats than between subspecies. This was reinforced by the fact that P. c. carbo birds entering inland areas were smaller than birds on the coast. These results also suggest that bird morphology is an important determinant of dietary differences. Our study demonstrated that P. c. carbo is an efficient generalist forager in continental areas, and food partitioning in type and size of prey between the two subspecies is low.     

VSD联合带腓肠神经营养血管逆行岛状皮瓣治疗胫骨慢性骨髓炎的术后护理及功能锻炼

目的:观察封闭式负压引流(vacuum sealing drainage,VSD)联合带腓肠神经营养血管逆行岛状皮瓣治疗胫骨慢性骨髓炎的术后护理及功能锻炼的效果.方法:2009年1月-2009年11月,收治28例胫骨慢性骨髓炎患者,采用VSD待创面肉芽组织新鲜、感染控制后,用带腓肠神经营养血管逆行岛状皮辩治疗胫骨慢性骨髓炎,术后予以特殊护理与康复治疗.结果:28例患者术后予以特殊护理与康复治疗,皮瓣顺利成活.28例患者均获随访,随访时间1～10个月.皮辩与周围皮肤色泽相似,无臃肿,两点辨别觉6～8mm.术后能穿鞋正常行走,皮瓣受力处无破溃.结论:VSD联合带腓肠神经营养血管逆行岛状皮瓣治疗胫骨慢性骨髓炎,术后予以特殊护理与康复治疗,疗效满意     

Migration of wild and captive‐bred Little Bustards Tetrax tetrax: releasing birds from Spain threatens attempts to conserve declining French populations

Populations of the Little Bustard Tetrax tetrax in the farmlands of Europe have declined greatly over the last century. In Western Europe, France now holds the only remaining migratory population, which currently numbers fewer than 300 displaying males. However, the movements of these birds are virtually unknown, in spite of the important implications of this information for the conservation of this species. We identified migratory movements and overwintering areas of French migratory populations, using wild individuals fitted with satellite or radio‐transmitters. Little Bustards completed their migration journey over a relatively short time period (2–5 days), with nocturnal migration flights of 400–600 km per night. All birds overwintered in Iberia. In addition, we tested the consequences of captive rearing on migratory movements. French wild adults and French captive‐bred juveniles behaved similarly with regard to migration, suggesting that hand‐raising does not alter migratory movements. However, birds originating from eggs collected in Spain and reared in western France did not migrate, suggesting a genetic component to migratory behaviour. These results therefore suggest that a conservation strategy involving the release in France of birds hatched from eggs collected in Spain may imperil the expression of migratory movements of the French population. More generally, to maintain the integrity of native populations, the introduced individuals should mimic their migratory movements and behaviour.