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Summary During agonistic encounters, both minors and majors of the European ant P. pallidula actively cooperate in defense. Minors seize the legs of the intruder and in some cases induce the recruitment of nestmates whereas majors kill the spreadeagled alien ant. The defensive strategy of P. pallidula is very flexible and adapted to both the number of alient ants and to the intruder's superiority in fighting. On the one hand, only a massive invasion of alien minors results in a slow mobilization of resident ants to the combat area, elicited by recruiters performing weak tactile invitations and trail-laying behavior. On the other hand, the presence of 10 majors induces a fast and massive recruitment achieved by intense trail-laying and tactile invitations from the recruiters. Because of their high response threshold to invitations, resident majors are mobilized only during these intense recruitments, their exit being additionally enhanced by their preferential stimulation. The adaptiveness of this defensive strategy is discussed. It is also suggested that simple decision-making rules of recruitment and caste differences in behavioral thresholds could account for the complexity of P. pallidula defensive strategies.Senior Research Assistant at Belgian National Fund for Scientific Research
Offprint requests to: C. Detrain 相似文献
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Sand dunes are complex systems that contain several habitats, often as mosaics or transitions between types. Several of these habitats are afforded protection under European Legislation and in the UK nationally within Special Areas of Conservation (SAC) and Sites of Special Scientific Interest (SSSI). Natural England has a statutory duty to report to Europe on the conservation status and condition of sand dunes; and is required to report to the UK Government on designated sites. To achieve this we have sought ways of capturing, analysing and interpreting data on the extent and location of sand dune habitats. This requires an ability to be able to obtain data over large areas of coastline in an efficient way. Natural England and Environment Agency Geomatics have worked collaboratively for over 16 years, sharing data and ecological knowledge. In 2012 work started to evaluate the use of remote sensing to map UK BAP and Annex I sand dune habitats. A methodology has now been developed and tested to map sand dune habitats. The key objective was to provide an operational tool that will help to map these habitats and understand change on sites around England. This has been achieved through analysis of LIDAR and Compact Airborne Spectrographic Imager (CASI) data using Object Orientated Image Analysis. Quality Control (QC) and accuracy assessments have shown this approach to be successful and 11 sites have been mapped to date. These techniques are providing a new approach to monitoring change in coastal vegetation communities and informing management of protected sites. 相似文献
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V. Plasman M. Plehiers J. C. Braekman D. Daloze J. C. de Biseau J. M. Pasteels 《Chemoecology》2001,11(3):107-112
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Summary. ((no summary.))A corrected version of the appendix is available for free download from 相似文献