Vertical-looking radar (VLR) has allowed long-term automatic monitoring of the altitudinal and temporal dynamics of high- flying insect populations. To investigate whether ground beetle, insect of Coleoptera, was ca...Vertical-looking radar (VLR) has allowed long-term automatic monitoring of the altitudinal and temporal dynamics of high- flying insect populations. To investigate whether ground beetle, insect of Coleoptera, was capable of migrating and its migration pattern by taking advantages of capability of the VLR for long-term real-time automatic monitoring, the migration of Coleoptera ground beetle was investigated by setting up radar observation points, making long-term observation using the VLR and related supplementary equipment, and analyzing low altitude air current and large area circulating current in combination with the meteorological data. Information obtained in 2005 and 2006 showed that the seasonal activities of ground beetles traps of trap lamps were mainly from late June to late August, peak period was mainly in August, seasonal traps of high-altitude lamps and ground lamps were featured by sudden increase and sudden decrease; in peak period, the height of radar echo point could be as high as 600 m, while it was mainly below the height of 450 m; night activities mainly occurred from 20:00 to 22:00, in very few nights, radar echo could last until about 04:00, changes in numbers of ground beetles within the searchlights were consistent with radar echo intensity; ground beetle images were successfully trapped in the sweep nets carried by captive balloons at the height of 200 m. Some species of Carabidaes had some degrees of migration, thus providing the foundation for investigating the migration of Coleoptera insects.展开更多
Background: A critical trait for successful urban dwelling by birds is the ability to tolerate high levels of disturbing stimulation by humans. If such tolerance is partly acquired gradually after colonization, specie...Background: A critical trait for successful urban dwelling by birds is the ability to tolerate high levels of disturbing stimulation by humans. If such tolerance is partly acquired gradually after colonization, species with a long history of residence in cities are likely to be more tolerant of such stimulation than recent urban colonists, but this has not often been tested.Methods: We tested whether introduced Rock(Columba livia) and Spotted(Streptopelis chinensis) Doves, historically long-term residents of Melbourne, Australia, were more tolerant of disturbance by humans than the very recent colonist, the native Crested Pigeon(Ochyphaps lophotes) by comparing the Flight Initiation Distances(FID) and time allocations to vigilance during foraging of all three species in urban Melbourne. That all three species are members of the Columbiformes reduces the possibility that any species differences in tolerance are simply phylogenetic in origin.Results: Flight initiation distance was shorter in Rock Doves than in the other two species, which did not differ in approachability by a human. Rock Doves retreated from an approaching human mainly by walking a relatively short distance, Crested Pigeons mainly by running a relatively short distance and Spotted Doves primarily by flying a comparatively long distance. The time allocation to anti-predator vigilance of Rock Doves was smaller than that of the other two species, whose allocations were similar.Conclusions: The very recent colonist of eastern Melbourne, the Crested Pigeon, was not the least tolerant of disturbance by humans of the three related species. Natural selection for tolerance therefore probably cannot entirely explain the pattern of tolerance evident among these urban dove species and behavioural flexibility is probably involved. Length of residency in a city is not an infallible guide to a species' level of tolerance of disturbance by humans.展开更多
基金the National Basic Research Program of China(973 Progra m,2006CB102007)the National Natural Science Foundation of China(30771385)+1 种基金National Key Technologies R&D Program of China during the 11th Five-Year Plan period(2006BAD08A01)National Public BeneficialResearch of the Ministry of Science and Technologyof China(2004DIB4J155)
文摘Vertical-looking radar (VLR) has allowed long-term automatic monitoring of the altitudinal and temporal dynamics of high- flying insect populations. To investigate whether ground beetle, insect of Coleoptera, was capable of migrating and its migration pattern by taking advantages of capability of the VLR for long-term real-time automatic monitoring, the migration of Coleoptera ground beetle was investigated by setting up radar observation points, making long-term observation using the VLR and related supplementary equipment, and analyzing low altitude air current and large area circulating current in combination with the meteorological data. Information obtained in 2005 and 2006 showed that the seasonal activities of ground beetles traps of trap lamps were mainly from late June to late August, peak period was mainly in August, seasonal traps of high-altitude lamps and ground lamps were featured by sudden increase and sudden decrease; in peak period, the height of radar echo point could be as high as 600 m, while it was mainly below the height of 450 m; night activities mainly occurred from 20:00 to 22:00, in very few nights, radar echo could last until about 04:00, changes in numbers of ground beetles within the searchlights were consistent with radar echo intensity; ground beetle images were successfully trapped in the sweep nets carried by captive balloons at the height of 200 m. Some species of Carabidaes had some degrees of migration, thus providing the foundation for investigating the migration of Coleoptera insects.
文摘Background: A critical trait for successful urban dwelling by birds is the ability to tolerate high levels of disturbing stimulation by humans. If such tolerance is partly acquired gradually after colonization, species with a long history of residence in cities are likely to be more tolerant of such stimulation than recent urban colonists, but this has not often been tested.Methods: We tested whether introduced Rock(Columba livia) and Spotted(Streptopelis chinensis) Doves, historically long-term residents of Melbourne, Australia, were more tolerant of disturbance by humans than the very recent colonist, the native Crested Pigeon(Ochyphaps lophotes) by comparing the Flight Initiation Distances(FID) and time allocations to vigilance during foraging of all three species in urban Melbourne. That all three species are members of the Columbiformes reduces the possibility that any species differences in tolerance are simply phylogenetic in origin.Results: Flight initiation distance was shorter in Rock Doves than in the other two species, which did not differ in approachability by a human. Rock Doves retreated from an approaching human mainly by walking a relatively short distance, Crested Pigeons mainly by running a relatively short distance and Spotted Doves primarily by flying a comparatively long distance. The time allocation to anti-predator vigilance of Rock Doves was smaller than that of the other two species, whose allocations were similar.Conclusions: The very recent colonist of eastern Melbourne, the Crested Pigeon, was not the least tolerant of disturbance by humans of the three related species. Natural selection for tolerance therefore probably cannot entirely explain the pattern of tolerance evident among these urban dove species and behavioural flexibility is probably involved. Length of residency in a city is not an infallible guide to a species' level of tolerance of disturbance by humans.