Many organisms have evolved adaptive coloration that reduces their risk of predation. Cryptic colo- ration reduces the likelihood of detection/recognition by potential predators, while warning or aposematic coloration...Many organisms have evolved adaptive coloration that reduces their risk of predation. Cryptic colo- ration reduces the likelihood of detection/recognition by potential predators, while warning or aposematic coloration advertises unprofitability and thereby reduces the likelihood of attack. Although some studies show that aposematic coloration functions better at decreasing attack rate than crypsis, recent work has suggested and demonstrated that crypsis and aposematism are both successful strategies for avoiding predation. Furthermore, the visual environment （e.g., ambient lighting, background） affects the ability for predators to detect prey. We investigated these 2 related hypoth- eses using 2 well-known visually aposematic species of Heliconius butterflies, which occupy differ- ent habitats （open-canopy vs. closed-canopy）, and one palatable, cryptic, generalist species Junonia coenia. We tested if the differently colored butterflies differ in attack rates by placing plasti- cine models of each of the 3 species in 2 different tropical habitats where the butterflies naturally occur： disturbed, open-canopy habitat and forested, closed-canopy habitat. The cryptic model had fewer attacks than one of the aposematic models. Predation rates differed between the 2 habitats, with the open habitat having much higher predation. However, we did not find an interaction between species and habitat type, which is perplexing due to the different aposematic phenotypes naturally occurring in different habitats. Our findings suggest that during the Panamanian dry sea- son avian predation on perched butterflies is not a leading cause in habitat segregation between the 2 aposematic species and demonstrate that cryptically colored animals at rest may be better than aposematic prey at avoiding avian attacks in certain environments.展开更多
Graph coloring has interesting real life applications in optimization and network design. In this paper some new results on the acyclic-edge coloring, f-edge coloring, g-edge cover coloring, （g, f）-coloring and equi...Graph coloring has interesting real life applications in optimization and network design. In this paper some new results on the acyclic-edge coloring, f-edge coloring, g-edge cover coloring, （g, f）-coloring and equitable edge-coloring of graphs are introduced. In particular, some new results related to the above colorings obtained by the authors are given. Some new problems and conjectures are presented.展开更多
文摘Many organisms have evolved adaptive coloration that reduces their risk of predation. Cryptic colo- ration reduces the likelihood of detection/recognition by potential predators, while warning or aposematic coloration advertises unprofitability and thereby reduces the likelihood of attack. Although some studies show that aposematic coloration functions better at decreasing attack rate than crypsis, recent work has suggested and demonstrated that crypsis and aposematism are both successful strategies for avoiding predation. Furthermore, the visual environment （e.g., ambient lighting, background） affects the ability for predators to detect prey. We investigated these 2 related hypoth- eses using 2 well-known visually aposematic species of Heliconius butterflies, which occupy differ- ent habitats （open-canopy vs. closed-canopy）, and one palatable, cryptic, generalist species Junonia coenia. We tested if the differently colored butterflies differ in attack rates by placing plasti- cine models of each of the 3 species in 2 different tropical habitats where the butterflies naturally occur： disturbed, open-canopy habitat and forested, closed-canopy habitat. The cryptic model had fewer attacks than one of the aposematic models. Predation rates differed between the 2 habitats, with the open habitat having much higher predation. However, we did not find an interaction between species and habitat type, which is perplexing due to the different aposematic phenotypes naturally occurring in different habitats. Our findings suggest that during the Panamanian dry sea- son avian predation on perched butterflies is not a leading cause in habitat segregation between the 2 aposematic species and demonstrate that cryptically colored animals at rest may be better than aposematic prey at avoiding avian attacks in certain environments.
基金This research is supported by the National Natural Science Foundation of China under Grant Nos. 10871119, 10971121 and Quality Control Standards on Undergraduate Medical Education under Grant No. 200804220001.
文摘Graph coloring has interesting real life applications in optimization and network design. In this paper some new results on the acyclic-edge coloring, f-edge coloring, g-edge cover coloring, （g, f）-coloring and equitable edge-coloring of graphs are introduced. In particular, some new results related to the above colorings obtained by the authors are given. Some new problems and conjectures are presented.
