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| Sarah E. J. Arnold; Vincent Savolainen; Lars Chittka. |
| Floral reflectance measurements are of great value to researchers who need consider the real colour of flowers, for example in the context of how the flowers appear to their pollinators. We have thus developed the Floral Reflectance Database (FReD) to assist these researchers, gathering together floral reflectance data in a publicly available, searchable online database. The first version of the database is now available online at "http://www.reflectance.co.uk":http://www.reflectance.co.uk. We anticipate that this resource will be of interest to researchers working on flower colour and animal vision. |
| Tipo: Manuscript |
Palavras-chave: Ecology; Bioinformatics. |
| Ano: 2008 |
URL: http://precedings.nature.com/documents/1846/version/1 |
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| Lars Chittka; Daniel Osorio. |
| Many palatable insects, for example hoverflies, deter predators by mimicking well-defended insects such as wasps. However, for human observers, these flies often seem to be little better than caricatures of wasps – their visual appearance and behaviour are easily distinguishable. This imperfect mimicry baffles evolutionary biologists, because one might expect natural selection to do a more thorough job. Here we discuss two types of cognitive processes that might explain why mimics distinguishable mimics might enjoy increased protection from predation. Speed accuracy tradeoffs in predator decision making might give imperfect mimics sufficient time to escape, and predators under time constraint might avoid time-consuming discriminations between... |
| Tipo: Manuscript |
Palavras-chave: Ecology; Neuroscience. |
| Ano: 2007 |
URL: http://precedings.nature.com/documents/1258/version/1 |
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| Peter Skorupski; Lars Chittka. |
| In recent years, colour vision abilities have been rather generously awarded to vari-ous invertebrates and even bacteria. This uncertainty of when to diagnose colour vi-sion stems in part from confusing what colour vision can do with what it is. What col-our vision can do is discriminate wavelength independent of intensity. However, if we take this as a definition of what colour vision is, then we might indeed be obliged to conclude that some plants and bacteria have colour vision. Moreover, there is a simi-lar confusion of what are necessary and what are sufficient mechanisms and behav-ioural abilities for colour vision. To humans, seeing in colour means seeing an image in which objects/lights have chromatic attributes - in contrast to the sensation that... |
| Tipo: Manuscript |
Palavras-chave: Ecology; Neuroscience. |
| Ano: 2008 |
URL: http://precedings.nature.com/documents/1766/version/1 |
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| Jeff Ollerton; Louise Cranmer; Ralph Stelzer; Steve Sullivan; Lars Chittka. |
| The Canary Islands are home to a guild of endemic, threatened bird pollinated plants. Previous work has suggested that these plants evolved floral traits as adaptations to pollination by flower specialist sunbirds, but subsequently they appear to be have co-opted passerine birds as sub-optimal pollinators. To test this idea we carried out a quantitative study of the pollination biology of three of the bird pollinated plants, Canarina canariensis (Campanulaceae), Isoplexis canariensis (Veronicaceae) and Lotus berthelotii (Fabaceae), on the island of Tenerife. Using colour vision models, we predicted the detectability of flowers to bird and bee pollinators. We measured pollinator visitation rates, nectar standing crops, as well as seed set and pollen... |
| Tipo: Manuscript |
Palavras-chave: Ecology; Plant Biology. |
| Ano: 2008 |
URL: http://precedings.nature.com/documents/1977/version/1 |
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| Peter Skorupski; Lars Chittka. |
| In recent years, colour vision abilities have been rather generously awarded to vari-ous invertebrates and even bacteria. This uncertainty of when to diagnose colour vi-sion stems in part from confusing what colour vision can do with what it is. What col-our vision can do is discriminate wavelength independent of intensity. However, if we take this as a definition of what colour vision is, then we might indeed be obliged to conclude that some plants and bacteria have colour vision. Moreover, there is a simi-lar confusion of what are necessary and what are sufficient mechanisms and behav-ioural abilities for colour vision. To humans, seeing in colour means seeing an image in which objects/lights have chromatic attributes - in contrast to the sensation that... |
| Tipo: Manuscript |
Palavras-chave: Ecology; Neuroscience. |
| Ano: 2008 |
URL: http://precedings.nature.com/documents/1766/version/2 |
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| Ralph J. Stelzer; Lars Chittka. |
| Circadian rhythms enable organisms to anticipate and to prepare for predictable changes in their environment. Most previous studies on circadian rhythms focused on solitary animals. However, in social insects, the colony as a superorganism has a foraging rhythm aligned to the patterns of resource availability. Within this colony rhythm, the activity patterns of individuals are embedded. In temperate regions bumblebee foragers show strong circadian rhythms that adjust their foraging activity to the changing light conditions in the course of the day. But what about circadian foraging patterns under continuous daylight? One would assume that the colony as a whole extends its foraging activity over the whole 24 hours of a day under such light conditions to... |
| Tipo: Poster |
Palavras-chave: Ecology. |
| Ano: 2008 |
URL: http://precedings.nature.com/documents/1719/version/1 |
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| Nigel E. Raine; Lars Chittka. |
| Despite the widespread assumption that the learning abilities of animals are adapted to the particular environments in which they operate, the quantitative effects of learning performance on fitness remain virtually unknown. Here we evaluate the learning performance of bumblebees (_Bombus terrestris_) from multiple colonies in an ecologically relevant associative learning task under laboratory conditions, before testing the foraging performance of the same colonies under the field conditions. We demonstrate that variation in learning speed among bumblebee colonies is directly correlated with foraging performance, a robust fitness measure, under natural conditions. Colonies vary in learning speed by a factor of nearly 5, with the slowest learning colonies... |
| Tipo: Manuscript |
Palavras-chave: Ecology. |
| Ano: 2007 |
URL: http://precedings.nature.com/documents/1298/version/1 |
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