Ultraviolet signals in birds are special
Recent behavioural experiments have shown that birds use ultraviolet (UV)-reflective and fluorescent plumage as cues in mate choice. It remains controversial, however, whether such UV signals play a special role in sexual communication, or whether they are part of general plumage coloration. We use a comparative approach to test for a general association between sexual […]
Signalling and phosphorus: correlations between mate signalling effort and body elemental composition in crickets
Recent findings in the field of ecological stoichiometry indicate that the relationships among key macronutrient elements (e.g. carbon, nitrogen and phosphorus) of organisms and their resources may underlie variation in fitness-conferring behaviours. The amount of phosphorus in an individual’s body is often correlated with its rate of growth and reproduction, and low-phosphorus diets are known […]
Does testosterone mediate the trade-off between nestling begging and growth in the canary (Serinus canaria)?
Nestling birds solicit food from their parents with vigorous begging displays, involving posturing, jostling and calling. In some species, such as canaries, begging is especially costly because it causes a trade off against nestling growth. Fitness costs of begging like this are predicted by evolutionary theory because they function to resolve conflicts of interest within […]
Changes in the visual environment affect colour signal brightness and shoaling behaviour in a freshwater fish
Aquatic organisms are exposed to highly variable light environments, which can affect the efficacy of colour patterns that are used for communication or camouflage. Specifically, dissolved organic matter that is common in turbid freshwater habitats tends to absorb short wavelength light causing a shift towards environments that are rich in longwavelengths (orange/red).We investigatedhowchanges in the […]
Studies on UV reflection in feathers of some 1000 bird species: are UV peaks in feathers correlated with violet-sensitive and ultraviolet-sensitive cones?
Nine hundred and sixty-eight bird species, covering all orders, were studied in search of distinctive ultraviolet reflections. All species in the following orders were completely surveyed: Struthioniformes, Tinamiformes, Craciformes, Turniciformes, Galbuliformes, Upupiformes, Coliiformes, Apodiformes and Musophagiformes. The coloured plumage regions in particular exhibited high proportions of UV-reflecting feathers. Bird orders with species which are believed […]