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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.anbehav.2005.10.031 Byline: Jennifer E. Evans, Innes C. Cuthill, Andrew T.D. Bennett Abstract: The visual systems of birds are hypothesized to have higher temporal resolution than those of humans, suggesting that they may be able to perceive the flicker emitted from conventional low-frequency fluorescent lights (LF; 100Hz in Europe, 120Hz in the U.S.A.). These lights are commonly used in the housing of captive birds and this may affect both their welfare and performance in experiments. We carried out mate choice experiments on European starlings, Sturnus vulgaris, under both low- and high-frequency fluorescent lights (HF; >30kHz, at which flicker is imperceptible). Indicators of male condition and size, together with the reflectance spectra and length of the males' throat feathers, were also recorded to ascertain which variables correlated with female preference. Females ranked males consistently under HF, but not LF, lighting, and individual females chose different males under the two lighting types. Under HF lighting, females chose to spend more time with males that had longer throat feathers. The flicker rate of the light clearly affected the choices made by the females, possibly because of nonspecific stress effects or decreased discrimination ability. Our results imply that careful interpretation of mate choice experiments is needed, especially with regard to the lighting types used, to elucidate the real cause behind any variation shown. Author Affiliation: Centre for Behavioural Biology, School of Biological Sciences, University of Bristol, U.K. Article History: Received 16 May 2005; Revised 13 July 2005; Accepted 31 October 2005 Article Note: (miscellaneous) MS. number: 8544R

Research on two species of birds, European starlings and blue tits, Sturnus vulgaris and Parus caeruleus, respectively, was completed to determine whether ultraviolet light preferences are context specific. It was found that neither species showed a preference for UV light except when they were viewing potential mates. Behavioral context seems to be relevant to the preference of wavelength compositions.

Female and male blue tits have been allowed to choose between partners with UV plumage reflectance, and partners lacking such reflectance, and both preferred UV reflecting mates. The preferences of the females were not significant, whilst those of the males were. There was no preference exhibited by either sex when a heterospecific replaced a conspecific. Male choice appears to be more strongly influenced by potential mates' visual appearance. This is the first time that a direct link has been found between male mate choice and UV reflectance.

It has been shown that the sexual preferences of female zebra finches areinfluenced by colour, either artificial or natural. However, these results have not been replicated. A new study examines colour preferences of female zebra finches and demonstrates that they may fail to exhibit this behaviour if ultraviolet light is removed. The lack of colour preference could be due to a change in the male's overall appearance, caused by the use of ultraviolet light filters. The new study highlights the importance of properly considering animals' sensory capabilities in experimental design.

Avian plumage has long been used to test theories of sexual selection, with humans assessing the colors. However, many birds see in the ultraviolet (

Zebra finches use ultraviolet light between 300-400 nano-meters to make their decisions regarding sexual selection. During mate selection, the females use ultraviolet light for hue perception and not for brightness differentiation. The females show a preference for symmetrical males and the symmetry can only be distinguished using ultraviolet light. The mate-choice experiments are modified with transparent filters to control the incident wavelengths available for making the sexual selection.

R. Biegler and R.G.M. Morris use flawed logic in their identification of 'if it moves, don't use it' as a fundamental rule for how animals select landmarks for orientation. The controls on their experiment were inadequate, as most rats in the varied-landmarks group had less practice finding the goal from each starting viewpoint. Studies of insects, birds and rodents show that animals do learn and remember a goal's location using unstable landmarks. The rebuttal view is that these criticisms do not disprove the basic findings about animals' preference for fixed landmarks.

Whereas humans have three types of cone photoreceptor, birds have four types of single cones and, unlike humans, are sensitive to ultraviolet light (UV, 320-400 nm). Most birds are thought to have either a violet-sensitive single cone that has some sensitivity to UV wavelengths (for example, many non-passerine species) or a single cone that has maximum sensitivity to UV (for example, oscine passerine species). UV sensitivity is possible because, unlike humans, avian ocular media do not absorb UV light before it reaches the retina. The different single cone types and their sensitivity to UV light give birds the potential to discriminate reflectance spectra that look identical to humans. It is clear that birds use UV signals for a number of visual tasks, but there are few studies that directly demonstrate a role for UV in the detection of chromaticity differences (i.e. colour vision) as opposed to achromatic brightness. If the output of the violet/UV cone is used in achromatic visual tasks, objects reflecting more UV will appear brighter to the bird. If, however, the output is used in a chromatic mechanism, birds will be able to discriminate spectral stimuli according to the amount of reflected light in the UV part of the spectrum relative to longer wavelengths. We have developed a UV 'colour blindness' test, which we have given to a passerine (European starling) and a nonpasserine (Japanese quail) species. Both species learnt to discriminate between a longwave control of orange vs red stimuli and UV vs 'non-UV' stimuli, which were designed to be impossible to differentiate by achromatic mechanisms. We therefore conclude that the output of the violet/UV cone is involved in a chromatic colour vision system in these two species. [ABSTRACT FROM AUTHOR]

Examines how ultraviolet vision and sensitivity influence the choice of a mate in female zebra finches. Removal of ultraviolet plumage spectra by filter treatment; Preference of females for males which exhibited ultraviolet and short ultraviolet spectra on their plumage; Reflectance intensity from the beak, brown cheek and white cheek regions.

Discusses whether animals have cognitive maps. Inability of experimenters to eliminate simpler explanations of short-cutting; Contradictory definitions of a cognitive map; Cognitive map theory as useless in the elucidation of spatial behavior in animals.

Focuses on the impact of science teaching on students. Role of young scientists in developing basic research; Financial problems of government research organization and universities; Importance of science degrees in the graduate students.

Assesses the impact of red fox on wildlife in Tasmania, Australia. Use of sodium monofluoroacetate to control opossums and wallabies grazing on crops; Similarity between arboreal marsupial and opossum; Decline of arboreal herbivores.