A5021411351- Animal Behavior and Reproduction
- Neurobiology and Insect Physiology Research
- Visual perception and processing mechanisms
- Plant and animal studies
- Avian ecology and behavior
- Retinal Development and Disorders
- Animal Nutrition and Physiology
- Amphibian and Reptile Biology
- Animal Behavior and Welfare Studies
- Ichthyology and Marine Biology
- Antioxidant Activity and Oxidative Stress
- Olfactory and Sensory Function Studies
- Wildlife Ecology and Conservation
- Color perception and design
- Leaf Properties and Growth Measurement
- Meat and Animal Product Quality
- Glaucoma and retinal disorders
- Multimedia Communication and Technology
- Human-Animal Interaction Studies
- Service-Oriented Architecture and Web Services
- Circadian rhythm and melatonin
- Insect Pheromone Research and Control
- Fish Biology and Ecology Studies
- Fish biology, ecology, and behavior
- Light effects on plants
Lund University
2013-2023
Google (United States)
2016
University of Auckland
2014-2015
Many animals use vision to detect, discriminate, or recognize important objects such as prey, predators, homes, mates. These may differ in color and brightness—having chromatic achromatic contrast the background other objects. Visual models are powerful tools investigate detection, but need be calibrated by experimental data provide robust predictions. The most critical parameter of current models—receptor noise—is usually estimated from a small number behavioral tests on thresholds, while...
Birds have impressive physiological adaptations for colour vision, including tetrachromacy and coloured oil droplets, yet it is not clear exactly how well birds can discriminate the reflecting object colours that they encounter in nature. With behavioural experiments, we determined discrimination thresholds of chickens bright dim light. We performed experiments with two series, orange green, covering parts chicken space. These allowed us to compare results model expectations determine...
Ultraviolet (UV)-sensitive visual pigments are widespread in the animal kingdom but many animals, for example primates, block UV light from reaching their retina by pigmented lenses. Birds have UV-sensitive (UVS) with sensitivity maxima around 360-373 nm or 402-426 (violet-sensitive, VS). We describe how these matched ocular media transmittance 38 bird species. UVS that transmit more (wavelength of 50% transmittance, λ(T0.5), 323 nm) than birds VS (λ(T0.5), 358 nm). Yet, models predict...
Raptors have excellent vision, yet it is unclear how they use colour information. It has been suggested that raptors ultraviolet (UV) reflections from vole urine to find good hunting grounds. In contrast, UV plumage colours in songbirds such as blue tits are assumed be 'hidden' communication signals, inconspicuous raptors. This ambiguity results a lack of knowledge about raptor ocular media transmittance, which sets the limit for sensitivity. We measured transmittance common buzzards (Buteo...
Birds have excellent spatial acuity and colour vision compared to other vertebrates while contrast sensitivity is relatively poor for unknown reasons. Contrast describes the detection of gratings varying frequency. It unclear whether bird brightness discrimination between large uniform fields as well. Here we show that budgerigars (Melopsittacus undulatus) need a Michelson 0.09 discriminate spatially separated achromatic in bright light conditions. This similar peak 10.2 (0.098 contrast)...
Color vision in birds is mediated by four types of cone photoreceptors whose maximal sensitivities (λmax) are evenly spaced across the light spectrum. In course avian evolution, λmax most shortwave-sensitive cone, SWS1, has switched between violet (λmax > 400 nm) and ultraviolet < 380 multiple times. This shift SWS1 opsin accompanied a corresponding short-wavelength spectrally adjacent SWS2 cone. Here, we show that spectral tuning modulating ratio two apocarotenoids, galloxanthin...
The evolutionary relationship between signals and animal senses has broad significance, with potential consequences for speciation, the efficacy honesty of biological communication. Here we outline current understanding diversity colour vision in two contrasting groups: phylogenetically conservative birds, more variable butterflies. Evidence coevolution exists both groups, but is limited to observations phenotypic differences visual systems, which might be correlated coloration. Here,...
Today, there is good knowledge of the physiological basis bird colour vision and how mathematical models can be used to predict visual thresholds. However, we still know only little about changes between different viewing conditions. This limits understanding signalling configured in habitats where light illumination background may shift dramatically. I examined discrimination zebra finch (Taeniopygia guttata) affected by adaptation backgrounds. trained finches a two-alternative choice task,...
In animal eyes of the camera type longitudinal chromatic aberration causes defocus that is particularly severe in species with short depth focus. a variety vertebrates, multifocal optical systems compensate for by concentric zones different refractive powers. Since constricting circular pupil blocks peripheral zones, often have slit pupils allow light to pass through all irrespective state constriction. Birds and were therefore assumed monofocal systems. We examined 45 (12 orders) bird using...
SUMMARY We have used behavioural tests to determine the intensity thresholds of colour vision in Bourke's parrots (Neopsephotus bourkii) and budgerigars (Melopsittacus undulatus). also examined relationship between these optical sensitivities single photoreceptors using morphological methods. lose brighter light (0.4 cd m–2) than (0.1 both birds light(`end civil twilight') humans (0.02 m–2,`moonlight'). The cones are similar (budgerigar 0.27 μm2 sr, parrot 0.25μm2 sr) but more (cone rod...
There was an error published in J. Exp. Biol. 216, 1819-1826.In supplementary material Table S1, the data for kestrel are actually sparrowhawk. The correct file is now available at http://jeb.biologists.org/content/216/10/1819/suppl/DC1. authors apologise any inconvenience that this may have caused but assure readers it does not affect results or conclusions of paper, Fig. S1.
Animal colours commonly act as signals for mates or predators. In many damselfly species, both sexes go through a developmental colour change adults, and females often show polymorphism, which may have function in mate choice, avoidance of mating harassment camouflage. the blue-tailed damselfly, Ischnura elegans, young males are bright green turn blue they reach maturity. Females red ( rufescens) violet violacea) immatures and, when mature, either mimic androchrome), acquire an inconspicuous...
Abstract Although predation is commonly thought to exert the strongest selective pressure on coloration in aposematic species, sexual selection may also influence coloration. Specifically, polymorphism species cannot be explained by natural alone. Males of wood tiger moth ( Arctia plantaginis ) are polymorphic for hindwing throughout most their range. In Scandinavia, they display either white or yellow hindwings. Female varies continuously from bright orange red. Redder females and males...
Most vertebrates have UV-sensitive vision, but the UV sensitivity of their eyes is limited by transmittance ocular media, and specific contribution different media (cornea, lens) has remained unclear. Here, we describe all (OMT), as well that lenses corneas birds. For 66 species belonging to 18 orders, wavelength at which 50% light transmitted through retina (λT0.5) ranges from 310 398 nm. Low λT0.5 corresponds more transmitted. Corneal varies only between 300 345 nm, whereas lens values are...
Birds are generally thought to have excellent vision with high spatial resolution. However, contrast sensitivity of birds for stationary targets is low compared other animals similar acuity, such as mammals. For fast flying body stability and coordination highly important, visual motion cues known be relevant flight control. We tested five budgerigars (Melopsittacus undulatus) in behavioural discrimination experiments determine whether or not stimulus improves sensitivity. The were trained...
Humans have selectively bred and used dogs over a period of thousands years, more recently the dog has become an important model animal for studies in ethology, cognition genetics. These broad interests warrant careful descriptions senses dogs. Still there is little known about vision, especially what can discriminate different light conditions. We trained tested whippets, pugs, Shetland sheepdog two-choice discrimination set-up show that patterns with spatial frequencies between 5.5 19.5...
Domestication processes tend to release animals from natural selection and favour traits desired by humans, such as food-production co-operative behaviour. A side effect of selective breeding is the alteration unintended traits. In this paper, we investigate how active for egg production in chickens has affected visual system, particular optical sensitivity that relates ability see dim light. We measured eye dimensions well pupil diameter at different light intensities (the steady state...