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Oilbirds are related to the nightjars and have sometimes been placed with these in the order Caprimulgiformes.However, the nightjars and their relatives are insectivores while the oilbird is a specialist fructivore, and it is sufficiently distinctive to be placed in a family (Steatornithidae) and suborder (Steatornithes) of its own.
Studies in bird behaviour include the use of tamed and trained birds in captivity. Studies on bird intelligence and song learning have been largely laboratory-based. Field researchers may make use of a wide range of techniques such as the use of dummy owls to elicit mobbing behaviour, and dummy males or the use of call playback to elicit ...
The difficulty of defining or measuring intelligence in non-human animals makes the subject difficult to study scientifically in birds. In general, birds have relatively large brains compared to their head size. Furthermore, bird brains have two-to-four times the neuron packing density of mammal brains, for higher overall efficiency. The visual ...
The four pigments in a bird's cone cells (in this example, estrildid finches) extend the range of color vision into the ultraviolet. [1]Tetrachromacy (from Greek tetra, meaning "four" and chroma, meaning "color") is the condition of possessing four independent channels for conveying color information, or possessing four types of cone cell in the eye.
Seabirds such as terns and gulls that feed at the surface or plunge for food have red oil droplets in the cones of their retinas. This improves contrast and sharpens distance vision, especially in hazy conditions. [4] Birds that have to look through an air/water interface have more deeply coloured carotenoid pigments in the oil droplets than ...
Carotenoid coloration exhibits high levels of sexual dimorphism, with adult male birds generally displaying more vibrant coloration than females of the same species. [ 31 ] These differences arise due to the selection of yellow and red coloration in males by female preference .
The brilliant iridescent colors of the peacock's tail feathers are created by structural coloration, as first noted by Isaac Newton and Robert Hooke.. Structural coloration in animals, and a few plants, is the production of colour by microscopically structured surfaces fine enough to interfere with visible light instead of pigments, although some structural coloration occurs in combination ...
Because of its unusual color stability, a cafeyl-acylated buffered formulation of it has been patented for use as food coloring. Peonidin, like many anthocyanidins, has shown potent inhibitory and apoptotic effects on cancer cells in vitro , notably metastatic human breast cancer cells. [ 1 ]