#biofluorescence

Deadly Allure

Much like flowers, many carnivorous plants utilize ultraviolet light (UV) reflectance patterns to lure insects. Although an abundant component of sunlight, UV is invisible to humans but it is highly conspicuous to the insect eye. Here at nightfall, a UV torch reveals a normally hidden fluorescence of blue light on the pitchers of Nepenthes mirabilis. Although this fluorescence itself may not be strong enough in the day to attract insects, its presence shows patterns in UV reflectance which may guide prey to the nectar-rich portions of the pitcher, such as the peristome and underside of the lid. Sarawak, Malaysia (Borneo)

MILLIPEDES GLOW IN THE DARK

A threatened cherry millipede coils into a defensive posture. This one looks entirely different in the beam of a regular flashlight (l) compared to the fluorescence displayed under a UV (ultraviolet) blacklight.

Read more: https://whitgibbons.com/millipedes

From the article:

Birds-of-paradise have some of the most famous mating displays in the world, but there's more to their colorful rhythmic gymnastics than initially meets the human eye. For the first time, scientists have discovered these spectacular avians absolutely glowing with gorgeousness in a dark room. Researchers at the American Museum of Natural History (AMNH) combed through the available archives and found that all 37 core bird-of-paradise species in Australia, New Guinea, and Indonesia are biofluorescent. Only a few fringe family members fail to glow under ambient UV or blue light.

Most male birds tested possess brightly fluorescent heads, napes, bills, and plumes that glimmer with green or greenish-yellow hues. Some even have fluorescent legs, feet, tails, and rings around their eyes. Many of these mysteriously colorful patches are starkly bordered by dark feathers with no fluorescence, and these parts of the body are often used in mating displays, when males flap, flutter, sway, bop, hang, and pose in an elaborate, attention-seeking dance that varies from species to species.

Note that this is different than bioluminescence. This is like those glow-in-the-dark stickers. They mention puffin beaks glowing under UV light.

(Check out the glasses they gave them in the second article!)

@todaysbird @alithographica

Birds-of-paradise are known for their bright and colourful plumage, but it turns out they are even more dazzling than previously thought. Researchers have found 37 of the 45 species show biofluorescence – in other words, patches of their plumage or other body parts absorb UV or blue light, and emit light at lower frequencies. “At a minimum, it would make these biofluorescent areas brighter – a yellow feather may be more green-yellow, a white feather may be brighter and slightly more green-yellow,” said Dr Rene Martin from the American Museum of Natural History in New York, who was first author of the study. Published in the journal Royal Society Open Science, Martin and colleagues reported how they studied preserved specimens of each bird-of-paradise species, held in the ornithology collection at the American Museum of Natural History. The team placed males and females of each species under blue light in a dark room and recorded the wavelengths and intensity of light emitted. In some cases they also shone UV light on the skins. The results revealed that males of 21 species showed biofluorescence on parts of their plumage such as their head, neck, belly and tail feathers, or on fleshy lobes known as face wattles. In addition, these species plus an additional 16 species showed – or were deemed likely to show – biofluorescence in their inner mouth and throat.

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Many birds are biofluorescent because many birds see in UV. I'd have been surprised if birds-of-paradise did not, given their bright colours.