# Birds/Plants/Lizards -Does camouflage extend to the ultraviolet? **URL:** \ **Category:** Factual Questions\ **Created:** [July 21, 2018, 7:57pm UTC](https://boards.straightdope.com/t/birds-plants-lizards-does-camouflage-extend-to-the-ultraviolet/818337 "2018-07-21T19:57:11Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![am77494](https://avatars.discourse-cdn.com/v4/letter/a/d2c977/32.png) [@am77494](https://boards.straightdope.com/u/am77494)\ **Post date:** [July 21, 2018, 7:57pm UTC](https://boards.straightdope.com/t/birds-plants-lizards-does-camouflage-extend-to-the-ultraviolet/818337/1 "2018-07-21T19:57:11Z")
Various life forms use camouflage to hide themselves from predators. Many predators have eyesight that extend beyond the human visible spectrum colors (ultraviolet ). So does the comouflage colors extend to the ultraviolet range too ? For example : when a chameleon camouflages itself against a leafy branch, does it colors match the leaf colors too when looked in the ultraviolet region of the spectrum ? What about green parrots and their ultraviolet color compared to green vegetation ? ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [July 22, 2018, 1:36am UTC](https://boards.straightdope.com/t/birds-plants-lizards-does-camouflage-extend-to-the-ultraviolet/818337/2 "2018-07-22T01:36:56Z")
Neither chameleons nor parrots are particularly camouflaged. ---
**Author:** ![am77494](https://avatars.discourse-cdn.com/v4/letter/a/d2c977/32.png) [@am77494](https://boards.straightdope.com/u/am77494)\ **Post date:** [July 22, 2018, 2:27am UTC](https://boards.straightdope.com/t/birds-plants-lizards-does-camouflage-extend-to-the-ultraviolet/818337/3 "2018-07-22T02:27:26Z")
> [@Chronos](#): > > Neither chameleons nor parrots are particularly camouflaged. This article says “The lizards’ skin also contains yellow pigments, and blue mixed with yellow makes green, a “cryptic” color that camouflages them among trees and plants, Milinkovitch said.” > **[The Secret to Chameleons' Ability to Change Color](https://www.scientificamerican.com/article/the-secret-to-chameleons-ability-to-change-color/)** > > The lizards' cells undergo structural changes that affect how light reflects off their skin This article says “Parrots, and many other animals, use pattern and color variation as a means of camouflage. The purpose for bold patterns and vivid colors is to disrupt the outline of an animal’s body.” > **[The Coloring and Camouflage of Parrots](https://birdtricksstore.com/blogs/birdtricks-blog/the-coloring-and-camouflage-of-parrots)** > > Have you ever wondered why parrots, being prey animals, are so brightly colored?  How is a brilliantly colored macaw supposed to blend into the green background of the rainforest canopy? Have you ever casually looked into your bird’s cage as you... Anyways, let’s not get into a debate in what counts as camouflage and what does’nt. I am really interested in knowing that when an animal blends into the surroundings, does it do so for its own color spectrum perception or it’s predators ? ---
**Author:** ![Tamerlane](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tamerlane/32/7602_2.png) [@Tamerlane](https://boards.straightdope.com/u/Tamerlane)\ **Post date:** [July 22, 2018, 3:26am UTC](https://boards.straightdope.com/t/birds-plants-lizards-does-camouflage-extend-to-the-ultraviolet/818337/4 "2018-07-22T03:26:55Z")
What an interesting question. I don’t know the answer, but would _assume_ the answer is yes for anything under enough predation pressure from critters able to perceive UV. Found this pretty [technical article](http://jeb.biologists.org/content/216/22/4290) which seems to indicate some do, but that the selective pressure for visual sexual markers can complicate matters. ---
**Author:** ![thelurkinghorror](https://avatars.discourse-cdn.com/v4/letter/t/7c8e57/32.png) [@thelurkinghorror](https://boards.straightdope.com/u/thelurkinghorror)\ **Post date:** [July 22, 2018, 4:19am UTC](https://boards.straightdope.com/t/birds-plants-lizards-does-camouflage-extend-to-the-ultraviolet/818337/5 "2018-07-22T04:19:30Z")
There is nothing “special” about the UV or IR range, it is simply the region of the EM spectrum immediately outside human perception. Therefore, AFAIK nature doesn’t put a hard edge at that region of the spectrum for humans’ benefit or detriment. ---
**Author:** ![Arkcon](https://avatars.discourse-cdn.com/v4/letter/a/96bed5/32.png) [@Arkcon](https://boards.straightdope.com/u/Arkcon)\ **Post date:** [July 22, 2018, 2:16pm UTC](https://boards.straightdope.com/t/birds-plants-lizards-does-camouflage-extend-to-the-ultraviolet/818337/6 "2018-07-22T14:16:05Z")
Tamerlane: found a decent reference, sure, under selective pressure, camouflage works outside of an animals visual range. Kinda a bonus for the species, it can still rely on visual cues for inter species communication. Insects that see into the UV tend to not see very deeply in the red, as I recall, ants and honeybees don’t see red very well, and red lights can be used to study them, which humans see well. That’s kinda the thing – animals see outside human range in some ways, and then fail to conform to human vision in other ways. ---
**Author:** ![naita](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/naita/32/5862_2.png) [@naita](https://boards.straightdope.com/u/naita)\ **Post date:** [July 22, 2018, 3:05pm UTC](https://boards.straightdope.com/t/birds-plants-lizards-does-camouflage-extend-to-the-ultraviolet/818337/7 "2018-07-22T15:05:43Z")
> [@am77494](#): > > Many predators have eyesight that extend beyond the human visible spectrum colors (ultraviolet ). What predators are these? As a mammal I’m biased towards our kind, and UV vision is pretty rare. ---
**Author:** ![Broomstick](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/broomstick/32/246_2.png) [@Broomstick](https://boards.straightdope.com/u/Broomstick)\ **Post date:** [July 22, 2018, 3:49pm UTC](https://boards.straightdope.com/t/birds-plants-lizards-does-camouflage-extend-to-the-ultraviolet/818337/8 "2018-07-22T15:49:49Z")
Among _mammals_ UV vision largely unknown - among insects, arthropods, fish, lizards, and birds a lot of species see into the UV. It’s been found that in some bird species where the male and female look identical to us their feather colors differ by gender in the UV. Which those birds can see. Nearly 70% of parrots, for example, have UV colors in their plumage we can’t see, and even those that don’t can see into the UV. ---
**Author:** ![thelurkinghorror](https://avatars.discourse-cdn.com/v4/letter/t/7c8e57/32.png) [@thelurkinghorror](https://boards.straightdope.com/u/thelurkinghorror)\ **Post date:** [July 22, 2018, 4:04pm UTC](https://boards.straightdope.com/t/birds-plants-lizards-does-camouflage-extend-to-the-ultraviolet/818337/9 "2018-07-22T16:04:18Z")
Rodents see somewhat into UV - it helps them see urine. Even if humans had the photoreceptors to see into UV, we would still not see very far as UV light doesn’t even reach our retina because the lens filters it out. People who have cataracts and get an artificial lens can sometimes see a little farther into the UV range. ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [July 22, 2018, 7:08pm UTC](https://boards.straightdope.com/t/birds-plants-lizards-does-camouflage-extend-to-the-ultraviolet/818337/10 "2018-07-22T19:08:34Z")
> [@thelurkinghorror](#): > > Rodents see somewhat into UV - it helps them see urine. Why do rodents need to see urine? > [@](#): > > Even if humans had the photoreceptors to see into UV, we would still not see very far as UV light doesn’t even reach our retina because the lens filters it out. People who have cataracts and get an artificial lens can sometimes see a little farther into the UV range. This is almost but not quite right. When artificial lenses were first introduced, anyone getting them could see a short ways into the UV because the pigment in the blue receptors responds to those wavelengths. But they found that exposing the retina to UV could damage it, so they changed the lenses to be opaque to UV. ---
**Author:** ![thelurkinghorror](https://avatars.discourse-cdn.com/v4/letter/t/7c8e57/32.png) [@thelurkinghorror](https://boards.straightdope.com/u/thelurkinghorror)\ **Post date:** [July 23, 2018, 8:09am UTC](https://boards.straightdope.com/t/birds-plants-lizards-does-camouflage-extend-to-the-ultraviolet/818337/11 "2018-07-23T08:09:53Z")
> [@dtilque](#): > > Why do rodents need to see urine? To follow conspecific trails/hiding places etc. > [@](#): > > This is almost but not quite right. When artificial lenses were first introduced, anyone getting them could see a short ways into the UV because the pigment in the blue receptors responds to those wavelengths. But they found that exposing the retina to UV could damage it, so they changed the lenses to be opaque to UV. Okay, then without your lens you would see a bit into UV. But then in the long term your eye is more susceptible to UV damage, so it’s a positive adaptation. Other species may not live long enough for UV to be a detriment. ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [July 23, 2018, 12:31pm UTC](https://boards.straightdope.com/t/birds-plants-lizards-does-camouflage-extend-to-the-ultraviolet/818337/12 "2018-07-23T12:31:01Z")
I don’t know of many predators with UV vision that UV camouflage would help protect against. One of the few is the Mantis Shrimp. Much has been said about the “amazing” vision of the Mantis Shrimp. The capabilities of mantis shrimp ARE amazing, but you should be aware that no one species has all the capabilities spoken about as part of Mantis Shrimp vision – it’s a case of a lot of them each having one or more facets. But it has indeed been suggested that their UV vision is used, in part, to locate prey ( [Mantis shrimp - Wikipedia](https://en.wikipedia.org/wiki/Mantis_shrimp) , especially note 24) That being the case, it wouldn’t surprise me if their potential prey tried to blend in in the ultraviolet as well as in the visible (clean water provides excellent UV transmission, by the way.) Most UV vision I know of, though, is by things like bees, who use it to locate pollen and nectar – flowers do the opposite of UV camouflage, making themselves VERY visible in the UV, standing out like neon signs against the humdrum non-UV would of chlorophyll. ---
**Author:** ![Broomstick](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/broomstick/32/246_2.png) [@Broomstick](https://boards.straightdope.com/u/Broomstick)\ **Post date:** [July 23, 2018, 12:52pm UTC](https://boards.straightdope.com/t/birds-plants-lizards-does-camouflage-extend-to-the-ultraviolet/818337/13 "2018-07-23T12:52:45Z")
> [@thelurkinghorror](#): > > Okay, then without your lens you would see a bit into UV. But then in the long term your eye is more susceptible to UV damage, so it’s a positive adaptation. Other species may not live long enough for UV to be a detriment. Birds live a long time, some of them having the same lifespans as human beings, yet they seem to do OK with UV vision. So I’m not sure that your conclusion is valid. It still leads to the question of how birds avoid long-term UV damage to their retinas. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [July 23, 2018, 12:56pm UTC](https://boards.straightdope.com/t/birds-plants-lizards-does-camouflage-extend-to-the-ultraviolet/818337/14 "2018-07-23T12:56:27Z")
> [@am77494](#): > > Various life forms use camouflage to hide themselves from predators. Many predators have eyesight that extend beyond the human visible spectrum colors (ultraviolet ). So does the comouflage colors extend to the ultraviolet range too ? > > For example : when a chameleon camouflages itself against a leafy branch, does it colors match the leaf colors too when looked in the ultraviolet region of the spectrum ? > > What about green parrots and their ultraviolet color compared to green vegetation ? [Apparently some camouflage using UV yes, but not to leaves…](https://www.nature.com/articles/srep19815) Aegean wall lizards (Podarcis erhardii) in Greece in the wild choose to sit on rocks that best match their back coloration as viewed and perceived by an avian predator from above (matching coloration as seen inclusive of the UV spectrum). Not so sure how common it would be though. You need a predator with UV perception (mostly birds, few lizards with uv perception of significance) and prey camouflaging in high UV and UV reflectance environments during the day. Fairly little UV gets through in dappled or shady (leafy) areas or underwater, so not much pressure to match UV patterns there. Not too many lizards see well in the UV portion of the spectrum. (Hence this big deal over [the desert iguana having UV perception](https://www.newscientist.com/article/mg12316742-500-science-ultraviolet-vision-brings-lizard-up-to-the-mark/) used see scent markers at a distance they could not smell them and possibly to better see plants of interest.) ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [July 23, 2018, 1:13pm UTC](https://boards.straightdope.com/t/birds-plants-lizards-does-camouflage-extend-to-the-ultraviolet/818337/15 "2018-07-23T13:13:55Z")
> [@Broomstick](#): > > Birds live a long time, some of them having the same lifespans as human beings, yet they seem to do OK with UV vision. So I’m not sure that your conclusion is valid. It still leads to the question of how birds avoid long-term UV damage to their retinas. [Yes.](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2992722/) > [@](#): > > Whether long-lived birds compared with short-lived birds have increased lipopigment in the retinal pigment epithelium, or better mechanisms for removal of peroxidized lipids in the outer segments, remains to be determined. … > > … With the exception of P. elegans that has an expected lifespan of around 15–20 years in captivity, all the other species investigated here are considered long-lived with lifespan of up to 50 years or more in captivity [37]. UV radiation is known to damage several components of the eye such as the cornea, lens, the retinal pigment epithelium and the photoreceptors, leading to apoptosis in the cornea and pigment epithelium [33], decreased lens cell viability [50,51], the induction of oxidative stress [52] and the inactivation of anti-oxidant enzymes like catalase [34]. UV radiation is also associated with several age-related conditions like cataract and macular degeneration [33,50]. In mammals, a long lifespan would appear to be associated with a loss of UV-sensitivity of the visual system with the peak sensitivities of the SWS1 pigments shifted to wavelengths greater than 400 nm [11]. Only short-lived species such as the rat and mouse among the Eutheria have retained UVS pigments although, from the species studied so far, this may be more prevalent among the metatheria [3,11]. The penetration of UV radiation in the neural retina in long-lived parrot species might be expected therefore to cause irreversible damage [34,52] and raises the question as to how these species tolerate UV exposure. One explanation may be that birds show a lower rate of mitochondrial free-radical production in comparison with mammals [53,54]. Furthermore, cells of long-lived birds exhibit exceptional resistance to oxidative-induced damage when compared with shorter-lived birds and mammals [55], although the underlying genetic and molecular basis for this higher oxidative resistance is unknown. A third explanation could be the presence of carotenoids, which are present not only in the oil droplets of the retina, but also in the serum of parrots at concentrations comparable to that in other bird species [12,56]. Carotenoids are known to be effective antioxidants and immunostimulants in birds (reviewed in [57]), with lutein and zeaxanthin being especially effective in conferring protection against oxidative damage in the retina [58,59] and light-induced photoreceptor apoptosis [60]. Similarly, psittacofulvin pigments, found so far only in parrot feathers, are thought to have considerable antioxidant properties [61–63], and could offer protection if also present in the retina. > > If such processes are occurring in the retina, the combination of a lower production of free radicals and an increased resistance to oxidative damage could protect the eye against the damaging effects of UV light exposure in long-lived parrot species. …