why are mandrils buts red?
358570
This is often thought of as heplful in the mating process. It gives a "target" of sorts. Kind of the same idea as baboon butts.
1042037
Color. Males have more of a red breast where females have more of a brownish color on their breast.
995583
The red color is found in many soils around the world.\nThe cause of that is the presence of oxides and hydroxides of Fe and Al.\nThose soils are known as ''weatherized'', usually done by many, many years of exposure to heat and humidity.
730209
mine did that but red. it's something to do with files being on different harddrives i think!!
676943
Red-eyed tree frogs are prey on by snakes, large birds, and even bats.  Birds are its major predator which spurred the developement of the frogs bright red eyes.  The red eyes of the frog act as a defense mechanism. Birds can see color and the bright flash of the red eyes popping open is enough to stun potential predators.  All the frog needs to do is stall the predator for less than a second to make its escape.
1090862
Bulls are color blind.\n\nIf you're thinking in terms of bull-fighting...it isn't the color of the red cape that attracts their attention.  It's the movement, the waving of the cape.
537014
Add red coloring.\n\nIt IS necessary, and it DOES NOT harm the birds.
263149
THeir fur is actually colorless, it absorbs light to heat their bodies.  It works so well, that they frequently have to swim in freezing waters to cool down or roll around in the snow.  They aren't very active either becasue then they would overheat.
871649
That is a very interesting question.\nno . . . . but there is one exception\nIn a camera flash, the light is reaching through the pigmentation\nto the retina, the light-sensitive membrane covering the back wall of the eyeball, which is the color red.\nthe only organisms that have eyes visibly red are ones that are albino\nalbino organisms have less melon(color) in there skin, hair, and eyes.\nresulting in the clear vision to their retina, which causes their eyes to be the color red.\n(i.e. white mice that have red eyes)
356865
Probably,because it is red,red is a colour of love and it also has thorns,love hurts a lot.Also when it dies in autumn it reborns in spring and so on.
1053811
Red, just about any warm blooded mammal has haemoglobin that has an iron base and accounts for the red colour. Difference in colour only occurs in animals such as insects or spiders because they have a different base, spiders have a copper base.
318615
Safranin reacts with lignin and stains it red. Therefore only the lignified tissues such as Xylem and Sclrenchyma are turned red and all other tissues like Parenchyma, Collenchyma and Phloem remain colour less.
660276
It's the motion of the cape that catches the bull's attention and not necessarily the color. The cape could be purple for all that matters to the bull. Red is more dramatic of a color and easier for the audience to see from a distance.
320173
Frogs come in variety of colors but the majority of them are green. Being green when sitting on green leaves has obvious advantages if you want to avoid becoming an easy meal for some hungry predator. \n\nFrogs are not green because they have green pigment in their skin.In their skins they have three types of pigment cells (called chromatophores) stacked on top of each other. At the bottom are melanophores, containing a mostly dark pigment called melanin. These are the same cells that can make human skin various shades of brown. On top of the melanophores are iridophores, packed with highly reflective bundles of purine crystals, and on top of the iridophores are xanthophores, usually packed with yellowish pteridine pigments. In the typical green frog, light penetrates to the iridophores, which act like tiny mirrors to reflect mostly blue light back into the xanthophores above them. These cells act like yellow filters, so the light escaping the skin surface appears green to our eyes.\n\nBy manipulating all three types of pigment cells, a wide range of colors can be produced, although usually the range extends from bright green to various shades of brown and gray. In frogs, all of these changes appear to be mediated by hormones circulating in the blood. The advantage of such color change is obvious. Imagine a frog leaping from a green leaf onto a brown tree branch. Melanin moves, reflective purine crystals shift position, yellow pteridine pigments cluster or disperse, and voila, that green frog that stood out like, well, like a green frog sitting on a brown branch is now a well camouflaged brown frog.
1037519
Good question!\n\nNature has evolved molecules that pigment various parts of organisms.  Plants and flowers are the obvious case in point, but in humans, skin pigments, and those in the iris (giving us blue, green brown etc. eyes) have also evolved.\n\nIt is QUITE POSSIBLE that at some point in the past, alternative pigmentation DID evolve in humans, and the only thing we CAN say with any certainty, is that if it did, if was later eradicated from the gene pool, and does not ersist any longer.\n\nMost notably, the only ANIMALS that have evolved the colours you mention have been birds, where the ability to fly away rather than the need to camoflage and blend in is the preferred means of evading redators.  So bright colours in these cases are NOT dangerous to the organism (bird) displaying them.\n\nIt is true that some other apes (primates) DO display bright colours.  Some have bright red backsides, and in some cases, bright blue pigment is evident on parts of the bodies.\n\nSo as a final thought:  in a world where bright colouring is no longer likely to be life endangering to humans, how long will it be before a random genetic mutation causes pigmentation other than the standard tan and browns that we are used to to evolve?!
499158
The red fox (Vulpes vulpes)is not endangered and in fact lives in a higher population density in cities than people are aware.\n\nTwo color variations exist which include silver (gray or blackish in color, sometimes completely black) and cross foxes (grayish color and darker stripe that looks like a cross, hence the name) and are always identified by their distinctive white tipped tail.  These color variations can be rare even though the species is thriving.
513335
Here are some pictures of red pandas ...\n\nhttp://images.search.yahoo.com/search/images?p=red+panda&sm=Yahoo%21+Search&fr=FP-tab-img-t&toggle=1&cop=&ei=UTF-8