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Q: What Animals/Insects Can See Ultraviolet Light? Which Ones Cannot? ( Answered 5 out of 5 stars,   0 Comments )
Subject: What Animals/Insects Can See Ultraviolet Light? Which Ones Cannot?
Category: Science > Biology
Asked by: prpro-ga
List Price: $25.00
Posted: 16 Sep 2005 07:21 PDT
Expires: 16 Oct 2005 07:21 PDT
Question ID: 568701
I need to know which animals/insects can see ultraviolet light and
which ones definitely cannot. Can someone provide a quick list?

I know man cannot see it; can dogs - cats - other land mammals?  I
know bees and spiders see it; do cockroaches? Which others?
Subject: Re: What Animals/Insects Can See Ultraviolet Light? Which Ones Cannot?
Answered By: czh-ga on 16 Sep 2005 14:54 PDT
Rated:5 out of 5 stars
Hello prpro-ga,

What an interesting subject! A quick overview of what animals have or
lack ultraviolet vision reveals that most mammals don?t have this
capability which is fairly common with other fauna. There is a lot of
research currently under way exploring this field so you should look
forward to continuing new discoveries. Below I?ve included some
articles and websites that show that many fish, amphibians, reptiles,
birds, insects and some mammals have ultraviolet vision.


~ czh ~

Exploring the Fourth Dimension

If you watched a wildlife series with, say, the red light source of
your television removed (or if you were red-green "colour-blind") and
you then came up with conclusions about colour variation in the
natural world, would anyone believe you? Probably not, but then that
is what we humans are doing every time we think we are seeing the
colour world of non-human animals. Unlike other variables such as
length, width, mass, or time of day, colour is not an inherent
property of the object; it is a property of the nervous system of the
animal perceiving the light. In an interdisciplinary collaboration
Andrew Bennett, Innes Cuthill and Julian Partridge have been combining
techniques from visual physiology and behavioural ecology to
investigate the colour world of birds.

Molecular analysis of the evolutionary significance of ultraviolet
vision in vertebrates

Many fish, amphibians, reptiles, birds, and some mammals use UV vision
for such basic activities as foraging, mate selection, and

The use of UV vision is associated strongly with UV-dependent
behaviors of organisms. When UV light is not available or is
unimportant to organisms, the SWS1 gene can become nonfunctional, as
exemplified by coelacanth and dolphin.

Molecular basis for ultraviolet vision in invertebrates.

Invertebrates are sensitive to a broad spectrum of light that ranges
from UV to red. Color sensitivity in the UV plays an important role in
foraging, navigation, and mate selection in both flying and
terrestrial invertebrate animals. Here, we show that a single amino
acid polymorphism is responsible for invertebrate UV vision.

Urine Vision? How Rodents Communicate With UV Light
John Pickrell in England
for National Geographic News
July 8, 2003

Many fish, reptiles, birds, and insects are able to see ultraviolet
light. Some even use pigments that reflect it to attract mates and
communicate. But most mammals have lost the ability to see ultraviolet
light and lack the cellular machinery necessary to detect it.

Now, a new study suggests that urine plays such an important role on
the rodent communication grapevine that it may explain why some
species have retained ultraviolet (or UV) sensitive cells and visual
pigments and other mammals haven't. The urine of many species of
rodent strongly reflects ultraviolet light, says the study published
in a recent edition of the journal Investigative Ophthalmology and
Visual Science.

Unique among mammals however, many rodents?such as rats, mice, and
gerbils?have retained the ability to see UV light, though the reasons
behind this have remained mysterious.

October 10th, 2003
Bats scan the rainforest with UV-eyes 
German and Guatemalan researchers discover new mechanisms for
ultraviolet vision in mammals

Bats from Central and South American that live on the nectar from
flowers can see ultraviolet light (Nature, 9. October 2003 p.
612-614). This was discovered by York Winter, a German researcher at
Munich University and the Max-Planck-Research Centre for Ornithology
together with colleagues from Germany and the University of Guatemala.
As bats generally lack cone pigments in their eyes, the flower bats
capture the ultraviolet with the rhodopsin of their rod pigments. This
mechanism was unknown in mammals until now.

Modern mammals lost their ability to see ultraviolet in the course of
evolution, contrary to birds and lower vertebrates. Of the originally
four cone pigments of ancestral vertebrates, the higher mammals have
retained only two.

What Do Rats See?

Rats have just two types of cones (called "dichromatic" vision): a
short "blue-UV" and the middle "green" cones (Szel 1992). The "green"
cones' peak sensitivity is around 510 nm (Radlwimmer 1998), but the
"blue" cones are shifted toward even shorter wavelengths than human
blue cones, peaking at 359 nm. This means rats can see into the
ultraviolet, they can see colors we can't see (Jacobs et al. 1991;

What is the function of ultraviolet vision? 
The function of ultraviolet vision in rodents is not well understood
yet and is currently an active area of research. Here are some
? Urine-mark visibility:
? The body under UV:
? Twilight ultraviolet vision:

Bats Scan The Rainforest With UV-Eyes

Modern mammals lost their ability to see ultraviolet in the course of
evolution, contrary to birds and lower vertebrates.

But what does a mammal do, if the need for UV-vision arises again, but
the necessary anatomical structure has been lost? The flower-visiting
bats use their rod receptor for UV-perception and catch the UV-photons
with the so-called beta-band of their photoreceptor, a peak of minor
sensitivity for light absorption. In these mammals, therefore, only a
single photoreceptor is responsible for the perception of light
radiation over the whole wavelength spectrum from about 310 nm to 600

That bats can see ultraviolet is also due to the fact that a UV-filter
is lacking from their eyes lenses. Normally, the UV-absorbing lens
protects a mammals eye from UV-radiation. UV-light not only damages
the retinal cells but it also causes an optical problem. The angle of
light refraction depends on the wavelength of the light. A point of
light is refracted at the lens, the refractive surface of the eye. As
different wavelengths are refracted at different angles, a light of
many colours such as one containing UV, will lead to an out-of-focus
image on the retina of the eye. But the smaller the size of the eye,
the less disturbing this effect will be. Thus UV-vision should only be
expected in small, nocturnal mammals such as the bats with their
small, 2 mm eyes.

The Compound Eye
The arthropod (e.g., insects, crustaceans) eye is built quite
differently from the vertebrate eye (and mollusk eye).
Why ultraviolet vision?

Ultraviolet vision is not limited to animals with compound eyes. A few
marsupials, rodents, a bat that feeds on nectar, and many birds have
also been shown to have ultraviolet vision.

How are satellite images different from photographs?

Many insects are able to detect wavelengths that humans are not able
to see. Bees, for example, can detect three colors: ultraviolet, blue,
and yellow, but not red. The ability to see red is actually rare for
all insects. The butterfly is an exception to this rule. Butterflies
are believed to have the widest visual range of any animal. Various
species of butterfly can detect wavelengths anywhere from 310 nm to
700 nm. To humans, male and female butterflies may look the same, but
butterflies are able to identify each other easily because of
ultraviolet markings on their wings. Butterflies and insects are also
attracted to ultraviolet nectar of certain flowers. The photos below
other simulate how humans, bees, and butterflies see the same flower.

Background Information -- Eye of the Whale Scene

Much of the electromagnetic spectrum is invisible to humans. Animals
vary in their ability to see certain wavelengths. For example, humans
cannot see ultraviolet light but many insects can

C. Insect eyes 

Insects have even more different types of eyes and vision systems than
the less advanced animals we've considered. Many insects need to see
in three dimensions while flying at high speed. Indeed, winged insects
have better vision than wingless ones. The variation of eye size,
resolution, and overall optical design in insects is also great.
Many insects see a wider spectrum of colors than humans do. Their
color vision spectrum may vary from ultraviolet, in the case of the
bee, to near infrared, in the case of some butterflies, and beetles.

Bee eyes sense polarization of visible light in the sky and also have
sensitivity to UV light. They seem to see blue colors best, but they
also see ultraviolet colors beyond the blue colors which humans see.
Don't forget that a yellow flower may have markings that reflect or
absorb light in the UV region. Flowers may also have narrow-band color
reflections that communicate to bees and other animals the type of
plant it is. Bees' extended range of color vision helps them to locate
flowers and food to function in their survival and growth.

Spiders Use Flower Ultraviolet Patterns to Attract Prey

Those clever spiders! Some spiders use sticky webs to trap a tasty
meal. Other spiders hide in the ground, and then pounce on
unsuspecting prey. Scientists have discovered a new way in which some
spiders trap their favorite food (honeybees). Australian crab-spiders
(Thomisus spectabilis) interfere with the ultraviolet signals on
flowers to attract honeybees.

The use of ultraviolet by flowers 

Apart from pollen guides, plants will use ultraviolet to their benefit
in other ways, such as ultraviolet pollen, ultraviolet nectar,
fluorescent pollen or fluorescent nectar. They can also use a
contrasting background to make the flowers stand out against a
different level of ultraviolet reflection from leaves or leaf hairs.
Ultraviolet light is also of use, to insects, for the identification
of plants. This is most apparent where many plants which appear
similar to humans, grow together (e.g. many composites). Yet these are
presumably distinguishable to insects.


Most birds have far better color vision, being able to see not only
blues and greens but also reds (long wavelength light) and often
ultraviolet wavelengths, which are shorter than those of the visible
spectrum.  Some bees and other insects also see ultraviolet.

The Ultraviolet Whistling Thrush and avian colour vision 

The retinas of most birds have four different classes of cones, rather
than the three we have in our retinas. Birds have visual pigments
maximally sensitive in the red, green and blue parts of the spectrum,
like us, plus an additional pigment that is most sensitive in either
the violet (400-426 nm) or the ultraviolet (355-380 nm). Note that
although the peak sensitivities differ between the two forms of the
fourth pigment ?called VS and UVS, respectively ?they both permit
birds to detect ultraviolet light. A number of experimental studies
have now shown that birds use their ability to see UV in much the same
way as they use other parts of the visual spectrum, i.e., for finding
prey and for signaling to other members of their species.

A Bird's Eye View: Ultraviolet Vision Lets Birds See What Humans Can't
In the mid-1980s, scientists first discovered that birds can see what
humans can't. To humans, the rainbow of visible colors spans the range
from wavelengths of 400 nanometers (violet) to 700 nanometers (red).
In between are the familiar purples, blues, greens, yellows, and

Birds, on the other hand, also perceive colors below the 400 nm
wavelength, in the ultraviolet range between 340 nm and 400 nm. This
slight extension of the spectrum of visible color results in a
markedly different perception of the world.


Considering the frequent evolution of gaudy colored plumage, it is not
surprising that birds active in the daytime have color vision
(nocturnal birds are thought to be color blind), and that color
perception is often obvious in bird behavior. One can watch a
hummingbird moving from red flower to red flower; bowerbirds show
color preferences when decorating their bowers. Just how refined that
color vision may be has proven difficult to determine. However, the
diversity of visual pigments found in birds' eyes, and the presence of
an array of brightly colored oil droplets inside the cones, suggest
that avian color perception may surpass our own. There is also
evidence that some birds' eyes are sensitive to ultraviolet light. In
hummingbirds the adaptive significance of this is clear, since some
flowers from which they drink nectar have patterns visible in the
ultraviolet end of the light spectrum. Why pigeons have the ability to
see ultraviolet remains a mystery. Equally surprising is the recently
discovered ability of pigeons to detect the plane of polarized light.
This probably serves them well in homing.

Birds of a feather may use UV light for identification

"We have known for a long time" that some insects use cues in the
ultraviolet light range to discriminate among species, said Bleiweiss,
author of the research that appears this week in the Proceedings of
the National Academy of Sciences.

But this is the first time it has been shown that bird species may use
this light range for species identification and reproductive

What do animals see?

Has a flat cornea that allows for clear vision underwater. Penguins
can also see into the ultraviolet range of the electromagnetic

Seeing Colors 

Scientists have determined through experiments that some animals may
see color since they have color sensitive cells. Birds see in all
colors, especially vibrant oranges, reds, and yellows, actually a far
greater range of colors than humans., including ultraviolet. Their
cones contain a tiny droplet of oil that acts as an especially
sensitive filter to red, yellow, and orange, which just happen to be
the colors of the flowers that these birds pollinate! Butterflies and
bees are particularly sensitive to ultraviolet light and some flowers
which these insect pollinate give off ultraviolet signals. Dogs only
have two types of color sensitive cells and are believed to see in
color but not as many as humans.

Ultraviolet colour perception in European starlings and Japanese quail

Whereas humans have three types of cone photoreceptor, birds have four
types of single cones and, unlike humans, are sensitive to ultraviolet
light (UV, 320-400 nm). Most birds are thought to have either a
violet-sensitive single cone that has some sensitivity to UV
wavelengths (for example, many non-passerine species) or a single cone
that has maximum sensitivity to UV (for example, oscine passerine
species). UV sensitivity is possible because, unlike humans, avian
ocular media do not absorb UV light before it reaches the retina. The
different single cone types and their sensitivity to UV light give
birds the potential to discriminate reflectance spectra that look
identical to humans.

4. Neuroethology of Colour and UV on the Great Barrier Reef

Most fish living in a coral reef environment are extremely colourful.
Some are even able to change their colours depending on the situation
they are in. Measuring the reflectance of many colour patterns of
coral reef fishes revealed that UV colouration is an important
component of fish body patterns (J Marshall). The main aim of this
project is to study the capability of the visual system of coral reef
fishes to perceive UV-A (300-400 nm) as well as the behavioural
significance of these UV colouration patterns to the fish.

The high energy short wavelengths of UV radiation have damaging
effects on all tissues and most importantly on photoreceptors.
Therefore many animals have UV absorbing filters (pigments in the
lens) to protect their retinae from photooxidative damage (i.e.
humans). However, it has been shown for birds, crustaceans and also
fish, that there are many species that have special mechanisms to see
UV radiation. For those species there must be certain benefits that
outweigh the possible dangers associated with the absorption of short

Deep-sea exploration beneath Katrina's wake

Frank has been conducting detailed studies of how the eyes of animals
on the deep seafloor work, in collaboration with others aboard.
Working with animals collected in special light-tight devices that
avoid damage to delicate deep-sea eyes, Frank has discovered a species
of deep-sea crab that can detect ultra-violet light, despite there
being no known ultraviolet light in deep water. UV sensitivity is
common in animals that live closer to the surface, but has never been
discovered in a deep species. The reasons for this seemingly bizarre
ability are not clear, but the sensitivity could point to a deep-sea
light source about which researchers are not aware, or to some unknown
characteristic of known light sources such as bioluminescence--the
light chemically produced by countless open ocean organisms.

Shedding Light on Light in the Ocean
New research is illuminating an optically complex environment

Predators?using light to hunt 
Not surprisingly, aquatic animals possess visual systems that are
specially adapted to the nature and properties of light underwater.
Animals living near well-lit surface regions have eyes similar to
terrestrial species. They have color vision, since light near the
surface still has color.

Many also have UV vision, which advantageously extends their range of
vision. Many animals contain compounds in their tissues that protect
them against UV radiation by scattering, reflecting, or absorbing UV
light. This makes the animals appear dark and silhouetted against an
otherwise bright background of UV light. With UV vision, animals can
see animals that are transparent in visible light.

Do fish see things we don't?

Scientists have long believed that the ability to perceive UV light is
virtually non-existent in vertebrate life forms. However, ants, bees,
flies, spiders and other insect-like creatures possess that ability.
Now, researchers have discovered UV-absorbing cone cells in a
vertebrate, the Japanese dace fish, that enables the fish to see
wavelengths down to 360 nm. They have also determined that carp and
common goldfish are able to perceive ultraviolet light too.

"ability to see ultraviolet" OR "ultraviolet OR UV vision"
prpro-ga rated this answer:5 out of 5 stars
EXCELLENT answer!  Thank you -- this is just what I needed!!

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