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What Birds Know About Fractal Geometry
sciencehabit writes "In a new study, researchers find that a single number that describes the complexity of feather patterns on bird chests, a parameter called the fractal dimension, is linked to whether a bird has a strong immune system or is malnourished. When scientists restricted the food of red-legged partridges, the patterns on their chests had a lower fractal dimension than those sported by their well-fed colleagues. The food-restricted birds, on average, weighed 13% less than their well-fed colleagues and had weaker immune systems, which makes fractal dimension an easily recognizable sign of a potential mate's health and vitality, the researchers contend."
'Fractal dimension' seems like a cool buzzword which will make it easier to get research noticed, so call it what you will, but a the color of birds feathers except for blues are determined by their diet. Blue is determined structurally. The pattern is determined by proteins following genetically-laid out patterns, same as like stripes or spots on other animals. There is some logic that birds with good diets would have 'better' patterns as determined by their prospective mates.
http://www.smithsonianmag.com/science-nature/Why-Are-Some-Feathers-Blue.html
http://www.birds.cornell.edu/AllAboutBirds/studying/feathers/color/document_view
Birds know nothing about fractal geometry. It would have been extremely cool if they did.
Is this related to the idea that the degree of golden proportion in the human face is a measure of beauty?
The notion of birds calculating the fractal dimension of a prospective mate's feathers seems about as farfetched as baseball fielders calculating the exact mathematical damped parabolic path of the ball to work out where to put their hand. It also indicates that if true, birds are much nerdier than my physicist friends and should in theory have less chance of getting a date. As such, this theory is debunked by birds not being extinct through lack of mating! I do buy the notion that birds could see the effect without doing the maths though.
Animals should be sliced and diced at our discretion for pure and possibly applied science. Life--all of it--is cheap.
Buy your next Linux PC at eightvirtues.com
Do we really need to starve birds to learn that if they are sick they lose the feathers?
Really.
Fractals have many uses http://en.wikipedia.org/wiki/Fractal#Applications_in_technology It is a perfectly reasonable hypothesis that birds recognize the fractal dimension of plumage in their own species. Conflating this with "being able to compute a fractal" is ignorant. Some birds are known to get information about magnetic fields through their visual channel. This does not mean they are solving Maxwell's equations.
It is possible to extract fractal dimension information from images. Typing in "fractal dimension image detection" into Google Scholar results in over 25000 references. If academics have figured out how to do this then evolution may also embody these concepts.
Posting on Slashdot is an opportunity to share knowledge and learn things. Unfortunately far to many people who post here show that they are ignorant and arrogant. I call them the Slashdot Pundits.
Just because you know one thing does not mean that things you haven't heard of are wrong. With Google and the like, it's easy to fact check. On this topic so far all we have seen is woefully uninformed people criticizing academics and making fools of themselves. I would think that shear embarrassment would tend to eliminate this kind of drivel, but I guess if you are stupid enough to make such uninformed statements, you are also incapable of understanding how bad it makes you look.
Why is Snark Required?
Animals should be sliced and diced at our discretion for pure and possibly applied science. Life--all of it--is cheap.
Glad you're so in favour of this! I look forward to you being first to come forward and hearing what exciting revelations come from you being sliced and diced. :-)
A useful experiment might be to prove or disprove the premise that "Slashdotters do not enjoy being sliced and diced". ;-)
Identifying the fractal patterns on a coconut husk would help a swallow identify where to grip it.
Now, that should be worth an Ig Nobel, no?
And so the weavers told the emperor raven that they could make him a spectacular robe of colored fractals that was invisible to stupid birds like sparrows...
perform by "scientist": to starve birds to see if their feathers change aspect !
Bravissimo dudes !
You saved the planet again by mistreating animals !
The title seems to be trying to suggest (to me at least, and based on the other comments here also to plenty of other readers) that birds can perceive fractal dimensions (FDs). However, if you read the journal article, it's all about a study of how the fractal dimension of the plumage correlates to different measures of the bird's health. They then also investigate some causative effects, by changing the bird's food intake and measuring the effect this has on FD. Nowhere in the article do they make any claim that birds can necessarily perceive or calculate a fractal dimension: the paper ends by saying "We therefore suggest that considering FD should shed new light onto the evolution and maintenance of complex animal patterns. " So they suggest (entirely reasonably IMHO) that it would be interesting to study that latter aspect, which is quite an important difference from what the Slashdot title is trying to imply.
That makes two of you.
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if you are studying some awful disease, like smallpox, most people do not have a problem with purposely starving a mouse.
if you are just doing it to measure fractals, a lot of people do have a problem with it... even meat eaters.
"oh but we need basic research and that justifies it because it might save someone some day" -- yeah no it doesnt, unless you have some examples. because i can give you thousands and thousands of examples of where 'science' committed horrifying atrocities against human beings in the name of 'basic research' and used that same argument to justify it. thats the whole point - its not about 'save the animals', its about basic morality.
It is truly the advancement of all humanity to study Fractal Patterns of bird feathers that have been starved; then to consider procreation in the same sentence.
The idea that something so complex could be automatic in a bird's perception based on visible traits is very interesting, but what intrigues me more is the possible correlation this could have to other species including humans. Immune malfunction, more specifically auto-immune disorders can be some of the hardest to diagnose (some can't actually be confirmed, only determined that you don't have anything else) and they have all sort of symptoms that resemble colds, allergies and other more easily diagnosed issues/illnesses. The idea that something visible could be measured and possibly have more meaning than all the x-rays and bodily fluid tests we have to date would prove an amazing breakthrough for health care. Of course that is a big IF that there is something in humans corresponds.
In other news, long beaked birds flourished when their food supply retreated into crevices.
Hence, we are monkeys.
Why are they starving birds? Says more about the experimenters than about fractals.
Birds know nothing about fractal geometry. One does not need to know the fractal geometry of a feather pattern to deem the pattern desirable.
Another point is that they didn't prove the link between fractal dimension and desirability. It is quite possible that the prospective mate does not notice the change in plumage but looks at the overall health of the bird. Now if someone took identically healthy birds and modified some bird's plumage to change the FD and that changed the selection probability then that would be proof.