Sunday, August 17, 2008

Blue-Eyed Lemurs: Or why gentlemen prefer blondes.

Each month on etsy I debut a new monkey made out of eco-felt and created to resemble a real species of primate. The August monkey for the Monkey of the Month Club is the blue-eyed lemur.

The monkeys are decorative ornaments that can be used year round. The felt is made by a company, the Kunin Felt Group, that makes it out of 100% post-consumer plastic bottles. I call them OrnaMonkeys.

The blue-eyed lemur is a species of lemur that is unique among primates in two regards:
* They have blue eyes.
* The males and females look different.

Their blue eyes arise from a recessive gene that also gives rise to blue eyes among humans. So far as I know, the blue-eyed lemur is the only other species of primate beside humans to regularly have blue eyes. Blue-eyed lemurs are a subspecies of black lemurs. When they mate, something they are able to do, the offspring usually have brown eyes.

I don't know why taxonomists decided to give the blue-eyed ones their own 'sub' species status, but it's a little silly really. The only thing that separates the two is the color of their eyes. It's as silly as designating all blue-eyed people a subspecies of Homo sapiens, except that people aren't endangered and lemurs are.

Taxonomic designations have real conservation consequences. The blue-eyed lemurs are considered critically endangered, which is more serious than simply being endangered. It means they more desperately need habitat protected and those rules enforced. Designating them in a special category might translate into more attention, stricter laws, tougher enforcement — and more money for their conservation.

But what is really cool, in my opinion, is not their blue eyes, but the fact that males and females of this species look radically different. All males are completely black. All females are reddish and have light faces. This pattern, known as sexual dimorphism, is more typically seen in birds where the males are brightly colored and the females are drab brown and hardly distiguishable form other species of bird. When birdwatchers go out birdwatching, they're usually looking for males - they're flashy and far easier to identify.

It's not all that different for these blue-eyed lemurs, except that I think the females look flashier.

There are loads of theories about why males and females look different. Most are variations on sexual selection - an evolutionary mechanism Darwin proposed as a compliment to natural selection. Sexual selection is an evolutionary process whereby male and female mate preferences diverge over time, either because males prefer and select lighter females to mate with or because females prefer darker males to mate with. It’s a bit like Gentlemen Prefer Blondes! Over time, the females get lighter and males get darker.

No one knows just why gentlemen prefer blonds and ladies flip over dark haired men, but one intriguing theory (at least for the human pattern) is that light hair is more typically seen among children than adults. So, light hair signals youth and is a desirable quality in females since it means they have a lifetime of reproductive potential ahead of them. That's why gentlemen prefer blondes. What's interesting, and provides some measure of support for this theory as it applies to these lemurs, is that males are born reddish like females and only darken to black with age. I don't know of a good theory about why females prefer darker males let alone whether they actually do, but there is some reasonably good evidence to suggest that men really do prefer the fairer sex.
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The blue-eyed lemur OrnaMonkeys are for sale on etsy. They all come with a fact sheet so recipients can learn about the monkeys. The Monkey of the Month Club makes a wonderful Christmas gift. Memberships go on sale in early October.


Unbalanced Reaction said...

So cute!

I never knew there were blue-eyed monkeys! How interesting.

RainbowMom said...

Another interesting post! :D

~ tracychong ~ said...

I love how you include the sciencey facts about your monkeys!

Ann said...

Love your blog and what an interesting and educational post.

p-ter said...

This is fascinating. You write that blue-eyed lemurs are due to the same gene as in humans; do you have a reference for this? Nothing popped up in a cursory googling.

Field Notes said...

You know, I can't recall where I learned that. I may take a while to track it down, but I'll try.

Eden said...

Those ornaments are adorable! I collect lemur items of all kind so whenever you're back from vacation and if you decide to sell more, I'd definitely be interested (If I can afford them, that is... Hah)

I think it's awesome that you include facts with these posts and with purchases, though! One thing I might point out in what you said, though, is that there are actually a whole lot of differences between the Common Black and Blue-Eyed Black Lemurs. Common blacks have very very large, noticable 'manes' of spiky hair around their face. The two species also have very different marking patterns (in the females, of course), different colors, and a lot of behavioral differences as well. The blue eyes were just where they got their name, not why they were listed as a new subspecies! ;)