Tuesday, December 29, 2009

Silver's Tongue, Dry Mouths and Their Possible Evolutionary Advantage

Here is a much better look at Silver's tongue. I learned something new about it. I've only seen Silver's tongue when it comes out forward, rather like a little black finger touching things. But here you can see that when it bends down it develops the curved shape and mobility that is found in many mammal tongues.

Which makes me wonder why his tongue never comes out and licks his beak as we do with our lips to clean or moisten them. Obviously his beak doesn't need moistening. And his mouth is dry so it wouldn't moisten anyway. And come to think of it that would make it pretty ineffective as a clean up tool as well. Scraping it on hard rough objects does a reasonably good job of cleaning it without having the possibility of abrading his tongue on a sharp spot.

Which leads me to the question-- what is the evolutionary advantage, if any, of having a dry mouth as opposed to a wet one?

Let us presuppose that there is an evolutionary advantage. No need for moisture as there are slime glands which aid in swallowing and other uses such as talking and cleaning are taken care of in other ways.

What might be an advantage to a completely dry mouth? It doesn't get your feathers moist but it would pick up a lot of the dust created by his "dust feathers" that condition the other feathers which wouldn't be optimal.

Also warm moist areas are hot beds of bacterial growth. Moist mouths do grow bacteria rather nicely. No problem with bacterial tooth decay in this case. Beak decay?

What about odor? Parrots are a prey animal after all.


African Greys don't really seem to have much of an odor at least to humans. Even parrot feces doesn't have an odor. It might develop a faint one over time which would explain why Silver doesn't defecate in his sleeping cage if he can at all help it.

Odor gives away one's location to predators and as Greys flock in the wild, a roost tree might well be a big give-away otherwise. Particularly if it were used more than a few nights in succession.

If you get within an inch or so of Silver's head and sniff, he tends to smell ever so faintly like waffles. My assumption was previously that what we think of as "waffle" fragrance is a grain smell he'd picked up from eating seeds. Though now that I think about it if he's eaten lasagna he doesn't smell like lasagna he still smells faintly like waffles. Is that actually him?


(See. Once you start being curious and asking questions it always brings up another question even if you answer the present one to your satisfaction. There is never ever a reason to be bored, for the game is always afoot.)

I just went and sniffed Silver's beak and then buried my nose in Silver's feathers. He found it quite odd. I had Sam do the same for a second opinion. He found that even odder but didn't decide to be affronted and pinch our noses. His feathers don't smell like waffles. I didn't think they smelled like anything. Sam thought they smelled like dust but she was cleaning out her very dusty closet a few seconds before so it would be nice to have a few more noses involved to get a larger opinion.

TANGENT ALERT--As I'd explained about the current hypothesis dealing with bacteria and mouths, she updated me on the issue of Kimoto Dragon saliva. It had been thought that the reason prey animals bitten even slightly by Kimoto Dragons and though they escaped yet died anyway had to do with the amount of evil bacteria in their mouths. Wrong. A year or so ago they discovered the venom glands in the KD's mouths and said, "Oh, Never mind what we said earlier...")

Yes, hmm. But back to what the evolutionary advantage of a dry mouth might be, if one of the advantages might be lack of odor, and does an African Grey parrot mouth actually lack odor or enough so not to give the bird away at a distance?

Okay, we pretty much can tell at this point that at least to humans Grey's bodies don't have a noticeable odor.

As to their beaks and odor another thought brought to mind by a habitual behavior. After eating dinner with the family, Quicksilver eats whatever we're eating barring chocolate, avocado and other things that can kill parrots, he always whets his beak clearing it of any food debris and then rips off a portion of newspaper, chews it with his beak, we've always had the idea he was cleaning the inside, and then spits it out. But when Silver eats nutri-berries--little balls of various seeds stuck together with tasty parrot nutrients he doesn't do the newspaper afterwards. Hence perhaps why his beak either smells like grain/waffles or nothing at all?

Okay but does Silver smell like anything in particular to an animal with a better sense of smell? Like the family cats for instance? We've actually questioned whether he smells like a bird to cats before because of the behavior of cats around him. Initially cats tend to be rather confused by him. Okay he flies which makes them a little excited which they almost immediately get over. And it isn't just his size as the pigeons are about the same size and weight and they continue to be exciting to the cats. Besides he speaks English which isn't right at all if attempting to put him into the eatable category.

But the strangest reaction is when cats are trusted enough not to jump on him and are allowed to come up while he's being held and sniff him. They don't find his smell exciting at all. In fact, most of the cats Silver has known, including Pyewackit who didn't have a model for behavior in the other family cats as they've been in NYC, begin to greet him as if he were another cat. For the non-cat people, cats who know each other greet each other by touching noses. (Personally I think cats speak to each other partially in an olfactory language but that's another line of enquiry...) Therefore when Silver is sitting on someone's knee while they lay on the bed and watch TV together, if a cat jumps onto the bed it will immediately come up and put its nose on Silver's beak. Note they don't do this to humans nor do they do it to any of the other birds in the house.
Who I might add smell, well, like birds.

So with this incredibly small sample we might stretch things a little and surmise that to humans African Greys don't smell like much at all and to house cats they don't seem to smell like the birds they understand as prey animals nor do they likely smell like the pork chop he might have had in conjunction with dinner as they don't lick him.

The conclusion? We haven't discounted the possibility that a dry mouth is an evolutionary advantage due to the lack of moisture and therefore odor.

Donegal Browne

1 comment:

Karen Anne said...

My (now all late) cats would touch my nose with theirs...

However, I am not sure if they originally did this by themselves or if I initiated it because I had seen them do it to each other and it became a learned behavior.