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.

Ah!

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?

Hmm.

(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

Monday, December 28, 2009

Quicksilver Parrot's Tongue and The Christmas Bow


The presents have been opened and while the humans are tidying up, Quicksilver stealthily puts one foot on the table, just a little as he knows he's not allowed on the table, and leans slowly in toward an enticing stray Christmas bow. The camera clicks.


BUSTED!

Well, it is Christmas after all, and we want everyone to be of good cheer and definitely merry, so I tell him it's alright and he can look at the bow. Besides I've been attempting to get a photograph of his tongue and this just might be the item to do that with.

Given permission he continues his lean and gently drags the bow toward him with his beak. You can't really see it here but already his black tubular ever so slightly tapered chubby dry tongue is shooting forward touching a spot, retracting an eighth of an inch and then touching another spot every second or so. After all, one has to get loads of sensory information about the bow first before deciding it just might be quite the ya ya to rip it to shreds.

A parrot's foot being scaly, and in Silver's case basically built for climbing and/or holding things, it isn't exactly the most exquisitely sensitive of sensory inputs. Very sensitive to pressure and positioning but it misses out on the finer points Plus being that his oral orifice is surrounded by a horny curved beak for prying food off things, there is some input there but not nearly what we have in our lips. Just keep in mind a beak is groomed by scraping it on bark or rocks and barring that, a dremmel tool, so not exactly a precise sensory instrument either.

And that is where Silver's tongue comes into play. He doesn't use it for manipulating sound by placing it in different parts of his mouth in the way we use ours while talking. His double larynx expands and contracts forming "whistles" that can be English words, the sound of clicking ice cubes, running water, or the smoke alarm. In fact he can talk quite well and still crunch seed with only a little muffling if he is talking and eating at the same time, His tongue is very sensitive. It does some moving of food around in his mouth but his other use of it often reminds me of a finger exploring new items in the environment. Touch, touch, touch, touch, touch.

It is dry. In fact his whole mouth is dry as a parrot hasn't in mouth saliva but rather has a couple of slime glands in his throat that lubricate food on the way down. In fact if he manages to beg chewing gum or hard candy from a human he'd really prefer it was moistened up by their mouth first to start dissolving the sugar otherwise he can't taste it.




Look at his expression. This is an engrossed parrot. If you look carefully at Silver's beak on the right side you can see a bit of his charcoal tongue coming out the side to feel the bow.
Sam drops a pan lid in the kitchen and Silver almost takes off in a hasty retreat. I tell him it's alright.

Reassured, he goes back to bow investigation. See the gray undulation the rear of his slightly open beak? That's his tongue still poking away at the bow.
Interestingly Silver didn't decide to dismantle the bow. I was very surprised. After he'd exhausted the tactile aspects of the bow he laid it down very politely and went off for further festive adventure.
Of course perhaps the bow avoided parrot mutilation because he knew that an attempt at shredding might just be found wanting in the behavior department and he isn't a dope. Silver knows that breaking the rules when the enforcer is standing right there eyeballing him is just plan dumb. You wait until no one is looking and then you shred the bow.
Donegal Browne




Friday, December 25, 2009

MERRY CHRISTMAS FROM ALL OF US


Merry Christmas from the Central Park Great Horned Owl,


Pyewackit,

Jamie, Claire, and Roger the Sand Hill Cranes,

Toad,

the Barn Swallows,

the Wild Turkeys,
Photo by Cheryl Cavert
Kay, Jay, and all the Tulsa Red-tails,
Photo by Cheryl Cavert
the peeing Red Fox,

the Dollar General Red-tailed Hawk,
Photo by James W. Blank Jr.
the fawns hiding behind the fence,

the squirrels and bunnies,

the wheat field that lured the turkeys,

Primus and Secundus,

the Kingbird,

the Killdeer,

the Robins,

the Turkey Vultures,
Photo by James W. Blank Jr.
the copulating turtles,

Riverside Park Mom and Dad,

the Skunk that cheered me up when I was lost,

the ducks,

Canada Geese,

Blue Jay,

Doorstep and Friend,

Steam the RT,

the Crows,

the bizarre and cheerful Lichen,

Mr. and Mrs. M,

Quicksilver,

the Monk Parrots of NYC,
Photo by Brett Odom
Pale Male Jr. and Charlotte,

Isolde,

all the Red-tails of NYC that haven't been named yet,

Rose of Fordham and the New York Botanical Garden,

the Screech Owls of Central Park,
and of course, Pale Male and Lola!

Wednesday, December 23, 2009

Pinkie Sits, Star Lays an Egg, and Did Charlotte Think?


Pinkie the Laughing Dove
Whenever I get back to NYC, the first thing that has to be done is a good scrubbing of all the bird cages. Not that the birds aren't cared for, and their cages cleaned by the family while I'm away, they just don't drag the cages out to the terrace or into the bathtub for a periodic scrubbing.

Above is a photo of Pinkie the Laughing Dove. Many will remember that he arrived after I received a call about a white dove stranded in a snowbank a few winters ago. Being a completely domesticated variety of bird, Pinkie is very interesting. When the other birds are out they go about whatever business they feel the need to go about, whilst Pinkie if put on a perch---any kind of perch...


...first checks out his surroundings, mostly for any possible rivals he can beat up on...

...and then he just sits and watches whatever is going on. And I don't mean sits a few minutes, we're talking hours here. As a matter of fact, during my daughter Sam's and my cage scrubbing extravaganza, Pinkie sat on that compote for two and a half hours. We were interested in how long he'd stay before hopping off. He never left the spot so we finally put him back in his cage so we could let the cats back into the area.
In the meantime, Star laid an egg. She had just laid right before the photograph and had been resting with her eyes closed. Laying an egg being very hard work. When I got near her with the camera she opened her eyes and if you know bird expressions you can tell that though she is looking at me she is still focused internally.
Note her body is still cocked in the contraction that expelled the egg and she remained that way for some minutes. Star is unreleasable as she had a shattered wing that could not be mended. No we won't have a hatch. Her egg is infertile. Though she flirts with Blue and Dot the unreleasable cocks, copulation isn't part of the fun.
And just in case...

...you've ever wondered what a pigeon track looks like, take a gander.


Speaking of ganders, Sam came home from college, (She's a Biology and Theatre major) with an interesting behavioral tidbit about Canada Geese. Scientists were wondering if the retrieval of an egg that has rolled from the nest in geese was wired in or whether the goose just understood the situation and rolled it back into the nest.

So they tied a line on one of the eggs. Not an easy task, if you know anything about geese and the wing battering that can dish out, now that I think about it. At any rate the field people would pull an egg slowly out of the nest and then watch to see what happened. The goose would get off the nest, walk over to the egg, and using nudges from her bill, roll the egg back into the nest. Dandy.

They then pulled the egg out again. The bird went to retrieve it, began to nudge the egg back and the scientists while the motion was in progress then pulled the egg another foot away from the goose. The goose though it could see that the egg was another foot away, continued to make the nudging motion at air all the way back to the nest. Then seeing the egg out there again returned to the egg and nudged it back to the nest in reality.
The scientific opinion was that this proved that egg retrieval in geese was a hard wired behavior triggered by seeing the egg out of place. Okay. But also, at least to me, it doesn't discount the goose knowing what she is doing while all this is going on but as it is a triggered behavior she can't stop the motion until visually cued by the nest itself or the other eggs or whatever, that the motion has been completed. What if geese are a species that eventually learn by experience as Red-tailed hawks do?
Keep in mind this only proves whatever it proves in Canada Geese it does not necessarily cross over to all avian species.
Speaking of Red-tails learning by experience, it is believed that an eyass on a Red-tailed hawk nest is pretty much on it's own when it comes to falling out of the nest. And no question this does happen periodically. Most of the NYC hawkwatchers have had some real heart stopping moments as eyasses just off their haunches headed for the edge but then stopped in time without falling out, while their parent sat by seemingly unconcerned.
But then there was this moment in 2005 on the Trump Parc nest of Pale Male Jr. and Charlotte, that made me wonder about hawk parents learning from experience. Good mannered eyasses of a certain age seem to be wired to defecate off the edge of the nest so they do have business there but this was different.
That year we'd nicknamed the eyasses Big and Little.
Well, one day as Charlotte was sitting with the eyasses as they tootled around the nest corbel, Little, recently off his haunches and practicing walking took off toward the edge at a rapid clip. Charlotte got up, made it over to him a few inches from the edge and abruptly sat on him.
Wow. That just didn't happen. Adult birds just don't ordinarily plop down on a running youngster. Or on any youngster. After a certain point of mobility, if it begins to rain or it's chilly it's the eyasses job to go burrow under the tending parent if they need the warmth.
For a number of reason I'd always thought that Charlotte might well have been mated and had young before hooking up with Junior. Is it possible that she'd had an eyass fall from the nest and had learned from the experience? Not having any completely nonlethal ways to keep an eyass from the edge--given the non-choices of a raptor's feet and beak, is it possible she somehow put it together that he should be stopped as he could fall off at the clip he was going and plus that sitting on him would stop him from falling?
Donegal Browne