Cuckoo in the nest

[Hermit]

^^^ That settles it. The bird I was asking about here is definitely a blackbird, as Jim mentioned earlier, an introduced species.

[JimC]

They thrive in suburban back yards - you don't see 'em in the bush...

[mistermack]

They thrive in suburban back yards - you don't see 'em in the bush...

Too dry I expect. And those giant Ozzie earthworms must take a lot of pulling out.
I'll bet they got the shock of their lives, when they first saw one.

[Svartalf]

I stake out my mating territory with a rather alluring border of empty gin bottles...

and you managed to net Bron rather than a drunken floozie?

[JimC]

[Svartalf]

but I thought this thread was about songbirds, not gardener birds.

[JimC]

They thrive in suburban back yards - you don't see 'em in the bush...

Too dry I expect. And those giant Ozzie earthworms must take a lot of pulling out.
I'll bet they got the shock of their lives, when they first saw one.

The giant earthworms are certainly fascinating; I've seen several. However, their range is restricted to a fairly small area in South Gippsland - they don't occur in suburban gardens in Melbourne...

[Xamonas Chegwé]

They thrive in suburban back yards - you don't see 'em in the bush...

Too dry I expect. And those giant Ozzie earthworms must take a lot of pulling out.
I'll bet they got the shock of their lives, when they first saw one.

The giant earthworms are certainly fascinating; I've seen several. However, their range is restricted to a fairly small area in South Gippsland - they don't occur in suburban gardens in Melbourne...

Course not. They have sense. To many Killerburras and Laser-eyed Bunyips around there!

[mistermack]

The giant earthworms are certainly fascinating; I've seen several. However, their range is restricted to a fairly small area in South Gippsland - they don't occur in suburban gardens in Melbourne...

They are a real mystery. Everywhere else on the planet, there appears to be a very real limiting factor on the size of earthworms. What it is, I haven't the faintest idea.
It's not like they have to support their own weight, on bones, or be able to run or fly.
You would think that some areas would have bigger ones than others, depending on conditions.
But there seems to be a real limit that kicks in, and keeps them down to a certain size.

But there you are, in one tiny bit of Oz, and they are not just a little bit bigger, they are bloody gigantic. How come the limit doesn't apply there?

I would like to see Dawkins explain it. He's an evolution man.

Edit. Having said that, it often happens that an evolutionary jump happens in small isolated populations that get cut off from the majority. But you would have thought that this would happen more than once, in many areas of the world.

[Brian Peacock]

When a bird breathes it takes in air through its bill, draws it in past its throat and into its windpipe (or trachea). The windpipe forks to carry some air to each of the lungs. These dual passages are called bronchial tubes (singular -bronchus, plural -bronchi). Air is then processed in the lungs and exhaled back along the same route.

This system of air passage has become adapted for the secondary purpose of sound production (as it has in humans too). At the point where the windpipe divides is situated the bird's sound producing organ, a "voice box" called the syrinx. Humans have no syrinx but a larynx instead. The larynx is a cavity in the throat and contains our vocal chords. The avian syrinx is called a lower larynx, being differently situated at the other end of the windpipe. It is as if the human larynx were positioned in the chest. Perhaps the first thing to say about the syrinx is that it is double-barrelled - as if a man had twin instruments between his lips and was playing one with the outflow of one lung, and the other with air from his second lung.

Theoretically a bird with one collapsed lung would then still be able to produce sound. If, however, it were a species that is known to produce two different sounds simultaneously, then clearly it would not be able to offer a normal contribution to nature's symphony.

Each half of the bird's voice box is in the mirror-position of the other, at the top of its own bronchus (so the set up is literally double-barrelled) and each consists of a pair of organs opposite each other on the wall of its bronchus. Thus if you were to slit open a bronchial tube, you would see on one side a little tympanum, a circular elastic membrane. This is the vocal chord; and opposite it would be a little "bump" of erectile tissue.

The stage is now set. The bird is about to take its cue. It forces air along the bronchial tube, past these two organs, both of which can be adjusted. The diameter of the tympanum can be changed and the degree that it protrudes into the bronchial tube can also be varied.



As air passes, so an acoustic disturbance is set up, the tympanum vibrates and sound is created. The pitch (frequency) of that sound and the loudness (amplitude) of it can be modulated. So far as the tympanum is concerned, these two effects are usually coupled. The function of the extendable little "bump" is believed to be to change the loudness without having to change the pitch. Bear in mind that the bird may be playing at the same time a second tune on his other half; also that this description is considerably simplified. It will be clear, however that such complexity is necessary to explain the amazing vocal gymnastics certain "higher" songbirds display. "Lower" birds have a syrinx that is of a rather simpler design. In either case the physiology and acoustics of bird vocalisation are unique in the animal kingdom; further, birds produce more complex sounds than any other animal, certainly including man.

One last point: birds do not sing only when inhaling. A grasshopper warbler Locustella naevia may "reel" for over two minutes, a nightjar may chur continuously for eight minutes, and a skylark may "pour forth its full heart" in completely unbroken song for 18 minutes. To replenish their oxygen these birds must breath in; and must do so while singing. In the case of the night jar, the bird discernably alternates soft short trills with loud long ones and these short trills are believed to be when the bird inhales. Less continuous singers may also use air travelling in either direction. The white-rumped shama, for example, is believed so to do.

mms://audio.bl.uk/media/wildlife/nightjar03.wma

http://www.bl.uk/listentonature/special ... rds16.html

[Xamonas Chegwé]

I take issue with describing birds as "higher" or "lower" based solely upon their song capability.

Every organism on Earth at exactly the same level of evolution (excluding possible parallel abiogenesis). Some birds sing better than others because their particular ecological niche and evolutionary path led to that ability being maximised. Others took a different path. Neither is higher or lower in some grand scheme of things. The same is equally true of primate brains!

[piscator]

When a bird breathes it takes in air through its bill, draws it in past its throat and into its windpipe (or trachea). The windpipe forks to carry some air to each of the lungs. These dual passages are called bronchial tubes (singular -bronchus, plural -bronchi). Air is then processed in the lungs and exhaled back along the same route.

This system of air passage has become adapted for the secondary purpose of sound production (as it has in humans too). At the point where the windpipe divides is situated the bird's sound producing organ, a "voice box" called the syrinx. Humans have no syrinx but a larynx instead. The larynx is a cavity in the throat and contains our vocal chords. The avian syrinx is called a lower larynx, being differently situated at the other end of the windpipe. It is as if the human larynx were positioned in the chest. Perhaps the first thing to say about the syrinx is that it is double-barrelled - as if a man had twin instruments between his lips and was playing one with the outflow of one lung, and the other with air from his second lung.

[JimC]

I take issue with describing birds as "higher" or "lower" based solely upon their song capability.

Every organism on Earth at exactly the same level of evolution (excluding possible parallel abiogenesis). Some birds sing better than others because their particular ecological niche and evolutionary path led to that ability being maximised. Others took a different path. Neither is higher or lower in some grand scheme of things. The same is equally true of primate brains!

However, surely we can say there is variation in the level of complexity. I am a humble sort of chap, so I won't describe myself as being "higher" than a planarian, but I will assert I have considerable more complexity...

[Brian Peacock]

[Xamonas Chegwé]

I take issue with describing birds as "higher" or "lower" based solely upon their song capability.

Every organism on Earth at exactly the same level of evolution (excluding possible parallel abiogenesis). Some birds sing better than others because their particular ecological niche and evolutionary path led to that ability being maximised. Others took a different path. Neither is higher or lower in some grand scheme of things. The same is equally true of primate brains!

However, surely we can say there is variation in the level of complexity. I am a humble sort of chap, so I won't describe myself as being "higher" than a planarian, but I will assert I have considerable more complexity...

Planarians are far more complex when it comes to regenerating lost body parts than you or I.

Likewise, the so-called "lower" songbirds almost certainly exhibit greater complexity in other adaptions. In fact, it is not even clear what he refers to when he uses that expression. Songbird is a common term for the order Passeriformes, a vast clade that includes half of all bird species! The suborder Passeri (which is 80% of the order) contains the most intricate singers, with the most complex syrinxes, although many species within several families of this clade are mute or produce only short repetitive songs.

So is the author making some taxonomic distinction between his "higher" and "lower" songbirds? Or is he simply categorising them by their singing ability?