Songbirds arose in Australian region

To: <>
Subject: Songbirds arose in Australian region
From: "Tony Lawson" <>
Date: Fri, 7 Aug 2009 07:39:13 +1000

New Zealand wren appear on the first branch which comprises 60% of all birds. All the earliest lineages are in New Zealand and Australia. Recent molecular work suggests that parrots and all song birds diverged from a common ancestor in the late Cretaceous. The evolutionary relationships have been controversial. The New Zealand Kakapo is the first branch off the parrot tree. Australia is the second step in the process. The early lineages for songbirds are in Australia and New Zealand. Only later did they move into Asia where they diversified, and later into North America. Joel Cracraft explains the study of evolutionary biology reveals similarities to humans with relevance to human health and wellbeing.


Robyn Williams: Back to birds. They are modern dinosaurs after all, aren't they. And to New Zealand and the origins of birds on Earth.

Could it be that many birds came from the antipodes and then spread to other parts of the world? Could we be bird central? It often seems like that, doesn't it! Well, Joel Cracraft is curator of birds at the American Museum of Natural History in New York, and his paper on avian origins is fast becoming a classic.

Joel Cracraft: Well, the New Zealand wrens, just a few species in New Zealand, are the closest relative for these large group of 60% of the rest of living diversity of birds, which are the songbirds. Songbirds are divided into two groups; the oscines which are the really true songbirds heavily into song, and then the sub-oscine birds which are mostly in South America, and also some like pittas and broadbills in Southeast Asia and Africa.

Robyn Williams: Where do the parrots fit into that scheme?

Joel Cracraft: Well, recent molecular work suggests that parrots are the sister group. They and all of these songbirds, passerine birds, diverged from a common ancestor, some time probably in the late Cretaceous. So the evolutionary relationships of parrots to some other groups of birds has been very, very controversial, but a lot of new genetic data seems to suggest that they are a sister group, and they all have the same pattern in the southern hemisphere.

Robyn Williams: Isn't that strange. Where would that put birds like the kakapo, the largest of all parrots, still surviving, just clinging onto existence. Where would you put that in the history? Very ancient or what?

Joel Cracraft: It is indeed, it's a first branch off the parrot tree and it parallels the smaller songbirds, these tiny, tiny, little New Zealand wrens, and then you have this giant parrot. Each of those two are the sister group of the respective major, major radiation. So with these two big orders, the Passeriformes and the Psittaciformes, the parrots, you represent there about 70% almost of the species of birds in the world. Those are two very ancient Gondwanan lineages.

Robyn Williams: And of course that would make Australia, say, the second step in the process?

Joel Cracraft: It would make Australia the second step in the process. Australia, that part of eastern Antarctica where it was connected, including the southern part of New Guinea, this is parrot and songbird central, this is where it all began. All the early lineages are in Australia and New Zealand, and then their close relatives are all over in South America, and only later did they get up to Asia where they diversified spectacularly in Asia, in Africa, and then they later got into North America and radiated there.

Robyn Williams: Of course I've actually seen green parrots flying around Los Angeles in recent times. I don't know where they came from but it's something of a spectacular sight, it reminds me of Sydney.

Joel Cracraft: These are all captive released birds that people have. Even in Chicago there is the famous monk parakeet colony. I've seen parrots outside this museum here in New York City. People release them and if they're like monk parakeets they're kind of colonial so they find places where they can live.

Robyn Williams: It's amazing that they can survive the winter.

Joel Cracraft: It is. I haven't seen them now for some years, but they're still around the area.

Robyn Williams: Tell me, how do you trace this history? Obviously you are now looking at DNA and the timelines, but how do you follow it up with fieldwork as well?

Joel Cracraft: Behaviour is also a very good set of data for relationships, and I've had a former post doc work on the relationships of birds of paradise using very detailed behavioural observations, treating the similarities and differences in behaviours as different kinds of characters. So you can compare those characters just like you can compare the DNA sequences as characters.

Robyn Williams: And they're all telling the same story in parallel? Because you said it's controversial.

Joel Cracraft: There just has not been that much comparative behaviour. It's rather surprising, most behaviourists are not doing huge comparative studies. And at the level of these birds, like all parrots and all songbirds, behaviour would not be sufficiently plastic to get enough characters to understand relationships, but you can do that within smaller groups.

Robyn Williams: It's interesting, David Attenborough always liked to be rather rude about Australian birds, he said they all squawk and they don't sing, but I can send him a correction from you indicating that there are plenty of associations. But he was also extremely passionately fond of birds of paradise, especially going to Papua New Guinea where there are so many wonderful ones. Have you looked there at the birds of paradise in PNG?

Joel Cracraft: Oh yes, we're studying those pretty heavily, trying to understand their relationships, because they are very different from one another, and we've been unable to link them up with behaviour or with looking at study skins, and now we have to use DNA. So it's a major challenge. They radiated very recently, only about eight or nine million years, mostly due we think to the uplift of the mountains, which took songbirds and lifted them right up to the top in the montane forest, left their relatives in the lowlands, and then climate change came along over the last million or two million years and the forest moved up and down as glaciations came and went, and that isolated many of the species that we see in New Guinea today.

Robyn Williams: Yes, one wonders whether the local people will stop hunting them because many of them are endangered, and of course the feathers are precious in ceremonial garb, aren't they.

Joel Cracraft: Actually most of the birds of paradise are probably okay. If they're going to be hurt they're not going to be hurt by so much of the hunting as they're going to be hurt by the forest being cut away for logging. Most of those species of birds of paradise are pretty narrowly endemic. That is, they're found only in one area, especially in the mountains where the ranges of these birds are separated by deep valleys, and there, if logging goes on, then they are in trouble.

But plume hunting, which started way back in the 19th century, actually was a way in which we discovered many new species because the hunters went out, collected these poor birds and took them back to England or to Germany or to the Netherlands, and all of a sudden people discovered, hey, these are new, these are different, we haven't seen these before. But usually the population densities of people in New Guinea were low enough that they would not hunt out too much. That's starting to change, but they don't do as much hunting now as they used to, but it still goes on in the remote areas.

Robyn Williams: Tell me, why is it, apart from the fact that for people like us it's really fascinating looking at the lineage of birds and the ancient history and how they developed...why do you think it's important really to do this kind of study?

Joel Cracraft: Evolution is the integrative science of biology, the idea that there's descent with modification, that's one of Darwin's key ideas. Two key ideas was descent with modification and natural selection leading to adaptation. And because evolutionary biology is so important for people, it tells us why we can study a fruit fly and if we find something that is important, let's say, for genetics or for developmental biology, the only reason it has any relevance to human beings is because of the similarities that are there by descent with modification. And so it's very important for us to understand the tree of life organisms because, just from a selfish point of view, humans need to know what things are similar in all these different kinds of organisms because that has applicability then to human health and wellbeing.

Robyn Williams: And next week, birds on the Great Barrier Reef and how their numbers are being affected by climate change. I was talking then to Joel Cracraft at the American Museum of Natural History in New York. 

<Prev in Thread] Current Thread [Next in Thread>
  • Songbirds arose in Australian region, Tony Lawson <=

The University of NSW School of Computer and Engineering takes no responsibility for the contents of this archive. It is purely a compilation of material sent by many people to the Canberra Ornithologists Group mailing list. It has not been checked for accuracy nor its content verified in any way. If you wish to get material removed from the archive or have other queries about the list contact David McDonald, list manager, phone (02) 6231 8904 or email . If you can not contact David McDonald e-mail Andrew Taylor at this address: andrewt@cse.unsw.EDU.AU