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More birds out there than previously thought

To: <>
Subject: More birds out there than previously thought
From: "Ricki Coughlan" <>
Date: Fri, 24 Jun 2005 05:52:47 +1000
I should state from the outset that I am a student of David's at CSU and was at the time that this article was prepared. I think that the broad thrust of this paper is pretty robust. One may argue about details but David has solid figures there. Notwithstanding Andrew's point about signalling differences between mammals, reptiles and birds, you can't argue with the many other obvious differences illustrated between the diagnostic methods which are in common use among other Classes versus those in use for Aves and to question why this is so is healthy. Of course differences in Classes will mean that slight biases in diagnosis will take place but unles there is something wrong with David's methodology, there are clearly substantial imbalances in diagnosis which cannot be accounted for by these differences alone.
 
In many respects David's paper is correct about "bird watchers". It bears consideration that many people wont go near waders or pelagic species because of percieved difficulties in forming accurate species diagnosis on the basis of appearance. Many are terrified of "little brown birds". The numbers of specialists in various areas who will relish the difficulties in diagnosing various hard to split groups of species accounts for a very small number of birdwatchers. Therefore your point Andrew, which contests whether lumping takes place due to the reluctance to accept new species is not convincing to me. 
 
Given that birds hear sounds up to 200 cycles per second, versus the roughly 20 cycles per second of humans, it is a fact that variances in syringeal morphology may not produce song which is distinctive enough to the human ear for accurate diagnosis and therefore the point that syringeal analysis may be of importance is very well made. There may be many species out there speaking entirely different languages and without further study of vocalisations, we may not be aware of it. The case raised with Crossbills (rare or not) illustrates just this point very well but also that behavioural differences as much as call are important. In this case diet: each species preferring a distinctive species of pine upon which to feed and David is clear on this point. He was also alluding to the fact that birdwatchers can play an important part in helping to gather information which will contribute to our knowledge on these matters. This case also demonstrates the fundamental importance of developing realistic and practical measures for understanding diversity as, with the loss or reduction of a specific pine, the loss of a hitherto unrecognised species of bird would also tragically occur.
 
The currently adopted Biological Species Concept (not necessarily included in David's discussion) does not give us the tools to properly understand the true diversity of birds and nor does a process weighted in favour of phenotypic analysis of species adequately serve scientists, birders or the birds themselves. David's call for a review of the later processes is timely.
 
Happy birding
Ricki
Broome WA
 
----- Original Message -----
From:
To:
Sent: Thursday, June 23, 2005 1:38 PM
Subject: Re: [BIRDING-AUS] More birds out there than previously thought

On Thu, Jun 23, 2005 at 11:30:29AM +1000, wrote:
>    There could be thousands more bird species than currently thought -
>    which will have major implications for bird conservation, a leading
>    bird researcher has found.  ...

The paper is linked to David Watson's home page at:
http://www.csu.edu.au/faculty/sciagr/eis/staff/watson.htm

As calls are a topic du jour, here is my mini-review.  Its an interesting
paper but I find his thesis that birdwatchers and consequently biologists
are reluctant to accept bird species which can't be diagnosed in the
field and that this leads to lumping of bird species, unconvincing.

He glosses over the extent that diagnosable characters might be more
frequent or better known in birds.  The nature and extent of signalling
in birds is clearly different to mammals & herps.

The case of crossbill identification by call is presented as a rare -
but there are many groups of species around the world where birdwatchers
rely on call for separation.

The former conspecific status of New Guinea and Australian logrunners
is presented to illustrate the difficulty of diagnosing species in the
field but the plumage differences described in Leo Joseph's Emu paper
are not trivial.  They seem easy to separate than (for example) many
seabirds - taxa accepted by birdwatchers.  Note also their calls are
said to be quite different.

Judging by this list, rather than being suspicious of species which are
difficult to separate in the field , many skilled birdwatchers apparently
relish the challenge.

I'm not sure of the relevance of the discussion of syringeal morphology
as an example of a character provided by internal morphology and hence
not available for field diagnosis.  Surely readily distinguishable
differences in syringeal morphology will be reflected in  call characters
- a diagnosable character.

The example of the 2 genetically divergent populations of New Guinea
logrunners which are said to be indistinguishable in the hand doesn't
mention call characteristics - maybe these aren't known - but as they as
passerines from a poor visual environment, it makes for an empty example.

Andrew

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