Hi John,
Yes. The codes we use, are a separate issue, set by whatever survey regime you are referring to. I am not aware of any system that uses
breeding code ‘C’ for courtship display. But then again I don’t
participate in many systems. Many years ago, I (with others) had a role in setting the breeding codes that COG uses, so I am willing to support them. That set as far as I know, and listed in the latest COG ABR (page 102), includes the ‘co’ (not C) for copulation
and ‘di’ for display. (I’m surprised to see them in lower case). There is no ‘C’ for courtship display in the COG system.
As for
The theory that a male can mistake another male for a female because of the lack of obvious sexual differentiation seems to be a bit unlikely. I imagine that in CPs
as in all birds where the sexes are similar, that the differences are more evident to the birds than they are to us humans!
Well that is a whole other issue and hard to get inside a bird’s brain. One that I took a real interest in many years ago (I did my honours thesis on the
issue) and still interests me. There are real differences between similar species in the extent of sexual dimorphism. So presumably those differences mean something. There is plenty of evidence that it means a lot in terms of their social behaviour. So, lack
of sexual dimorphism must mean something but yes there could and quite likely are differences we don’t see, at least in some cases.
I accept your right to think something “seems to
be a bit unlikely”, also what you “imagine” in your last sentence. Your “!” also is valid but are these doubts true? It is not science. You might well be
right at least in some cases. However I don’t think we yet know the answers to that, certainly not in all cases.
A lot of sexual behaviour is directed to anything that might look right and what happens next depends on the response that occurs. The story
by John Layton certainly fits my interpretation, and what is more, you see behaviour that appears to be that, all the time. More often in feral pigeons (Rock Doves). Let’s face it, the same often occurs in homosexual humans who will approach another same sex
person not knowing their proclivities, to proposition them and will wait to see what reaction it elicits. Randy dogs do it to anything alive of the right size, Muscovy Duck drakes will also. Not much different to what I wrote about the pigeons.
Philip
From: John Harris [
Sent: Friday, 25 May, 2018 2:37 PM To: Philip Veerman Subject: Re: [canberrabirds] Combative Crested Pigeons
We are so used to seeing CPs displaying in all seasons that I for one, when reporting, no longer bother to choose breeding code ‘C’ for courtship display
in the case of CPs unless it turns into ‘C’ for copulation (I have sometimes wondered why C can stand both for Courtship display and for Copulation. The latter is a reasonable indication of breeding. Display is not in the case of CPs and probably others
and should have a code further down the list). I have regularly seen CPs fighting with their wings in early spring in the large flock which hangs around here. This normally followed a display by one but sometimes BOTH birds and I have always presumed this
two be two competing males. Someone probably needs to study CP behaviour and see if the courtship display which males put on for females is the same as the ‘aggressive’ (?) display males appear to put on for competing males. The theory that a male can mistake
another male for a female because of the lack of obvious sexual differentiation seems to be a bit unlikely. I imagine that in CPs as in all birds where the sexes are similar, that the differences are more evident to the birds than they are to us humans!
From:
Philip Veerman <>Date:
Friday, 25 May 2018 at 12:25 pm
To:
'John Layton' <>, chatline
Subject:
RE: [canberrabirds] Combative Crested Pigeons
I am curious to know (as I don’t) if this relates to a problem of lack of sexual dimorphism. Can it be that a male is approaching a female
for sex and she is not interested and this is the reaction. Or more likely is it that a male is approaching a male for sex thinking it is a female. So both likely thought the other was a likely female. In what John described I think that is what happens because
the initial behaviour is both birds were initiating a sexual contact. If there truly is no outward sign of gender, there is no way to tell, other than by the reaction it gets.
Normally a disinterested bird will simply move away (you see that all the time too) but some may attack in response.
Philip
From: John Layton [
Sent: Friday, 25 May, 2018 11:31 AM
To: Canberra birds Subject: [canberrabirds] Combative Crested Pigeons
Re Crested Pigeons fighting here’s an excerpt from a post I sent to the chat line in September 2007:
Two Crested Pigeons landed in the bare-branched White Cedar tree. They faced one another cooing, bowing and tail-fanning. Suddenly, one bird flew at the other kicking it once, twice, thrice in the chest. The impacts were palpable, the dominant
rooster appeared to be the Bruce Lee of Crested Pigeons.
The bashed bird left and the victor was soon joined by a female (we suppose) and much lovey-dovey, bill-and-neck rubbing ensued before the pigeon-pair tired of our voyeurism and repaired to a more secluded tryst.
John Layton
Holt.
