I don’t think this is the best place for a prolonged discussion about what can qualify or not qualify as ‘DI’. I would have thought the test was whether the bird was engaged in breeding behaviour in a practical sense. Bowerbirds maintains bowers and practise display behaviour year-round - this being imitated by young non-breeding birds. Peafowl – when in breeding plumage – will ‘display’ at anything, as will immature birds that lack the train. From: John Harris [
Sent: Friday, 24 January 2014 6:16 PM
To: Martin Butterfield
Cc: Bill & Raelene;
Subject: Re: [canberrabirds] cisticolas breeding So the Australasian Grebe I saw today in breeding plumage is not displaying because it is not doing anything. On the other hand, the Cisticola in breeding plumage screeching on the end of a reed is displaying because it is doing something intended to persuade, even though I may not be able to view the female. I am not being trivial here. I have often been in a quandary about obviously proactive behaviour, even though I cannot see the female. It seems that even if the female is not even present, the male is at least declaring his territory, and his intention to ‘copulate’ with the female/s. I don't count myself as 'learned' but here is an opinion. I have never seen a 'universal' definition of what is a breeding display written down. The concept is something along the lines of "behaviour intended to persuade a bird of the opposite sex to copulate". This covers a large range of species-specific behaviours: - Whistlers do what is almost a choreographed dance around in a tree;
- Wedge-tailed Eagles perform a spectacular display flight;
- Male musk ducks do their water-shovelling display;
- a Pallid Cuckoo flying to another Pallid Cuckoo and offer it food in the middle of doing a call and response routine.
- Most anything done by a Satin Bowerbird around the bower
I'm not sure that it is always the male that is the actor, but whether the other participant is visible depends on the situation. I've certainly seen male Satin Bowerbirds going though a very vigorous display routine without a female in sight for several minutes. Then she has emerged from dense undergrowth at which point I offered them privacy. Clearly what the male was doing was DIsplay and would have been even if I had left before the female revealed herself to me (I suspect the BB knew she was there all along). On 24 January 2014 16:47, John Harris <m("biblesociety.org.au","john.harris");" target="_blank">> wrote:
You raise an interesting question which perhaps some of our learned COG
colleagues may be able to clarify.
What constitutes display (‘di’) for the purpose of COG reporting?
Does the female have to be visible for it to count?
John
On 24/01/2014 4:01 pm, "Bill & Raelene" <m("grapevine.com.au","graham.br63");">>
wrote:
>John
>Yes. What you say is as I had expected. I have seen what you describe as
>display at the wetland in Forde but did not report it as I was unsure.
>It may be too late this season, but I will keep an eye out for it.
>many thanks, Bill Graham
>On 24/01/2014 3:45 PM, John Harris wrote:
>> Yes cisticolas are under-reported and not just in the breeding season.
>> They are a wet grassland bird and exceptionally wary and unobtrusive
>> outside breeding season when the male calls constantly from the tops of
>> reeds and grasses. They are also dull coloured like dry grass except in
>> the breeding season. I reported them breeding here this spring.
>> I am fortunate to back onto the grasses and reeds which border
>>Ginninderra
>> Creek and I have been watching them for years. For 8 or 9 months of the
>> year you have to be very patient to see or hear one at all but they are
>> there. If observers don¹t choose to go and patiently wait in wet
>> grassland, they won¹t ever see them at all, let alone when breeding.
>> If the male in breeding plumage screeching from the top of a grass stalk
>> counts as display, then Geoffrey Dabb came here with me in Spring and
>>took
>> a very good photo. If you troll back through the COG chatline you can
>>find
>> it - no don¹t bother, the link is
>>
>>http://bioacoustics.cse.unsw.edu.au/archives/html/canberrabirds/2013-10/m
>>sg
>> 00438.html.
>> Cheers
>> John
>>
>>
>>
>>
>>
>>
>>
>>
>> On 24/01/2014 8:39 am, "Bill & Raelene" <m("grapevine.com.au","graham.br63");">>
>> wrote:
>>
>>> The records for cisticolas breeding for the last 30 years seem to
>>> indicate undereporting/ under reporting/underreporting. How is it that
>>> so many experienced birders are missing them? I think I have seen
>>> display but am not sure. Are there any photos of display? What can
>>> account for this deficit?
>>> Bill Graham
>>>
>>>
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--
Martin Butterfield |
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