RE: Pilotbird breeding records?

["Philip Veerman" <>]

Yes John's quote is correct and of course applies to birds that incubate eggs but my point is why should cuckoos still do this? Along the same lines, what about megapodes that build incubating mounds? I suppose someone knows.

 

About: I've been told that there is no code for it in the Blitz/COG records. Yes that appears to be true. I was in the discussions that set these up, at least for the GBS which followed the new COG database in about 1992. I guess we didn't even think of brood patch, as typical field obs without handling a bird would not reveal it. You could say it is a significant oversight. Though I have not heard the question raised before. The only other thing is it is not necessarily associated with a place. As in a bird with a brood patch could be some distance from a nest. A bit of a hollow reason and I suspect brood patch can be less tenuous as a breeding record than display or carrying food (which are of limited use especially if not reinforced by better evidence of the same birds at the same site on other days).

 

You will notice though that the breeding categories are sequenced on the GBS Chart in order of decreasing significance of evidence of local breeding. A nest with young is first because it is more important than nest with eggs, because it has progressed further and is more important than dependant young because even though that is the next step, they could have come from outside the GBS area, so the site may not be local. Or those were my reasons. Looking at the COG data sheet for the blitz, I do not see the same sequence and do not see a basis for the sequence (certainly is curious putting display first, which is the weakest evidence of local breeding). Although the constraints on GBS don't apply to other records, so this is a trivial point and I had not noticed before.

 

Philip

 

-----Original Message-----From: Laura Johnson [ Sent: Wednesday, 30 October 2013 6:32 PM      To: John Brown; 'COG_Mailing_List'
Subject: [canberrabirds] RE: Pilotbird breeding records?

Wow, thanks for the info, John! Super interesting!

---

From: John Brown       Sent: Wednesday, 30 October 2013 6:24 PM      To: 'COG_Mailing_List'
Subject: [canberrabirds] RE: Pilotbird breeding records?

 

My understanding is that the brood patch is triggered as part of the hormonal response to breeding to aid the incubation of the egg while sitting on it, then disappears once breeding over. My understanding is supported by the infallible basis of government policy, Wikipedia:

 

http://en.wikipedia.org/wiki/Brood_patch

 

Also a brood patch is very different that an bald patch, and bald patch such as could conceivably be caused by a parasite it obviously not evidence of breeding.

 

So this is evidence of current breeding. I've been told that there is no code for it in the Blitz/COG records. Is that true? If it is, then it would be a shame to be not able to record this type of breeding record, even if the opportunity to collect this kind of data is limited to approved research projects.

 

John

 

 

 

From: Philip Veerman [
Sent: Wednesday, 30 October 2013 6:08 PM
To: John Brown; 'COG_Mailing_List'
Subject: Pilotbird breeding records?

 

Pilotbirds are residents so surely they must breed here. The COG Atlas (now very old) has a mention of one nest building from 1988. Presumably they are hard to find breeding. I'm intrigued about "FYI, brood patches were also found on: Shining Bronze-Cuckoo". Do brood parasites also form this? I would have thought this feature would have been deleted over time.

 

Philip

 

-----Original Message-----From: John Brown Sent: Wednesday, 30 October 2013 4:59 PM      To: COG_Mailing_List       Subject: [canberrabirds] Pilotbird breeding records?

 

At New Chum Road mist netting which happened to coincide with the Blitz, we netted a pilotbird with a brood patch. There was some speculation about whether or not there were records of pilotbirds breeding in the ACT?

 

FYI, brood patches were also found on:

 

Shining Bronze-cuckoo

White-browed Scrubwren

Brown Thornbill

Striated Thornnbill

Eastern Spinebill

Yellow-faced Honeyeater

Crescent Honeyeater

White-napped Honeyeater

Golden Whistler

Eastern Yellow Robin

Bassian Thrush

 

John