FW: [canberrabirds] What is meant by fledging?

To: 'canberrabirds' <>
Subject: FW: [canberrabirds] What is meant by fledging?
From: Philip Veerman <>
Date: Thu, 1 Dec 2016 09:48:35 +0000

Further to this: I have just watched a David Attenborough doco (2014) on TV: “fishing leopards”. To my surprise DA (once) used the term “fully fledged” to describe part of the process of young leopards becoming independent from mum. In that case nothing to do with either growing feathers or leaving a nest but still having the same general idea transplanted to a mammal, but that is a first in my knowledge.




From: Philip Veerman [
Sent: Sunday, 13 November, 2016 3:14 PM
To: 'John Harris';
Subject: RE: [canberrabirds] What is meant by fledging?


Like most words, they mean what is generally accepted. If there is doubt, then define the use in the communication. There is a pretty strong hint in all the preceding that the term fledging (in various forms) does not apply at all well to birds that hatch in a developed state and able to leave the nest on day one. Such as the rails as you mention, and many others. There is also the complication that arises when you try to define words that some of these birds the chicks are able to feed themselves and others the parents feed them, even if they are equally active at hatching. The word is best used for those birds that stay in the nest for weeks, as chicks (nestlings) and when they leave the nest are fledglings. In some, leaving the nest that can be an immediate one off event, in others that process by itself can take several days. That was Martin’s question. I still believe the word origin is from having grown feathers as in “fully fledged” will mean lost down and covered in feathers, even though I support the functional use as having left the nest.




From: John Harris [
Sent: Sunday, 13 November, 2016 2:20 PM
Subject: Re: [canberrabirds] What is meant by fledging?


When does the precise definition of ‘fledged' matter and when does it not matter?  How much does it matter, for example, when reporting on eBird? I have recently reported Coot chicks and chose FL, the only sensible Breeding Code for Coot chicks swimming around near their parents.  I did not see them being fed but if I had, and if I had therefore used the code FY, does that matter to anybody? Does anyone ever do such fine-grained research on eBird data or is the fact of a confirmed breeding event all that really matters? For a water bird chick swimming, there is actually no higher code than FL and so I don’t imagine that the amount of down etc matters.

On the other hand, last year Julie Clarke made some amazing observations and photos of Buff-banded Rail breeding in Forde Creek. She and I wrote a paper on it which was published by Australian Field Ornithology. In this case the meaning of ‘fledged’ and other technical descriptive words became potentially very important. For us, this was the most difficult part of the paper. It was one thing to have field notes and photos but quite another to use technical terminology correctly. Over more than a month, chicks covered completely in down developed juvenile plumage which gradually developed into adult or near-adult plumage. But to divide these up into distinct stages was impossible. We avoided the word fledgling as unhelpful. If a chick with down was a fledgling, then began to grow flight feathers and then became a juvenile with juvenile feathers but had not yet flown, was it still a fledgling during all that development? Or, as some definitions would have it, did it only become a fledgling at first flight?    In the end, the word ‘fledgling’ was too vague and ill-defined for us amateurs. 


<Prev in Thread] Current Thread [Next in Thread>
  • FW: [canberrabirds] What is meant by fledging?, Philip Veerman <=

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