Hobbies

["Philip Veerman" <>]

I should point out (although it is stated in my formal writings but not in my email) that there is a significant component of change to behaviour adding to the extent of the monthly pattern of the graphs I provided earlier. As in there is a change in abundance over the year but its extent as measured by the GBS method is increased by greater conspicuousness late in the breeding season. Even so I am not sure how to interpret the wider spread and mid spring peak in this new graph. I wonder is that based more on recent years and is there a change of annual pattern. Is there a denominator to that graph? Raw numbers are hard to interpret.

 

I also generally agree with Geoffrey on this. On the point ‘Breeding’ should not be attached to the noun, but should be a separate annotation meaning ‘breeding recorded’. Yes I think or hope that is generally understood to be the case, or at least I am not confused by this.

 

Clicking on Twin Peaks got me somewhere quite different......... Even so I suspect it is not mainly migration in both directions except to a small extent (mainly because the dip is not very great, nowhere near as low as winter) but more likely to be the time of arrival locally from the north and then time of finishing of local breeding prior to mostly leaving again.

 

Philip

 

-----Original Message-----From: martin butterfield [ Sent: Monday, 3 September 2012 6:48 PM      To: Geoffrey Dabb
Cc: m("canberrabirds.org.auSubject","canberrabirds");">      Subject: Re: FW: [canberrabirds] Hobbies

I think Geoffrey's
point is good.  IMHO Steve's graph suggests the label is correct for
Hobbies (or at least the Australian Hobby).

Martin

On 3 September 2012 18:42, Geoffrey Dabb <> wrote:

A small comment, in view of my long-running campaign to have those labels rationalised.  It is good the ABR splits off ‘rare’, ‘common’ etc (although these need definition).

 

‘Resident’ should mean all or nearly all individuals remain in the COG area year round.  ‘Migrant’ should refer to a regular pattern of all or nearly all individuals leaving the COG area altogether each year.  If only members of an age-class (eg juveniles) remain year-round that should not make a species ‘resident’.

 

‘Resident/ Migrant’ should mean that some individuals remain year round (not just juveniles unless this is stated in a definition) and some leave the COG area altogether (if indeed that is known).

 

‘Breeding’ should not be attached to the noun, but should be a separate annotation meaning ‘breeding recorded’.

 

There may be other understandings of what the labels mean, but they should be stated.

 

From: martin butterfield [ Sent: Monday, 3 September 2012 6:04 PM      To: wallaces      Cc:      Subject: Re: [canberrabirds] Hobbies

I note that the description of this species in the Annual Bird Report is Breeding Resident /migrant.  Presumably the bimodal graph reflects the Twin Peaks of migration in both directions.

Martin

On 3 September 2012 17:49, wallaces <> wrote:

Attached is a graph of the number of Australian Hobbies observed and the number of breeding records by month for the last 31 years of data on the COG database. It shows the pattern similar to Philip's description but also shows a peak in October.

Steve