Golden Whistlers

["Philip Veerman" <>]

Thanks Geoffrey,

 

I would like to add another suggestion not inconsistent with your point 2, that builds on a wider range of species. The trends could easily relate to habitat and survival factors outside Canberra. Both species are mostly migratory. The Rufous Whistler migrates through other parts of Australia, mostly open country to the north of ACT. Over the years that habitat has decreased significantly and the trend of reduction in abundance for the Rufous Whistler is similar to that of some other species that migrate in a somewhat similar manner. The Golden Whistler migrates mainly locally into the high country and that habitat has probably not degraded as much and so the species is probably not suffering declines during its time outside Canberra that the Rufous Whistler does. As for Geoff's point 4, it cold be true but I don't see why that would be so and if it is, I would not know why that would change things as in why would the two species show opposite trends.

 

Another factor possibly relevant is what species were printed on the charts, although people should not be reluctant to add new species. Could some forget? These are all listed on Appendix 6 of The GBS Report. The Golden Whistler was not printed on V1 & 2 of the GBS chart but was on V3, 4 & 5. The Rufous Whistler was printed on V1 to 5 of the GBS chart but is not on the current one (but then I am befuddled at some aspects of the selection on the current one. A report on the GBS database as I built it automatically and instantly selects and sequences the 50 (or however many you want - but that is the number printed on the chart) most often recorded species over the last x number of years) to sensibly select to print on the chart but I was informed that this option was not used in the latest version.

 

Tiny point of correction: The GBS Report covers to June 2002 (not 2001).

 

Philip

 

-----Original Message-----From: Geoffrey Dabb [ Sent: Tuesday, 24 April 2012 12:01 PM      To:
Subject: FW: [canberrabirds] Golden Whistlers

I have recently inflicted a few miscellaneous graphics on this chatline.  The explanation is that I am revising my off-the-shelf talk on Canberra birds that I give to various non-bird groups, and I am seeing if any proposed offerings provoke expressions of derision or  incredulity.  Below is an oldy that I shall probably keep.  The point is the changing character over time of observations of garden birds.  Here we have the advantage of Philip’s graphs showing such changes, up until 2001.  The story here is the decline of the Rufous Whistler along with the rise of the Golden Whistler.

 

I would give weight to the change in habitat, as plantings mature and become denser.  Trends with respect to some other species tend to support that conclusion.  Other possible factors are:

 

1.       RW retreating from developed areas (the Brown Tree-creeper effect.).

2.       RW numbers down overall eg by reason of dryer than usual conditions in woodlands over several years.

3.       Less woodland components in garden sites.

4.       More observers recognising call, or correctly identifying brown GWs.

 

 

From: Geoffrey Dabb [
Sent: Tuesday, 24 April 2012 8:22 AM
To:
Subject: FW: [canberrabirds] Golden Whistlers

 

 

 

From: boy nature [
Sent: Tuesday, 24 April 2012 8:03 AM
To: Jack & Andrea Holland;
Subject: Re: [canberrabirds] Golden Whistlers

 

Ive had very vocal golden whistlers at my house in Kaleen and also at M&Ds in Hawker over the past few weeks.
They are obvious winter migrants and seen at the Pinnacle. But a rarity in the garden, itself.
Benj

 

----- Original Message -----

From: Jack & Andrea Holland

Sent: 04/18/12 06:59 PM

To:

Subject: [canberrabirds] Golden Whistlers

 

I was reminded by Milburn’s posting last night that on Sunday afternoon I had two male Golden Whistlers calling loudly in the mixed feeding flock in my GBS site in Chapman, together with a female/immature.  While the latter has been more conspicuous this year than for quite a few years, I certainly found having two males together unusual.

 

Jack Holland