Sorry one other point, in case someone dredges up this one. In the early years of the GBS there was one data entry of I think 300 House Sparrows on one week,
one site. This was in the early days of the GBS, before any database existed and calculations were limited to single year single species and any data input entry could only be fixed by retyping the entire line in that horrible data input system that we had
back then. Anyway there was a long string of counts of 30 on this chart, of which one was accidentally typed in as 300. The error was included in the ABR stats for the year and found (I think not by me) only after The GBS Report was published. Because the
species was common then, the statistical implications of the error were not overly great, just a fake slight bump in the graphs. Note that for
the first 14 years it was the second most common species but it has since declined.
The only other data error I know of in The GBS Report was someone, also in the very early years, had a Pallid Cuckoo observation on the ninth day of the month
and for some odd reason put a 9 on the GBS chart (instead of 1) and it was entered as such. This was found, (I think also not by me), only after The GBS Report was published. That is two known accidental errors in 54165 count data input entries that I failed
to pick in proof reading those hundreds of GBS charts.
It is possible that these two have been fixed.
Philip
From: Philip Veerman [
Sent: Wednesday, 21 February, 2018 11:54 AM
To: 'John Layton'; 'Canberra birds'
Subject: RE: [canberrabirds] Large flock of House Sparrows
As most of you may know, as not the first time I have mentioned it, I did my honours thesis (long ago) on a comparative study of the social behaviour of House
Sparrows and Tree Sparrows. At La Trobe University where both were then common, and in general the Tree Sparrow is a more sociable species (much more cohesive). Whilst this is the time of year for post-breeding gatherings, I reckon that is an exceptional gathering
by number, also outside my experience, especially in any kind of cohesive group. Given the time, I suggest it could have been travelling to a particularly good night roost but for that you would expect to see converging flocks. Maybe due to post-breeding movement
but they aren’t migrants, also more likely a particularly restricted or good food source.
A little tease about: some of the females were probably immature. No doubt some of the males were also immature. About equal actually. Just because juveniles
look similar to adult females doesn’t make them female.
Philip
From: John Layton [
Sent: Wednesday, 21 February, 2018 10:59 AM
To: Canberra birds
Subject: [canberrabirds] Large flock of House Sparrows
At 19:00 Hours yesterday I noticed several groups of small birds flying past the window. Went outside and saw the outer foliage of a spreading apricot tree was crowded
with House Sparrows, both males and females, although some of the latter were probably immatures. Arrestingly, the warm reddish rays of the westering sun imparted a ruddy patina to their dowdy plumage.
Groups of between 8 to twelve birds kept arriving from the south, most landed on the apricot while some continued north. After a few minutes, groups began leaving the
apricot and flying back in the direction they had come. Then, just thirty metres away, they paused for a few seconds in a bushy birch before flying on out of sight. This movement continued for maybe 5 minutes until no sparrows remained in the area.
After a good objective think I believe the total number I witnessed easily exceeded 100 perhaps 150. I suppose all this was some kind of post-breeding movement? Regardless,
it’s the largest flock of House Sparrows I’ve seen in Australia.
John Layton
Holt.
