Why have all the birds gone?

The title is a little reminiscent of a famous Pete Seeger song, but unfortunately that doesn't supply any answers.  As far as I can tell none of the missing bird species have gone to young girls; husbands, the army or graveyards.

We have had a reduced number of observers in the lower parts of the area this year and this would certainly explain part of the 'problem'.  Here follow my other thoughts on the comparison of the  number of species observed in August 2012 and 2013.

		2013
		Yes	No
2012	Yes	72	25
	No	4	na

To deal with the four species 'added' in 2013 first, 1 is unusual (Nankeen Night-heron); the Pallid Cuckoo was an early return; and the Gang-gang and Silvereye are just chance.

More interest is in the (much larger number of) species seen in 2012 but not 2013.

Late arriving migrants
From comments in the COG bulletin 'Gang-gang' it seems that many migrants are delayed in their return to the Canberra Region, despite the warm winter.  For the purpose of this note I take that to be an explanation for 5 species: Fan-tailed Cuckoo; Grey fantail; Horsfield's Bronze-Cuckoo; Noisy friarbird; Shining Bronze-cuckoo.  Interestingly I first heard a Noisy Friarbird on 2 September, so they are only a little late.

Waterbirds
Apart from good rain in June and adequate rain in July, we have been through a relatively dry Autumn-Winter.  Although the dams and other wet areas aren't as dry as in 2009 there isn't a lot of water around.  (interestingly, an observer who has moved to Corryong comments that there is water everywhere down there).  5 species of waterbirds are MIA this year: Australasian Shoveler; Hoary-headed Grebe; Black Swan; Hardhead; Latham's Snipe.

Raptors
There was a surprising absence of reports of raptors in August 2013.  The Spotted Harriers which were regular over the swamp in the Plain have not been reported for a while; neither the relatively common Nankeen Kestrel nor Black-shouldered Kite have been seen; and the less frequently reported Little Eagle and Australian Hobby have been absent.  Perhaps the dry weather has decreased prey numbers?  Perhaps it is an outcome of reduced observer numbers on the Plain?

Quail
These birds are often hard to spot unless a lot of time is spent in the grassy areas.  This is an area where we have been lower on reports in August.  Neither of the local species (Brown Quail and Stubble Quail) were reported this month.  (This could also cover the Spotted Harrier; Latham's Snipe and Golden-headed Cistcola also found - like the rain in Spain - mainly on the Plain.)

Others
This leaves a group of 8 species.  Of these 2 (Red-rumped Parrot and Double-barred Finch) are usually easy to spot along the roads of the Plain but I haven't done so in August 2013.  The other 6 species are all relatively unusual in the area, and their absence is not remarkable.