Please help complete the puzzle by reporting roosting and feeding sites within 20km of Toowoomba, and early morning/late afternoon flight paths. Please phone Neil urgently on 4635 8815 or by posting a timely response on this Forum.
Years ago when I watched marked egrets from a hide in the Lockyer Valley at early stages in their nesting it struck me that there was generally only one bird at each nest as darkness fell. Where was the mate? Possibly hanging around the edge of the colony or camping out at some other roost or heronry? The mystery now seems to be solved, they stop out overnight.
Since the egrets have nested at the Toowoomba Water Bird Habitat, Helen and I have been able to watch their east-west comings and goings in the vicinity of the Alderly-Rowbotham Streets intersection on a daily basis. A substantial number fly in the‘wrong’ direction, both in the late afternoon (east towards the Toowoomba Range) and early morning (west towards the Habitat). Why would an egret head away from its colony when there is only half an hour of daylight left for feeding? These are not passerines, they take hours to fill their oesophagus with food for their chicks.
From a series of high vantage points - Table Top, Derrymore Road at Iredale and Spa Water Road - I was able to progressively map the late afternoon movements of flocks from Toowoomba to a roost near Granny Williams Bridge south of Helidon. Egrets, singly and in small flocks, came from the west over the Range at Leslie Street, descended into the valley south of Table Top, veered northeast to follow the course of the Monkey Water Holes, then east, skirting the higher ground leading up to Mt Davidson, into the valley of Spring Creek. About 100 would have roosted at Granny Williams Bridge, which is roughly 16 km from the Water Bird Habitat as the egret flies.
My best guess is that, having been relieved from nest attendance and flown east to their feeding grounds too late in the day to get a decent feed, they opted to spend the night nearby and return to their hungry chicks the following morning after catching a full cargo of grasshoppers etc. Granted, it would require tracking using transmitters on the birds or following them in a light aircraft to confirm the entire movement pattern. However, the circumstantial evidence is strong and since this was quite a small satellite roost I would think that there must be others awaiting discovery along other radii out from the Habitat heronry.
Please get in touch if you know of any. [Neil McKilligan, telephone 4635 8815]