The swamp harriers had delayed their migration to the mainland, or so it appeared.
There they were, a small flock gliding and hovering above a pick-your-own-fruit nursery on the road to Richmond.
Just a glimpse at first, before I pulled over. All the same there was something odd about this harrier flight. Not just the timing, but the fact the harriers which should have headed north were in a flock, when harriers are usually seen flying solo or in pairs.
All was soon revealed without having to resort to my binoculars. These were not harriers at all, but kites designed to look like birds of prey, kites on a line anchored to spikes amid the rows of strawberries and raspberries ripe for picking. Bird-scarers in fact. Like species that raid crops – starlings, currawongs, and sparrows and silvereyes among them – I had been fooled.
Although I’m well aware of the toll birds take on agricultural produce, especially on grape and fruit crops at this time of the year, the harrier scarers were new to me. The closest example is that of a standing figure of an owl used to deter birds, which I am told has limited effect because the birds it is supposed to frighten off merely learn over time it is not real.
A fluttering shape takes the variation on the scarecrow theme to different heights. All birds know how to read bird shapes in the sky, and will squawk in alarm as soon as they see the outline of a hawk or harrier, falcon or even an eagle.
When I studied the literature on the raptor scarers I soon learned they were effective to a degree, a cost-effective alternative measure to netting and shooting. I’ve also visited vineyards where scarers that produce a loud boom, like that from a shotgun, are used to control the damage caused by a main threat to grape crops, silvereyes.
Birds are not only deceptively intelligent, in search of food they are canny, crafty and shrewd and measures to stop them require equal cunning and innovation.
I have personal experience of the difficulties of agricultural bird control from the days in my youth I helped out on a friends’ farm in Britain.
A commercial orchard was situated on a neighbouring property and the farmers placed traps to catch bullfinches – birds with a particular penchant for stripping the flower buds of apple trees in spring. Setting the traps was labour intensive and orchardist conducted extensive research to find a less costly solution. The farmer discovered non-commercial fruiting plants the bullfinches preferred and he placed these among the apple trees.
The measures worked a treat, much to the relief of the farmer who was pained by the act of catching the elegant black and red bullfinches, one of most beautiful birds of the hedgerows