The final pieces of the migration jigsaw still had to be put in place as the “dynamic duo” set off for their latest bird-watching safari at the Waterworks Reserve.
The “dynamic duo” comprised myself and well-known birding guide Denis Abbott and, leading a walk as part of the Hobart Council’s Bush Adventures program, we had in our sights two migrant species which had so far eluded us in the spring, the pallid cuckoo and satin flycatcher.
The satin flycatcher is traditionally the last migrant to arrive but as we set off early on a fine Sunday morning I expressed concern that so far the pallid cuckoo, which times its arrival earlier in spring, had failed to show at any of the locations where I usually see it across southern Tasmania.
The term “dynamic duo” is one that has been bestowed upon us by the Bush Adventures co-ordinators and is not one that entirely fits the bill, if you will excuse the pun. During a pre-walk briefing to an assembled party which included nature-lovers from the United State and Japan, Denis Abbott preferred to refer to us more appropriately as “two old cockies on the fence”.
It looked like a perfect day for birding, a hot summer sun, no hint of rain or wind to rustle the canopy and make identifying birdsong difficult. A scarlet robin sang with a mellow twitter as our party headed off from the reserve entrance along the road skirting its two lakes.
But immediately we were again expressing concern that pallid cuckoos were absent from a place where I always find them in spring, a patch of silver peppermint gums in dry woodland set back a little way from the road.
At this time in the previous year I had seen black-headed honeyeaters driving off a pair of cuckoos from what was clearly a tree in which the honeyeaters were nesting.
The hobby of bird-watching is one of the few amateur pursuits where observations can make a valuable contribution to science and so our party of bird-watchers was on the lookout, notebooks at the ready, for numbers of birds, and their general distribution throughout the reserve.
All these records go into central data bases operated by local bird and state-wide bird groups, like BirdLife Tasmania, and ultimately a national census, the Atlas of Birds, compiled by the parent national birding body, BirdLife Australia at its Melbourne headquarters.
A note, for instance, of a scarcity of cuckoos might tell of a decline in numbers reaching Tasmania, caused by factors such as land-clearance or drought on the mainland which would have affected insect populations providing the cuckoos with food in their wintering grounds. Lower cuckoo numbers could also reflect a decline in the birds which act as surrogate parents for this parasitic species in Tasmania itself.
In recent years the counts of bird numbers – and especially arrivals of birds in areas where they are not normally found – have been used as evidence of possible global warming and changing weather patterns.
Back on the trail in the Waterworks Reserve, meanwhile, healthy numbers of most of the resident species were recorded, and a relatively large number of some migrants, including two other species of cuckoo, the fan-tailed and the shining bronze.
Missing, however, was a showpiece species of the reserve, the endemic dusky robin. We couldn’t even hear the robin singing, as I often do, but as we listened intently there came a surprise.
A satin flycatcher was uttering its harsh, staccato rhythmic song high in the canopy of a stringybark gum. We could not see the bird in the tightly-packed canopy of leaves but were happy that at least it had arrived.
Another vital piece to the spring migration jigsaw was in place and only the pallid cuckoo was needed to complete the picture.