WITH DON KNOWLER
In fast-paced, troubled times, I increasingly look for certainties such as the rituals and rhythms of life that tell you all is well with the world. My certainties are generally geared to the seasons and there is nothing as certain or reassuring as the arrival of the welcome swallows (pictured) on my patch in spring.
Over 17 years, I have always timed them for the first weekend of September. The sight of their erratic, joyous flight brings with it the vision of summer, even when snow lingers on the summit of kunanyi/Mt Wellington.
I had high hopes of a bumper swallow spring when one of my correspondents, David Kernke, owner of Shene historic estate at Pontville, said swallows had arrived there in mid-August. I counted down the days, expecting at any time to see them further south at the Waterworks Reserve, but the swallows were still not in my neighbourhood past their normal arrival date.
Migratory birds of many species usually arrive on warm northerly winds, and this year I noted the normal swallow arrival time coincided with a cold snap with snow-laden westerly and south-westerly winds. In the past, I might have attributed the late arrival to unfavourable weather. But in uncertain times of declining bird populations, the arrival of spring has been marked by a growing anxiety about how Tasmanian birds are faring in winter on the mainland.
Numbers of the migratory birds are showing marked declines across the world. Among them are the world’s swallow species. Fewer barn swallows, which breed in the US and Canada, are arriving from their wintering grounds in South America, and there is also a marked fall in the number of European swallows that have trans-continental flights that link northern Europe with the far tip of the African continent. The European swallows’ cousins, the house martin and the sand martin, are also failing to arrive in the numbers of old.
Ornithologists are still seeking reasons for the decline, but two factors are thought to be in play regarding the European species: land clearance and increasing global temperatures. Though I haven’t seen evidence of dramatic declines in Australian swallow and martin species, our swallows and other migratory birds cannot be divorced from the factors affecting them elsewhere.
On a more positive note, my anxious wait for the swallows ended in the first week of September. A merry twitter across the twin lakes of the Waterworks Reserves put my mind at rest – at least until next year.
And on another note, my book on kunanyi/Mt Wellington, The Shy Mountain, is being launched by Charles Wooley at the Hobart Bookshop on Wednesday at 5.30pm. All are welcome and I hope to see you there.