Another Life/Michael Viney: Spring was once something nature did all on its own, to the rapture of poets and the comfort of farmers and gardeners.
It came from "out there" in some unknowable nexus of the earth's whirling weather. It was teasing and capricious, sometimes cruel, redolent of Gaian grace and favour, ineffably remote from human effect.
Now that spring has lost its innocence in the progress of man-made climate change, science turns to phenology to track what Bill McKibben called memorably "The End of Nature". Phenology studies the timings of recurring natural phenomena - first bud-bursts and flowering, first dollops of frogspawn, first fall of autumn leaves, the comings and goings of migratory birds, and so on. Once an expression of human awe and appetite for order, phenology now finds an almost forensic purpose in charting the progress of man-made global warming.
Scientists in countries across the world, ready to offer the policy-makers reliable, unambiguous signals of climate change, have assembled a great range of natural indicators.
Having no glaciers or ice-sheets to measure, Ireland's choice had to be made from more familiar and datable events. The essential limitation was the lack of long-term observation and reliable records. In Britain, the UK Phenology Network can call on some 250 years of obsessional note-taking. Irish efforts have been tentative and sporadic. (In the Irish Naturalists' Journal of a century ago, there was an opportunity to list "Song First Heard After Winter Silence", which seemed properly poetic.)
Veteran readers will know that, each spring since 1996, I have been writing numbers on cards to chart the breaking into leaf of half a dozen different trees in my garden. Ten years is very few as such records go, and the oak tree alone shows some robust signs of a trend. Three decades of data are much better, and have helped to identify the spring budburst of native trees as the best "climate signal" for Ireland. This comes from a team of Trinity College botanists, led by Alison Donnelly and working with Maynooth's climate expert, John Sweeney. They have used records collected between 1970 and 2000 at four sites in Ireland - the Valentia Observatory in Co Kerry, Johnstown Castle and the JFK Arboretum in Co Wexford and the National Botanic Gardens at Glasnevin, Dublin. These form part of a network of International Phenological Gardens set up across Europe in the mid-20th century and planted with an assortment of cloned trees and shrubs supplied from Germany.
Over those 31 years, the trees at Valentia have shown the clearest response to climate change, both in earlier bud-burst and the fall of their leaves in autumn. There, a rise of 1 degree has advanced spring by a week (a finding echoed in similar studies in Europe) and added two weeks to the length of the growing season. However, the precise environmental factors sparking the start of growth seem to be "far more subtle and complex" than the level of average spring temperature and will need more study.
The earlier arrival of migrant birds in spring has been another candidate as indicator - though how, exactly, birds leaving Africa are supposed to know the state of Ireland's spring insects still baffles me. A swallow spotted over Dundalk on March 6th was two days too late to beat a record from 1952. The Trinity team have been analysing 20 years of swallow arrivals recorded in the East Coast Bird Report and find that plotting the dates against mean March temperature shows a two-day advance for every rise of 1 degree. Wheatear and grasshopper warbler are also showing earlier arrivals.
Meanwhile, this spring has produced Ireland's first really expert "nature watch" website with interactive phenology maps, nature blogs and chatroom, species profiles and pictures and international news.
The website - www.biology.ie - is the creation of Paul Whelan, a biologist and computer expert who, retiring to Cobh for health reasons, set out to fill a huge gap in Ireland's popular engagement with nature, biodiversity and the impact of climate change. Whelan's ideas are also buzzing on ways his site could be developed to serve professional ecologists. His e-mail address is xyz@eircom.net.
Even now, the site can accept "first sightings" sent in from web-enabled mobile phones; a direct feed of GPS co-ordinates comes later.
As I write, the first tree-bud swelling towards bursting belongs to my young horse-chestnut tree - the spring sticky-bud of one's first classroom but still a foreigner, like sycamore and lime. Oak, ash and alder are my natives. I shall enjoy, in all of them, the surge of growth and renewal, but just wish it still had nothing to do with us.
There's real pleasure, too, in using the range of new stamps just issued by An Post to mark National Tree Week. Susan Sex, the superlative botanical artist, has painted sessile oak, yew, ash and strawberry tree and managed to keep them living and blowing in the wind even in images you could cover with your thumb.
See them at www.irishstamps.ie.
EyeonNature
A pair of collared doves were coming to the bird table since early February. After three weeks the male came on his own and I thought she was nesting, but 10 days later they were together again.
Morna Hilton, Annascaul, Co Kerry
The female may have been egg-laying and being fed by the male.
A big black and white cat chased a fox across my lawn. The fox hid in a low hedge, the cat sat down and yowled, the fox crept out, ran across the lawn and the cat gave chase.
Doris Findlater, Blackrock, Co Dublin
Despite the urban belief that foxes kill cats, a wise fox would hesitate to engage with the claws of a large cat.
Your words keep city life and Dart commuting rich, as I watch out always for our feathered and furred friends en route. For the last few weeks half a dozen cheeky black guillemots have been playing on the Liffey, just beyond the Famine Memorial.
Áine Hutchinson, Malahide, Co Dublin
I think a pine marten has become a regular nocturnal visitor to the bird table. How can I verify this?
Melanie Restall, Boyle, Co Roscommon
Sit up and watch.