According to the UK papers and a handy "first daffodil" blog, the nation's favourite harbinger of spring, the daffodil, began making an appearance in the distinctly wintery month of January. But, before succumbing to excitable proclamations on the cause, meditate on the fact that several cultivated varieties of daffodil flower naturally before Christmas. "We grow a very early variety which flowers in December," confirms Angela Singleton of the National Botanic Garden of Wales. Some wild species can flower as early as October.
Even so, there is one daffodil that should know better. The Lanarth variety, which was spotted in October, has a sensor to tell it that the winter is over, thus making its appearance unusual and not so easily explained away. Other suggestions that something isn't quite right were the arrival of snowdrops in January ("Snowdrops signal spring is on its way," The Sentinel. January 27, 2009) as as well as lesser celandines spotted in Cardiff, rooks building nests in Oxfordshire and song thrushes bursting into tune in Glasgow ("Spring arrives early in Northern Ireland," The Belfast Telegraph, 5 February 2009).
But rather than generalising from a single year, conclusions must be drawn from a detailed knowledge of previous springs. This is where phenology comes in. It was founded by Robert Marsham who was best known for his "Indications of Spring". Starting in 1736, Marsham consistently noted the dates for some 27 natural events for more than 20 animals and plants. These included tree leafing times and the arrival of migrant birds. These records or "phenophases" were maintained by generations of the same family, only ending with the death of Mary Marsham in 1958. During this time, "the first leafing date of oak appears to have advanced by about eight days, corresponding to overall warming of the order of 1.5°C in the same period," write Sparks & Carey in "The responses of species to climate over two centuries: an analysis of the Marsham phenological record, 1736-1947" (Journal of Ecology 83, 321-329, 1995).
Since then, the task has been taken over by the Nature's Calendar Survey - the data for which is provided by the public. According to its site: "Over the past 30 years phenology has provided biologists with clear evidence that spring is arriving earlier. Trees have been coming into leaf sooner. Migrant birds are arriving earlier with swallows now a week ahead of their dates in 1970. Frogspawn is being spotted before Christmas in the south-west, while comma and holly blue butterflies have been sighted as early as March."
So, spring is springing earlier. 1.7 days earlier according to some scientists (AR Stine, P Huybers, IY Fung (2009), Changes in the Phase of the Annual Cycle of Surface Temperatures. Nature in press, doi: 10.1038/nature07675). While this may be good news for eager lambs, it's not so popular among those who value the distinctness of the UK's seasons.
Justin Schamotta - Justin was born in South Africa, raised in the Welsh Valleys and now resides in Brighton. He has been co-editor of Bulb magazine, deputy ...
