Some of our most famous naturalists are also among the greatest of our diarists, carefully noting observations of a changing flora and fauna over several decades. For the rest of us, while we may not be great diarists we are often persistent in our record taking, hoarding away observations on the animals and plants that we see each day. Such private notes are intended for our own pleasure, should we choose to read them back in later years, and at the end of our days they are unlikely to pass into wider circulation. However, the simple observations that we collect do have tremendous potential for wider use, particularly if they are collected in a systematic fashion. For example, the information held in the nature diaries of a whole generation of naturalists is now being used to study the impacts of global climate change as part of phenological studies.
Phenology is the study of regularly recurring biological phenomena, such as the spring arrival of migrant birds or the emergence of insects from hibernation. There is a long history of systematic recording of this kind within Norfolk. Robert Marsham, of Stratton Strawless, began recording the timings of 27 different indicators of spring in the year 1736, a tradition that was continued by subsequent generations of his family up until 1958. Records from elsewhere within Britain go back to 1703 but even these are dwarfed by the records of cherry flowering that have been collected in Kyoto, Japan, since 705 AD.
More widespread phenological recording began in Britain in 1875, through a network of observers coordinated by the Royal Meteorological Society, but this ceased in 1947. Fortunately it overlapped with an ongoing scheme operated by the British Naturalists’ Association and a further project was launched in 1998; known as the UK Phenology Network (www.phenology.org.uk) it now involves some 19,000 observers and is the largest study of its kind in the world. The new scheme has already produced a wealth of information and, by using historical records as well, has been able to show that spring is now happening earlier than it did just a few decades ago. Different groups of plants and animals have been shown to respond in different ways, with insects seemingly reacting to changing spring temperatures more rapidly than the bird species that feed on them; such that hatching dates of great tits no longer coincide with peak numbers of their caterpillar prey species. Such changing patterns may have a tremendous impact on the nature of our countryside and it is only because of the observations collected by naturalists that such patterns have come to light. So, why not make greater use of your own observations by contributing to phenological recording.