Norfolk Wildlife Trust is asking people to share their first sightings of three species associated with spring in their next citizen science survey, which launches on Monday 1 March.
Phenology is the recording and study of the timings of natural events, and the ‘father of British phenology’ was a Norfolk man. From 1736, Robert Marsham recorded, from around his home in Stratton Strawless, 27 indicators of spring. Once seen as a relatively unimportant pastime of amateur naturalists, it is now seen as an important way of knowing how our seasons are changing, especially in relation to climate change.
This spring Norfolk Wildlife Trust invites you to take part in its own phenology survey and share your first sightings of three species: swallows
, orange-tip butterflies
and common frogs
. Whether you are lucky enough to have them visit your garden, or you see them on your local patch, you can help NWT map sightings within our county to build a picture of where – and when – they appear.
The common frog
is the most likely candidate for the ‘first show’. Frogs usually emerge from their hibernation sites in February and March, where they then set off to their breeding grounds. The average date for clumps of frogspawn to be seen in Norfolk is 10 March. Although still classed as common throughout the UK, the common frog has declined since the 1970s. It is thought that loss of breeding habitat is a major cause for this, but also disease is believed to be a contributing factor.
The orange tip butterfly
is widely distributed throughout the UK. In Norfolk it can be commonly encountered along roadside verges, in woodland glades and in damp meadows but does also visits established gardens. The orange tip is an early spring butterfly with first emerging insects on the wing from mid-April. Scientists from the Natural History Museum compared information on historical temperature records to find that 92% of the 51 species of butterfly studied emerged earlier in years with higher spring temperatures. The orange tip butterfly was found to emerge nine days earlier for every 1oC increase in temperature between March and May.
are migratory birds and in the UK they are the typical harbinger of spring. First arrivals to the UK usually occur around 20 March, with spring migration taking place from mid-March through to mid-May. The UK swallow population is estimated in the region of 705,000 territories, and although they are still widely distributed their numbers saw a decline from the 1800s to 1995.The main reason for this is believed to be deterioration in the quality of feeding habitat in both their breeding and wintering grounds.
Gemma Walker, Senior Community Officer at Norfolk Wildlife Trust said: “We have picked three fantastic indicator of spring for our survey that we hope people in Norfolk will spot in their gardens and on their local patch, and are asking all sightings to be added to our wildlife spotter map.
“You don’t have to be an expert to make a valuable contribution to local knowledge of Norfolk’s wildlife. Recording wildlife is an easy way to get involved in wildlife conservation as it helps us to understand a species’ distribution across the county, and identify any areas particularly important or lacking in these species.”
NWT’s winter survey looking for visiting birds saw more than 3,000 sightings of brambling, redwing and fieldfare added to NWT’s spotter map. As with all wildlife records, NWT will share the data with Norfolk Biodiversity Information Service.