Butterfly transects of Kingston Hill Fields
Meadow Brown, a clear winner in abundance in the field during June
Four approximately weekly transects, which involved a walk around the perimeter of the field, were carried out in June 2023 by Steve Berry.
Ten species of Butterflies were recorded; Large Skipper, Small White, Large White, Brown Argus, Common Blue, Dark Green Fritillary, Marbled White, Meadow Brown Gatekeeper and Small Heath. On a warm day at the end of June he counted 473 Butterflies. That however was dwarfed by another total I was told about the day before of 624! Multiply that up to the whole of the field and the number could be five times that as it’s only possible to see butterflies and positively identify them from perhaps 10 meters either side of the path which might be only 20% of the field.
The highest density of most species was found near the west and southern edges of the field. With the eastern edge having by far the highest number of Butterflies. This seems at odds with my subjective impression of the density of Orchids and other forbs, the west side of the field having the longest grass and the least forbs. This raises two issues. We can have an opinion as to the value of parts of a habitat, but wildlife will choose what it actually requires. As ever this is a reminder that diversity within a habitat is crucial, plants and insects have different specs for their ‘des res’.
The west side of the field has by far the most butterflies. With the southwest corner of the field which has the longest and most dense grass sward having the highest number of Meadow Brown, the field's most common species. These make up 52% of the total number of Butterflies counted.
The second most abundant species was Small Heath, 30% of the total numbers counted. These were dominant in the south and east of the field. The Butterfly Conservation website says Small Heath like 'grassland where there are fine grasses, especially in dry, well-drained situations where the sward is short and sparse.' The south and east sides of the field certainly fit the description for the ideal habitat for this species. Butterfly Conservation list them as 'priority: High', it is also a 'species of principal importance under the NERC Act in England' and has UK BAP status: Priority Species. Clearly there is consensus among conservation bodies that this is a species needing protection. Steve counted 94 individuals in one day during his transect. Clearly there is likely to have been many times this number in the whole field.
Most of the other Butterflies found in the Kingston Hill field along with Meadow Brown are listed by Butterfly Conservation as 'Priority: Low' with the exception of Dark Green Fritillary, only seen once in June in the northeast of the field which has a 'priority: Medium'. But all this could change in a brief period of time. 'The State of the UK's Butterflies 2022 report' found that 80% of butterflies in the UK have declined since the 1970s. Really all Butterflies should be accorded a high conservation priority. Interestingly the ‘Bugs Matter’ Citizen Science survey found that ‘the UK's flying insect population has declined by as much as 60% in the last 20 years’ so Butterflies seem to have fared better than many insect species.
Without Steve Berry’s diligent work, we would not have known that the Kingston Hill field was so suitable for Small Heath.
