Suffolk Natural History, Vol. 52
Annex J- Small Heath The Small Heath was recorded in 122 tetrads this year which represents a disappointing decrease of 20 tetrads when compared to the 142 achieved in 2014. The first record was received on 4 May and interestingly was seen at sites in both the east and west of the county on this date. It was last reported on 29 October at RSPB Boyton Marshes. The maximum count for the year was made on the transect walked at RSPB North Warren on 1 July and resulted in 118 being recorded. Elsewhere, counts of 50+ were recorded at key sites in both the east and west of the county. The 2015 distribution map below clearly shows the strongholds of this butterfly as the heaths of the Sandlings in the east of the county and of the Brecklands to the west. However, the Small Heath is not confined to heath land. It is highly adaptive and can be found in a variety of grassy habitats including woodland rides but the key requirement is a short sward of fine grass species. The decrease in distribution is like that seen for Grayling this year and the fact that both butterflies share similar habitat should be considered as a major concern. Again, as with Grayling the year’s shortfall may relate to habitat loss or increased disturbance.
Figure 9. Distribution map for Small Heath 2015. The UKBMS Summary of Changes Table for 2015 identifies a series trend (over last 39 years) of -56% for the Small Heath population and this fall in abundance is described as “very highly significant”. A comparison between 2014 and 2015 showed a percentage change in abundance of -10%. In Suffolk it remains a weak but stable population and as with the Grayling it is clearly very vulnerable and requires continued monitoring. Trans. Suffolk Nat. Soc. 52 (2016)