Hampshire and Isle of Wight Butterfly and Moth Society
Hampshire and Isle of Wight Butterfly and Moth Society
| Family: | Nymphalidae |
| Subfamily: | Satyrinae |
| Genus: | Pyronia |
| Species: | tithonus |
| Authority: | (Linnaeus, 1771) |
The Gatekeeper, also known as the Hedge Brown, is a golden butterfly that provides a welcome sight in the middle of summer, when the fresh adults start to emerge. This butterfly spends much of its time basking with wings open, when the sexes are easy to tell apart - only the male has the distinctive sex brands on the forewings. In England and Wales this common and widespread species is found south of a line between Westmorland in the west and South-east Yorkshire in the east. In Ireland it is confined to coastal areas of the south and south-east counties. The butterfly is also found in the Channel Islands, but is absent from Scotland and the Isle of Man. The habitat this butterfly requires is found over most of the British Isles, and so we can only assume that the restriction to its range is governed primarily by climate. Colonies vary greatly in size, depending on the available habitat, ranging from a few dozen individuals to several thousand.
| #Individuals | #Tetrads | 2022 | 2023 | Abundance Trend | 2022 | 2023 | Distribution Trend |
|---|---|---|---|---|---|
| 44370 | 73311 | +65% | 745 | 881 | +18% |
| #Records | #Individuals | Earliest Record | Latest Record | |
|---|---|---|---|---|
| All Records | 142,966 | 899,379 | 24/03/1999 | 19/10/1995 |
| 2023 | 13,112 | 73,311 | 10/6/2023 | 25/9/2023 |
| Location | Date | Quantity | |
|---|---|---|---|
| Earliest Record | Newtown | 10/6/2023 | 4 |
| Latest Record | Noar Hill transect: Section 8 | 25/9/2023 | 1 |
| Highest Count | Stockbridge Down | 20/7/2023 | 207 |
One of the issues with 'raw' trend data is that there is inherent bias based on the number of recorders. For example, the number of individuals and populated tetrads recorded are likely to increase if there is an increase in the number of recorders. In order to remove this bias, the normalised trends use data that has been recalculated using the average number of recorders over the trend period. This normalisation gives a much better picture of the true trends.
Average #Recorders: 793.36
Average #Recorders: 793.36