Hampshire and Isle of Wight Butterfly and Moth Society
Hampshire and Isle of Wight Butterfly and Moth Society
| Family: | Nymphalidae |
| Subfamily: | Satyrinae |
| Genus: | Hipparchia |
| Species: | semele |
| Authority: | (Linnaeus, 1758) |
This butterfly, the largest of our 'browns', is a master of disguise - although fairly conspicuous when in flight, it can mysteriously disappear as soon as it lands, perfectly camouflaged against a background of bare earth and stones, always resting with its wings closed. When it first lands, and when disturbed, the butterfly will raise its forewings for a second or so, revealing dark eye spots that stand out against a beautiful spectrum of browns. This butterfly also has a curious technique for regulating body temperature by leaning its wings at different angles to the sun.
This butterfly is known for the variation between geographically-isolated populations, with 6 named subspecies occurring within the British Isles. This butterfly forms discrete colonies and, while some colonies are inland, the overall distribution of this butterfly would suggest that this is primarily a coastal species, at least in the British Isles. This butterfly is found on the Isle of Man and in the Channel Islands, but is absent from Orkney and Shetland. Colonies vary considerably in size, the smallest containing a couple of dozen and the largest several thousand - especially those found on large expanses of land, such as the heathlands of the New Forest.
| #Individuals | #Tetrads | 2022 | 2023 | Abundance Trend | 2022 | 2023 | Distribution Trend |
|---|---|---|---|---|---|
| 1999 | 1459 | -27% | 67 | 62 | -7% |
| #Records | #Individuals | Earliest Record | Latest Record | |
|---|---|---|---|---|
| All Records | 7,573 | 32,087 | 03/06/2002 | 15/10/2022 |
| 2023 | 483 | 1,459 | 22/6/2023 | 25/9/2023 |
| Location | Date | Quantity | |
|---|---|---|---|
| Earliest Record | Mottistone Down transect: Section 2 | 22/6/2023 | 2 |
| Latest Record | Yateley Common East transect: Section 4 | 25/9/2023 | 1 |
| Highest Count | Browndown North | 20/8/2023 | 26 |
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: 52.56
Average #Recorders: 52.56