Hampshire and Isle of Wight Butterfly and Moth Society
Hampshire and Isle of Wight Butterfly and Moth Society
| Family: | Hesperiidae |
| Subfamily: | Hesperiinae |
| Genus: | Thymelicus |
| Species: | lineola |
| Authority: | (Ochsenheimer, 1808) |
The Essex Skipper forms discrete colonies that vary from a small number of individuals to several thousand. Where it occurs it can therefore be very common. This species is very similar in appearance to the Small Skipper and, because of this similarity, was not recognised as a separate species until 1889. The male is distinguished from the female by the sex brand on its forewings, which is a short line of specialised scent scales. Despite its name, the Essex Skipper is now found over much of the southern half of England and it was first recorded in Wales in 2000 and in Wexford in south-east Ireland in 2006. On the British mainland it is to generally be found south of a line between Dorset and North Lincolnshire. It is believed that the increase in distribution is being assisted by the steep and grass-covered embankments that are often found on motorways and major trunk roads which acted as corridors - allowing this species to reach new locations more easily.
| #Individuals | #Tetrads | 2022 | 2023 | Abundance Trend | 2022 | 2023 | Distribution Trend |
|---|---|---|---|---|---|
| 803 | 1141 | +42% | 123 | 135 | +9% |
| #Records | #Individuals | Earliest Record | Latest Record | |
|---|---|---|---|---|
| All Records | 7,354 | 27,641 | 26/05/2007 | 21/09/1996 |
| 2023 | 378 | 1,141 | 11/6/2023 | 16/8/2023 |
| Location | Date | Quantity | |
|---|---|---|---|
| Earliest Record | Blacknest Fields | 11/6/2023 | 1 |
| Latest Record | Pilot Hill transect: Section 5 | 16/8/2023 | 2 |
| Highest Count | Monks Walk | 26/6/2023 | 33 |
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: 56
Average #Recorders: 56