Hampshire and Isle of Wight Butterfly and Moth Society
Hampshire and Isle of Wight Butterfly and Moth Society
| Family: | Nymphalidae |
| Subfamily: | Nymphalinae |
| Genus: | Euphydryas |
| Species: | aurinia |
| Authority: | (Rottemburg, 1775) |
The Marsh Fritillary has the most colourful uppersides of all of our fritillaries, being a highly-variable chequered pattern of orange, brown and yellow markings. The bright colours fade after a few days and leaves the butterfly with a shiny appearance - early Lepidopterists naming this butterfly the "Greasy Fritillary" as a result. This butterfly is primarily a wetland species as its modern name suggests.
Colonies of this butterfly are known to fluctuate wildly in numbers. It may be present in some numbers one year, for the population to crash the following year before recovering as unexpectedly. This species does not do well in adverse weather conditions and also suffers greatly from larval parasitism by an Apanteles species of wasp. Unfortunately, this charming butterfly is one of our most threatened species and has suffered severe declines in recent decades.
The butterfly is found primarily in south-west England with a small population in north-west England, the islands of south-western Scotland and the adjacent mainland, and north-west and south-west Wales. It is also locally widespread in Ireland. It is not found in the Isle of Man or Channel Islands. This butterfly forms discrete colonies and even the slightest barrier will prevent dispersal - such as a hedge or a river. Colonies are typically part of a meta population with several colonies located close to one another.
| #Individuals | #Tetrads | 2022 | 2023 | Abundance Trend | 2022 | 2023 | Distribution Trend |
|---|---|---|---|---|---|
| 298 | 364 | +22% | 11 | 12 | +9% |
| #Records | #Individuals | Earliest Record | Latest Record | |
|---|---|---|---|---|
| All Records | 1,105 | 5,094 | 27/04/2007 | 26/06/2023 |
| 2023 | 53 | 364 | 13/5/2023 | 26/6/2023 |
| Location | Date | Quantity | |
|---|---|---|---|
| Earliest Record | Magdalen Hill Down (extension) | 13/5/2023 | 27 |
| Latest Record | Yew Hill transect: Section 1 | 26/6/2023 | 1 |
| Highest Count | West Minley Meadow (B) | 26/5/2023 | 58 |
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: 14.8
Average #Recorders: 14.8