BUTTERFLY REPORT FOR 2010 (Medina Valley Centre) Rachel Luxton

Transcription

1 BUTTERFLY REPORT FOR 2010 (Medina Valley Centre) Rachel Luxton The butterfly index for 2010 is given in figure 1, together with the previous years records for comparison. The transect was walked 25 out of the 27 weeks of the recording season. Sunshine was recorded at greater than 50 percent for 90% of the weeks recorded. A map of the transect with the areas highlighted can be seen in figure 2. This year saw permanent changes in area 9, with the removal of the roundabout and flowerbed in the car park. The annual cut and raking of the unimproved grasslands was made quicker by the new tractor. The brambles in area 7 have been cut back throughout the season to suppress their growth and hopefully the ongoing cutting will keep them from encroaching this area. The butterfly garden has now been planted with some drought-resistant plants and shrubs and the main insect garden has been moved to area 4, near the summer house. The total species count for 2010 was 19 species, a decline of 2 species, as the brimstone and small skipper were not seen within the grounds this year. There was also a decline in the overall total number of butterflies from 650 in 2009 to 552 in April 2010 had a quiet start to the butterfly recording, due to the lower temperatures (see figures 3 & 4). In week 1 the first peacock was recorded. In week 3 a comma was sighted and week 4 brought the first orange tip. During May the temperatures were still relatively low but reached a high of 19 C by the end of the month. Week 5 saw the first small white and speckled wood. The first red admiral and green-veined white were recorded in week 6. The increase in temperature in week 9 saw the first common blue, which had a very successful year. The first meadow brown was recorded at the beginning of June, in week 10 and then the first marbled white towards the end of June, in week 13. July saw an increase in the numbers of butterflies, but not as high as 2009, due to lower than average temperature of C, compared to 21.1 C in The first brown argus and gatekeeper were seen in week 16. During August the numbers of common blue were high, with 48 individuals recorded in the peak of week 20. The temperature in September dropped to an average of below 20 C, resulting in a drop in the number of butterflies recorded. However, red admirals were seen again at the beginning of October as the second generation were on the wing, also during this week comma, peacock, red admiral, small copper and the speckled wood were still on the wing. The vegetation on the unimproved grasslands was cut back after the recording was finished this year, in the second week of October. Individual numbers showed a dramatic, 250% increase in the common blue and a smaller increase in the small white. The brown argus was recorded for the first time since before A number of species had a decline in population, including the gatekeeper, with the large white, meadow brown and speckled wood all showing a 50% decline. The brimstone, painted lady and small skipper were not recorded in 2010 but the painted lady was found in large numbers in 2009.

2 Figure 1: Butterfly species list and sightings at Medina Valley Centre (SZ503909) for 2009 and Species Brown Argus - 5 Brimstone 2 - Chalkhill Blue - - Clouded Yellow - - Comma Common Blue Dingy Skipper - - Gatekeeper Green Hairstreak - - Green-veined white 11 9 Grizzled Skipper - - Holly Blue 4 6 Large Skipper 6 3 Large White Marbled White 8 8 Meadow Brown Orange Tip 9 7 Painted Lady 63 - Peacock 6 4 Purple Hairstreak 1 1 Red Admiral 4 4 Ringlet - - Silver-washed Fritillary - - Smaller Copper Small Heath - - Small Skipper 3 - Small Tortoiseshell 7 10 Small White Speckled Wood Wall Brown 7 5 White Admiral - - Number of species recorded Total number of individual butterflies indicates that the species has been recorded in the reserve, but not seen this year.

3 Figure 2: Map of the Transect walked around the Medina Valley Centre grounds, showing areas 1-10.

4 Figure 3: Weeks when species were observed in The Transect was not walked during weeks 15 & 17. April May June July August September Oct. Species/Week Brimstone Brown Argus Clouded Yellow Comma Common Blue Dingy Skipper Gatekeeper Green Hairstreak Green-veined White Grizzled Skipper Holly Blue Large Skipper Large White Marbled White Meadow Brown Orange Tip Painted Lady Peacock Purple Hairstreak Red Admiral Ringlet Silver-washed Fritillary Small Copper Small Heath Small Skipper Small Tortoiseshell Small White Speckled Wood Wall Brown Key 1-9 individuals individuals >20 individuals Figure 4: Temperature recorded at the end of the Transect walk in The Transect was not walked during weeks 15 & 17. Temperature at the time of survey Temperture (degrees C) Week Number

5 Butterflies photographed around the Centre grounds Large White Brown Argus

6 Purple Hairstreak