Ocean Mist

Posted by Jes

Crabtree/Lullybeg Reserve Report

The Lullybeg transect was walked from April to the first week in October and the results have been forwarded to the National Biodiversity Data Centre. The figures outside brackets refer to all butterflies counted on the site while figures inside the brackets are transect counts.

Species 2011 2012 2013
Dingy Skipper

Green-veined White

Orange-tip

Large White

Small White

Cryptic Wood White

Brimstone

Common Blue

Small Copper

Red Admiral

Painted Lady

Small Tortoiseshell

Peacock

Silver-washed Fritillary

Marsh Fritillary

Ringlet

Wall

Speckled Wood

Meadow Brown

Small Heath

Large Heath

17[11]

49[45]

45[41]

1[0]

4[2]

0[0]

14[5]

81[74]

18[17]

26[5]

0[0]

58[26]

22[13]

1[1]

15[9]

185[125]

1[1]

7[3]

62[48]

88[70]

1[1]

31[28]

41[26]

11[11]

1[1]

4[2]

1[2]

36[14]

68[61]

23[10]

8[1]

0[1]

315[140]

168[53]

4[0]

19[8]

154[104]

1[1]

49 [4]

180[126]

122[100]

1[1]

33[28]

106[86]

14[10]

1[1]

11[11]

1[0]

53[21]

54[52]

17[8]

7[1]

2[0]

335[296]

233[123]

7[3]

41[25]

550[405]

2[2]

38[8]

303[250]

231[199]

0[0]

Total 695 in 25 visits 1,240 in 25 visits 2,039 in 26 visits

The Cryptic Wood White, Common Blue, Red Admiral, and Large Heath show declines in 2013 from the 2012 figures. All the other species showed increases that were spectacular in the Small Tortoiseshell, Ringlet and Small Heath. The Green-veined White, Peacock, Marsh Fritillary, Meadow Brown showed impressive increases. The chief factor behind these figures is weather. The average temperature for the transect walks in 2011 was 15.64 degrees Celsius, while 16.40 degrees Celsius was the average for the transect walks in 2012. In 2013 17.69 degrees Celcius was the average temperature; the lowest was 9 Celcius on 06/04/2013 and the highest was 25 Celcius on 18/07/2013 and 20/07/2013. This significant improvement in the temperatures played a role in the great rise in abundance as might other factors beyond our control such as parasite/host cycles. In 2013 the months April and May saw cold conditions and only 29 butterflies were counted. June saw some beautiful weather especially during the first and fourth weeks while July’s conditions were hot, dry and sunny throughout, ideal for butterflies. Favourable, though less spectacular weather, continued throughout the rest of the flight season.

The management work carried out during the autumn of 2011 and the spring of 2012 and spring 2013 may have helped to improve the conditions for some species. Scrub clearing was carried out in February 2013 in an area that holds an abundance of Devil’s-bit Scabious (the food plant for the caterpillars of the Marsh Fritillary butterfly) in the hope that the Marsh Fritillary would breed there. A Marsh Fritillary butterfly laid her eggs on a plant in the cleared area, showing that conservation actions bear fruit. The most important finding is the recovery in the Marsh Fritillary population on the reserve. Only three Marsh Fritillary larval nests were found on the site in the autumn of 2012 and spring 2013. In the autumn of 2013, 15 larval nests were found. The nests are currently more widely distributed than in all the years following 2007. Further scrub control carried out in November 2013 in the core breeding area will help to maintain the flow of sunlight to the grassland; direct sunlight is crucial for the Marsh Fritillary.  The site remains in excellent condition for most species and four of the butterflies that have a threat category assigned to them under the IUCN criteria showed increases [Dingy Skipper, Marsh Fritillary, Wall and Small Heath].

A final point to emphasise about the success witnessed at the reserve concerns habitat. Weather and climate which are important factors affecting butterfly populations  are beyond our control but habitat condition is capable of being influenced by human activity. There is little doubt that the Marsh Fritillary would have become extinct on the site without our management.

That the reserve is in excellent condition is thanks to the efforts of our members, helpers from the Kildare Branch of BirdWatch Ireland and our partners Bord na Móna who enable our conservation work to continue and for their assistance especially Eamon Mulhall who assisted with the machine work we needed and Catherine Farrell, who liaises closely with Butterfly Conservation Ireland.