Ocean Mist

Posted by Jes

Butterfly Season Report

The summer of 2013 saw spectacular weather but what would 2014 offer? Happily 2014 delivered a fine summer after the prolonged stormy weather early in the year.

February 2014 was the wettest month on record.  When this cleared in March a fairly pleasant month followed with the temperature reaching 16°C at Johnstown Castle on March 15th. April was typical for its mix of sunshine and showers, cold and warmth; thus the lowest temperature recorded was -6.6°C on April (grass temperature at Mountdillon on April 20th) and the highest temperature of 20.4°C was recorded at Newport on 28th April. High sunshine levels were recorded in April. The better weather occurred during the last two weeks of April although stormy weather occurred too.

May was disappointing with high rainfall, below average sunshine and temperatures near May’s long-term average. However there were some good days with the month’s highest temperature of 22.3°C recorded on the 28th. June’s conditions comprised of above average sunshine, below average rainfall, above average temperatures and below average wind speeds .The majority of highest temperatures were recorded between the 16th and 18th during the mid-month period of high pressure, with the highest maximum of 27.1°C on the 17th. There were periods of dull, rainy weather but these were not prolonged. July’s weather was similar but sunshine levels were more variable.  Nearly all highest temperatures were recorded between the 23rd and 25th, with the month’s highest temperature of 27.6°C recorded at Carlow (Oak Park).

The first week of August saw good weather but overall August was disappointing with below average temperatures, above average rainfall, average sunshine levels and some stormy weather. August’s highest temperature of 22.5°C was on the 5th. September’s key indicators were highly favourable for butterflies. It was generally dry, warm everywhere with the month’s highest temperature of 23.9°C recorded at Shannon Airport, there were high or very high sunshine levels and the average wind speeds were the lowest on record.  Some pleasant weather in October helped to extend the flight time for our late season fliers. The month’s highest temperature of with 19.4°C was recorded on the 31st October. Even November saw some good conditions.

Early season flyers suffered in 2013 due to the very cold spring but in 2014 these did better; Orange-tips and Green-veined Whites saw improved but unspectacular numbers. Typically, the first butterflies sighted in 2014 were those that pass the colder months in the adult state; a Small Tortoiseshell (11/01) and a Peacock (12/01) were the first records of free-flying butterflies in 2014.

Regarding the more widespread species, numbers were high for Peacock, Speckled Wood, Meadow Brown, Ringlet, Small White but the Large White had a poor year; this may be linked with high infestation by its parasites. There was one spectacular record of the species on 04/09 when over 100 were seen at The Hook, Co. Wexford; these may have been immigrants. The Cryptic Wood White appeared in reasonable numbers. The Holly Blue’s numbers continued at their low levels. Two broods of the latter were noted in the southeast while the Common Blue which showed in better numbers than in 2013 with a partial third generation in the midlands with records as late as 08/10 and 11/10. The Small Copper appeared in low numbers throughout its flight times in 2014.

The Small Tortoiseshell’s second brood did not appear in high numbers in 2014. Although it was found throughout the country its numbers were frequently but not uniformly low. High levels of parasitic infection of second brood larvae (such as by Pteromalus puparum which infects final stage larvae and fresh pupae) coupled with cold August weather might be implicated in its lower numbers. While there were numerous records for Brimstones it did not appear in high numbers during 2014. The Small Skipper had its best year since its discovery with over 100 found on 19/07. Available records suggest that the Essex Skipper performed well and its presence in Kildare was re-confirmed on 20/07.

Habitat specialists had mixed fortunes. By mid-May the Pearl-bordered Fritillary and Wood White were flying in their limestone scrubland habitats but there were few reports of these two species. There was only one record of a second brood Wood White in 2014 despite targeted searches. The available data suggest that the Dark Green Fritillary showed in good but not exceptional numbers while the Marsh Fritillary had a good year after two disastrous years on its wetter inland sites in 2011 and 2012. The Silver-washed Fritillary had an excellent year with good records from around the country with increases noted on new semi-natural woodland on cutaway bogs.

The Small Heath showed in good numbers and flew from Mid-May to late September. The late September records hint at the possibility that a third brood occurred in some areas in 2014 but the complicated brood structure of this grassland species makes verification of the generations difficult. The Large Heath was recorded from 09/06 to 05/07 but there are too few 2014 records available for a determination of its progress to be attempted; the same comment applies to the Grayling but there is nothing to imply that this mainly coastal species is in peril. Indeed 57 were recorded along the historic Kiltacky track in Co. Clare on 08/08. The most range-restricted of the browns, the Hedge Brown, was the least recorded butterfly during 2014 and needs to be watched; despite a warming climate no northwards extension of its Irish range has been observed and it may be retreating. The Wall Brown maintains its range but continues in low numbers in most locations and its distribution, which has shrunk since the early 1990’s, shows no signs of recovering. The Small Blue appeared to have a good year.

The Green Hairstreak was found in its boggy haunts but with one notable exception numbers were low while the Purple Hairstreak, a woodland specialist continues to be spotted in some new woods. However there were few records of this elusive tree-topper in 2014.The Brown Hairstreak is the latest butterfly to emerge and it does not appear to have recovered its numbers since the poor summers in 2011-12.

What of our migrants? The Red Admiral showed in great numbers with a recorded flight from 10/03 to 25/11. A count of up to 150 was made at The Hook on 13/09. It was the most commonly recorded butterfly during October and November. The Clouded Yellow featured mainly along the coasts but it penetrated inland too, with an individual record from Co. Offaly in early September. Records were mainly of singletons but some larger figures of c.12 were noted. It was another year of low numbers for the Painted Lady and like the Clouded Yellow it featured mostly later in 2014.

The most interesting feature of 2014 concerns the Comma. History was made when Brian Power, Alexander Harding and Jesmond Harding confirmed breeding by the Comma on 17 May 2014 in County Carlow. A total of 91 sightings of adults and five sightings of larvae were made (adult sightings refer to records on BCI website) making 2014 a record year for numbers of the species counted in Ireland. It is a beautiful and intriguing butterfly to add to the Irish list and the story of its discovery as a breeding Irish butterfly can be read in the Annual Report 2014.

A table showing first date/final date/abundance for each species follows.

We thank everyone who recorded butterflies during 2014.

Species First Date Last Date Highest count
Dingy Skipper 09-May 24-Jun 18
Small Skipper 02-Jul 27-Jul 100 plus
Essex Skipper 09-Jul 30-Jul 46
Wood White 16-May 03-Aug 6
Cryptic Wood White 09-May 27-Jul 30
Clouded Yellow 16-May 20-Dec 12
Brimstone 11-Mar 22-Sep 12
Large White 08-Apr 01-Oct 100 plus
Small White 01-Apr 02-Oct 30
Green-veined White 06-Apr 09-Oct 50
Orange-tip 14-Apr 30-Jun 20
Green Hairstreak 17-Apr 25-Jul 60
Brown Hairstreak 03-Aug 21-Aug 8
Purple Hairstreak 11-Jul 15-Aug 22
Small Copper 24-Apr 02-Oct 10 plus
Small Blue 01-Jun 30-Jun 40 plus
Common Blue 07-May 11-Oct 100 plus
Holly Blue 07-Apr 27-Oct 26
Red Admiral 04-Jan 06-Nov 150 plus
Painted Lady 19-Aug 30-Nov 3
Small Tortoiseshell 11-Jan 24-Dec 150 plus
Peacock 12-Jan 17-Dec 76, 195
Comma 05-Apr 23-Oct 50
Pearl-bordered Fritillary 16-May 28-May 12
Dark Green Fritillary 14-Jun 07-Aug 30 plus
Silver-washed Fritillary 19-Jun 07-Sep 39
Marsh Fritillary 17-May 01-Jul 200
Speckled Wood 06-Apr 30-Oct 250 plus
Wall 18-Apr 11-Sep 16
Grayling 21-Jun 21-Sep 57
Hedge Brown 03-Jul 21-Jul 12
Meadow Brown 14-May 21-Sep 478
Ringlet 11-Jun 31-Aug 300 plus
Small Heath 09-May 26-Sep 100
Large Heath 09-Jun 05-Jul 10