Donegal Butterflies May 28 – June 06 – Summary Report  

I visited Donegal in the period May 28 – June 06 and the following is a summary of the main butterfly sightings in the period by various Donegal recorders and myself.
I saw flying CB, DS, GH, GVW, LW, MF, OT, PL, P, RWW, SB, SC, SH, SmT, SW, SpW, WB.
Additional species seen by other recorders were DGF, LH, MB and RA.  Larvae of SmT were widespread.  

New 10 km sq records for the period, all in west Donegal were:

B60 DS and OT
B61 GH
B80 RWW
B84 SW
B90 MF

I visited the islands of Tory and Aranmore with Ethna Diver and these island summaries include the butterflies seen:  

Tory on June 03 – for those not familiar with this island it is about nine miles off the NW coast of Donegal, is some 2.5 miles long and about 0.75 miles wide and is the land occurring on 10 km sq B84. It is low-lying rocky and windswept. It has at present a population of about 120. The most obvious vegetation over much of Tory is Bird’s-foot-trefoil, which in early June was a blaze of colour. Extensive beds of Nettles adjoin the two main villages – East Town and West Town. Not surprisingly with this vegetation the two most abundant butterfly species on the island are CB and SmT. Neither species were flying at the time of our visit, although the weather was calm with warm hazy sunshine and a temperature in the high teens. Previous butterflies recorded on Tory during the current survey are: CB, CY, G, GVW, LW, MB, PL, P, RA, R, SmT. We hoped to extend this number and as this was my first visit to the island I was interested to see the habitat for myself.

Particular emphasis was given to checking for the presence of OT, SC, SH and SW.

During our stay we saw only a few flying butterflies, although at about this time there were at least 21 species flying in mainland Donegal. Of the about ten butterflies we saw in 3.5 hours of walking around the island the biggest number were unidentifiable smaller whites, which by their rapid flight may well have been SW. Of those we clearly identified there were GVW 1,LW 2, PL 1 and SW 1. We also saw four groups of caterpillars on nettles, one of which was final instar SmT and the other early instar ones were probably SmT but could also have been P.

Future surveying - The west side of the island probably has the best prospects for SH and possibly SC. There are two lakes on this side and the late growing Corncrake-meadows are mostly on the west of the island. Further checking is necessary later in the season, when larger numbers of butterflies should be seen and will give a better picture of butterfly numbers on Tory.  

Aranmore on June 05 – Aranmore, off the butterfly-rich Rosses area of west Donegal, is very much better provided than Tory with a variety of butterfly habitats and good shelter on the south and east sides of the island. Also it has many flower gardens and the approx 520 residents cultivate some brassicas. It occurs on 10km sq B61. Before this visit seventeen butterfly species had been recorded on Aranmore, during the current survey. These are CB, DGF, G, GVW, LW, MB, MF, OT, PL, P, RA, R, SC, SH, SmT, SpW, WB. Over the years LW, SH, SmT and WB have been among the most numerous butterfly species on Aranmore. The additional species targeted on this visit were GH and SW with an outside possibility of LH (probably too early). A visit to the MF site on the east side of the island failed to produce any MF although it did yield GH 2 as well as GVW 3, OT 1, SH 20 + and WB 3. The habitat still appears good for MF and the colony may have moved or the main MF flying season on Aranmore may not have been reached. At other sheltered sites we recorded CB 3, P 2, SC 2, SH 4, WB 1. The warm sunny weather with temperatures in the high teens gradually gave way in the early afternoon to cloudier cooler conditions with few flying butterflies so we did not search for LH. With 18 species now confirmed the chances are good of eventually reaching 20 butterfly species on Aranmore.

The Various Species -  May 29 – June 06

CB - having been first recorded in Donegal this year on May 23 at Cruit, the CB gradually became more widespread and increased in numbers during the period, especially in warmer sites such as in dunes and limestone pavement. Con O’Donnell recorded two CB inland at Dunlewey (B91) on June 01, and was told by locals CB had been out there for a week.

DGF - on June 02 Richard McCafferty recorded one DGF at Meenalargan, nr Glenties.

DS - the DS gradually became less numerous over the period. DS was confirmed on eight of its previously known nine 10km sqs in Donegal (all except G86). The new sq record on B60 was of a single specimen on this exposed and heavily sheep-grazed mini-sq on the side of Dunmore Hd and was just over the boundary of the B-grid sq and was seen on May 30 by Maurice Simms and myself. A small sheltered reasonably good DS site exists close by on neighbouring sq G69 and which is only lightly grazed. This new sq for DS is as far as is known the most northerly DS sighting in Ireland for DS. Repeated efforts to locate DS on good sites on B70 and B80, the main geographical area to the north of the known Donegal DS colonies, continued to prove fruitless.

GH – a very good year for this species in Donegal with GH widespread and in places numerous.

A few GH kept in captivity readily laid on Whins, Bilberry and Tufted Vetch, although not on Bird’s-foot-trefoil. With three new 10km sqs added in 2010, the GH has now been confirmed on 67 10km sqs in Donegal. The new sqs are B61, G48 and G85.

GVW – in most cases numbers were reducing over the period. Exceptions were the colder districts in mountainous areas and parts of Inishowen, where the GVW was still very numerous.

LH – the first Donegal LH of the year was reported by Frank Smyth at the warm usually early site at Rowantreehill, east of Ballyshannon with 11 LH of the Scotia form recorded there on June 04.

LW – a few scattered sightings in the early part of the period but increasing numbers in coastal south Donegal towards the end as evidenced by records from Frank Smyth in Rossnowlagh and Ethna Diver in Bundoran. I saw at least three on Tory on June 03.

MB – four MB were recorded on June 06 by Ethna Diver on limestone pavement some 1km south of Ballyshannon.

MF – in the past five years the MF has been a priority species in the Donegal Butterfly Survey.

With the new 10km sq record on B90 nr Fintown, where a single MF was seen on June 01 by Richard McCafferty and myself at a site previously discovered by Frank Smyth as having good potential. The MF has now been confirmed as present on forty-five 10km sqs in Donegal. B90 has proved a difficult sq on which to find MF as much of the area has sheep grazing. Apart from the 10km sq records, several new sites with MFs have been recorded this year on sqs already known to have MF. These new sites include B71 nr Burtonport where six MF were seen on June 05 by Ethna Diver and myself; G69 at Pound Lough (01) and at Carrickalahagh, part of the Sheskinmore Nature Reserve, where Maurice Simms counted 71 MF on June 04. This latter site is over one km from the previous main Sheskinmore MF site; G79 at Tullyard west of Glenties, where Richard McCafferty recorded one MF; G85 at Magheracar, nr Bundoran with 5 MF recorded there by Ethna Diver on June 06 and which is some eight km from where Frank Smyth recorded larval webs at Ardloughill last October; G86 at Coolcholly just NE of Ballyshannon, where Frank Smyth recorded 50+ MF on June 05; known MF sites with over fifty flying MF recorded were: Graffy (G89) where Richard McCafferty and I counted 70+ MF on June 05 and nr Rabley Hill (G77) where Ian McCambridge and I saw 50+ MF on June 04. I visited Inishowen on June 03 together with Ethna Diver and Sue Shiels but despite careful checking failed to find any MF on good habitat but in marginal flying weather at Meenalooban (C33), Dunree (C23), Altahalla (C34), Lough Fada and Drumaville (C44). I also saw no MF on the Aranmore site on June 05 and Danny Gillespie found no MF during the first week of June at the Muckros site (G67). Elsewhere all existing MF sites that were visited, including Glashagh (B82/B83), which had been seriously degraded by sheep but now seems to be sheep-free still had MF. The species seems to be again enjoying exceptionally good weather in Donegal during its main flying period in late May and early June.

OT – this widespread and common butterfly, a real signal that spring has arrived in Donegal, generally reduces in numbers throughout May and small numbers continue into early June. In the colder areas of Donegal, such as the mountains and far north however this species reaches its peak in late May and remains abundant throughout most of June. Thus large numbers were still recorded this year in the first week of June in North Inishowen and in highland districts on the north side of the Bluestack Mts (G99).

PL – just a handful of the migrant PL have been reported in Donegal so far this year. Ethna Diver and I saw one on our visit to Tory on June 03, which was the only PL record during this period. The offshore islands and hilltops are often the first to register PLs in Donegal.

P – this species is one of the first butterflies of the year to be seen in Donegal on its emergence from hibernation. By May numbers are reducing, however a wide scattering of faded individuals were still appearing during the period with among the latest, one seen by Frank Smyth at Rowantreehill, nr Ballyshannon on June 04 and two seen on Aranmore by Ethna Diver and myself on June 05.

RA – a small trickle of RA appeared in Donegal during May. The latest record was on June 06, when a single RA was seen by George McDermott nectaring on Cotoneaster at Drumaville, nr Malin in north Inishowen.

RWW (Real's Wood White) – the RWW is local but widespread and in places is a plentiful butterfly in south Donegal.

However North of the Blue Stack Mts it is widespread but appears to be very rare with the colony behind Ards Forest the only site in north Donegal, where the RWW can reliably be seen. Although the species has now been recorded on twenty-three 10km sqs, all the northern sites except for Ards are of single specimens. This year two additional sqs were added – B70 and B80, the latter seen by me on May 30 in habitat, rich in Bird’sfoot Trefoil but apparently lacking Meadow Vetchling. Other new sites for RWW this year included at Kilmacreddan (G77), Mulnamin (G79), Glenmacannive (G89), and Magheracar (G85). RWW still probably remains under-recorded in Donegal due to confusion with other small whites.

SB – the SB remains plentiful in most of its coastal sites in south and west Donegal. Numbers were beginning to decrease in the later part of the period. Perhaps the strangest site for SB in Donegal is at the low metamorphic limestone cliffs at the back of the pier at Portnoo (G69/79), which are north-facing. Indeed on May 30 at this Portnoo site Maurice Simms and I witnessed a SB flying around a few isolated plants of Kidney Vetch some distance down a sheltered sheer coastal cliff, which also had Bird’sfoot Trefoil and Sea Pinks upon which nectared GH and WB.

SC – The SC is a widespread but local butterfly in Donegal, with large numbers rare, except at some favoured warm dune sites. The SC continued to appear widely in ones and twos throughout the period.

SH – SH is a widespread and often common butterfly in much of Donegal, occurring in both dry and damp locations. Indeed it can be seen flying together with the LH at sites such as at the Poisoned Glen and Lough Barra (B91) and Rowantreehill (G95). In the warmest sites in south Donegal it appears around mid-May but in cooler damper sites may not show until well into June. Many dozens were to be seen at St John’s Point (G76) as on June 04 when Ian McCambridge and I saw close on a hundred SH scattered over an area of less than 0.5 ha.

SmT – the SmT overwintered generation was almost over by late May. Indeed pristine specimens seen on Cruit Island on May 23 would appear to have been newly emerged from this year’s pupae. Con O’Donnell reported a faded SmT on June 01 at Gweedore (G82) and a fresh specimen the same day at Glentornan (B81). On May 28 Ethna Diver and I saw a site where SmT larvae had already pupated nr Bundoran and Frank Smyth reports the same from near Rowantreehill. Many young SmT larvae were seen widely, especially in south Donegal.

SW – as with the RWW probably is under-recorded. Frank Smyth recorded 7 SW at Carrickfad, nr Rossnowlagh on June 04 along the area of south Donegal Bay where the SW usually is common around this time of year. Ethna Diver and I identified a SW on Tory on June 03 and which is a new 10km sq record for B84.

SpW - small numbers of SpW were widely recorded during the period but numbers were usually in ones

WB – the WB continued to be widespread and locally numerous in its coastal strongholds along the west coast of Donegal. There are no signs of any decrease in WB in Donegal and it remains a common butterfly in its favoured habitat of dry flowery rocky ground. It continues as one of the common butterflies on Aranmore but none were seen on Tory.