Glanville Fritillary - Favourite Photo of 2018

[MrSp0ck]

Trois Vaux
County : Channel Isles(Alderney)
Gridref : WA556062
Year established : 2008
Number of sections : 6

i cant seem to find it on the pull down sites list at UKBMS, but in the past it was not in its aphabetical order position, and there was a New Trois Vaux entry, cant find that either at the moment.

looking at the pictures on a google search its just like the thrift cliffs habitat it likes on the coast. its in a bay in the south west of the island and the gannet colony islands are to the west the rough point is 49.7053941,-2.2329873,17z

[bugboy]

The Channel Islands Transect data for 2017 is on this link

http://www.ukbms.org/SpeciesListbyYear? ... &year=2017

which shows the bulk of the monitored population is there these days. Thats what bumped the total up in the total count.

Thanks, Martin. Do you happen to know where in the CI "Trois Vaux" is? This population is largely overlooked in all our discussions of this species, yet seems to be the best of the lot in the UK and islands (at least it was in 2017 by a long way).

Dave

There's a Trois Vaux Bay on the western tip of Alderney, presumably this is the spot.

[Matsukaze]

The Normandy/Channel Islands butterfly atlas shows the fritillary as occurring on all the main islands as well as right around the coast of the Cotentin peninsula. Whether the butterflies regularly fly between the islands or between the islands and the mainland I do not know - I have my doubts as they seem to find the Straits of Dover too far for them.

I note from the BMS website linked to earlier that none of the west coast Isle of Wight colonies are monitored by transect (at least, there are no results for them appearing there).

[Matsukaze]

Broadening out a bit more, does anyone know the current status of the Glanville Fritillary in the Channel Islands? In fact, I recall hardly ever seeing any mention of butterflies here (or on the BC website) from this area on the doorstep of northern France. I'm sure I've read somewhere about Glanville colonies, as well as Large Tortoiseshell and Continental Swallowtail.

Dave

There have been a few records of Map on Jersey in the last decade or so, though there is no evidence I am aware of that it is anything other than a vagrant.

I photographed the ovipositing Swallowtail in summer 2017 near the tip of Pointe de Grouin in Brittany, pretty much due south of Jersey. Its next step was presumably to head out to sea northwards, in company with numerous Painted Ladies.

[MrSp0ck]

With the loss of the Sand Point Glanvilles, there are too few UK Glanville Transect sites, HB and Mottistone were in sync with eachother for about 5 years, a few butterflies either way, and will probably sync up again this year. The other IOW UKBMS sites dont seem to have been monitored for a few years now. The distance between the IOW and the UK is ok for GF butterflies to fly between, and probably the CIs and France. They seem to be very mobile on the land, and had moved some distance from Wrecclesham and hutchinsons before the declines due to the bad weather in February/March in the last few years. The 2018 UKBMS Data seems to go up in March on the links, and the bug where you could see it early has been fixed, [thanks to me] correcting a lot of the data errors before they should have been pointed out. The Black Hairstreak in Sussex was an error at that time, it was not in the area of Ditchling Common thankfully.

The 2018 Glanville data todate shows the following

Glanville Fritillary 0 0 1 3 16 29 36 61 94 39 33 14 6 2 0 0 0 0 0 0 0 0 = 334

with Marsh Fritillary on = 1312 and Heath Fritillary on = 1780

So Glanvilles are the rarest of the 3. How many of the 334 are on IOW or the mainland still needs to be seen.

[MrSp0ck]

Here is a breakdown of the Transect 2018 Glanvilles
CI SItes
Bonne Terre = 2 in weeks 12&13
Longis = 70 in weeks 9-16
Trois Vaux = 93 in weeks 9-16
Blaye =35 in weeks 11-17 [36 seen on transect -1 in index]
Community Woodland =60 in weeks 9-17

Channel Islands =260
UK = 70
Total 330 the other 4 may be due to the indexing system, or on the smaller sites i havnt checked on the CI yet

UK Sites
Mottistone Down = 60 in weeks 8-12 [61 seen on the transect -1 in index]
Hutchinsons Bank = 7 in weeks 7-11 [we had 8 actual butterflies seen on Transect -1 in index]
Coombe Bottom & St Boniface Down (Ventnor) = 3 in weeks 9-11

It looks like it will be a better year at Hutchinsons Bank in 2019, the warm spell was when the larvae woke up, unlike 2018 when we had the beast from the east at the worst time, which affected the post hibernation larvae very bad.