What an April!

[robpartridge]

Here in the east at least, April is drawing to a close in true drought-busting style. Would anyone like to venture any thoughts as to how the weather this month is likely to affect the rest of the season, or even the prospects next year for species like the Orange-tip? Locally, the spring species seem to have hardly had an opportunity to mate and lay eggs so far. And if May is as cold as some forecasters are suggesting?

Rob Partridge

[robpartridge]

Or I could just have read 'Rain'!

Still, interesting that that post started on April 10th and it is still pouring here in Cambs tonight. This must be having some serious effects on any butterflies that emerged any time since the first few days of the month.

Rob

[Padfield]

Doubtless the weather will have some impact and doubtless there will have been individual tragedies - individual butterflies who lived and died unproductively. But I don't think it is necessarily as gloomy as all that.

To start with, the normal flight period for orange tips in the south of England is April to early July. I have seen orange tips in mid-July in the Chilterns. I don't see any reason why a wet April should actually kill the butterflies that would fly in May and June in a normal year. In fact, individual butterflies may live longer when they don't fly, especially if it is cold. Some will be biding their time in the chrysalis while others will be bunkered down somewhere. The May orange tips will fly - or, if May is a wash-out too, the June orange tips will fly. If April, May and June are all wash-outs, then I agree - things might look grim for Anthocharis cardamines.

The rain should guarantee lush vegetation for when the orange tips do get a chance to breed, leading to fat, healthy caterpillars ready for a bumper season next year...

Guy

[David M]

I'm glad that someone else has started this thread, for I was contemplating doing so myself, though this would have contributed still further to the sense of bereavement I've felt throughout much of this month.

To put things into stark terms, last April I recorded the following butterflies as 'firsts' in 2011:

Green Veined White - 8 April, Sale, Cheshire
Orange Tip - 8 April, Sale, Cheshire
Speckled Wood - 8 April, Sale, Cheshire
Holly Blue - 9 April, Swansea Vale
Large White - 9 April, Swansea Vale
Red Admiral - 10 April, Cwm Clydach, Swansea
Small White - 10 April, Cwm Clydach, Swansea
Painted Lady - 20 April, Merthyr Mawr, nr.Bridgend
Small Copper - 20 April, Merthyr Mawr, nr. Bridgend
Grizzled Skipper - 20 April, Merthyr Mawr, nr. Bridgend
Pearl Bordered Fritillary - 22 April, Haugh Wood, Herefordshire
Wood White - 22 April, Haugh Wood, Herefordshire
Green Hairstreak - 23 April, Prestbury Hill, nr. Cheltenham
Duke of Burgundy - 23 April, Prestbury Hill, nr. Cheltenham
Dingy Skipper - 23 April, Prestbury Hill, nr. Cheltenham
Small Blue - 25 April, Kenfig Dunes, nr. Porthcawl
Small Heath - 25 April, Kenfig Dunes, nr.Porthcawl
Wall Brown - 25 April, Kenfig Dunes, nr.Porthcawl
Common Blue - 29 April, Swansea Vale

That's 19 different species seen for the first time in that year during April.

This year it's just one - Orange Tip, seen on 1st April before this deluge began.

Whilst I appreciate that April 2011 was abnormally warm and sunny, I couldn't have ever imagined that April 2012 would be so dreadful in comparison. Since Good Friday (6th April), there hasn't been a single day in south Wales when the temperature has been in the sixties. Worse still, it has rained and rained and rained and rained.....

I accept that rainfall is necessary, but for it to obliterate all but the most momentary opportunities for spring buttterflies to fly is a worrying event. I assume that larvae and pupae have some inbuilt means of delaying their growth/emergence in tandem with conditions, but what of those imagos that were already on the wing? Surely an Orange Tip can't artificially extend its own life by two weeks because climatic conditions are so atrocious?

I guess we'll have to wait and see, and in the meantime if things get markedly better over the next week or so we'll perhaps be back on here pontificating on what we were all so concerned about in the first place.

New month, new broom (hopefully).

May simply CAN'T be so appalling as April. If it is, then I really WILL start to worry.

[robpartridge]

That is a truly startling difference between two Aprils, and congratulations on the record-keepin, which puts mine to shame.

At 10.20 am it is still raining here in Cambs; about 16 hours of more or less continuous rain, easterly winds and low temperatures. I take the earlier point that Orange-tips often have an extended emergence, and that a good May and June will enable them to make up some lost ground. I wonder what happens to over-wintered Small Tortoiseshells and Peacocks in these conditions, though. They can probably go back into some sort of torpor until things brighten up but they didn't get many feeding opportunities here. Any early batches of eggs or hatched caterpillars will be tested by these conditions, won't they? I agree with Larkin - "Things are tougher than we are" - and they certainly need to be at the moment!

Rob

[Mark Tutton]

Well as I look out of the window on the sunny south cost the rain is torrential and has been for twelve hours or more. So much for getting out to look for PBF as I had hoped Perhaps just as worrying are the gale force northerly winds that we have had over night. Combined with the rain it has brought down large amounts of branches, buds and young leaves from the oaks and limes close by. I am presuming that this could also destroy numbers of Purple Hairsteak larvae and the like which will find themselves on the ground
Unbelievably the rain has got even heavier as I type this!!!

Mark

[David M]

I wonder what happens to over-wintered Small Tortoiseshells and Peacocks in these conditions, though. They can probably go back into some sort of torpor until things brighten up but they didn't get many feeding opportunities here.

I wouldn't worry about those species that overwintered as adults. They emerged very early this year and will probably have done most of their essential tasks prior to this dreadful spell. Even had the weather remained mild and sunny, I doubt many of us would still be seeing significant numbers of Peacocks, Small Tortoiseshells and Commas as they'd already been on the wing for a month.

[robpartridge]

Fair points, and as species these two seem to be amongst the more robust. But I suspect that if numbers are low in the summer, some of us will be blaming that terrible April.

After 24 hours, it has now stopped raining in Cambs, and the sun has appeared; within minutes a bumblebee was visiting the lilac blossom,

Rob

[David M]

After 24 hours, it has now stopped raining in Cambs, and the sun has appeared; within minutes a bumblebee was visiting the lilac blossom

That's not surprising. It probably hasn't had a drink of nectar for the best part of a week!

[Reverdin]

I fear more for the Nymphalids than the Pierids, weather up here same as elsewhere, the overwinterers were out in force last 2 weeks of March.... and I haven't seen one since, but the nettles were still "winter style" when they were about, so ?? any eggs. now the nettles are flourishing. The rain has kept the butterflies still, but even when the sun has broken through, the temperature has been below the hardiest flight capability... yeeeesh.. not a great combination I think.

[essexbuzzard]

Yes,i fear for the Nymphalids. I find it hard to beleive that they can feed, mate and lay eggs within a week or two of good weather in March since their emergance,and even if they could,neither nectar or caterpillar plants were ready,as far as i could tell. And i've yet to find any brimstone eggs on the local buckthorns,suggesting that none have been laid yet. Last year they were peppered with eggs by early April .Given a good year on two,they will bounce back,but i fear not this year.

[robpartridge]

Well...purely in the interests of science, I rearranged work matters today so that I could get out into the sunshine, just to confirm that all butterflies had been wiped out by the deluge. Along The Rushway footpath, a couple of hundred metres from my home, in the lee of a mature hedgerow, I counted the following between 1300 and 1430, in about 250 metres of field margin:

Peacock - a minimum of 15, all behaving like males on territory
Whites - at least 25, including 3 Large, 4 Small, 6 Green-veined and a male Orange-tip
Speckled Wood, female
Brimstone, male.

Clearly these did not all emerge early this morning; some of the Green-veined were well-worn. According to my records, at least a week has passed since there were any suitable flying conditions, so these were perhaps at least that old. So things really are tougher than we are.

I took a picture of a Peacock enjoying the mud and of a Large White feeding on rape flowers but haven't worked out how to put these into a post yet,

Rob