How are numbers doing?

[NickMorgan]

I fear that the weather has really taken it toll on numbers now. I kept hoping that after a period of rain or poor weather the butterflies would bounce back. However, today was the third day of reasonable weather we have had (relatively speaking!!). We had sun most of the day and the temperature was probably around 15 degrees. There was a fairly strong easterly wind, though. I did my transect at lunch time, but probably only saw about half the number of butterflies I would have expected (reasonable number of species, but just not very many of them). The Warden at the local nature reserve reported the same.
This afternoon I walked along our coastal path to inspect a flooding issue and in five kilometres I only saw one Green-veined White.
Two days ago I checked out a choice little disused quarry with a local enthusiast. She pointed me to areas where normally she says she sees lots of Small Coppers or Common Blues and we only saw two of each. Strangely we saw another five species, but only one of each of them.
I notice that I don't see many butterflies when I am driving around, either.
Is this a trend all over the country this year?

[David M]

It's bad all over. Like you, I'm seeing no butterflies at all whilst driving around. It's almost as though they've been lost forever.

It'll take a fair period of good weather to turn things round, but right now that's not happening, and if it doesn't happen before the middle of July, then virtually every British species will have had its prime adult flight period.

One can only hope the earlier stages are faring better.

[IAC]

Hi chaps,
With all due respect, you wont see many butterflies whilst driving around...I have always found more whilst on foot.

Iain.

[Gruditch]

My transect has been dismal. The avarage total butterfly numbers for the first 10 weeks is 452, this year its just 199.


Regards Gruditch

[Pauline]

The only butterfly which seems to be positively thriving is the Small Heath. Why does this seem to be an exception? Any ideas?

[Neil Hulme]

Hi Pauline,
Yes, Small Heath is doing nicely, and I would also add Dingy Skipper (at least in Sussex). Otherwise it's a poor show.
Neil

[P.J.Underwood]

I think the Wood Whites in Botany Bay are doing well.Fairly strong early on,and still some left of the first brood when the sun is out.Could be a good emergence of the second brood.
P.J.U.

[NickMorgan]

Yes, Small Heath numbers seem to be at about their normal level. I guess that it must be something to do with the weather just as they are about to, and just after they have emerged.

[Willrow]

Yes, Small Heath and Dingy Skipper are both doing relatively well, I would add to these two species Wood White and more recently Speckled Wood albeit after a rather worrying start to their season, co-incidentally both these woodland species have the benefit of at least some partial shelter from the heavy rain, however the high winds have also added greatly to the general battering our poor butterflies have and still are having, the weather forecast for the remainder of June and early July is not exactly favourable either, it will be very interesting to see what effect on emergence there is for the other woodland species White Admiral, Purple Emperor and Silver-washed Fritillary lets hope they at least have as reasonable a season as the other woodlanders mentioned earlier.

Bill

[Neil Freeman]

Earlier this year I observed an Orange tip in my garden roost in a quite exposed position and remain there for 3 days and nights during some pretty horrible weather including heavy rain.
At the end of the three days I was amazed to see him fly off, within minutes of the sun appearing, looking and acting like he was recently emerged.

This gave me an appreciation of how hardy some of our butterflies really are. The real problem I believe is the effect that the weather has on the development of larvae and Pupae.

I also remember last year people being concerned about the effects of the drought in some parts of the county with foodplants being dessicated in some areas. If butterfly numbers are down this year, how much will it be the result of this years weather when, in some cases at least, the drought of last year may well have played a significant part.

Lots of questions and no simple answers, lets just hope that the year does not bring too much bad news.

Neil F.

[hilary]

I have found it hard to find the right time for transects - to cold, windy, wet or overcast. Even on the better days, on the colder site there is a fraction of what there usually is, even the 'Common' Blue has not been seen.
It seems some birds like Blue and Great Tits have found it hard this year - probably because, some think, the moth caterpillars were in short supply. I noticed them and Sparrows and Hedge sparrows searching the garden and getting very near to me, presumably not getting tamer, just more intent on searching. Besides feeling for the birds, it also seems that moths and butterfly larva may be getting double trouble this year.

[The Annoying Czech]

My transectual numbers in Central Europe are following:

May 2 - 44 ex. (winning species: Map)
May 18 - 133 ex. (winning species: Small Heath)
May 31 - 111 ex. (winning species: Common Blue)
June 15 - 76 ex. (winning species: Lesser Marbled Fritillary)

But I have a colleague with app. ten times lower numbers (having transect right in the city), whereas another one, having extensive pastures, will probably have the numbers higher, expecially number of species.

I have to say I'm walking through the preserved biotopes, 1 km long walk at the most, around the bog commies didn't have money to destroy in 50s - 80s

I'm used to walk in the morning, ca till 11 a. m.

[Mark Senior]

I have to say that everyone is being a bit too gloom and doom .
Firstly we are in what is traditionally the June lull between the spring butterflies and the summer butterflies .
The erratic seasons in recent years have blurred this somewhat .
Secondly bad weather certainly affects the numbers of butterflies seen but partly because many watchers do
not go out and look for butterflies because of the poor weather .
A couple of years ago we had a good summer and we were all remarking how the numbers of Silver Washed Frits
for example were well up " because of the good weather " . As I pointed out at the time , the butterflies were
the result of eggs laid in the previous year which had been supposed to have been a terrible year because of a bad
summer for several years in a row .
There is no doubt that some species are not doing well , the Common Blue had a bad year last year for some unknown
reason and with the poor weather this year so far this seems to have continued .
Butterfly numbers are dependent on many complex factors which we do not fully understand and when numbers of a
particular species are down , we usually do not know whether that is down
a) too few eggs laid
b) insufficient food plant
c) predation of larva and/or pupa
d) effect of weather on any of the stages
e) effect of disease on any stages of the development
f) etc anything else I have forgotten to mention .

[LauraS56]

Hi chaps,
With all due respect, you wont see many butterflies whilst driving around...I have always found more whilst on foot.

Iain.

Quite a lot of my casual records are drive-by sightings. Depends where you drive, I guess. On country roads with uncut verges, you can get quite a few in most years.

[m_galathea]

Quite a lot of my casual records are drive-by sightings. Depends where you drive, I guess. On country roads with uncut verges, you can get quite a few in most years.

Isn't it rather sad how removed man has become from nature? Has butterfly watching become something which revolves around counting numbers only?

I'm with Mark on this one. Most of the butterflies are still there, they are just much more difficult to observe when the weather is bad. A point I would add is that it doesn't require a very long break in the weather for butterflies to mate and lay their eggs.

In conclusion, get outside, get some fresh air and enjoy Britain's fantastic butterflies!

Alex

[NickMorgan]

Well, I don't know. I spend quite a bit of time outside with my work and I walk the dog twice a day. There have been far more days when I have seen no butterflies this year since the end of March than days when I have seen butterflies.
My original point is that numbers are down on my transect and those of the countryside rangers here, so I think that the number of butterflies is genuinely down this year. I can also take a pretty good guess why!!!

[Gruditch]

There have been far more days when I have seen no butterflies this year since the end of March than days when I have seen butterflies.

Agreed, even on fine days.

Most of the butterflies are still there, they are just much more difficult to observe when the weather is bad.

Possibly, the average number of recording on my watch is down by over 50% but on the only perfect week for recording this year, I found that numbers were still down, but only by 25%

We can only record what we see, and speaking to others involved in the BMS, this Spring could be one of the worst ever. Lets hope things pick up.

Regards Gruditch

[m_galathea]

Possibly, the average number of recording on my watch is down by over 50% but on the only perfect week for recording this year, I found that numbers were still down, but only by 25%

That is interesting, and it is good to know that the recorded number was not so bad during good conditions.

Do you think there is the chance that in a season with a high percentage of bad weather, that the recorded numbers of butterflies could be down because they get things done with quickly so to speak (ie mate, lay eggs and die)? This could mean that there is still a large population of butterflies in a given area, it's just that they are missed in bad weather (for obvious reasons) and then missed during the good spells because their adult life was so short. This may go some way to explain the phenomenon that Mark described:

A couple of years ago we had a good summer and we were all remarking how the numbers of Silver Washed Frits
for example were well up " because of the good weather " . As I pointed out at the time , the butterflies were
the result of eggs laid in the previous year which had been supposed to have been a terrible year because of a bad
summer for several years in a row .

That's my theory at least.

Alex

[Gruditch]

Do you think there is the chance that in a season with a high percentage of bad weather, that the recorded numbers of butterflies could be down because they get things done with quickly so to speak (ie mate, lay eggs and die)?

No, I would expect that if an individual butterfly has a period of bad weather during its flight time, because of the inactive time, it would do the opposite, and live longer.

Regards Gruditch