I have mentioned in my previous couple of posts how things
have changed for Speckled Woods and Wall Browns over the last five years in
East Lothian. These two species have both extended their range northwards and
only arrived in the county within the last ten years.
I have been comparing 2017 figures with the previous four
years for all of the species occurring here and it is apparent that
some species have done very much better than others. I had my own perceptions
of how well each species had done, but it is interesting to see the combined
records from all of the volunteers.
The problem with doing a comparison like this is that each
year I have had more people send in their records to me, so you would expect to see more
records for each species. However, this hasn't been the case with many of them.
For instance, when looking at the Large White, Small White
and Green-veined White, there is a marked difference in how they did in 2017.
These three species that share very similar life cycles, with a spring
generation and a summer generation. It is odd that the Small White apparently
had a poor second generation, but the other two species did as well as ever.
In the graphs below the red line shows the 2017 records. The blue line is the average figure for the last five years.
I had thought that there had been fewer than normal Peacocks around in 2017, but when I looked at
the records received they appeared to have done better than normal.
This is in contrast with the Small Tortoiseshell, which
seemed to have a very poor year. I was surprised to see that there were more
records than I expected.
2017 was an amazing year for Red Admirals. They have been increasing in numbers over the last few years and it is thought this is because they are now able to survive the winter in the UK. Whether this is because the temperatures are warmer than in previous years, or if they have adapted to our climate is unknown. It will be interesting to see how the very cold winter we are experiencing just now will impact on their numbers later this year.
What I find most interesting is that the species, such as
the Wall Brown, Speckled Wood and Small Skipper, which have all moved into East
Lothian in the last nine or ten years, have continued to increase in numbers,
while some long-established species have been declining.
Most people who submit butterfly records to me it was felt that 2017 was a poor year for butterflies. As I mentioned previously we may be showing a falsely rosy picture of how the butterflies did, as we had more people sending in records. However, the differences between the species is valid.
It will be interesting to see what happens in the years to
come.
This is very sad news. Butterflies are such an important of the ecosystem, and global warming is our responsibility. At least some species did better than others.
ReplyDeleteHi Maria, I am hoping that 2017 was just a blip and that this year may be better. I noticed that 2014 was a very good year and the three summers since have been rather dull. It would be so nice to have a decent year now that we have some good data to compare it with.
DeleteHi Nick, i have not been coming here coz it is still winter so you wont be posting. Am so sorry. Nevertheless, i still always envy the quality of your photos. I still don't know how to do like that in your heading, lols.
ReplyDeleteWhat you are doing as in compiling your data is very good, but maybe we are still very far from doing so. I don't know if we also need that here, as there are more pressing things to do first. By the way, that first white resembles our Psyche, Leptosia nina, which flies so near the ground with slow fluttering, yet very difficult to photograph as it never really stops that much until the morning when air is still laden with high RH.
Thank you Andrea. I can only credit my Panasonic Lumix FZ150. I usually set it to macro and leave everything else on Auto. Sometimes I adjust the exposure, but usually there isn't time to change the settings. The Orange Tip in the heading picture was on a single Forget-me-not so the background was quite distant. It is also a species that stops flying as soon as the sun goes behind a cloud. So nice and easy, unlike your Psyche!
DeleteWOW Nick very interesting graphs, congrats!
ReplyDeleteThis seems like a full time job you've taken up!
And great photos to illustrate it
All the best and enjoy your sunday :)
Thank you Noushka. It is almost a full time job, but it is something I enjoy and my interest is leading to meeting more interested people and getting involved with exciting projects.
DeleteSuch lovely butterflies.
ReplyDeleteAre there rules for recording sightings? I always wonder that about bird counts too. How does one know they are not counting the same one over and over?
Interesting to read what you have said about photographing them. I find they flutter away as soon as I get near. I wonder if there is an insight chart somewhere about how to photograph each type.
Hi Tammie Lee, there are recognised methods of monitoring butterflies such as transects. For the ad hoc records, it is a case of counting what you see, but taking account of the likelihood of counting the same butterfly twice. Easy if you are walking in a straight line, or looking at a buddleia bush, but less easy if you are working in the garden. If I am not sure, I err on the low side and will not count a butterfly that could be a repeat.
DeleteTammie Lee. Regarding photography, I find it best to understand the species. Some male butterflies have favourite perches they return to. Others have particular species o flowers they like to feed from or lay eggs on. A good butterfly book will describe these behaviours.
DeleteThank you for sharing how to count butterflies. I am always curious about that, and also counting birds, which I may try some time.
DeleteYes, maybe a butterfly book is what is next for me. It makes so much sense what you say, if you understand them it could be easier to capture their portraits.
Thank you.
Hello Nick!:) So sorry for my delay in getting back to you, and many thanks for your visit. Lets hope the Small White does better this year, and that the cold wintery weather will not mean a decline in numbers of the beautiful Red Admiral this year. The heavy snow falls you have experienced, and being snowed in for a few days, can't have been much fun, and could have had a devastating affect on the wildlife, I hope not, and all in all, I think the graphs for last year are encouraging! It will be interesting to discover what happens this year.
ReplyDeleteI'm hoping to attract more butterflies this year by replacing my old Lavender, Buddleia, and Lantana, with new young plants, and by planting more Sweet William, and Yarrow, where I have seen the Small Tortoiseshell and a host of colourful butterflies feeding before. All the best!:)
Good luck with your new planting, Sonjia. I hope you are successful in attracting butterflies. I have been planting many new plants at our property in the Scottish Borders. It is great to be able to do something for nature.
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