...the first five months of 2015 were indeed rather poor, at least in my garden. The continued dire weather of the past 24 hours has prompted me to compare the results here at Westcott, Bucks with those for the first five months of last year. To be more meaningful I should perhaps have gone back over ten years (thereby risking boring you all to death!) but the differences shown here do serve to illustrate the point:
2014
|
Jan
|
Feb
|
Mar
|
Apr
|
May
|
Total
|
Individual moths seen
|
9
|
26
|
694
|
759
|
1037
|
2525
|
Species seen in month
|
6
|
11
|
29
|
60
|
133
| |
New species in month
|
6
|
9
|
21
|
41
|
96
|
173
|
2015
|
Jan
|
Feb
|
Mar
|
Apr
|
May
|
Total
|
Individual moths seen
|
8
|
30
|
414
|
578
|
454
|
1484
|
Species seen in month
|
5
|
10
|
24
|
46
|
99
| |
New species in month
|
5
|
8
|
18
|
32
|
73
|
136
|
Effort was comparable over the two years (I ran the trap virtually every night). By 31st May 2014 a total of 2525 moths of 173 species (112 macro, 61 micro) had been recorded while the figures for the same period this year were 1484 moths of 136 species (94 macro, 42 micro) so a reduction of more than 1000 individual moths. The figures for this May were particularly poor, showing a decline over April whereas one would normally expect a month-on-month increase as we head towards summer.
Dave Wilton
The observation that there are whole days when nobody has anything to post - at the end of May - is a good indicator, I think, of the poor state of affairs.
ReplyDeleteInsects generally have a capacity for rapid recovery because of the large numbers of progeny and all this may have little lasting effect, except with low density or small, isolated populations. In those situations some populations may be below the point of recovery.
Andy King.
My garden has actually been better this year than last, although my totals are orders of magnitude below Mr Wilton's! 2013 was way better than both though and 2012 with the warm March had silly numbers of Orthosia species, although there was virtually nothing for the rest of that spring with the rain! That's as far back as I go.
ReplyDeleteDave Morris
I did a similar garden comparison to the end of March but looking back over ten years and found that, yes, 2015 wasn't one of the best but by that time it certainly wasn't bottom of the league table (2006, 2008, 2009 & 2013 had all produced fewer moths). For example, looking at macros only, by 31st March 2006 I'd recorded 60 moths of 15 species, by 31st March 2013 I'd seen only 22 moths of 9 species (!!) whereas by 31st March 2015 the figures were 402 moths of 22 species. 2006 went on to be one of the best years in recent memory and things recovered in each of the other years too, so there's still hope...
DeleteThere are always going to be variations from site to site but the really noticeable thing about 2015 here is the significant decline in overall numbers during May which I think many other people have noticed too.