Canklow

Site Details: 

Walker : Steve Branch              Distance : 947m     Altitude 68m    Walk time 25 mins

This urban green space lies below Boston Castle and Urban Rotherham and the river Rother.  It is  bordered  to the east and south by  Canklow woods which is dominated by Oak and Birch is used by many dog walkers and for exercise, To teh west it is bordered by back gardens, 

It is largely unmanaged and the somewhat dry, acidic unimproved grassalnd with a good variety of species 

Sections:

S1 to S3 at the bottom of this shallow bank bordering houses and their gardens and  tends to have the highest counts  particularly of Gatekeeper, Large Skipper and Ringlets  Flowering plants attract the Vanessids, S4 sees more birds foot trefoil and subsequently Common Blue  and Small and Easses Skipper. S5 loops into scrubby woodland  and Speckled woods appear alongside Ringlet in the shade. S6 and S& skirt the northern perimeter of scrubb and small trees and Meadow browns begin to be seen  in more numbers. S8 and S9 follow down teh slope along teh southern boundary and and teh small skippers  along with meadow browns  and gatekeepr predominate, 

Results 2024:

Countywide, after a warm winter  April turned  cold, very wet and dull and everything just about stopped and it was near impossible to transect walk all month. By May  there were already  losses  among our spring species being  down a third in numbers.  June brought Arctic winds, a complete reversal of  the Hot June of 2023 when nine  species reached all time highs here and across the UK.  For the  first two weeks of this June  temperatures  were 8’C cooler than  in 2023 around  a frigid  9’C  with  only 5 good days of sun at the end of the month.  The  first three weeks of July had  the same theme of  cool and damp with 5 warm sunny days at the end. Transect walking for many  was very difficult.  The  persistence of the cold and damp over such a long period had a devastating effect with numerically two thirds of our butterflies in the critical later stages of their development; mortality was very high. It was  also one of the longest June  ‘Lulls’  lasting from late May to the beginning of July. When the main flight  season did arrive it  was  slow to build up  and there was no usual peak. Better weather in August helped  save the second generation and very unusually numbers actually went up at the start of September.

  Losers

        For many species it was a triple whammy after  the heat and droughts of the previous 2 years and  last July’s poor flight period this year made it a perfect storm. Overall, annual numbers were down 41% against the average and 45% down on last year.  Half our species were down more than 50% and a quarter down more  than 70%. The Lycaenids, Vannesids and the Fritillaries were amongst the worst affected. Many transect walkers did not see  a single Common Blue, Small Copper, Holly Blue, or Brown Argus until late into their 2nd broods..  Four of our long term declining species Common Blue, Small Heath, Small Skipper and Green-veined White  had  their worst year ever recorded. 

The Winners and less bad losers 

      Northern Brown Argus  had an exceptional year up near 50%  Other species bucking  the trend were Brimstone and Marbled White. The  damp  loving Ringlet on many limestone/dry sites  were up a half  while on most wet sites they fell by a half.  However if it wasn’t for Ringlet holding up the overall numerical losses, this year would have been significantly worse. It often happens when Meadow Brown has a very poor year, like this one, Ringlet does proportionally better, and vice versa in a warm year. 

It has all happened before… many times.    

It was our worst year since 2016 but  not nearly as bad as 2009  when numbers  were  down 50%.  2024 comes after a run of 6 relatively good years since 2018  along with  rapidly rising temperatures including 2 of our hottest summers which were followed by two of our best butterfly years in 2019 and 2023. It is  likely 2024 was a blip

Transect reports

Results 2023:

County wide 2023 results reflect  the 2022 and  2023 spring drought with Small Tortoiseshell and Peacock nearly halved for the second year against their 5 year average. Red Admiral arrived in force in July and took advantage of soft nettle growth of the rains and had their best year ever. Drought sensitive species on thin soils were badly hit,  particularly Dark -green Fritillary and Northern Brown Argus but also Ringlet, Green-viened White and Small Heath.  Less drought affected species along with the hottest June on record built even more on gains last year leading to Comma, Brimstone, Holly Blue and most Browns  having a fantastic year reaching all time highs. A increase of 9% overall was mostly due to sheer numbers of Meadow Browns and Gatekeepers ment 2023 nearly pipped 2014 as best year in modern times.  Most noticeable was the large differeces between mositure retaining mineral soils of the valleys and thin, dry limestone or sandy soils. A large number of damp grassland, hedgerow and woodland  dominated sites benefitted hugely with 3 sites seeing more than 50% increase . A smaller number of thin, chalky, sandy or craggy sites did badly some down up to 25%.

Canklow in many ways reflect the county trends for this a  sandy site but the main influence on numbers were the loss of the skippers particularly Large  but also Ringlet and small heath all of whom are damp lovers.  All the vanessid species did better agaianst county trend  as did all the whites except  GV white and Oraneg tip that prefer damp.  The real winners were Meadowm Brown and Gatekeeper which was universal across teh county. Losses equalled gains.