Low Ox Pasture

Kilnsey Crag

 private property 

  Northern Brown Argus Transect

Sites Description: 

NB :This is a private site with no public access and permissions are required to survey

Recorders:       Paul Millard  + Andrew Rhodes   + Nyree& David  Fernley            Distance: 1422m                    Altitude 279m     Walk Time 50 mins

The transect is located above Kilnsey Crag and lies within the Malham and Arncliffe SSSI. The habitat comprises species rich calcareous grassland and is one of the larger Northern Brown Argus colonies in Wharfedale. Populations of BAP moth species Least Minor Photedes captiuncula, locally scarce Thyme Plume Merrifieldia leucodactyla and Cistus Forester Adscita geryon are also present. 


Results: 2023

County wide 2023 results reflect  the 2022 Heat and 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 moisiture 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%.

Low Ox  this year was a tad down on average but shows many similarities to the county-wide picture with the universal big fall in damp loving species namely Ringlet and Small Heath. However bucking the trends  most other species did better.  Surprising winners here which were big losers elsewhere are Dark-green Fritillary, Green viened White and Small Tortoiseshell.  Meadow Brown was double its 5 yr average which conteracted the 50% fall Northern Brown Argus. Although the general trend in overall numbers remains upwards but NBA is still downwards


Results: 2022

There has been a considerable increase in abundance on this site over the last 9 years nearly doubling over this period. Northern Brown Argus is holding its own although this last year  was a bit of a disaster possibly with the drought.  Small Skipper returned in numbers for the first time this year indicating there are some changes in the grassland habitat which are positive. In contrast Common Blue seems to going down while teh browns are going up  and teh steap rise iN meadow brown this year more than compensates  for a disaster in the Vanessids which has occured throughout teh county . Dark green fritillary is also rising quite fast even though it is well down this year.