Managed by Forestry England  and  YWT

Site Details 

Recorders:  Steve and Penny Relf         Length 2867m    Walk Time 1 hour      Altitude 18m 

Allerthorpe Common lies on river and lake sands, which were deposited during the last glacial period 10,000 years ago. The soils are acidic  and support a surprising range of habitats for such a small pocket of lowland heath - wet heath, dry heath, acid grassland, woodland, scrub and open water. Ling heather, tormentil, sheep's fescue and wavy hair-grass grow on the drier areas of the site. Cross-leaved heath and purple moor grass grow in the damper areas. Patches of gorse  and areas of mature birch and willow woodland. The Transect route covers a good many of these habitats


Section 1  in the wood is prefered by Brimstone and  Speckled wood . Gatekeeper, Large Skippers and Meadow Browns with Peacock prefer prefer  S4 +S5 while  Ringlets very much favour S6 

The section counts are shown opposite

2023 Results

County wide 2023 results reflect the worse affects of the 2022 and  2023 spring drought with Small Tortoiseshell and peacock nearly halved against their 5 year average. Red Admiral arriving in force in July took advantage of soft nettle growth of teh 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, Holly Blue and  most Browns  having a fantastic year reaching all time highs. A increase of 9% ioverall 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%.

2023 results  reflect the county trends  as a woodland site with overall gains  higher than the county average , The biggest driver here was Brimstone and Allerthorpe contains the counties strongets colony but similar percentage increases were seen across the county .  Small skipper numbers  here had a massive increase although there was alot of variation over the county.  There are sites nearby with similar big increases while this species is known to respond  positively to dry warm conditions.   Comma here hasnt seen the boom seen elsewhere and the browns follow the county pattern,

Transect reports

2022 Results

The Skippers follow the county trend downwards as do the whites with small  white being the exception with a large increase over last year.  In this largely woodland site Brimstone is exceptionaly abundant and third most common species and had another good year simalar to last.  Other species generally follow the county trend with teh Vannesids  overwintering well but , other than Comma, halving with the second generation largely absent , while, cCmma had a really good summer brood. Speckled Wood as elsewhere were abundant and well up on last year.  The browns followed almost exactly other county sites with Ringlet well up and Meadow Brown a tad down.  Overall a bit down on last year which was teh case in other woodland sites nearby mostly because of the Vanessids collapse.