Sunday 3 January 2021

The Butterflies of Northamptonshire in 2020

I think it goes without saying that 2020 was a difficult year for many reasons and the devestating impact of the Coronavirus pandemic put butterfly recording justifiably on hold for the majority of the Spring. Official transect walks were temporarily cancelled and non essential car journeys to nature reserves were not allowed. We did however receive quite a few records during the lockdown as people used their hour of daily exercise to explore the local countryside or urban parks and counted the butterflies they saw as they did so. Some lucky people live within walking distance of some of our key sites and they provided records from these areas too. By the end of May the rules restricting movement began to relax slightly and people could drive further and exercise for longer but the importance of social distancing of course meant some popular sites to see key butterfly species were quite rightly avoided by many. This of course means that, during the spring especially, we received much fewer records than usual so comparisons between yearly butterfly totals is tricky. This needs to be taken into consideration when analysing the localised spring butterfly species such as Dingy Skipper, Grizzled Skipper and Green Hairstreak and I have mentioned when I think this is a contributing factor in the butterfly statistics in the individual species accounts below. Weather wise spring started well with prolonged sunshine during April and May however clear skies lead to a few ground frosts. Daytime temperatures were regularly above 20c during mid May but high winds came in towards the end of the month leading to a fairly unsettled summer with average temperatures and a few sunny days interspersed with regular periods of strong wind. As for butterfly recording in the county we have so far received 29,499 records detailing the locations of 103,206 individual butterflies. The records used to compile this report come from the UKBMS transect walks, the Wider Countryside Butterfly Survey, the Big Butterfly Count and casual recording. There has been a big uptake in people using the iRecord website and the excellent iRecord Butterflies smartphone app to submit records which is something I would like to encourage. We were lucky enough to have two exciting projects continue in Northamptonshire during 2020 with Back From the Brink's Roots of Rockingham Project based in the Rockingham Forest area and Woodland Wings Project down in the south of the county along the Yardley Whittlewood Ridge. We sadly said goodbye to Woodland Wings officer Caz Temple at the end of the year as she left to pursue another project and I would like to thank her for her superb achievements in conserving and raising awareness of the butterflies in Bucknell, Hazelborough, Salcey Forest and Yardley Chase. Finally I would like to say a huge thank you to everyone who has taken the time to contribute records during this challenging year and lets hope there are better times ahead.

Dave James - Northamptonshire Butterfly Recorder

Northamptonshire Records 2020




Chequered Skipper 

Fortunately the lockdown restrictions were relaxed just in time for the Chequered Skippers flight period which allowed for some monitoring of the reintroduction area. For up to date news about this exciting project please see the Roots of Rockingham area of the Back from the Brink website naturebftb.co.uk/the-projects/roots-of-rockingham or see page 12 of the local Butterfly Conservation branch Autumn Newsletter (link posted at the bottom of the page)

Chequered Skipper, Rockingham Forest 2020

 

 Small, Essex and Large Skipper

Small and Essex Skippers didn't have a particularly good year with Small Skipper down by 23% and the Essex Skipper down by 65%. The Large Skipper however showed a slight increase with a 26% increase over the 4 year average. These grassland species could be encountered anywhere where there is suitable habitat. The first Small Skipper was seen on the 31st of May at Earls Barton gravel pits and the last ones were seen on the 23rd of August in Salcey Forest and near Kings Cliffe. The first Essex Skipper was recorded on the 21st June at Glapthorn Cow Pastures and the last was seen on the 6th of August in Yardley Chase. The first Large Skipper was seen on the 19th of May at Summer Leys Nature Reserve and the last ones were recorded on the 23rd of August at Kings Cliffe and Salcey Forest.

Large Skipper


Large Skipper Larva and Feeding Tube

An Essex Skipper hiding away in Salcey Forest


Small Skipper Distribution

Essex Skipper Distribution

Large Skipper Distribution

Dingy Skipper

The Dingy Skipper shows a 22% decrease from the 4 year average but as the majoroity of it's flight period was during lockdown that is to be expected. The locations with the highest numbers were Fermyn Country Park, Old Sulehey, Priors Hall, Ring Haw and Twywell Hills and Dales. The first was seen on the 16th of April at Twywell Hills and Dales and the last on the 9th of June at Weekley Hall Wood. However, 2020 was a particularly remarkable year for the Dingy Skipper in Northamptonshire with the rare occurence of a single second brood specimen discovered at Twywell Hills and Dales on the 26th of July which remained on site until the 2nd of August.

Dingy Skipper

Dingy Skipper Distribution
 

Grizzled Skipper

The Grizzled Skipper shares the same flight period as the Dingy Skipper so the lockdown rules in place during the marjority of it's time on the wing no doubt contributes to its 19% decrease from the 4 year average. The best places to see this species were Barford Meadow, Fermyn Country Park, Priors Hall and Twywell Hills and Dales. The first was seen on the 15th of April at Twywell Hills and Dales and the last was seen on the 26th of June also at Twywell Hills and Dales.

Grizzled Skipper

 
Grizzled Skipper Distribution

Wood White

The Wood White had a good year in the county and shows a 31% increase over the 4 year average. The discovery in 2019 of a small number of Wood Whites in the private Geddington Chase by Back from the Brink project officer Susannah O'Riordan led to further surveying in 2020 where 54 were recorded on a single day at the end of May. This firmly places Geddington Chase as a new entry on the list of stronghold sites for the species in the county. Even more excitingly butterflies from here made their way to nearby Harry's Park Wood where 2 were seen on the 31st of May and a Wood White even made it's way all the way to Fermyn Wood with 1 recorded on the 13th of June. Other key sites for the species were Bucknell Wood, Hazelborough Forest, Hazelborough Wood, Salcey Forest and the private sites of Sywell Wood and Yardley Chase. There was a large second brood observed in the county too with numbers reaching double figures in Yardley Chase. The first Wood White of the year was seen on the 2nd of May in Bucknell Wood and the last were recorded on the 11th of August in Bucknell Wood, Hazelborough Forest and Salcey Forest.

Wood White

Wood White Egg

Wood White Distribution

 

Clouded Yellow

The migrant Clouded Yellow had a better than average year with a 27% increase and a good spread of records around the county. By far the best place to see them was the area between Hanging Houghton and Cottesbrooke. They were first recorded at this location on the 1st of June and breeding no doubt took place as at the end of July they reappeared in the area and were regularly recorded on site throughout August and into September allowing a lot of local butterfly enthusiasts the opportunity to see them. The first of the year was recorded on the 17th of May in Daventry and the last was seen on the 1st of October in Yardley Chase.

Clouded Yellow


Clouded Yellow Distribution
 

Brimstone

The Brimstone showed a 17% increase during 2020 and could be seen all over the county. The highest numbers were recorded in Bucknell Wood, Hazelborough Forest, Summer Leys and Twywell Hills and Dales. The first of the year was seen on the 14th of February at West Lodge near Desborough and the last of the year was recorded on the 24th of November in a Brackley garden. 

Brimstone

Brimstone Distribution

 

Large, Small and Green-veined White

While the Green-veined White had an average year the Small and Large White saw quite a big increase in records. The Small White was 45% above the 4 year average and the Large White shows a 41% increase. All three species could be encountered anywhere in the county. The first Large White was seen on the 25th March in a garden in Wootton and the last was seen on the 10th of October in Barton Seagrave. The first Small White was seen on the 22nd of March in Duston and the last were seen on the 22nd October near Cogenhoe. The first Green-veined White was recorded on the 7th of April near Brackmills and the last was seen on the 11th of October in Upton Country Park.

Large White

Large White Distribution

Small White Distribution


Green-veined White Distribution

 

Orange-tip

The Orange-tip had a good year in the county with a 45% increase in the records. The flight period of this butterfly was during the lockdown and the big increase in people recording during daily local health walks along the roadside verges and countryside footpaths where this butterfly thrives could well have contributed to this increase. The first Orange-tip was seen on the 16th of March in Plumpton Wood and the last was seen on the 23rd of June in Sulby gardens.

Orange-tip

Orange-tip Distribution

 Green Hairstreak

The Green Hairstreak shows a 28% decrease from the 4 year average but once again this spring butterfly's flight period was predominately during the lockdown so this certainly could have contributed to the fewer records. The sites with the highest numbers were Collyweston Deeps, Fermyn Country Park and Twywell Hills and Dales. The first was seen on the 17th of April on the outskirts of Corby and the last was seen on the 31st of May at Collyweston Deeps.

Green Hairstreak

Green Hairstreak Distribution

 Purple Hairstreak

The Purple Hairstreak had a better than average year with a 12% increase in the records. They were recorded in nearly all the main woodlands with the highest numbers being seen in Bucknell Wood, Hazelborough Wood and Forest, Polebrook Airfield, Salcey Forest and Whistley Wood. The first was seen on the 15th of June near Pipewell and the last was seen on the 24th of August in Salcey Forest 

Purple Hairstreak

Purple Hairstreak Distribution

 White-letter Hairstreak

The White-letter Hairstreak shows a 39% decrease from the 4 year average and a 15% drop from the previous year. The weather was quite poor during it's flight period though which may have contributed to this drop in records. The sites that held the highest numbers were Brampton Ash, Bucknell Wood, Easton-on-the-hill and Finedon Pocket Park. The first was seen on the 12th of June at Upper Harlestone and the last was recorded on the 8th of August in a Badby garden.

White-letter Hairstreak

White-letter Hairstreak Distribution

 Black Hairstreak

The Black Hairstreak looked on course to have a good year but unfortunately poor weather hit just as they were reaching their peak. The first ones were recorded very early on the 27th of May (this beats the previous county record by one day) at Glapthorn Cow Pastures where several freshly emerged butterflies were seen. On the 1st of June 74 were recorded in a single day at Glapthorn and 23 were recorded in Salcey Forest on the 2nd of June which was the day before the inclement weather set in. After the wind and rain subsided a marked drop in numbers was seen. As well as the aforementioned Glapthorn Cow Pastures and Salcey Forest Black Hairstreaks were also found at Fermyn Woods Country Park, Lady and Souther Wood, Fineshade Wood, Southwick Wood, Polebrook Airfield and Yardley Chase. The last Black Hairstreaks of the year were seen on the 28th of June in Salcey Forest and Lady Wood.

Black Hairstreak

Black Hairstreak with pupal case

Black Hairstreak Distribution

 Small Copper

The Small Copper had a good year in the county and the records show a 46% increase above the 4 year average. The sites that held the most numbers were Harlestone Firs, Ravensthorpe Reservoir, Sywell Country Park and Twywell Hills and Dales. The first Small Copper was recorded on the 24th of April at Twywell Hills and Dales and the last was seen on the 22nd of October in Harlestone Firs.

Small Copper

Small Copper egg

Small Copper Distribution

Brown Argus

The Brown Argus shows a 52% decrease from the 4 year average and a 63% drop in records from the previous year. They were recorded in only single figures in all of it's locations with a peak count of just 9 on the 25th of July at Summer Leys Nature Reserve. The first was seen on the 5th of May at Twywell Hills and Dales and the last was seen on the 11th of October also at Twywell Hills and Dales.

Brown Argus

Brown Argus Distribution

 Common Blue

Similarly to the Brown Argus the Common Blue didn't have a good year either and shows a 45% decrease from the average. The highest count in a single day was 38 at Ring Haw on the 30th of July and they were also seen in fairly good numbers at Hollowell Reservoir, Great Morton Sale, Summer Leys Nature Reserve, Twywell Hills and Dales and Welford Quarry. The first of the year was seen on the 22nd of April in near Kettering and the last was seen on the 16th of October in Brackmills.

Common Blue

Common Blue Distribution

 Holly Blue

The Holly Blue had an average year in the county but the fact that this butterfly embraces urban environments as well as rural meant it also added a much welcome dash of colour during daily health walks in lockdown. The sites with the highest numbers were Abington Park, Eastfield Park in Northampton and Twywell Hills and Dales with good numbers also being seen in private gardens in Brackley, Cogenhoe and Kettering too. The first of the year was seen on the 3rd of April in Flore and the last of the year was seen on the 4th of September in the 20th of September in Kings Sutton.

Holly Blue

Holly Blue Distribution

 White Admiral

The White Admiral had a good year in Northamptonshire and shows a 59% increase in records from 2019 which puts it 21% above the 4 year average. One of my favourite moments of 2020 was experiencing the abundance of White Admirals during a summer's walk in Hazelborough Forest on the 23rd of June! The best sites to see them were Bucknell Wood, the Fermyn Wood complex, Hazelborough Forest and Wood, Salcey Forest and Wakerley Wood. The first one was seen on the 13th of June in Bucknell Wood and the last of the year was recorded on the 30th of July in Fineshade Wood.

White Admiral

White Admiral Distribution

 Purple Emperor

The Purple Emperor had a poor year in 2020 with records 38% below the 4 year average. Although numbers were fairly low in the Fermyn Wood complex (the peak count was 31 Purple Emperors on the 26th of June) this species continues to spread and is now firmly established in many of the Northamptonshire woodlands with Bucknell Wood and Salcey Forest now becoming primary sites to see them for those wishing to avoid the crowds in Fermyn. The first of the year was seen on the 21st of June in Salcey Forest and the last of the year was recorded on the 23rd of July in Souther Wood.

Purple Emperor

Purple Emperor

Purple Emperor mud puddling in Bucknell Wood

Purple Emperor
Purple Emperor Distribution
 

Red Admiral

Although slightly down from 2019 the Red Admiral had a good year in the county with a 25% increase over the 4 year average. They were seen all over the county with particularly high counts in Bucknell Wood, Fermyn Wood, the Nene Wetlands, Summer Leys Nature Reserve and some of the villages including Achurch, Bugbrooke, Islip and Wootton. The first of the year was seen on the 29th of January in West Hunsbury and the last of the year was seen on the 22nd of November in a Hollowell garden.

Red Admiral

Red Admiral Distribution
 

Painted Lady

The fluctuating peaks and troughs of Painted Lady butterfly migrations over the years coupled with 2019 being an invasion year led to a predictable slump in numbers during 2020. However, it was quite a big drop and the species shows a 78% decrease in records from the 4 year average. The first of the year was seen on the 4th of April in Burton Latimer and the last was seen on the 26th of September at Wicksteeds Park.

Painted Lady


 Small Tortoiseshell

The Small Tortoiseshell had a superb year in 2020 with a 50% increase in records from 2019 and a 127% increase over the 4 year average. The first of the year was recorded on New Year's Day in Desborough and the last of the year was seen on Christmas Day in Northampton, both no doubt unexpectedly woken from overwintering diapause. Numbers well into double figures were recorded with 83 seen along the Jurassic Way near Harringworth on the 15th of June, and on the 9th of August 64 were recorded at Harrington Airfield and on the same day a huge 130 seen at Sywell Reservoir. 

Small Tortoiseshell

Small Tortoiseshell Distribution
 

Peacock

The Peacock had a fantastic season in 2020 and shows a 271% increase over the 4 year average. This species was recorded all over the county with some incredible numbers coming from some locations and some equally impressive larval webs recorded too. Double figure counts came in thick and fast during the summer months with one recorder counting over 200 on a walk around the village of Old on the 17th of July. Other peak counts include 67 at Canons Ashby on the 18th of July, 86 in Bucknell Wood on the 21st of July and 56 in Wakerley Wood on the 24th of July. In total 8313 adult Peacock butterflies were recorded in the county during the year. On the 13th of June an estimated 600 Peacock larvae were found in Farthinghoe Nature Resrve. The first of the year was seen on the 18th of January in a Thrapston garden and the last was seen on the 17th of December at Pitsford Nature Reserve.

Peacock

Overwintering Peacock with Herald moths

Peacock Distribution

 Comma

Although slightly down from the previous year the Comma shows a 21% increase in records above the 4 year average. The first of the year was seen on the 11th of March in Wollaston and the last of the year was recorded on the 26th of November in Spanhoe Wood.

Comma f.hutchinsoni

Comma larva

Comma Distibution

Dark Green Fritillary

In recent years the Dark Green Fritillary has been steadily colonising the north of the county and it certainly shows no sign of slowing down it's expansion. The records show a 134% increase from 2019. The best place to see them in the county is west of Yarwell with peak counts of 15 at Ring Haw on the 13th of June and 101 at Great Morton Sale on the 24th. Other records came from Brampton Ash, Brockhall, Croughton Quarry, Fineshade Wood, Roade Cutting, Salcey Forest, Summer Leys Nature Reserve, Sywell reservoir, Twywell Hills and Dales and Wakerley Wood. The first of the year was seen on the 28th of May at Ring Haw and the last was recorded on the 12th of August also at Ring Haw.

Dark Green Fritillary

 
Dark Green Fritillary Distribution

 Silver-washed Fritillary

Although a now common butterfly in our woodlands the Silver-washed Fritillary numbers were slightly down and showed a 23% drop below the 4 year average. However, it was still a notable year for the species as the valezina colour form continues to appear in our woodlands with increasing regularity and Salcey Forest and Weekley Hall Wood were added in 2020 as new entries to the list of where to see them. The first Silver-washed Fritillary of the year was seen on the 9th of June in Hazelborough Forest and the last of the year was seen on the 22nd of August in Bucknell Wood.

Silver-washed Fritillary

Silver-washed Fritillary form valezina, Salcey Forest

Silver-washed Fritillary Distribution

 

 Speckled Wood

The Speckled Wood had an slightly below average year but was still a very common sight in the county. The first of the year was seen at Glamis Wood in Wellingborough on the 6th of April and the last of the year was recorded on the 28th of October at Summer Leys Nature Reserve.

Speckled Wood

Speckled Wood Distribution

Marbled White

The Marbled White had a slightly below average year but continues to increase it's range in the county. This grassland species could be seen almost anywhere with suitable habitat but the biggest counts came from New Duston, Ring Haw, Roade Old Quarry, Twywell Hills and Dales and Weekley Hall Wood. The first of the year was seen on the 1st of June in Southwick Wood and the last of the year was seen on the 23rd of August in Weldon.

Marbled White

Marbled White Distribution

Gatekeeper

The Gatekeeper had a good year in Northamptonshire and the records show a 51% increase above the 4 year average. This species could be seen all over the county but particularly high counts came from the Hollowell Reservoir, Polebrook Airfield, the Nene Wetlands and Priors Hall. The first of the year was seen on the 20th of June at Great Oakley Hall Park and the last of the year was recorded on the 26th of August in Desborough.

Gatekeeper

Gatekeeper Distribution


Meadow Brown

The Meadow Brown had a good year in the county and shows a 44% increase in records above the 4 year average. Abundance wise it's hard to match this butterfly and in all 17,127 adult Meadow Browns were recorded in Northamptonshire during 2020. The first of the year was seen on the 26th of May near Cogenhoe and the last were seen on the 5th of September at Summer Leys, Ring Haw and Harlestone Firs.


 

Ringlet

The Ringlet had the poorest year of the Brown butterflies and shows a 23% drop below the average. The first of the year was seen on the 29th of May at Glapthorn Cow Pastures and the last of the year was seen on the 23rd of August near King's Cliffe.

Ringlet

Ringlet Distribution

 

Small Heath

Although down in numbers from 2019 the figures for the Small Heath during 2020 show it to be 54% above the average. This grassland butterfly can be encountered at a number of sites but the best areas to see them where Collyweston Deeps, Croughton Quarry, Deenethorpe Airfield, the Jurassic Way near Harringworth, Pistford Nature Reserve, Priors Hall, Ring Haw, Southwick Wood and Twywell Hills and Dales.

Small Heath

Small Heath Distribution


If you'd like to read further news about Northamptonshire's lepidoptera during 2020 the superb newsletter by the Beds and Northants local branch of Butterfly Conservation can be read here - Autumn 2020 Newsletter