Sussex Branch

Annual Report

Brimstone feeding on Cowslip, in Kithurst Meadow

Sherie New on 29/04/2024

Male Wall Brown feeding on Buttercup, at High and Over, Seaford

Trevor Rapley on 08/05/2024

Male Small Blue at Washington Chalk Pits

Dave Browne on 05/06/2024

Weather conditions were largely poor, with wet, windy, and cloudy periods affecting butterfly activity and development however some species showed resilience and recovery potential, underscoring the importance of favorable spring conditions for future seasons. The highlights include:

• There were unusual early appearances of species like Orange-tip and Green-veined White in March, due to a mild winter.
• Poor weather in April and May led to low butterfly numbers.
• In late summer and autumn there was a modest recovery in sightings; some migratory species (Small Whites, Large Whites) showed increased activity.
• Brimstone, Duke of Burgundy, Purple Emperor, Small Pearl-bordered Fritillary, Wall Brown, Small Blue and Chalk Hill Blue were good performers however there were notable low numbers of Grayling, Silver-spotted Skipper and Painted Lady.

Read the full report here: 2024 Annual Report

Sussex Butterfly Magazine

This year the Sussex Butterfly Magazine for 2024 consolidates the Spring Report and the Autumn Newsletter into a single publication making it more efficient to produce and distribute. Click on the cover image to view the whole magazine.

An egg-laying Continental Swallowtail, Brighton

Philip Booker 18/07/2023

An "urban" Wall, Polegate

Peter Farrant 28/07/2023

Mating-pair of Long-tailed Blues, Lancing Ring

Neil Hulme 08/10/2023

• The spring of 2023 was cold and wet in Sussex. This resulted in most spring butterfly species emerging 10-14 days later than average, with below-average breeding seasons.
• Butterfly numbers were generally very low until May 20th, when warm sunny conditions finally arrived. For example, by mid-May, butterfly numbers on Chantry Hill were only about 15-20% of what they are in an average year.
• The only early-emerging butterfly species that had an above-average season were Green Hairstreak, Duke-of-Burgundy, and Holly Blue.
• Iconic spring species like Pearl-bordered Fritillary had low peak counts at their usual locations. Spring skippers were particularly late, with Grizzled Skipper and Dingy Skipper not appearing until the very end of April.
• The latter part of May and the first three weeks of June were very warm and dry, more like mid-August than early summer. These conditions allowed caterpillars to grow rapidly, meaning that butterfly species emerging in June, July and August were not negatively affected by the cold spring.

Read the full report here:

Grizzled Skipper ab. tarus, Marline Valley LNR

Nicholas Turner 09/05/2022

Large Tortoiseshell at Knepp

Neil Hulme 05/07/2022

Grayling at Deep Dean

Patrick Moore 21/07/2022

• Spring and early summer saw a wide variety of butterfly species, with a notably early emergence for many due to the warm, settled weather from March 9th onwards. This resulted in an exceptional month for butterfly activity in March, potentially the best since 2012.
• The early emergence continued into April, with many species appearing 7-14 days earlier than average. The warm weather allowed many species enough time to complete a second or even third brood.
• However, the summer months brought drought and a prolonged heatwave, which, while accelerating breeding cycles, also led to shorter lifespans for adult butterflies and potential food shortages for larvae due to desiccated vegetation.
• Overall, 2022 proved to be a good year for many species, including Pearl-bordered Fritillary, Small Pearl-bordered Fritillary, Dark Green Fritillary, Duke of Burgundy, Wall Brown, and Small Blue. Some species, however, such as the Brown Argus, Small Copper, and Small Heath had a poor season.
• Notably, there were interesting records for Clouded Yellow, Large Tortoiseshell, and Long-tailed Blue, all of which bred in Sussex in 2022.

Read the full report here:

Roosting Dingy Skipper at Well Bottom

Dave Browne 29/04/2021

Mating-pair of Silver-studded Blues at Iping Common

Katrina Watson 16/06/2021

Male Dark Green Fritillary ab. cadmeis Lemp, at Deep Dean

Bob Eade 02/07/2021

The spring and early summer months of 2021 were marked by unusual weather patterns that significantly impacted butterfly activity in Sussex. Here's a breakdown:

• While late February saw a glimpse of an early spring with warm southerly winds and sightings of all five overwintering species, our hopes were quickly dashed by a dramatic shift to frigid Arctic air in early March.
• April, despite plentiful sunshine, experienced significantly lower temperatures than average, coupled with record-breaking frost and dryness. This unusual combination hindered the usual spring vegetation growth, potentially impacting butterfly populations.
• The cold weather persisted into May, accompanied by heavy rainfall, making it a largely forgettable month for butterfly enthusiasts. This cold and wet spring resulted in a delayed emergence for most butterfly species, pushing their appearance back by 10-21 days compared to typical years.
• A shift towards warmer, sunny weather in late May marked a turning point, leading to increased butterfly activity. June witnessed the emergence of several species, including the Duke of Burgundy and Small Blue, both of which seemed less affected by the cold spring thanks to their adaptation to the harsh conditions often found on downland.

The challenging weather conditions during spring and early summer had a mixed impact on different species. While some, like the Duke of Burgundy and Small Blue, thrived, others, including the Orange-tip, Green-veined White, and Small Copper, struggled. This period highlights the delicate balance between weather patterns and butterfly life cycles, showcasing how adaptable some species are while underscoring the vulnerability of others to environmental changes.

Read the full report here:

Green Hairstreak, egg-laying on Birdsfoot Trefoil, in a Storrington garden

Martin Kalaher 01/06/2020

Male Chalk Hill Blue in the evening light at Friston

John Williams 06/08/2020

Comma feeding on Blackberries at Arlington Reservoir

Bob Eade 31/08/2020

• The spring and early summer of 2020 witnessed unusual weather patterns. February was recorded as the wettest on record, with rain and wind persisting until the end of March. However, this was followed by an exceptionally sunny period, with April being the sunniest on record. Furthermore, April and May experienced record-breaking dryness, with only 2mm of rainfall throughout May.
• These weather conditions had a mixed impact on butterfly species. While the wet winter led to a poor breeding season for butterflies overwintering as adults, the subsequent sunny period triggered an early start to the breeding cycle for many species. Consequently, first emergence dates were observed to be 10-14 days earlier than usual. This shift resulted in an extended breeding season, allowing some species to produce additional partial broods.
• Specific examples of early emergence include Brown Argus, which emerged on May 12th, 10 days earlier than its 10-year average, and Marbled White and Small Skipper, both of which emerged significantly earlier than their 10-year averages in June.
• The report highlights both positive and negative impacts of the unusual weather on different butterfly species. Pearl-bordered Fritillary experienced a "fantastic spring," with large numbers observed at several locations. However, Purple Emperor suffered a particularly "appalling year" due to a combination of factors, including the warm spring followed by a cool and wet June.
• The early summer was also marked by a drought that negatively impacted the Purple Emperor, causing sallow trees, a key food source for their larvae, to brown and shed their leaves prematurely. Despite these challenges, July proved to be a significant month for butterfly enthusiasts, with a record-breaking 28 butterfly species observed at Chantry Hill. Other notable observations included second-generation Dingy Skippers at multiple downland sites, a high count of Grayling at Deep Dean, and 20 butterfly species recorded in a single North Lancing garden.

Read the full report here:

Pearl-bordered Fritillary perched on a Bluebell, in Rewell Wood

Neil Hulme 28/04/2019

Female Small Blue, Hollingdean Park Butterfly Bank, Brighton

Jamie Burston 02/05/2019

Aberrant Brown Hairstreak in a Storrington garden

Martin Kalaher 01/08/2019

• 2019 saw a significant influx of Painted Ladies (Vanessa cardui), described as a "once in a decade" event. The last similar influx occurred in 2009, but 2019's numbers were notable, with sightings across Sussex gardens and countryside.
• White Butterflies - All three species (Large White, Green-veined White, and Small White) experienced poor numbers, each showing a 42% decrease compared to 2018
• Common Blue and Holly Blue - Both species showed significant declines. At Mill Hill, Common Blues decreased by 60% and at Anchor Bottom, Common Blues decreased by 75%
• Black Hairstreak - The colony at Ditchling Common was active in June, continuing to attract observers to view this reintroduced species
• White-letter Hairstreak - This elm-dependent species benefited from tree planting projects using disease-resistant elm cultivars across Sussex
• Large Tortoiseshell - A single sighting was recorded on May 2nd

Read the full report here:

Continental Swallowtail at Mt. Caburn

Keith Wilson 07/05/2018

Camberwell Beauty at Bury Hill

Mark Aldridge 23/06/2018

Purple Emperors on a sap bleed at Knepp

Neil Hulme 24/06/2018

2018 will be remembered for the long, hot summer, though it had a cold start with the "Beast from the East" arriving early in the year, delaying butterfly sightings.

• The first butterfly sightings of 2018 were recorded on January 10, including Red Admiral, Comma, and Brimstone.
• Fritillaries for the Future Project, led by Neil Hulme, ended in March 2018. It aimed to create habitats for Pearl-bordered and Small Pearl-bordered Fritillaries, species that had suffered population declines due to habitat mismanagement.
• A large population of Black Hairstreak butterflies was discovered at Ditchling Common Country Park. This butterfly, which has never naturally occurred in Sussex, was likely introduced in the 1950s in Surrey and slowly spread over time.
• Drought during the summer of 2018 caused food plants for caterpillars to wither, raising concerns about the long-term effects on butterfly numbers, similar to the drought of 1976.

Read the full report here:

Pearl-bordered Fritillary on a Bluebell, at Abbots Wood

Trevor Rapley 27/04/2017

Marbled White on a Pyramidal Orchid at Fairmile Bottom

Bill Brooks 29/06/2017

Silver-spotted Skipper at Ditchling Down

David Cook 31/07/2017

A major recovery year after a terrible 2016, which was marked by low butterfly numbers due to an unusually mild winter and cold spring.

• Small Copper butterflies made a noticeable comeback after a poor 2016. Several other species also showed population rebounds due to more favorable weather conditions throughout the year.
• Discovery of the Queen of Spain Fritillary at Halcombe Farm was a highlight for the year.
• Possible return of the Large Tortoiseshell butterfly, with sightings at North Stoke.
• A Continental Swallowtail emerged from a caterpillar found on parsley purchased in Brighton, likely indicating the arrival of foreign species.
• Conservation initiatives included the 'Fritillaries for the Future' project aimed to create habitats for Pearl-bordered Fritillaries across Sussex and the reintroduction of the Small Pearl-bordered Fritillary to Rowland Wood

Read the full report here:

Mating-pair of Duke of Burgundy on the Storrington Downs

Neil Hulme 29/05/2016

Mating-pair of Wood White

Douglas Neve 23/05/2016

Mating-pair of Dingy Skipper at Heyshott Escarpment

Vince Massimo 23/05/2016

2016 was a difficult year for butterflies in the UK, with many common species experiencing significant population declines.

• The report begins with a somewhat pessimistic prediction about the decline of butterflies in 2016, due to the unusually mild and wet winter of 2015–2016, with December 2015 breaking records for warmth and wetness. This disrupts the butterfly life cycle by increasing pathogen activity, risking premature emergence, and leading to energy depletion.
• Local observations and reports confirmed that butterfly numbers in 2016 were alarmingly low, with sightings of common species becoming rare.
• The 2016 Big Butterfly Count recorded significant declines in various species. Notably, the Gatekeeper, Comma, Small Copper, Small Tortoiseshell, and Peacock experienced some of their worst numbers in recent years.
• The report highlights climate change's role in altering weather patterns, which in turn impacts butterfly populations. Increasing frequency of extreme weather events (e.g., heatwaves, heavy rainfall) could further affect butterfly life cycles and habitats.
• A new book, "The Butterflies of Sussex," was announced, compiling findings from a five-year survey from 2010 to 2014, with records from 2,500 contributors.

Read the full report here:

Pearl-bordered Fritillary on a Bluebell, at Abbots Wood

Trevor Rapley 27/04/2017

Marbled White on a Pyramidal Orchid at Fairmile Bottom

Bill Brooks 29/06/2017

Silver-spotted Skipper at Ditchling Down

David Cook 31/07/2017

The report focuses on the rare Scarce Tortoiseshell butterfly (Nymphalis xanthomelas) and its surprising sightings in Sussex.

• The butterfly, primarily found in Eastern Europe and Asia, began expanding its range in 2004, reaching the Netherlands by 2014. Prior to 2014, there was only one recorded sighting in the UK, in Sevenoaks, Kent, in 1953.
• In 2014, the Scarce Tortoiseshell was sighted again in the UK, beginning with Norfolk and later in multiple eastern counties. In early 2015, further sightings occurred along the UK’s east coast, sparking excitement among naturalists.
• In April 2015, Jan Charteris spotted a Scarce Tortoiseshell in Sussex, confirming it as a first for the region.
• A review of photographs and sightings led to the discovery that a 2014 sighting in Beckley Woods, Sussex, was actually a Scarce Tortoiseshell, predating the Norfolk sighting. This sighting marked it as the first for Sussex and the second record for the UK.
• Further discoveries by lepidopterist Tim Freed revisited past sightings and identified a Scarce Tortoiseshell in Stansted Forest from 2010. This finding allowed both the Scarce and Large Tortoiseshells to be included in The Butterflies of Sussex.

Read the full report here: