Sussex Branch

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: