This talk gives a flavour of how recording has changed, and also how a few species have changed in distribution over 20 years too. we used to receive 30,000 records, now we receive 120,000 per year. Butterfly transects are a much more scientifically robust method of surveying for butterflies. Andy then explains how butterfly transects work and an idea of where they are. Hampshire is the most transect monitored county in the UK, Hampshire started with 60 transects, now we have 180. The consistent effort from year to year means you can make direct comparisons between butterfly species and also you can conclude information about flight periods, for example silver studied blue (heathland species) we have it in good numbers on heaths, in 2020 these was a spike in flight periods in June (early season), last year there was a cold April and so the main flight period was skewed to early July also not as strong year. Pearl-bordered fritillary butterfly has started to emerge earlier and earlier. Same is true for the Glanville fritillary (which we get on the south coast of Hampshire on Hordle Cliffs and Hurst Castle) It is getting a day earlier every 2 years. Transect data can allow you to draw comparisons between species on individual sites compared with the average for Hampshire and the average for England. There is a very high correlation between the patterns of species locally, nationally and regionally. One possible reason could be parasites. The big butterfly count has encouraged a lot of people to get involved, a citizen science project, was a long weekend, but now run it over 2 or 3 weeks to allow people to submit their records. 30 thousand records a year come from this, which is approximately 25% of the records received. Jersey Tiger Moth, day flying- in 2001 it was unknown in the county- only 2 sightings in Hampshire. Today it is increasingly common in Hampshire especially in coastal areas and spreading north. Now very common in Greater London, probably because it likes it warmer, and there is a noticeable heat island affect round our cities. Another development which has really encouraged people who haven't been involved before is the i-Record Butterflies App Launched in 2014, 12% of records are now coming from the i-record butterflies app. Number of Recorders has shot up, in 2002 only had 2-3 hundred people recording butterflies, now we have over 4 thousand recorders! Coverage is also good, 75%-80% of tetrads in Hampshire have some sort of butterfly record every year. Brown Hairstreak (Thecla betulae) the rise in this butterfly may be due to climate the last 10-15 years it has really increased, Noar Hill and Shipton Bellinger is another good area. You can see a genuine spread of the species but also increased recorder effort. also spreading elsewhere in the UK. Easiest to find this butterfly by looking for the eggs as the adults are very elusive. does also occur in West Sussex and Surrey, so not surprising it is spreading. We are just waiting for it to turn up in central Hampshire. This really highlights the value of lots of recorders, really good coverage, lots of quality data to really help understand how species are changing.

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