There was plenty of activity yesterday morning at a brand new Brown Hairstreak site discovered just last year near Shurnock in Worcestershire. Despite arriving at the known master tree at around 9:30am, it was still quite chilly and the sun was rather hazy. No doubt all the Brownies were hiding at the top of the ash, trying to warm up! I was there for a good 45 minutes before I saw the first one take flight. Between 10:15am – 11:30am, I estimate I saw between 4-5 individuals (most likely males), with 10+ sightings. As soon as the sun started warming up at around 11am, the males were literally buzzing around the top of the ash. Amusingly, 1 male spiralled quite low down to bask for a few minutes before deciding to have a little fly at head height along the treeline. He then changed his mind, flew way out into the field, skipped over my head and zoomed back into an apple tree just below the favoured ash. Strangely enough, 1 male and 1 female Brown Hairstreak have been observed in this apple tree previously (by Simon Primrose on 28th August), and 2-3 males were also seen in an alder tree which is situated right next to another master ash, roughly 50m from the favourite. I had 2 Brownies in this 2nd ash yesterday, plus 1 male in the very same alder tree. It was clearly turning its nose up at the attractive ash next door, preferring to explore the alder top to bottom instead. I must also mention that most of the sightings yesterday were of quite worn/faded looking specimens.
I also had a look at the other ash trees in the same field and managed to spot a definite hairstreak that descended out of an ash and landed high up in a hawthorn bush. However, I wasn’t able to confirm if this was a Purple or Brown Hairstreak. Still, it requires some further observation, as do other trees in the area that I have on my ever growing list.
Despite multiple searches of the main hedgerows, no females were to be seen anywhere.
So, at this point, we have 3 confirmed master trees bordering the same field. Ash 1 and 2 are roughly 50m apart, and ash 2 and 3 are roughly 300m apart. Considering the concentration of eggs that were found in these locations, all 3 trees are clearly within the main colony boundary. Does anyone know how many males can occupy a moderate-large sized ash before others start being used?