The continuing warm weather continues to result in some interesting sightings over recent weeks.
Report and pictures from our lepidopterology and odonatology expert, Keith Powrie
A fairly early start, (for butterfly counting, that is) because of the expected high temperature yielded 25 butterflies. Most of them had been seen during the previous weeks, but a couple of Brown Argus were seen avidly nectaring on the Eupatorium.
Vey few Odonata were seen, although a very brief glimpse of a Hawker dragonfly with untinted wings was seen in the vicinity of where a Common Hawker was spotted during the ‘bioblittz’, a few days earlier. A more positive sighting was made of a Black Darter, flying off from Lower Falls Pond.
The butterfly count fell below the weekly average this week. Whether it was the fact that we started early to avoid the excessive heat, as butterflies are not overly fond of extreme heat, nor are we for that matter. or the cold nights of recent. or a mixture of both, who knows.
24 butterflies were counted, compared to the average of 42 for Week 18. Still no evidence of the normally abundant Green-veined Whites!
Gatekeepers & Meadow Browns were few and far between, as were Peacocks and Red Admirals. One Large Skipper was discovered, in a new haunt, by Lower Falls Pond. The dark background with clear and distinct orange markings, indicate that it was probably a female.
The summer species of dragonfly have started to emerge with several Common Darters seen, plus one, competing with a Ruddy Darter, for territory on Upper Falls Pond.
After several below average night-time temperatures, butterfly numbers were down on last week, however, they were still above average.
Peacocks and Large Whites were still in evidence in reasonable numbers and one of the Small Coppers seen last week continued to frequent its favourite spot at the end of the Long Walk, opposite the Decennium Border.
Commas, the least numerous of the common Nymphalids,(Admirals etc.) have now started to appear. Their name derives from the small, white, ‘comma-like’ marking on the underside of the otherwise camouflaged, hindwing. Like many other species, they are attracted to the Eupatorium.
Dragonflies were still few and far between. The Brown Hawker, seen last week was still present. Southern Hawkers were observed at 2 different sites, or it was the same one, twice.
A few stalwart Azure Damselflies, were hanging in there, trying to keep the species going. along with a lone male Blue-tailed Damselfly.
The average butterfly count for Week 16 is 36.
With the temperature in the mid 20’s and sun for the majority of the walk, and astounding 55 were counted today (17th) It is the highest count since the phenomenon of 2014. The second emergence of Brimstones, saw a record count of 12.
Last week’s figure of 12 Peacocks was increased to 15, and the discovery of 2 Small Coppers was the earliest for this species’s summer brood. Whether the warm weather has brought them out early, or the fact that they might have hatched from within the Gardens and not had to migrate in, who knows. The larval food-plant is Sheep’s Sorrel, mot something desirable in the Gardens!
2 Brown Hawkers, or possibly the same one in two different sites, were seen hawking around the Gardens – the first sign of any dragonfly activity for some while.
While the dragonflies appear to remain as larvae in the ponds, probably as a result of the cool weather of recent weeks, the butterflies continue to flourish.
This week, last year, a grand total of 15 were counted. This year, more than twice as many were seen, 37 in all. The most abundant were, without doubt, the Peacocks, with 12 being seen, often in groups of 2 or 3.
The summer brood of Brimstones were also on the wing, numbering 6 in all.
Both Large & Small Whites were seen but strangely, none of the more common Green-veined Whites were discovered. As well as the more regularly seen Large Skipper, a single, less frequent, Small Skipper was also spotted.
But the star attraction has to be the pair of male Silver-washed Fritillaries in an aerial dispute over territories. Whether the reduction in disturbance, due to ‘Lockdown’, has prompted this upsurge in numbers, who knows! Then why haven’t the Odonata responded similarly?