www.ukbutterflies.co.uk

I don't think there can be any doubt that Small Tortoiseshell numbers in the south of England (particularly the south east) are declining. Their scarcity has been reported many times on here over the years although this year numbers seem to have picked up, whereas where I live in south Wales they have been relatively scarce this spring.

Of course, in Wales there is a range of altitudes and generally wetter weather conditions, meaning that nettles are rarely desiccated. Even in hot summers like last year, the adults can still find suitable, healthy LHP by flying to greater altitude, which is something this species does as a matter of routine. That's not the case in the SE,

With desiccation of the Small Tort larval foodplant in hotter summers become more likely, I wonder why Comma which also uses nettle, is thriving?

Incidentally Neil your underside shot of that Small Tort is stunning. The detail is amazing and everything in sharp focus. Taken a Lumix bridge camera?

Jack

Thanks, Jack. The ST shots were taken with the trusty Lumix.

With regards to Comma, again, it is important to look at the hard data and consider latitudinal effects. The 43-year UKBMS series does indeed show how well this species has been doing in recent decades, demonstrating a 130% increase since 1976. However, this increase will be largely attributable to the spectacular spread in geographical range of the species, as it continues its rapid march northwards, in response to climate warming (maps showing this spread are nothing short of amazing - see The State of the UK's Butterflies 2015 p.12).

However, the shorter term (weather-related/2018 drought) picture is less favourable, with a 2018 nationwide decrease of 33% on the 2017 figures. How did it fare last year in sun-drenched Sussex? In my diary (late 2018) I commented: "It also explains why I observed a much greater reliance (than normal) upon elm as a larval foodplant in the Comma, which also had a poor year in Sussex; the supply of succulent nettles had simply dried up."

The use of an alternative foodplant does give some advantages over the Small Tortoiseshell, but despite this the Comma did suffer a significant dip, from which the 'hangover' was clear to see this spring, at least down here. My own data (which these days is collated in excel rather than notebooks) suggest that I've seen fewer in the early part of this year than at any time since I've been a recorder. Postings by others to the BC Sussex website show a similar pattern - reports of Comma have been notably few and far between. Fewer than 150 individuals have been reported (including 4 hutchinsoni which is yet to get going). That's poor, but nowhere near as bad as Small Tortoiseshell.

BWs, Neil

Neil commented:

commented: "It also explains why I observed a much greater reliance (than normal) upon elm as a larval foodplant in the Comma, which also had a poor year in Sussex; the supply of succulent nettles had simply dried up."

I have to wonder - if push came to shove - whether Small Tort might accept alternative foodplants. Captive breeding experiments perhaps?

Jack

Alright Neil? I read the data with much displeasure – those numbers don’t look good and I understand your concerns . I’ve read in various places of a decrease in numbers of the Small tort of between 70 and 78% which is shocking. I can also remember seeing loads when I was a kid crawling over any Buddleia I found and I’m not denying that the Small Tort has drastically decreased.
That being said my optimism/hope comes from the fact that for the last couple of years the numbers of Small Torts that I’ve seen during the spring have stayed to pretty much the same level – building to highs of 15 or so in a 10-15 minute walk at my workplace which is a pretty good density. Also each spring I don’t struggle to see them, they’re often the most common butterfly on my early spring visits outnumbering Peacocks by about 3 to 1 on average. There is also the observation that people that I know that live in the South East have often told me how they may only see a handful of Small Torts over the year whereas in the spring I can see a handful most days.
I also based my optimism/hope on the fact that in Wiltshire since 2008 the Small Tort has made something of a comeback moving from a classification as a Scarcity to Widespread, with the expected fluctuations the graph overall shows a positive correlation (from the County report). Again I pose the idea that perhaps there is a West/East divide although this can only be conjecture on my part as I don’t know the data from other Western counties and I can only base it on anecdotal evidence - with a massive dollop of hopefulness thrown in too Fingers crossed...
Have a goodun

Wurzel

I must reiterate, I’m in no way disagreeing with anything Neil has said. I’m delighted Small Tortoiseshell is still doing ok here, it’s just the second generation thing, which seems to suffer much lower success rate, either from predators, poor condition of the nettles, or probably both. I will enjoy this flight for the next few weeks, as I don’t expect to see much after mid- July. I hope I’m wrong...

When I was a kid, the guidebooks all stated that Comma larvae preferred hops and nettle was a secondary source of LHP.

To my knowledge, Small Tortoiseshell is a species that relies almost totally on nettle.

Has anyone seen them lay (or larvae) on anything else?

Hi all

Thanks for your comments. However, I don't see or hear anything which allays my fears. The total of Small Tortoiseshell first brood (late May - present) individuals which have so far been reported to the BC Sussex (19) and BC Hants & IOW (18) websites are easily beaten by single day counts of species such as Black Hairstreak and Marsh Fritillary. I appreciate that these are colonial species, but the comparison is nevertheless quite shocking.

Wurzel: I suspect that the post-2008 improved status rating for the species in Wiltshire is based on the spectacular but sadly short-term recovery (nationwide and headline-making) seen in 2013 and 2014, before the species again slumped. As an aside, the terms 'Scarcity' and 'Widespread' are a little confusing, as one refers to abundance and the other to distribution; the distribution of Small Tortoiseshell has remained unchanged.

There will always be peaks and troughs, based on weather patterns and parasitoid load, but the long-term data is what gives cause for concern - or in the case of Comma, celebration.

It will be interesting to see the national figures for 2019, but until then I'll have to turn my attentions to other matters ... the Purple Emperor is now out!

BWs, Neil

Emperor Out - At Last!

Yesterday (25 June) I made visits to Littlehampton Golf Course and the Knepp Wildland, with the common denominator being about a dozen Painted Lady. A similar number of White-letter Hairstreak was seen at the former site, including the first female. Plenty of Marbled White and 'golden skippers' at the latter, where Matthew Oates had a fleeting glimpse of a male Purple Emperor.

Neil Hulme wrote:...until then I'll have to turn my attentions to other matters ... the Purple Emperor is now out!

Your work never stops does it, Neil?

Nice Marbled White by the way.

Hi David. Too many butterflies, too little time!
BWs, Neil

Purple Emperor Appearing At Last!

Yesterday (27 June) saw the first Knepp Wildland Purple Emperor safari of the year and we were fortunate to see a pair of males doing battle just before the end of the event; the species has started late this year, as the cool June weather has slowed things down significantly. However, we enjoyed plenty of action from White-letter and Purple Hairstreaks, White Admiral (pictured), Marbled White, Comma and 'golden skippers'. By the close of play in the evening, the emperor tally had risen to seven.

Purple Emperor numbers increased today and 12 were seen on a private safari, with a further four on territory by late afternoon. The best is yet to come. A similar supporting cast was flying, together with a few White Stork.

More From Knepp

Another great day (29 June) at the Knepp Wildland started with a Purple Emperor safari on which nine individual males were seen, along with the usual supporting cast at this time of year. Finding emperors was quite hard going, as they (and other species) were clearly seeking respite from the 30+ deg. heat.

A mid-late afternoon survey along the Green Lane transect produced 14 Purple Emperor, two of which were probably re-counts from the morning walk. However, one territory had become occupied by an additional male by the evening, bringing the day's total to 22.

Today was more about quality than quantity. One angry male chased Long-tailed Tit, Chaffinch, Marbled White, Painted Lady and dragonfly from its territory. Another repeatedly chased lumps of earth thrown into the air, ensuring that a number of visitors were provided with their first ever sightings of this species.

White Admirals are also performing well for the crowds; although numbers are modest (5/6) they can reliably be seen in several areas.
Image by Mark Hulme

HI Neil,
One in the sky will do for now, until the groundings start.
Nothing at Chiddingfold Friday or Saturday ( back there next week ).

How's the neck ache!.
Trevor.

Great airborne shot by Mark, Neil. I'm sure they'll be on the ground very soon.

Good to see numbers steadily rising.

Hi Trevor. They've now started coming down.
Hi David. The numbers have finally started to build, so it's time for the annual turkey shoot at Knepp.
BWs, Neil

Emperors Kick Off In Style

The Purple Emperors of the Knepp Wildland finally kicked off in style today (1 July). While I searched the Green Lane and main hard tracks (26) Matthew Oates worked the sallow fields (56), giving a total of 82, which included just a single female. I photographed one on the ground in the late afternoon and heard reports of a further three on the deck between 10 am and 11 am.

White Admiral numbers reached double figures (the most I've ever seen in the Southern Block) and Purple Hairstreak was swarming in the oak canopy by 6.30 pm.

Cracking shots Neil

Have a goodun

Wurzel

White Admiral has always been one of my favourite species ever since caught a tatty one in east Norfolk in the early 1950s – they weren’t supposed to occur there in those days. Much as I love Purple Emperors, White Admirals seem to be more graceful as they flit among the brambles (and sometimes come down to the floor). I had in fact planned a trip down south this week for these charismatic species but circumstances required a change in plan. I went to the Outer Hebrides instead (work that one out if you can!)

Your WA photo Neil does it great justice.

Jack

That one must score a 10 on the Hulmometer!.
Beautiful specimen.

Trevor.