Neil Hulme

[Neil Hulme]

Last Of The Many?

The Long-tailed Blues I saw yesterday (10 October), with my brother who's visiting from Antwerp, might be the last I see this year, bearing in mind the weather forecast for the foreseeable future and the likelihood of rapidly diminishing returns. I'm sure that more will emerge, but they won't hang around for long, assuming they can get airborne. With a couple of exceptions (Lancing Station and an undisclosed site in East Sussex), where there remains evidence of colonial behaviour in local populations of significant size (as seen in 2013), most sites seem to be emptying out rapidly (as seen in 2015); I suspect they're flying south. Many of the eggs laid by the late wave of primary immigrants (during late September) are unlikely to produce adults, unless an Indian Summer materialises unexpectedly.

There is no doubt in my mind that we have been cheated of something really spectacular, by the collapse in the weather just as the UK brood started to emerge. That said, I've collated more than 200 records for Sussex in 2019, including primary immigrants (two distinct waves) and locally hatched adults. This surpassed the 2013 and 2015 events.

Yesterday, we started at Lancing Station, where a small group (including Mark Tutton) was treated to plenty of action through the security wire. Mark had seen a definite female, but the four males we viewed ourselves were all Sussex-born males, all now showing signs of their age. I suspect they will hang on here, hoping to ambush virgin females.

We then moved on to the Newhaven area, but drew blanks at Buckle Bypass (where earlier counts had reached 11) and Tidemills. However, we finished on a high, with a very smart male in a sheltered glade below Newhaven Fort.

It may nearly be time to say goodbye to the Long-tailed Blue in 2019, but I'm certain of one thing; they'll be back!

[bugboy]

That law of sod strikes again, I'm just glad I got the encounters I did rather than put all my Blues in one basket (I booked next week of work specifically to find them ). Realistically I guess we have to admit that butterflying in October in the UK will always be rather hit and miss, at least for the foreseeable future.

[Neil Hulme]

Small Tortoiseshells, Long-tailed Blues And Climate Change

If anyone (other than Trump) should doubt the effects of climate change, it's worth looking at some basic statistics, which suggest that the excitement of seeing exotic species such as the Long-tailed Blue in the UK should be viewed as the silver-lining to a very dark cloud.

Looking first at the Small Tortoiseshell, the phenology of this species has hurtled forward by an unprecedented three-and-a-half weeks (minimum) over twenty years (at least in Sussex), which I suspect has led to an increasingly high proportion of the first brood (the progeny of over-wintering adults) going on to produce a second brood, with correspondingly fewer going into early hibernation (historically a risk spreading strategy). This second brood appears to be falling foul of desiccated nettle-beds in our warmer summers, such as 2018.

I believe that a string of hot summers will prove disastrous for the species in my region. However, rearguard actions are likely to be fought following cooler, damper summers, so it's the longer term trend which is most worrying. This year, I have seen 18 Small Tortoiseshells, 14 of which were post-hibernation butterflies, on the best site I know of in Sussex.

Following last year's drought, I have seen far more Long-tailed Blues in 2019 than I have Small Tortoiseshells; I have made 93 sightings of a minimum of 48 individuals. Since 2013 I have seen a minimum of 102 individual Long-tailed Blues in Sussex and Kent; I had never seen this species in the UK prior to 2013.

In the 1970s this would have been considered unimaginable. Exciting as Long-tailed Blues are, we should be very worried for the sake of our children and grandchildren.

[Jack Harrison]

I don’t have your expertise Neil, but I certainly have my suspicion that Small Tortoiseshell is routinely double brooded here in north Scotland (historically usually single brooded). Some enter hibernation (well, come indoors /go into the shed) by early July. Then after a lull a few fresh individuals are seen right through August and September; I speculate that these are second brood.

One aspect of warmer summers in southern Britain puzzles me. The climate is still cooler than say southern France where there are far more species. No doubt we would have more species if it were not for that stretch of water. A bigger puzzle is why the highly mobile Continental Swallowtail hasn’t become established along and near the south coast. Unlike LT Blue, Swallowtail has no problem surviving winter.

On a plus note, global warming might benefit the north. Small Torts and Peacocks are abundant up here. I have yet to see a Comma but they have been reported as near as the Aviemore and Aberdeen areas. It can’t be long.

Jack

[trevor]

HI Neil,

I too have concerns about the Small Tortoiseshell. At a farm in Halnaker, West Sussex,
they overwinter in the farm outbuildings and usually emerge from hibernation around
late March. Several years ago about 40 were seen in an unmanaged meadow, nectaring,
courting and basking. This Spring there were far fewer to be seen.
My East Sussex count for this year amounts to 5, including two together at Ditchling Common.
In Wiltshire, where I spend a few days most months, they are still seen and my best encounter
for 2019 was 5 in a Lacock garden centre.

In contrast, when I was a boy, Small Torts were an every day sight, and in some numbers
in our Godalming garden, favouring the French Marigolds.

It says something when sightings of Purple Emperors outnumber those of the Small Tortoiseshell,
which has been my experience for the last two Summers.
Trevor.

[MrSp0ck]

Small Tortoiseshells in Surrey are just as bad, in 1997 we had over 100 on the Hutchisons Bank transect this year just 8. We had a web of larvae, but nothing came of these. with 1420 Small Blues and 8 Small Tortoiseshells, most other species had higher counts, we even had 4 purple emperors. At the moment we have Clouded Yellows still flying around, a few Red Admirals, and no Small Tortoiseshells.

[David M]

It may nearly be time to say goodbye to the Long-tailed Blue in 2019, but I'm certain of one thing; they'll be back!

It's probably not going to be long before it's an annual event, Neil.

Shame about how the weather took a turn at a critical moment. I'm sure had conditions remained benign we'd have seen plenty more of this lovely lycaenid.

Isn't that just the problem with many UK species though? Whilst temperatures generally are rising, causing butterflies to manufacture new ways to respond, we are still at a fairly northerly latitude and such cool, stormy conditions in September and October cannot be ruled out. I suppose if they did become rare occurrences, species such as Wall Brown might break out of their 'developmental trap'?

[Neil Hulme]

Thanks for your comments, all.

Jack: I suspect it's only a matter of time before the 'Continental Swallowtail' becomes established here (it has certainly tried and succeeded in the very short-term), but it has probably never arrived in the sort of numbers required to form a self-sustaining population. As a species which wanders through the countryside in lower numbers than, for instance, Long-tailed Blue, and periodically crosses the Channel in much lower numbers, it is less likely to establish a firm bridgehead.

Whereas the LTB finds it easy to set up late summer/autumn breeding colonies, it cannot survive our winter. However, I suspect this is a true migrant and returns south - or at least that part of the brood which completes its life cycle in a timely manner.

David: I think it is entirely plausible that the Wall will break free from the 'developmental trap', given added climate warming.

BWs, Neil

[Neil Hulme]

Blues And Reds

Yesterday (15 October), while on the way to Knepp to enjoy the deer rut, I made a detour to Lancing Station, to see if the Long-tailed Blue is still flying here. Three very active males were present on the north side of the track, clearly visible through binoculars.

[David M]

Just in case you didn't know (and I guess you do), there has been another Long Tailed Blue sighting in Wales, Neil, although this one met a disappointingly sticky end:

https://www.facebook.com/groups/Butterf ... 946252047/

[Andy Wilson]

In the 1970s this would have been considered unimaginable. Exciting as Long-tailed Blues are, we should be very worried for the sake of our children and grandchildren.

I read this and the comments of other people with great interest. I would just add a few points:

Climate change is a fact. It is happening and has already happened. The scientists and politicians can argue about whether it is anthropogenic or not .

Populations of butterfly species in Britain have fluctuated considerably over the years, not only because of climate change but also due to other factors. Take the example of the Comma, which declined in the 1800's to a low point in the early 1900's, but has now recovered and is continuing to expand northwards into Scotland, well beyond its original range. Another case is the Black-veined White, which became extinct in Britain in the early 20th century for reasons that seem unclear. The same is true of the Large Tortoiseshell, but it may be coming back now (together with its cousin, the Scarce Tortoiseshell). The Mazarine Blue was apparently once quite common and widespread in Southern England, but became extinct (probably) because of changes in haymaking practices. Maybe the Swallowtail was once widespread in England, but for some reason shrank to a remnant population that evolved into the separate sub-species britannicus. Who know what species of butterflies lived in Britain before the early naturalists first wrote about them?

Butterflies in general are in long-term decline, but (IMHO) that is more to do with intensive farming practices and insecticide use. I am not belittling the gravity of climate change, nor am I suggesting we do nothing. It also goes without saying that I am a great admirer of the conservation and reintroduction work that Neil and others have done. However, in our little corner of the world, we will see numbers of butterfly species go up as well as down. The Small Tortoiseshell is a great rarity now where I live in East Sussex. As a teenager in the 1960's, I paid them no attention, so common they were. The same could be said for the Wall Brown -- there were loads where I grew up in Surrey. Their decline is a great pity, but on the other hand I have delighted in seeing several Long-tailed Blues this year and one in 2013. In 2017 I was lucky enough to see one of the Queen of Spain Fritillaries at Peacehaven. I also look forward to Continental Swallowtails establishing themselves in Sussex, and perhaps Southern Small White!

[MrSp0ck]

Yes things are on the Move, the Wall is beleived to have died out in the 1980s practically overnight on some Surrey Sites, trying to fit in a 3rd brood, but couldnt at the time. It probably has been able to for a decade but there are none left to try. Our Glanville Fritillaries have produced a 2nd Brood this summer and the resulting larvae are about to get to hibernation size in the next week, so can fit a 2nd brood in with success in Surrey. The the Brilliant Butterfly Banks project research is being carried out, on some species, some re-introduced and habitat created on nearby sites. The coontinental Swallowtail was established here until the cold winter of 1947. It tried to come into the Dover area in 1999 and survived a few years, and again into Sussex in 2014. The Dover site is full of Fennel.

2nd Brood Glanville Larvae

[Neil Hulme]

Hi David. I don't do facebook, so am keen to know the fate of the Welsh Long-tailed Blue. I know that a Swallow swallowed one elsewhere!

Thanks for your comments, MrSp0ck and Andy.

Andy, you are of course right in pointing out some of the other factors which have caused problems for many of our butterfly species, particularly since the mid C20th. We've lost c.80% of our chalk grassland (which now covers just 4% of the South Downs National Park) to the plough since WWII; this can never be reclaimed to any significant extent. Following WWII, and again after the 1987 blow-down, we created huge swathes of uniform, dark conifer plantation. However, the public forest estate is managed in a far more sympathetic manner these days, and we will hopefully see further improvements in the future. On the other hand, we are unlikely to see the return of Hazel coppicing on anything other than a hobbyist or nature reserve scale, although biomass plants give a glimmer of hope for even this lightweight material. Then there's the spread of concrete and agricultural intensification, involving the loss of hedgerows and copses (some now being replanted) and the use of herbicides and pesticides. Add the draining of wetlands, water and air pollution and increased Nitrogen deposition and it's not difficult to see why so many (but far from all) of our species have declined, since the inception of UKBMS (1976) and long before.

However, my piece above was specifically about the effects of climate change on the Small Tortoiseshell and Long-tailed Blue; the changing fortunes of these species are largely independent of those factors listed above. LTB is here entirely as a migrant and prefers urban and semi-urban habitats, such as allotments, gardens and wasteland. Small Tortoiseshell is a non-specialist of the wider countryside, requiring nothing more than nettle-beds - or at least those which are not subject to summer drought.

The problem for some species (particularly habitat specialists) is that climate change is exacerbating those problems listed above. Species will generally move northward in response to climate change, as some non-specialists have done with ease, such as Comma. However, the patches of high quality habitat required by specialists have become so fragmented and isolated, and the intervening areas so hostile, that many species will find it difficult to make the great leaps required in response to our warming climate.

When all these factors act together, we see that climate change causes problems both directly and indirectly. As always, there will be winners as well as losers, at least in the shorter term. However, if we continue to make such a mess of our planet, the future of our butterflies may become the least of our worries.

BWs, Neil

[Neil Hulme]

Giants

My brother, Mark, spent a few days at Knepp while on a recent visit from his home in Antwerp. He did far more justice to the giant Red Deer of the Wildland with his more sophisticated camera, especially in the dingy weather conditions we've experienced lately.

The first shot shows a clonking great stag, which lost an eye in last year's rut. It hasn't put the ladies off.

[Neil Hulme]

Red Admiral Eggs

Yesterday (20 October) I paid another visit to the Knepp Wildland, primarily to enjoy the deer rut. The Reds have now finished their business for the year and are no longer charging around or bellowing, but the Fallow are still going strong. There is plenty to see for those interested in fungi, including rarities associated with the ancient oaks in the Middle Block. Although common, I found a particularly nice example of Beefsteak Fungus. Butterfly interest was restricted to a single Red Admiral, which was busy laying eggs on nettles growing along the base of a south-facing hedgerow. I've also seen a few Peacock and Comma here in recent days.

[David M]

Hi David. I don't do facebook, so am keen to know the fate of the Welsh Long-tailed Blue. I know that a Swallow swallowed one elsewhere!

Yes, this is the fate that befell the Skokholm Island LTB:

...Having caused a mini twitch, she headed back out towards the pup only to find a Long-tailed Blue on pretty much the same patch of Goldenrod! This stunning first for Skokholm was only briefly twitchable as when it looped up towards its next patch of Goldenrod it was snapped up by an east bound Swallow. We’re awaiting details of how many Pembrokeshire records there have been, but it can’t be many...

https://skokholm.blogspot.com/2019/09/o ... K5T6nXjMPw

[Neil Hulme]

Thanks for the clarification, David. Long-tailed Blues are still flying in Sussex, with a couple seen at Lancing station yesterday.
BWs, Neil

[Neil Hulme]

Turn Of The Fallow

With the Red Deer rut at Knepp now over, yesterday (22 October) I turned my attention to the Fallow. This species is now in full flow, with plenty of belching and clashing of antlers. I started at Knepp, but photography of the Fallow here is difficult, as most of the action occurs deep within the stands of sallow (in areas which are out-of-bounds).

A change of venue to Petworth Park, in beautiful autumn sunshine, provided plenty of opportunities for the camera. A wonderful day was marred by the second attack on deer by unleashed dogs that I've witnessed in just the last three days. Sadly, the standard of dog ownership in the UK appears to be at an all-time low.

[NickMorgan]

Neil,
Jumping back to your Long-tailed Blues and climate change.
It is all very worrying, although I am also finding it currently very interesting.
In East Lothian (South-east Scotland) we have also seen a dramatic decline in Small Tortoiseshell numbers. I am not convinced that this is to do with climate change rather than parasitism yet. Something that could be looked into relatively easily.
What we do have by way of an enormous silver lining is a big increase in species. Looking back at 1970s records there were only 12 species regularly recorded here. We now have double that.
It seems odd to think that Orange Tips first appeared here in 1978, Ringlets in 1984 and Peacocks in 1985. Imagine life without three of our most abundant species!
A bit of a jump but our first Comma was found here in 2001, Holly Blues in 2007, Speckled Woods in 2009 and Wall Brown in 2010. We also had our first Small Skipper in 2011. The last three species are now also amongst our most common. A couple of colonies of Holly Blues were suddenly discovered here this year after 11 years of just the odd one or two being seen each year.
The first record I can find for Small Pearl-bordered Fritillary is 2013 and Green Hairstreaks is 2014, but I suspect both of those species had been flying under the radar for some time.
And our most recent arrival is the Large Skipper which we have seen randomly over the last few years since 2014.
Many of these species have worked their way up the east coast around the Lammermuir Hills, which form a southern barrier.
So, all very exciting. I then managed to get my hands of a book by Thomson of Scottish Butterflies. This contains information on historical records and I discovered that many of these species were found here in the late 1700s, but had disappeared by the mid 1800s. This corresponds nicely with a dip in average temperatures, sometimes referred to as the little ice age. Maybe that gives us a little hope that things are returning to what they once were, but I share the general concern about the impacts that we are having on the climate and the planet in general.

[Neil Hulme]

Thanks for your comments, Nick.

Unfortunately I don't have time to respond in too much detail, as I'm currently setting up a new wildlife consultancy business, so need to focus on building websites etc.

In brief, there has been much research done on parasitoids of the Small Tortoiseshell by Dr Owen Lewis and others, which failed to prove a causal relationship. However, I suspect that parasitoid loading will have been influential, at least to some extent, both temporally and spatially.

Although it is indeed exciting that many species are marching northwards, it is often at the expense of others. This is seen in other groups too, so it's not good news for e.g. Red-backed Shrike, Willow Tit or Ptarmigan (although habitat degradation and other factors also play their part). Shorter term local benefits are likely to be dwarfed by threats on a global scale, as climate (and ultimately habitat) becomes increasingly homogenised over a wider latitudinal range. It is difficult to see any other outcome than an overall reduction in global biodiversity in the longer term.

Rather than things returning to what they once were, this link https://commons.wikimedia.org/wiki/File ... arison.png shows where we currently are in relation to pre-Little Ice Age times. I always find these graphs terrifying!

BWs, Neil