Adapting to a Warming Climate

[Piers]

Last night I attended the Royal Entomological Society annual Verrall Lectures and Supper at the Natural History Museum.

Professor Chris Thomas gave a very interesting lecture outlining how certain British butterflies are adapting (and even evolving) to deal with a changing climate far faster than could have been predicted even a little as ten years ago. It was fascinating stuff, backed up by research and studies that were hot off the press.

Of particular note was a study of the Brown Argus butterfly: This species has historically used Common Rock Rose (Helianthemum nummularium) as a larval host plant, and it was always considered that the northerly movement of this species would be limited by the distribution of larval food plant, which peters out north of the Southern counties, becoming widely distributed again further North. Conventional thinking was that the species would have (at best) extremely limited ability to bridge the gap to the northern counties because of the absence of larval host plant.

This species has historically also been recorded to have used Cranesbills (geranium) as larval food plant, but almost always choosing to lay upon H. nummularium.

It has been discovered however, that in the last decade the Brown Argus has expanded northward at a pace that could not have been predicted, as it is using Doves Foot Cranesbill (Geranium molle) (an opportunist annual plant of disturbed ground, field margins etc.) as a larval host plant.

Furthermore, experiments with both 'old' and 'new' colonies have revealed startling results: When females from old long established colonies are presented with both H. nummularium and G. molle as plants upon which to oviposit (under controlled conditions), in almost every instance the female chooses H. nummularium. However, females from 'new' colonies when presented with the same options almost always choose to oviposit upon G. molle.

Thus the butterfly has quickly (very quickly) adapted to be able to exploit the opportunity that a warming climate has presented for a northerly migration of the species from the southern counties.

Similar examples were provided with other species.

Of particular interest also was the changing habitat requirements for species whose optimum environment (particularly for oviposition) had been thought to have been set in stone. Such species (Silver Spotted Skipper being a prime example) have actually been shown to decline rapidly where land management practises are in line with conventional thinking, i.e. to provide habitat that was previously considered to be optimum for the species (closely cropped, steep south facing down land with plenty of bare ground in the case of the S. S. Skipper).

Research has shown that in these situations the species is now seeking shaded areas (even relatively dense cover) in which to lay because the open down has actually become too hot for successful larval development.

It would seem that current management practises eschewed by local wildlife trusts and other conservation bodies for several species (the Duke springs to mind) are already somewhat out of date and potentially detrimental to the species rather than being beneficial. In the case of the Duke, it is possible that the species shall continue to seek even shadier environments in which to oviposit in order to ensure that the larvae have the necessary microclimate (particularly humidity) to ensure successful development.

If only there was some way in which this information could be quickly and efficiently disseminated to those folk 'on the ground' who make the decisions regarding habitat management.

Felix

[Padfield]

I remember well when the brown argus began taking dove's foot cranesbill, because it suddenly became more widespread in East Suffolk, moving from the sandling heaths into gardens and more urban areas. It was about the same time speckled woods moved east - they were previously absent from the Suffolk Coastal region. I noticed that brown arguses, males and females, showed great interest in the dove's foot cranesbill on our lawn. Here is the first photo I took of a brown argus in our garden (taken long before I went digital, with my old SLR). The plant in the top left of the picture is dove's foot cranesbill (or small-flowered cranesbill, which also flowers on our lawn):



I know feelings run very high on the current climate change/global warming issue, and I don't want to start a fight, but as a neutral physicist I would have to sound a note of caution, at least, for those who might be giving undue weight to projections of further significant or even catastrophic warming in decades to come. All serious warming scenarios rely on substantial positive feedback on top of anthropogenic greenhouse emissions and so far as I can see, having closely studied many different parties' analyses for the last 5 years, there really isn't any compelling evidence that the climate does respond in this way. It might, but it might not - and the models incorporating feedback mechanisms to reproduce conditions leading up to the model's creation have tended to be extremely unsuccessful in predicting subsequent conditions. I've found the recent CRU scandal very enlightening, for a whole host of reasons!

Guy

[Pete Eeles]

This has to be one of the best threads I've ever seen on UKB! Thanks for the summary, Piers, and the additional observations, Guy. Although the relative distribution of Brown Argus and Northern Brown Argus is, presumably, going to become even more contentious that it already is!

So - the fact that species are able to rapidly respond to changing conditions is, IMHO, very encouraging. For the species mentioned, it would seem that we don't have to wait for thousands of years to pass before they acclimatise - although I suspect that there are winners and losers, no doubt.

But a key point is that the various conservation bodies need to keep up! And they can only keep up if they are given guidance from scientists specialising in Lepidoptera who, in turn, are given the support they need. Specifically, they need money. This is often in the form of grants and, in the current climate, this is becoming more and more difficult to obtain.

I'd therefore encourage anyone reading this to support appropriate bodies where they can - whether this is financially (making a donation) or supporting (or disagreeing with) any policies that might be proposed. For example, we may have a change of government soon. That might be good or bad for our Lepidoptera. So when a candidate turns up on your doorstep looking for a vote, ask them what their policy is with regard to conservation and then vote accordingly

Cheers,

- Pete

[Matsukaze]

Of particular interest also was the changing habitat requirements for species whose optimum environment (particularly for oviposition) had been thought to have been set in stone. Such species (Silver Spotted Skipper being a prime example) have actually been shown to decline rapidly where land management practises are in line with conventional thinking, i.e. to provide habitat that was previously considered to be optimum for the species (closely cropped, steep south facing down land with plenty of bare ground in the case of the S. S. Skipper).

Research has shown that in these situations the species is now seeking shaded areas (even relatively dense cover) in which to lay because the open down has actually become too hot for successful larval development.

Did the research confirm that the butterflies were actually changing their ovipositing behaviour, or was survival in the cooler microclimates higher?

I know feelings run very high on the current climate change/global warming issue, and I don't want to start a fight, but as a neutral physicist I would have to sound a note of caution, at least, for those who might be giving undue weight to projections of further significant or even catastrophic warming in decades to come. All serious warming scenarios rely on substantial positive feedback on top of anthropogenic greenhouse emissions and so far as I can see, having closely studied many different parties' analyses for the last 5 years, there really isn't any compelling evidence that the climate does respond in this way. It might, but it might not - and the models incorporating feedback mechanisms to reproduce conditions leading up to the model's creation have tended to be extremely unsuccessful in predicting subsequent conditions. I've found the recent CRU scandal very enlightening, for a whole host of reasons!

From the butterflies' perspective, the recent warming temperatures have seen their climate conditions move north faster than they can follow, so they may go on expanding for a little while yet. This appears to be true of the Small Skipper and Marbled White, at least, based on the study below, where the butterflies were introduced to sites somewhat north of their existing range:

Willis, S.G., Hill, J.K., Thomas, C.D., Roy, D.B., Fox, R., Blakeley, D.S. & Huntley, B. Assisted colonization in a changing climate: a test-study using two U.K. butterflies. Conservation Letters 2(1): 46-52 (2009). http://www3.interscience.wiley.com/jour ... 1&SRETRY=0

[Gruditch]

it would seem that we don't have to wait for thousands of years to pass before they acclimatise

Yeah I was a bit perplexed by that statement in another thread. A Human breeds on average at about 25 years of age, (14 for parts of Andover ). Yet in that same time, Silver-studded Blues will of turned over 25 generations, Common Blues 50. It would take over a thousand years for Humans to knock out that many generations.

I'm with Guy as far as climate change is concerned.

Regards Gruditch

[NickB]

I am all for taking a balanced view based on evidence presented wrt climate change. There has been a lot of bad press (some self-induced!) towards scientists who are putting forward evidence of that change. Change there certainly has been; and a coincidence with an increase in industrial activity from the 19th century appears to have been established. The controversy is if man's influence is greater than any natural process that may also be driving such change.
Much of the noise from the nay-sayers has roots in political lobbyists for the very industries that would have restrictions put on their actions should legislation be made to combat, say, greenhouse gases. I think we must beware of popularist movements which latch onto these negative arguments and shift the agenda away from the real issues, to ridicule science and scientists.

After all, it is quite easy to convince someone that nothing needs to be done, especially if doing something means a change in the way they live. As Mark Twain said, "I'm all for progress; its change I hate"...
N

[Chris]

Pete's right, this is an interesting thread, but please can we stop it descending into an argument about whether climate change is or isn't being accelerated by man! None of us will live long enough to read enough evidence to confirm whether our exit from this ice age is being facilitated by us!

Furthermore, experiments with both 'old' and 'new' colonies have revealed startling results: When females from old long established colonies are presented with both H. nummularium and G. molle as plants upon which to oviposit (under controlled conditions), in almost every instance the female chooses H. nummularium. However, females from 'new' colonies when presented with the same options almost always choose to oviposit upon G. molle.

Felix

I find this much more interesting. I'm not sure why the evidence presented above is "startling"? From my understanding of genetics and population dynamics, this is "expected".

[Piers]

Forgive my phraseology. For 'startling' read exciting/interesting/fascinating/etc. etc.

I'm not sure why the evidence presented above is "startling"? From my understanding of genetics and population dynamics, this is "expected".

Actually, this ain’t necessarily so…and this has been demonstrated with species that have been translocated. For example: There is a colony of Silver Studded Blue on a heathland site at Wheal Busy (I think) in Cornwall. This colony was accidentally translocated from a donor dune system colony many moons ago through, it is generally considered, sand being transported to the local rail depot. Since first establishing itself at the new heathland site the colony has thrived but stubbornly refused to breed on the larval host plants normally associated with heathland colonies of this species; instead breeding almost exclusively on Greater Bird’s Foot Trefoil (an atypical food plant, utilised by the dune colonies in Cornwall), despite the far greater abundance of alternatives, and even in the face of a decreasing abundance of Greater Birds Foot Trefoil.

There was no reason to suppose that the Brown Argus would adapt to a new larval food plant in the manner in which it has in order to take advantage of the ecological opportunity that presented itself for the species to move northwards in favourable climatic conditions. The scientists doing the research certainly did not expect this; particularly as the butterfly has modified it's behaviour considerably (and remarkably quickly) to exploit an opportunity rather than respond to a threat.

Felix.

[Neil Jones]

[quote="Felix"

There was no reason to suppose that the Brown Argus would adapt to a new larval food plant in the manner in which it has in order to take advantage of the ecological opportunity that presented itself for the species to move northwards in favourable climatic conditions. The scientists doing the research certainly did not expect this; particularly as the butterfly has modified it's behaviour considerably (and remarkably quickly) to exploit an opportunity rather than respond to a threat.

Felix.[/quote]

Quite right. One of the problems is that the "change in state" from one foodplant to another isn't straight forward. There may be intermediate genetic conditions which are less fit evolutionarily than either
A classic example of this is the human appendix which prior to the last hundred years or so was a fairly significant cause of death from appendicitis. It is hypothesised that the problem is having a smaller appendix makes you have a greater risk of dying because it is more likely to block up and become infected. It stays with us because making it shrivel away makes you less evolutionary fit and likely to survive to reproduce.

I too would not like to see the debate degenerate but as someone who has studied the subject of climate change denialism I do think I have a moral duty to bring its true nature to light. I would accept that rational thinking demands looking at new ideas with scepticism but we must also consider the risks involved. It is notable for example that many of the corporate lobbyists involved have also tried to persuade people that smoking is harmless. The involvement of the tobacco industry is well documented.
See this piece from BBC Newsnight.

http://www.youtube.com/watch?v=fubJLYm4JJk

I found this comment interesting from this chap who is qualified to know.
Eric Rignot, University of California, Irvine
http://www.faculty.uci.edu/profile.cfm?faculty_id=5467
This is how he was quoted in the highly respected journal Nature recently

"Given the overwhelming scientific evidence for climate change, we should deal less and less with climate sceptics. Otherwise we should also deal with folks who think Elvis Presley is still alive, that Earth is less than 6,000 years old and that we cannot possibly have descended from monkeys."

The real deniers as opposed to just sceptics often say things which offend my sense of reason. I'd rather not use inflammatory language but I believe given the evidence that
it is perfectly reasonable to describe some of the ideas as stark staring bonkers.

Take these three examples. Ian Plimer who claims repeatedly that more CO2 is emitted from volcanoes , when the evidence clearly shows the contrary.

Viscount Christopher Monckton who claimed that the Copenhagen treaty was to set up a world communist government. See this about his eccentric claims and behaviour.
http://www.monbiot.com/archives/2009/12 ... quisition/
The article ends with this comment on his false statements.
"In one new member they have landed a Nobel laureate, member of the House of Lords, saviour of the British armed forces and inventor of the universal cure. They should be feeling very pleased with themselves. Or very scared."

Then David Bellamy who has completely lost my respect.
This article and the accompanying video shows him being trounced
over daft claims he made about glaciers. In reality he got his information
from a conspiracy nut who believes the queen is the head of an international drugs gang.
David Bellamy and Bad science Bellamy and bunkum.

He has also been working against decent conservation organisations like Buglife on
the hysteria surrounding ragwort.
Ragwort the sense and the nonsense.

It seems that dyed in the wool denialism is psychologically linked with conspiracy theories and political extremism. I know of a local councillor who denies climate change
and he was in trouble in the local press a few years ago. He had had mugs made inscribed in Welsh, "Taniwch dros Gymru. Meibion Glyndwr sy'n rheoli." Roughly "Light a fire for Wales. Meibion Glyndwr rules." Not the most sensible thing to say!

In essence, it may not be possible to prove anthropogenic climate change absolutely, as just like any other branch of science absolute proof is very difficult to obtain. However,
the evidence is very strong that we should act. It is also very easy to show that the denialists are not to be trusted as I have done above.

[Chris]

Good post Neil. For the record, I'm no denialist - quite the reverse, but I get tired of ill-presented evidence and the enraged debate that usually follows. Your examples of climate change denialists being misinformed and largely mad are interesting... I'm sure though, with a little research I could find three examples of climate change "embracers" displaying equally unfounded views. My point: not to challenge you about whether we're accelerating climate change and whether we should act, but to highlight that it is a vast field of work, with many individuials involved on both sides and it is inherently unclear. Simpler to hold your own view and act individually where you can. A lot of the actions we can take to curb climate change are inherently sensible whether the climate is changing or not, so if we must preach, let's not pin our motives on climate change, but common-sense. My penneth-worth.

On the example of brown argus, I'll expand on my comment:

The evidence presented suggests that within the population of brown argus, most individuals elect H. nummularium (HM) as a foodplant, but there are a small number of individuals that choose G. molle (GM). This is supported by the statement "in almost every instance the female chooses H. nummularium"; i.e not in every instance, with the remainder presumably choosing GM and possibly other plants.

HM is widespread in southern counties, and again in northern counties, with a belt of absence in-between deemed too large for individuals to bridge. However, GM survives throughout the range.

So the most 'fit' population to expand northwards are the small population that choose GM. Furthermore, subsequent generations of butterflies found in these new sites are more likely to also choose GM. With each subsequent generation on these new sites, I would expect the proportion of individuals that choose HM to decrease (they're not passing on their genes, leaving the recessive GM selecting genotoype to conquer) to a point where almost no individuals select HM.

Furthermore, experiments with both 'old' and 'new' colonies have revealed startling results: When females from old long established colonies are presented with both H. nummularium and G. molle as plants upon which to oviposit (under controlled conditions), in almost every instance the female chooses H. nummularium. However, females from 'new' colonies when presented with the same options almost always choose to oviposit upon G. molle.

So the above statement is expected, no? The question I have is why the spread did not begin sooner? Is the "mutation" to choose GM recent or does it require a fortunate combination of other factors for the individuals to spread to new sites, foodplant present or not?

I have over-simplified the genotype/phenotype relationship and don't believe for one moment that there is one gene responsible for foodplant selection, but have talked as such for simplicity.

[Piers]

The question I have is why the spread did not begin sooner? Is the "mutation" to choose GM recent or does it require a fortunate combination of other factors for the individuals to spread to new sites, foodplant present or not?

Adaptation to enable exploitation of favourable climatic conditions over the last decade, presenting an opportunity for the butterlfy to move in a northerly direction. That's what has made this study so fascinating. There was no reason to suppose that the Brown Argus would adapt to a new larval food plant in the manner in which it has (and so rapidly as it has) in order to take advantage of the ecological opportunity that presented itself for the species to move northwards. The scientists doing the research certainly did not expect this; particularly as the butterfly has modified it's behaviour considerably (and remarkably quickly) to exploit an opportunity rather than respond to a threat.

Felix.

[Chris]

Adaptation to enable exploitation of favourable climatic conditions over the last decade, presenting an opportunity for the butterlfy to move in a northerly direction. That's what has made this study so fascinating. There was no reason to suppose that the Brown Argus would adapt to a new larval food plant in the manner in which it has (and so rapidly as it has) in order to take advantage of the ecological opportunity that presented itself for the species to move northwards. The scientists doing the research certainly did not expect this; particularly as the butterfly has modified it's behaviour considerably (and remarkably quickly) to exploit an opportunity rather than respond to a threat.

The adaptation was always there - G.Molle is a recognised foodplant of brown argus. What's changed is the climate. The larval food plant is not new, unless I've missed something here? The overall population has not modified it's behaviour, rather the change in climactic conditions has contributed to allowing the smaller population of GM selecting individuals to expand.

It is fascinating, I agree.

[Neil Jones]

Good post Neil. For the record, I'm no denialist - quite the reverse, but I get tired of ill-presented evidence and the enraged debate that usually follows. Your examples of climate change denialists being misinformed and largely mad are interesting... I'm sure though, with a little research I could find three examples of climate change "embracers" displaying equally unfounded views.

Yes you could BUT the important thing is you would not find them as leading figures amongst their movement. With the exception of the local councillor the examples I chose are LEADING AND PROMINENT CLIMATE DENIERS. Plimer's book for example is full of nonsense that is easily debunked not just his daft claim about volcanoes and CO2, but there was an article in the Spectator praising it recently.
Monckton was recently at a notoriously nutty creationist "university" in the USA. Real Christian Taliban anti-science territory and he praised it!
I have really made a study of this. There are leading journalists like Christopher Booker who also has claimed that Asbestos is harmless using a fraudulent expert as a source. Or Melanie Phillips a creationist ( a history denier) who believes that the MMR vaccine is dangerous despite the evidence. Without going into a deep discussion about the finer details of the psychological research on this they all seem to show at least one or other of a series of cognitive problems which are connected with poor ability to work with scientific facts. The examples I have chosen are far from the worst you could find.

If you looked at the leading people on the other side you would find rational sensible people including some very bright scientists Like Sir John Hougton for example.

My point: not to challenge you about whether we're accelerating climate change and whether we should act, but to highlight that it is a vast field of work, with many individuials involved on both sides and it is inherently unclear.

Ok Chris we are not going to fall out here but I do think that the steady drip of
poor journalism on the subject may be giving you a biased position of the level of doubt.
It really isn't that unclear. it is no where near 50:50 it is well over 90% sure.

[

[Chris]

Pete's right, this is an interesting thread, but please can we stop it descending into an argument about whether climate change is or isn't being accelerated by man!

Such a shame that this is what's happened, especially as we're all arguing on the same side - please can we stick to the butterflies?

[Piers]

Such a shame that this is what's happened, especially as we're all arguing on the same side - please can we stick to the butterflies?

I completely agree Chris. This thread was not about climate change per se; and I suggest that this is not the thread (or even perhaps the forum) for lengthy essays upon the subject. In this instance it has detracted from what could have been an interesting thread. We all have opinions upon the subject of climate change and climate science, and there are already active forums out there which cater for the subject.

Felix.

[NickB]

I can certainly understand that, as we have been discussing, butterflies, if able, do respond quickly to changes around them, whether from "hands-on" environmental management or as a result of other factors....
so, ...can anyone shed any light on the adoption of butterflies as an indicator of environmental change by government agencies? What is the butterfly distribution data used for?
N

[Piers]

From the BC Website:

Butterflies as indicators

Insects make up the largest proportion of terrestrial wildlife in Britain (over half of all species), so it is crucial that the fate of insect groups is assessed in order to monitor overall biodiversity. Butterflies are recognised as valuable indicators, both for their rapid and sensitive responses to habitat or climatic changes and as representatives for a wide range of other wildlife. As insects, the responses of butterflies are more likely to reflect changes amongst other insect groups, and thus the majority of biodiversity, than established indicators.

The excellent baseline information that exists for British butterflies enables them to be used as indicators for monitoring the progress of sustainable development and biodiversity protection policies, including the Convention on Biological Diversity target to reduce
of the rate of biodiversity loss by 2010.

UK Butterfly Monitoring Scheme data are being used to create a range of policy-relevant indicators suitable for governmental use at UK and country levels. Most important would be a UK headline indicator to complement the current ‘Quality of Life’ indicator based on wild bird populations.

A butterfly indicator would bring popular appeal, be representative of wider biodiversity and be better than existing indicators for monitoring some UK BAP habitat types. A similar butterfly headline indicator has been adopted for the England Biodiversity Strategy, and monitoring data are being used to develop European indicators under the auspices of Butterfly Conservation Europe (http://www.bc-europe.eu).

Butterfly distribution and population data enable precise, objective and cost-effective assessments of priorities for the UK BAP, and for the national, regional and local plans that stem from it. The same data also allow progress towards BAP targets to be measured. The population status of most UK BAP butterflies can now be reported annually from the UK Butterfly Monitoring Scheme.

Felix.

[NickB]

Thanks - I was wondering whether any of these grander objectives has an example of a local or other level initiative that our members may be aware of?
From other threads (Conservation) I was wondering where these "policy-relevant indicators" are used and at what level? Or is this for another thread?
N