The Last Stand of the English Red Squirrel, and my Red Squirrel Quest.... (1 Viewer)

[Gomphus]

The National Trust not allowing shooting is truly bizarre. Does anyone know why this is? I have my theories, of course-for example, the Trust not wanting urban members who have grown up with the cute, endearing grey squirrel to suddenly be presented with the harsh reality.

I know that other organisations are afraid of the reaction of the "public" if they are seen to be shooting/trapping "cute" Grey Squirrels, so not a far fetched theory, the National Trust are similar I'm sure. People need to be educated to the threat Greys pose. At my local patch (well away, sadly, from any Reds) we requested Greys be controlled due to the predation of nests, damage etc as the numbers are rising, and whilst the the running authority was in favour in theory, sadly, in practice far too controversial....sad.

Good to hear the control of Greys in some areas is having a positive effect.

Cheers

 

[breffni]

Recently read a paper on the genetics of Irish red squirrels. While the consensus of opinion seems to be that British reds are pretty much all now hybridised with various introduced continental stock, principally scandanavian, it may be that the "English" (not sure they recognise that political boundry but anyway) red squirrell is making its "last stand" (we'll forgive that anthropomorphism too) in Ireland!

It would seem that some of the stock that was introduced into Ireland in the early 19th century was collected in Kent. Of the two genetic groupings in Ireland today, one is continental in origin but the other is not, and so may well be the last of the "English" stock...

 

[breffni]

Below the abstract from the study:
Origin of, and conservation units in, the Irish red squirrel ( Sciurus vulgaris ) population . Finnegan '07.
Conservation Genetics
Abstract Knowledge of genetic relationships among wildlife populations is fundamental to their conservation, particularly where translocations are concerned. This study involved a survey of mitochondrial DNA variation in the Irish red squirrel population. Our main aims were: (1) to determine whether the Irish red squirrel population is distinct from that found in Britain, given known translocations that took place from Britain in the 1800’s; and (2) whether inclusion of Irish data into a reanalysis of European red squirrel data could reveal patterns of postglacial spread in Ireland. We found evidence that the current Irish red squirrel population may be a mixture of native and translocated stock, and relationships between Irish and European haplotypes supported a number of colonisation events of the island. Although only one haplotype was common to both Ireland and Britain, it is probable that the most common haplotypes in Ireland are British introductions that have since become extinct in Britain. There was a significant regional genetic structure in Ireland (P < 0.001), as well as between all Irish and British regions. Although it is likely that the red squirrel will not be fundamental in tracing the colonisation of Ireland by mammals, the data demonstrated that individual regions within Ireland, as well as the Irish population as a whole, are distinct both from the British population and from each other and, therefore, these populations should be treated as separate Management Units (MU) in conservation strategies.

 

[breffni]

Alan, I've read back through the thread bit and, if you dont mind, would like to play devils advocate a bit regarding the culling of greys. The extant population of british red squirrels is apparently primarily composed of intruduced eurasian red squirrels and there is no known genetically distinct endemic population as far as I can make out - eurasian red squirrels are "not threatened" per IUCN. It is also impossible to completely remove the grey population through a cull. It would seem to me that given these two circumstances, the drastic measure of culling greys is questionable and that there are possibly other conservation issues that deserve more attention...

 

[Martin Thomas]

An interesting and not unreasonable argument but evidence does suggest that endemic populations do still exist. From Hale et al (2004):

"The genetic structure of the British S. vulgaris populations is complicated by several introductions from continental Europe over the last 150 years. There is literature evidence for introductions of individuals (probably S. v. fuscoater and/or S. v. varius) from Europe to Scotland (Harvie-Brown 1880-81), as well as Lancashire (Segar 1968; Lowe and Gardiner 1983) and County Durham (J. Reynolds personal communication) in England. There is no evidence for introductions to the northwest of England (Cumbria), and some individuals from Cumbrian populations display coat colour characteristics similar to those described as common in the 18th century in English populations".

Having just spent much of the day watching up to 5 reds at a time feeding in my garden it's hard not to want to do everything possible to protect them!

 

[ColonelBlimp]

Plus greys are marching up from Northern Italy and, due to the actions of the "oooh don't hurt the poor fwuffy thing" brigade it looks like they are going to be past the Alps in great numbers soon.

That "not threatened" IUCN verdict might be a little premature...

 

[breffni]

An interesting and not unreasonable argument but evidence does suggest that endemic populations do still exist. From Hale et al (2004):

"The genetic structure of the British S. vulgaris populations is complicated by several introductions from continental Europe over the last 150 years. There is literature evidence for introductions of individuals (probably S. v. fuscoater and/or S. v. varius) from Europe to Scotland (Harvie-Brown 1880-81), as well as Lancashire (Segar 1968; Lowe and Gardiner 1983) and County Durham (J. Reynolds personal communication) in England. There is no evidence for introductions to the northwest of England (Cumbria), and some individuals from Cumbrian populations display coat colour characteristics similar to those described as common in the 18th century in English populations".

Having just spent much of the day watching up to 5 reds at a time feeding in my garden it's hard not to want to do everything possible to protect them!

The quoted abstract continues: "Changes to landscape connectivity in Britain during the 1980s greatly altered dispersal patterns, resulting in an increase of gene flow from populations in the north-east of England and the Borders into Cumbria. The morphological characteristics of the Cumbrian population also changed over this period, from traits similar to the British subspecies before 1980, to traits similar to the continental European subspecies after 1980." (see http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=151165)

Despite exhaustive research, no genetically distinct population of British red squirrels has been found to date. If a population of native british red squirrels, genetically distinct from continental populations, could be identified, I think that all manner of extraordinary measures to protect it could be justified. Alas no such population has been found to date, and the evidence appears to be that whatever remnant there is, is hopelessly hybridised with the introduced animals. The doubtless beautiful red squirrels that are feeding in your garden, and the many photographed on this thread, are almost certainly the progeny of introduced continental red squirrels and, as such, have no particular conservation value that would justify a cull.

 

[breffni]

Plus greys are marching up from Northern Italy and, due to the actions of the "oooh don't hurt the poor fwuffy thing" brigade it looks like they are going to be past the Alps in great numbers soon.

That "not threatened" IUCN verdict might be a little premature...

I fully agree that extraordinary measures are justified in Italy, however this has no bearing on the situation in Britain.

 

[ColonelBlimp]

My statement you quote was in response to the earlier post:

Alan, I've read back through the thread bit and, if you dont mind, would like to play devils advocate a bit regarding the culling of greys. The extant population of british red squirrels is apparently primarily composed of intruduced eurasian red squirrels and there is no known genetically distinct endemic population as far as I can make out - eurasian red squirrels are "not threatened" per IUCN. It is also impossible to completely remove the grey population through a cull. It would seem to me that given these two circumstances, the drastic measure of culling greys is questionable and that there are possibly other conservation issues that deserve more attention...

...linking in to the merit of a cull discussed.

Also, on what do you base the statement that it is impossible to completely remove the grey population via a cull?

 

[Martin Thomas]

As I said, you have presented a very balanced argument and I'm highly respectful of your genetic understanding (I'm guessing you're a scientist?). I too don't believe a mass cull is the correct action but I also don't think it unreasonable to protect the remaining red squirrel population where feasable and realistic.

Genetic hybridisation and dilution has taken place in a whole raft of supposed UK species thanks to the Victorians and with introduced species which we now regard as 'virtually' endemic, (e.g. rabbit and little owl), we are sometimes faced with awkward conservation dilemas. Unfortunately, there are times when genetics has clouded rather than clarified conservation efforts and large scale perspectives can easily be lost.

When looked at on a haplotype level (as I did with water voles when attempting to assess suitability of a 'local' population for a reintroduction breeding programme) there are some fascinating phylogeographic pictures which emerge and some conservation practitioners believe we should maintain these macro scales.

I guess it all comes down to whether you're a 'lumper' or a 'splitter' and who presents the strongest argument when it comes to politics and the availability funding. It's not hard to find a great many examples of a complete waste of major resources and vice versa. Chris Packham's recent comments on Giant Panda conservation drew vitriolic responses but he made a very good point about something we often are reluctant to do - namely, put a value on our wildlife.

Let's hope the Italians learn from the consequences of the UK failing to act on the spread of grey squirrels here.

 

[Martin Thomas]

My statement you quote was in response to the earlier post:



...linking in to the merit of a cull discussed.

Also, on what do you base the statement that it is impossible to completely remove the grey population via a cull?

Many of the practical, scientific and financial reasons were discussed in the recent thread here.

 

[breffni]

My statement you quote was in response to the earlier post:

...linking in to the merit of a cull discussed.

I don't follow?

Also, on what do you base the statement that it is impossible to completely remove the grey population via a cull?

Private property is the basis of my statement.

 

[breffni]

As I said, you have presented a very balanced argument and I'm highly respectful of your genetic understanding (I'm guessing you're a scientist?). I too don't believe a mass cull is the correct action but I also don't think it unreasonable to protect the remaining red squirrel population where feasable and realistic.

Genetic hybridisation and dilution has taken place in a whole raft of supposed UK species thanks to the Victorians and with introduced species which we now regard as 'virtually' endemic, (e.g. rabbit and little owl), we are sometimes faced with awkward conservation dilemas. Unfortunately, there are times when genetics has clouded rather than clarified conservation efforts and large scale perspectives can easily be lost.

When looked at on a haplotype level (as I did with water voles when attempting to assess suitability of a 'local' population for a reintroduction breeding programme) there are some fascinating phylogeographic pictures which emerge and some conservation practitioners believe we should maintain these macro scales.

I guess it all comes down to whether you're a 'lumper' or a 'splitter' and who presents the strongest argument when it comes to politics and the availability funding. It's not hard to find a great many examples of a complete waste of major resources and vice versa. Chris Packham's recent comments on Giant Panda conservation drew vitriolic responses but he made a very good point about something we often are reluctant to do - namely, put a value on our wildlife.

Let's hope the Italians learn from the consequences of the UK failing to act on the spread of grey squirrels here.

Reading back through the thread it seems to me that there are a lot of opinions but not much science. At the end of the day this may be more a social/cultural/political issue than a scientific one, certainly judging by the kind of invective on the other thread!.

In the meantime a genetically distinct population of reds that may represent the last remnant of the native British population has been identified in Ireland - any comments on that?

 

[ColonelBlimp]

I don't follow?

Basically I wasn't directly talking about the situation in Britain in specifics-the IUCN classification AFAIK is for the species in general, and so the "unthreatened" verdict may be premature due to greys being present in Europe, and Britain being an example for what generally happens next.

Private property is the basis of my statement.

If a cull is done on a small scale, however intensively, it will have no bearing on the overall situation as regards to grey presence as it will soon be filled up by outsiders again. My point about a cull being effective or not is that a nationwide, intensive cull has never been tried, and so calling it unfeasible is a little unproven-difficult and possibly not-cost effective as opposed to expanding border areas around red colonies, that I would agree with.

In the meantime a genetically distinct population of reds that may represent the last remnant of the native British population has been identified in Ireland - any comments on that?

If it does turn out that the vast majority of the British population are not actually British, this has little bearing on the actual effect on the ecosystem of it versus the grey, whose delerious effects are easily seen, or even public perception of it very much.

 

[breffni]

Basically I wasn't directly talking about the situation in Britain in specifics-the IUCN classification AFAIK is for the species in general, and so the "unthreatened" verdict may be premature due to greys being present in Europe, and Britain being an example for what generally happens next.



If a cull is done on a small scale, however intensively, it will have no bearing on the overall situation as regards to grey presence as it will soon be filled up by outsiders again. My point about a cull being effective or not is that a nationwide, intensive cull has never been tried, and so calling it unfeasible is a little unproven-difficult and possibly not-cost effective as opposed to expanding border areas around red colonies, that I would agree with.



If it does turn out that the vast majority of the British population are not actually British, this has little bearing on the actual effect on the ecosystem of it versus the grey, whose delerious effects are easily seen, or even public perception of it very much.

The IUCN is made up of hundreds of scientists with a very high level of expertise in these kinds of risk assessments - I'd suggest perhaps contacting them and alerting them to this hitherto underestimated threat to the eurasian squirrel at species level (what you have in Britain) - perhaps they'll upgrade the threat. More information about the criteria that the IUCN use can be found here http://www.iucnredlist.org/info/2007RL_Stats_Table 1.pdf - note that 20%+ of mammals are threatened. As i said, I agree that extraordinary measures are justified in Italy because there are at least two threatened valid sub-species which are of conservation interest, unlike the British population.

I do not believe that it would be practically possible to achieve a 100% cull of 2.5 million arboreal animals that are dispersed in urban areas, private estates and generally throughout the countryside. Perhaps in years to come a more realistic biological solution will become available. Attempts at culls on this scale in the past have proved costly failures.

What are the "delerious effects" that greys effect that reds do not? I think greys probably have a greater adverse effect on hazel but generally both damage forestry in the same way and indeed a major reason for the decline of British reds was human persecution for damage to trees up until very recently. Personally I do not think that this is a sufficient reason for a cull but forestry people would probably disagree - but thats an economic argument, not a conservation one.

In summary, a cull cannot be justified on conservation grounds. Depending on your point of view a cull may be justified on economic, social, cultural, political or maybe even religious grounds (god knows!) Reading through the thread I can't help feeling that what is really at issue is some sort of urban/rural conflict...

Here is an interesting resource regarding squirrels in general: http://www.sciencedaily.com/releases/2003/02/030221080311.htm

 

[ColonelBlimp]

The IUCN is made up of hundreds of scientists with a very high level of expertise in these kinds of risk assessments - I'd suggest perhaps contacting them and alerting them to this hitherto underestimated threat to the eurasian squirrel at species level (what you have in Britain) - perhaps they'll upgrade the threat. More information about the criteria that the IUCN use can be found here http://www.iucnredlist.org/info/2007..._Table 1.pdf - note that 20%+ of mammals are threatened. As i said, I agree that extraordinary measures are justified in Italy because there are at least two threatened valid sub-species which are of conservation interest, unlike the British population.

All I am saying is that seeing what has happened in England with grey/red interaction does not bode well for the same in Europe, which looks as if it is a very early version of the British situation.

I do not believe that it would be practically possible to achieve a 100% cull of 2.5 million arboreal animals that are dispersed in urban areas, private estates and generally throughout the countryside. Perhaps in years to come a more realistic biological solution will become available. Attempts at culls on this scale in the past have proved costly failures.

I have never said that such a cull would be possible or impossible, merely that it could be either way, as well as being definitely difficult, as all I have said is that such a cull has never been tried and as such it cannot be dismissed out of hand. All the culls up to now have been rather half-hearted and have not been universal, leaving some for example in more urbanised areas to recolonise.
I have already said that in purely conjectural terms a gradual expansion of bordering areas may well be preferable in terms of cost and efficacy.

What are the "delerious effects" that greys effect that reds do not? I think greys probably have a greater adverse effect on hazel but generally both damage forestry in the same way and indeed a major reason for the decline of British reds was human persecution for damage to trees up until very recently. Personally I do not think that this is a sufficient reason for a cull but forestry people would probably disagree - but thats an economic argument, not a conservation one.

I had quite a debate with another person elsewhere on this issue and there are a number of papers criticising grey actions on a conservational standpoint as well as an economic standpoint- for example, both damage trees but greys tend to do it on more varied species and at a higher intensity due to their higher average population density. This density links in with threatening conservation efforts-for example, they have been observed to threaten some woodland bird populations (Hewson et al., 2004). I can dig out more sources if you want.

In summary, a cull cannot be justified on conservation grounds. Depending on your point of view a cull may be justified on economic, social, cultural, political or maybe even religious grounds (god knows!) Reading through the thread I can't help feeling that what is really at issue is some sort of urban/rural conflict...

I assume you are basing this on the confusion as to whether British red squirrels are just that. A native species, and a potentially (probably IMO) native subspecies under great threat from an invasive species deserves our conservationary efforts to be directed upon it. If we don't do something, we will lose it, and there will be no point pondering genetics differences any more.

I don't really understand your urban/rural comment-it is not as if all rural areas are filled with reds, and all urban areas with greys, and it is us nasty people in tweed going about with shotguns killing the cuddly streetwise greys!

 

[breffni]

I think we'll just have to agree to differ on this...the red population is just not of sufficient conservation interest to justify a cull of greys...

(...but please do post those references on the difference between red and grey impact on native ecosystems - i hardly think this could justify a cull based on what i've seen so far but would keep an open mind.)

 

[ColonelBlimp]

Bit short of time, so for starters, some stuff in here:

http://conservation-issues.co.uk/Articles%20Pages/Grey_Squirrel_Article_07-07.htm

More here:

http://www.redsquirrels.info/RevChap4.pdf

 

[breffni]

Thanks. I checked out the first link.

This is a self-published article that describes how grey squirrels are “A major threat to our native biodiversity” and is backed up by several bibliographic references:

Three points are made:

1. Grey squirrels are displacing native red squirrels. No argument there except that the damage has probably already been done - see http://www.ingentaconnect.com/conte...2/05268366;jsessionid=ao19gni5bd68c.alexandra - evidence to date would suggest that S v leucourus is already extinct in Britain (but as previously mentioned, a small distinct population may be alive and well in Ireland). Even if a small population of distinct reds were to be found in (say) Cumbria, their problem is not greys, it is the introduced continental reds with whom they will inevitably hybridise, which is why it is such an intractable problem!

2. Grey squirrels degrade the economic and amenity value of forestry. True, but reds have the same effect and that this effect is in fact beneficial from a biodiversity point of view and so contradicts the title of the article. Squirrels, both red and grey, improve woodland biodiversity by killing some trees, thereby opening up opportunities for other species. There is also passing mention of grey squirrels eating shoots and tubers of rare woodland plants but no reference is given and I could find none elsewhere. Note that shoots and tubers form an important part of red squirrel diet also.

3. Grey squirrels are “having a serious impact on Britain’s already imperilled woodland birds” – in fact the article cited is far more tentative than that and has limited data - it would possible to say that grey squirrels are possibly having an effect on two woodland species (hawfinch and chaffinch) but that much more research is needed to prove it – see http://www.bto.org/research/reports/researchrpt_abstracts/2006/rpt_328.htm
and http://www.forestry.gov.uk/pdf/rwbs-full-report.pdf/$file/rwbs-full-report.pdf. More than half of woodland bird species are, in fact, stable or increasing in population and the main hypotheses for those declining have nothing to do with squirrels.


The second link is a delightful account of how both red and grey squirrels damage trees and includes some great photos of tree damage – you can almost see the vast numbers of invertebrates crawling around the dead bark! This type of damage is a tremendous boost to woodland biodiversity and a conservation benefit.

Nothing in either link comes close to justifying a national cull of grey squirrels.

 

[ColonelBlimp]

Don't have much time again (ho hum) but I'll just say this: I believe conservation should be primarily focused on removing human influences on the natural world. Invasive species are an example of this, and so should be removed.

Even though the intorduction of a species such as this may have potentially beneficial effects, ecosystems in general are extremely complicated and we must be conservative not acquisitive-all changes such as increased bark stripping may bring benefits butn these will always be balanced by damage to some of the group.

Even though British reds may not be genetically purely British, they are the closest to the pre-human influence state of play, and so should be conserved over an addition whose total effects are not completely known.

Otherwise, where do we draw the line with introductions? Allow them for biodiversity? Aesthetics? Unless we have a hardline attitude against invasive species we risk the degradation of our natural diversity.