Do New Laws Surrounding Grey Squirrel Release Go Too Far?

In October this year, UK laws surrounding non-native species will change, and licences will no longer be issued for the rescue and release of grey squirrels. This is mainly because grey squirrels pose a threat to the native red squirrel, both through the transmission of the squirrel pox virus (SQPV), and through ecological displacement. Having volunteered at a rescue centre and helped in rehabilitating grey squirrels myself, but also being a conservationist, the issue is a tough one for me. Whilst I agree that some control is necessary in efforts to save the red squirrel, I believe that this latest measure goes too far. A lot of unnecessary suffering will be caused for grey squirrels, as well as emotional anguish for the people who usually care for them. The laws will leave rescuers and rescue centres in limbo, where any squirrel that is brought in cannot be released, so either needs to be euthanised or kept in captivity forever.

In response to the imminent change in laws I signed a petition earlier this year, entitled: 'Make grey squirrel rescue exempt from Invasive Alien Species Order 2019'. It has now generated over 570,000 signatures, although the government has responded by saying that they have no intention of making grey squirrels exempt. However, as a result of signing the petition I recently received an email from a group of MP's called the 'Environment Audit Committee' inviting me to put across my views on invasive species. Feeling that this might be the only forum where I could air my concerns about the change in the invasive species laws, I decided to do some research on the subject of grey squirrels and their control, as well as how they affect reds, in order to write an informed response.

A brief history of reds and greys 

It might seem pretty clear cut; red squirrels are a native UK species, and the greys are an introduced, non-native species originating from North America. The increase in grey squirrels since their release from private estates between 1870 and 1930 has run parallel to the decrease in reds as they have out-competed them for food and habitat, and introduced them to the squirrel pox virus (SQPV) which greys carry but are resistant to. However, this is only part of the story. After almost going extinct in the 18th century due to deforestation and habitat loss over much of the UK, red squirrels were subsequently reintroduced from Europe many times over. Although it had been thought that there was originally a distinct British subspecies of red squirrel, reintroduction's have diluted the gene pool, meaning they are of mixed genetic stock, and not indistinct from other European populations which are globally of least concern for conservation. 

After they were reintroduced, reds re-populated the UK rapidly, and quickly became labelled a pest species. They were persecuted and hundreds of thousands were culled, only finally ending in 1927. Interestingly, the same reasons that reds were considered pests; tree destruction affecting timber production and preying on birds nests, are the same reasons why greys are considered pests now. The greys do cause damage to trees by stripping bark and have an economic cost with regards to the timber industry, but this is no more serious than the damage red squirrels caused when they were dominant. Any evidence that they prey on birds nests is very limited, with the RSPB stating that they are not a significant threat to bird populations. It seems then that the main issue with greys is what their spread has meant for the red squirrel. They have displaced reds in two ways; firstly they can exploit food sources better and are less susceptible to food shortages, so when they move into an area they coexist for a while as reds slowly decline. Secondly, they act as a carrier of the squirrel pox virus without actually contracting it. Although the disease existed in the red squirrel populations before greys arrived, the greys brought it to previously unexposed areas as they spread, replacing the reds as they died off. A study has even suggested that humans might be exacerbating the problem by putting out food on bird tables which brings reds and greys into closer contact than normal.

What can be done then? Although alternatives are being looked into, at the moment it appears that culling through various means is the only way to hold back the tide of grey squirrels. But is this a long-term solution? 

Is culling grey squirrels a viable option?

In conservation hard decisions have to be made, especially as we are now in the midst of a mass extinction crisis. Whilst it may seem cruel, I believe that there are huge benefits to be gained from the eradication of invasive species, especially where they have decimated populations of native ones. For example, a recent study has found that the removal of a few introduced species such as mice and cats from 169 islands around the world would save huge numbers of at-risk species, especially seabirds, who are vulnerable to these ground predators they are not adapted to dealing with. The same applies to the culling of grey squirrels to save the reds, and this approach has been effective in certain areas of the UK. In Anglesey, Wales, for instance, the removal of over 6000 greys has allowed red squirrels to rebound in numbers. This has been helped by the fact that Anglesey is virtually an island and so re-population by greys is easy to manage.

This example seems to be an exception though, and in fact most areas of the country where culling has been taking place there is reported to have been little or no effect on overall grey squirrel population numbers. 1.5 million greys were culled in the 1950's to no avail, and numbers in culled areas return to normal after 3-10 weeks. There is no doubt that extensive culling and monitoring of grey squirrels is largely the reason that reds still persist in certain areas, thanks to the tireless efforts of passionate and dedicated groups and individuals across the country. However, the sheer number of grey squirrels, around 2.5 million in the UK, has led Stephan Harris, Carl Soulsbury and Graziella Iossa to conclude in a comprehensive review of grey squirrel management that there is limited evidence to support grey squirrel culling for the benefit of reds in the long-run, and that eliminating them from the UK by culling is impossible. 

Are new laws surrounding rescue and release necessary, and what are the alternatives?

The near impossibility of eradicating the grey squirrel makes me wonder how necessary the new laws surrounding rescue and release are. If large scale culling has proved ineffective, the numbers of greys coming out of rescue centres will be largely insignificant in affecting red squirrel populations, as long as there are rules in place that any greys rescued from or around important red squirrel areas are relocated elsewhere. Whilst the government says "There is no requirement for vets to euthanise injured or healthy squirrels as a result of this order", the reality is that if forbidden to release grey squirrels, rescue centres will have no room to keep them all long-term, and so will most likely have to euthanise them. I think this is a betrayal of the public's good nature, as people bringing in wild animals expect them to be released. If they think that they might be euthanised even when they are healthy, they may feel inclined to look after them themselves. Whilst this may be well intentioned these are wild animals and should not be kept as pets, and I think we will see an increase in this once the laws come in to effect.

If getting rid of greys is impossible, is it better to accept that they are here to stay? For many people grey squirrels are the only squirrels they have ever seen, and certainly have a popular following if the numerous petitions against culling and changes to the rescue laws are to go by. Benefits of grey squirrels are overlooked, and as they are now fully established may be having positive influences we don't fully understand. In their report, Harris, Soulsbury and Iossa suggest that damage caused by greys to trees can provide habitat for fungi and invertebrates, and that those trees killed by grey squirrels can provide nesting sites. They also particularly target sycamore trees, which are an invasive species themselves.

Although Britain's red squirrels are declining, they are of least concern for conservation globally as populations elsewhere are still very healthy and genetically they are virtually indistinct as mentioned earlier. I do not mean to suggest that we should just consign them to their fate, and it would certainly be a sad day if they were allowed to disappear from our shores altogether or existed only on islands and heavily controlled reserves. With the UK now being one of the most nature-depleted in the world, with one in seven native species facing extinction and half in decline, there must be a re-evaluation of priorities so that resources and efforts are used realistically in order to conserve what red squirrels we have left.

Localised culling must be a part of red squirrel conservation in the short-term, if only to maintain the status-quo in strongholds where they remain. Whilst habitat loss is not a threat for reds at the moment, forests planted in Scotland and England have not increased the area of habitat they can utilise and many new forests in the north of England exclude greys but support only small populations of reds. Increasing good quality habitat is essential then in any plan to ensure reds spread to other areas. The resurgence of the pine marten, a natural predator of squirrels, could also be a positive as they are better at catching greys, and their return has resulted in population crashes of greys in Ireland. Two other potential long-term solutions include finding a cure for the squirrel pox virus, which would greatly slow the spread of greys, or finding a way to sterilise greys. An injectable vaccine for SQPV does exist, and scientists are working to develop a way to deliver it orally. This would never be cheap enough to roll out across the whole country, but would be useful to combat the disease in targeted areas. A contraceptive for grey squirrels also exists, and trials have been carried out in parts of the country. The problem is specifically targeting grey squirrels as in areas they coexist there may be risks of reds becoming sterilised too if they eat bait intended for greys. It might even be possible to require rescue centres to sterilise and vaccinate grey squirrels when they are brought in, so they can be released but pose no further risk to red squirrels.

What is the future for reds and grey squirrels? 

Although in principle we should be eradicating invasive species, this issue is complex and does not have an easy fix. The attitude that greys must be gotten rid off at all costs I feel is outdated, and is not as simple in practice. If money and effort currently used for the mass culling of greys was used in other ways, I believe that we would be closer to a long-term solution than at present. I hope that the government will change their mind on the laws surrounding release of grey squirrels, as I believe this is an insignificant measure which will not have any impact on the population overall. This is definitely a controversial topic and emotive for many, so I'd be interested if anyone wanted to share their views on the matter!