How birth control could see the return of the native Red Squirrel
Updated: Mar 25, 2021
I remember the first time I saw a Red Squirrel. I was eight years old on a visit to Brownsea Island; the tiny creature, so different to the greys I was used to seeing, fascinated me for its tufted ears and vibrant colour. Now, I realise what a privilege it was to have that encounter.
Brownsea Island is one of the safest strongholds in the south of England for the now endangered species, home to around 200 of them. But why is it necessary?
The UK population of red squirrels was once around 3.5 million, however, it has now dropped to an estimated 140,000. This is in comparison to the predicted 2.5 million greys, which, ever since their introduction to the country in the late 19th century, are labeled with the blame for the decline of the smaller, red squirrel.
Now, the conflict between the squirrels is a talking point once more, as a result of the UK government supporting a project to use oral contraceptives to control the populations of Grey Squirrels.
At the end of January, Environment minister Lord Goldsmith revealed plans to support work with the UK Squirrel Accord (UKSA) to introduce an oral contraceptive for the species.
The proposed plan would see hazelnut spread, laced with the contraceptive, placed into feeding boxes and located in areas populated by Grey Squirrels.
The five-year project with the UKSA is currently in its third year and, following a trial in Yorkshire, results so far have shown that Grey Squirrel populations can be easily targeted in small woodland areas to ensure the contraceptive is effectively consumed. Further research is to be continued to assess the plan on a wider scale.
A threat to woodlands
Goldsmith referenced the squirrel’s impact on woodlands as a need for this intervention.
Bark stripping, which can either kill trees outright or cause infections to set in, is commonly caused by Grey Squirrels and, according to a new report by the Royal Forestry Society, a partnership of the UK’s largest forestry organisations, Grey Squirrels will cost the sector at least £1.1 billion over the next 40 years – in damaged timber, lost carbon revenue and tree replacements.
The wider costs also include impacts on the wider biodiversity, as Grey Squirrels are fond of targeting broad-leafed varieties including oak, which support many other species.
Additionally, this damage to woodland diminishes government efforts to tackle climate change via their new woodland regeneration programme with a plan to plant tens of thousands of acres of new woodlands.
Grey vs Red squirrel
But it is the conversation around the declining Red Squirrel population that has meant population management has been a problem for so long.
Grey Squirrels have displaced Red Squirrels through competition and disease. As discussed in our The Biome Podcast ‘Red Squirrels and Grey Squirrels’ Emma Hodson explains ‘the Grey Squirrel carries squirrel parapoxvirus, also known as squirrel pox. The Grey Squirrel can carry the virus but rarely dies from it, as it is a pathogen that it has evolved with so it has developed immunity through continuous exposure.
‘So even though it doesn’t affect them or kill them they can still carry it. But the Red Squirrel doesn’t haven’t any sort of immunity and the mortality rate for untreated infected wild squirrels is 100%... and they will die most likely within four to five days of being infected… shockingly it is responsible for 80% decline in Red Squirrels.’
The desire to preserve our native Red Squirrel has Royal backing, with the Prince of Wales inviting the formation of the UKSA. Additionally, as a patron of the Red Squirrel Survival Trust, he has written of the importance of protecting the reds: ‘These charming and intelligent creatures never fail to delight’, describing them as the ‘symbol’ and ‘benchmark’ of healthy woods.
Contraception vs culling
The UKSA’s efforts into the project were to offer a non-lethal management method to control population densities and support eradication efforts.
But this isn’t always the case, last month Conservation group Reclaiming Reds argued that controlling Grey Squirrel numbers is essential for a plan to bring Red Squirrels back to Knowsley Estate in Preston.
The plans put forward by the group, which involve trapping and shooting Grey Squirrels, has garnered fierce opposition by animal rights activists, who branded them ‘disgraceful’.
In a petition, Liz Sullivan, one of the activists, described the plans as the ‘normalisation of violence towards wildlife’.
The UKSA’s contraception plans could alleviate this reliance on culling, with fertility control offering a complementary and alternative method for wildlife management.
Dr Giovanna Massei, a wildlife management expert, described the intentions in an interview with Botstiber Institute for Wildlife Fertility Control.
‘I believe wildlife fertility control has a very, very big role to play… there are a number of contexts where I see it being used in the future, it could be used as alternatives to traditional methods such as culling or in addition to it.’
In support of this mixed approach, a study into the use of culling and fertility control on Grey Squirrel populations suggested that ‘fertility control alone is unlikely to achieve rapid enough reduction to… completely replace culling’.
So, as it stands the eradication of squirrel culling may be out of reach, however, the chances of seeing Red Squirrels back in their native habitat is looking ever more hopeful.