不要责怪灰松鼠:它们的英国入侵与我们有更大的关系

DNA分析显示，灰松鼠并不是我们想象的那么好的入侵者, 人类在英国的传播中发挥了更大的作用.

Grey squirrels were imported to the UK from the 1890s onwards, 传统观点认为，它们在英国迅速蔓延是因为它们能够适应新的景观. 不同种群的灰松鼠被认为杂交出了一种“超级松鼠”，这种松鼠能够更好地适应和传播.

However, new research shows greys may not be as hardy as once thought, 并且在征服不列颠群岛的过程中得到了人类更多的帮助. Dr Lisa Signorile compiled a DNA database of nearly 1,在云顶国际官方网站攻读博士学位期间，她在英国和意大利研究了500只灰松鼠 Zoological Society of London.

她能够证明不同的松鼠种群在基因上仍然是不同的, 这意味着它们没有进行太多的杂交，也没有创造出超级松鼠. 人口之间的差异也意味着Signorile博士和合作者能够追踪新地区的人口来自哪里.

In many cases, new populations of grey squirrels are not related to nearby populations, 和 instead have come from a long way away. The only way they could have travelled so far was by human intervention. For example, 阿伯丁的人口与汉普郡的人口关系最为密切, around the New Forest area.

Poor invaders

“自20世纪30年代以来，人们一直认为灰色松鼠都是一样的, spreading across the country as one invasion front. After a century, genetics has proved that this isn’t correct. 它们并不擅长繁殖和混合——事实上，它们有明显的近亲繁殖迹象,” said Dr Signorile.

“灰松鼠并不是像我们想象的那样疯狂的入侵者——它们的蔓延更多是我们自己的错.” The research is published in two papers, in the journals Biological Conservation 和 Diversity 和 Distributions.

Signorile博士还发现，传播灰松鼠最严重的罪犯之一是第11任贝德福德公爵, Herbr和 Russell. Russell was involved in many successful animal conservation projects, 但他在沃本公园的家中放生了许多灰松鼠，并将它们作为礼物送给了英国各地.

罗素还在摄政公园释放了大量的灰熊，很可能造成了伦敦灰熊的流行. Signorile博士说:“那时候我们还不知道入侵物种会造成如此大的破坏。.

Still on the move

Although not as good invaders as previously thought, greys still outcompete native red squirrels for resources, 和 carry diseases that kills reds but not greys. Greys have largely displaced reds in Engl和 和 Wales. “Eradication or control programs are still needed, in particular in areas where red squirrels are present,” said Dr Signorile.

Scotl和 is one of the last places to be invaded, but humans are still helping grey squirrels move into new areas today, albeit more unwittingly. Signorile博士还调查了最近出现的灰色斑点的来源.

她发现2010年在斯凯岛捕获的一只海豚来自格拉斯哥. In this case, 基因分析证实了一篇报道，这只松鼠藏在一辆汽车引擎盖下，逃到了斯凯岛.

Dr Signorile also examined the case in Italy, 那里的灰松鼠是最近才引进的，直到2012年都可以作为宠物出售. 她对该国不同地区人口的分析证实了灰色松鼠的非法交易. “这表明，‘有吸引力和可爱’的物种往往会被人类传播得更远,” said Dr Signorile.

Preventing the spread

除了揭示灰色松鼠的成功在一定程度上是基于我们的帮助这一令人惊讶的结果之外, Signorile博士说，这项研究还表明需要新的方法来解决它们的传播. “We put a lot of money into controlling grey squirrel numbers, 但没有人试图阻止他们的流动，也没有人阻止人们把他们带走. 决策者应该研究如何防止灰色病毒通过人手传播.

“公众也需要意识到不小心移动松鼠的风险. People think grey squirrels are already everywhere, so it is not a problem, but it can be, 尤其是在苏格兰那些还没有定居人口的地区.”

遗传研究的结果也可以应用于其他入侵物种, said Dr Signorile, especially where human movements may play more of an important role. 这些包括更具“观赏性”的物种，被认为是有吸引力的, such as London’s ring-necked parakeets 和 Chinese water deer.

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“Mixture or mosaic? 英国灰松鼠的基因模式支持人类介导的“跳远”入侵机制” by Signorile, Lurz, Wang, Reuman, 和 Carbone is published in Diversity 和 Distributions.

“用DNA分析来调查人类介导的入侵物种易位”, Reuman, Lurz, Bertolino, Carbone, 和 Wang is published in Biological Conservation.