The Animal Health and Welfare (Scotland) Act 2006 provides for duty of care for animals in captivity (live-trapped animals). This makes it an offence to inflict, or allow others to inflict, cruelty or abuse on a grey squirrel held captive.
The Wildlife & Countryside Act 1981 (as amended) makes it illegal to release, or allow to escape to the wild, any captive grey squirrel.
The (Prohibition of Importation and Keeping) Order 1937 makes it an offence to keep a grey squirrel in captivity except under licence.
The Grey Squirrels (Warfarin) Order 1973 does not allow the use of warfarin on grey squirrels for the purpose of tree protection in Scotland.
This is not a definitive guide to the legislation and you should refer to the original legislation if you need more details.
In England, Wales & Northern Ireland
Squirrels and the Law
The red squirrel is a protected species in the UK and is included in Schedules 5 and 6 of the Wildlife & Countryside Act 1981 (WCA) (amended by the Countryside & Rights of Way Act 2000). It is an offence to intentionally kill or injure a red squirrel or intentionally or recklessly damage or destroy any structure or place a red squirrel uses for shelter or protection, or disturb a red squirrel while it occupies such a place.
Therefore you must be very careful about when and where you fell any trees. See the section on felling advice for more detail.
The grey squirrel is regarded as an invasive non-native species following its inclusion under Schedule 9 of the WCA. Grey squirrels are also listed in the IUCN international list of 100 worst invasive non-native species. This highlights the damage that grey squirrels cause to our native flora and fauna; a problem severe enough to be recognised at a level of global significance. As such, the grey squirrel is regarded as a pest species and is afforded no protection under the WCA. Under Schedule 9 of the WCA, it is illegal to release a grey squirrel into the wild, or allow one to escape.
This means if you trap one, you are obliged to humanely dispatch it. You must not let it go as this act would be illegal.
Anyone who carries out, or knowingly causes or permits any of the above acts to occur could be committing an offence.