Terrestrial mammals (including bats)
It is no surprise that an isolated island group like Shetland has a very restricted terrestrial mammal list. Apart from migrant and vagrant bats, all of the terrestrial species have been introduced by humans. Other than cetaceans, the only native Shetland mammals are Grey and Common Seal.
Bats are recorded in Shetland just about annually, but most remain unidentified. They can usually only be identified in the hand or by using a bat detector, a device that can record the diagnostic calls, which are usually too high-pitched to be heard by human ears. Nevertheless, despite these difficulties, seven species have been recorded in the islands. NB In Britain. it is illegal, without a license, to intentionally catch, handle or disturb wild bats. Some species are known to be carriers of rabies so if you do find a bat in Shetland do not handle it.
Rodentia: Muridae (rats & mice)
Wood Mouse Apodemus sylvaticus
Common throughout the islands. Known in Shetland, more appropriately in these almost treeless islands, as the 'Hill Mouse'. It will enter occupied houses, but tends to do so in winter rather than summer. The distribution includes Foula (named as A. s. thuleo Hinton 1919) and Fair Isle (A. s. fridariensis Kinnear 1906), but absent from Out Skerries. The population on Yell is also given a subspecies name (A. s. granti Hinton 1914), but the status of populations on other islands appears to undetermined; they are presumably as distinct from Mainland British populations as the named subspecies. The understanding of how this species arrived in Shetland has a complex history. In the 1950s, Venables & Venables (1955) considered this species to be indigenous to Shetland, colonising naturally after the last ice age. Berry & Johnston (1980) believed that the species had been brought as a commensal (a species dependant on man) from Norway by Norse settlers. More recently, however, remains have been found in pre-Norse Bronze Age excavations, meaning it arrived with earlier human colonists..
House Mouse Mus musculus
Common almost throughout the islands, but seemingly much scarcer than the 'Hill Mouse'. It is a commensal species, dependant on humans for survival, and usually found indoors. Presumably arrived with early human colonists around the same time as the 'Hill Mouse'.
Black Rat Rattus rattus
Presumably extinct. First recorded on ships arriving sometime between 1654 and 1680. The only documented localities were at Lerwick Harbour and on Whalsay, both thriving ports. The species is a commensal which is frequently on board vessels (an alternative name is Ship Rat). There have been no recent sightings, although it has been known to be on some visiting vessels. The species is not native to Europe but has been recorded in Britain since at least Norman times.
Brown Rat Rattus norvegicus
Common almost throughout the islands. Originally introduced to Shetland from visiting vessels, probably slightly later than the arrival of the Black Rat; Venables & Venables (1955) suggest that it may have been in about 1730. Far more resilient and adaptable than Black Rat, it thrives in parts of Shetland, but is said to be scarce or absent on Yell, Fetlar, and in west Mainland.
Lagomorpha: Leporidae (hares & rabbits)
Brown Hare Lepus europaeus
Extinct. Introduced at Cunningsburgh in about 1830 by the MP Samuel Laing. By the 1890's they had spread over much of the south and central Mainland with a few in west Mainland. Small numbers were also released at Reafirth and Windhouse on Yell in 1882 but these quickly disappeared. As the species spread they caused 'considerable damage to the crops' and were enthusiastically persecuted. The last known records involve several in the Lunna area in 1935 and two trapped in a turnip rig at Spiggie in 1937.
Mountain Hare Lepus timidus
Locally common on hills on Mainland and may also survive on the island of Vaila. Introduced by a Mr. Anderton from Perthshire who released two pairs to Vaila in about 1900 and by Dr. Munro who released individuals on the Kergord estate in about 1907.
European Rabbit Oryctolagus cuniculus
Common throughout the islands, even on uninhabited islands. Originally kept for meat and fur in warrens, often on isolated islands or in dunes e.g. on the West Isle, Burra at Minn and the Links of Meal) and on the isles of Oxna, Hildasay and Papa Little in 1654 (Leigh 1908) and on the island of Balta off Unst in 1774 (Low 1879). It has spread from these locations, presumably after they stopped being actively managed, but they must have been introduced deliberately elsewhere e.g. said to have introduced to Foula in 1879 (Evans & Buckley 1899). Myxomatosis spread through the islands in the 1970s and 1980s and severely depleted the population. It has recovered since, but large warrens no longer occur.
Eulipotyphyla: Erinaceidae (hedgehogs)
European Hedgehog (Erinaceus europaeus)
Common almost throughout the islands, including Fair Isle, but apparently extinct on Foula and absent from Out Skerries. The earliest introduction appears to date from about 1860 at Veensgarth at Tingwall (Evans & Buckley 1899). the dates of subsequent introductions to other islands are unknown.
Chiroptera: Vespertillionidae (vesper bats)
Serotine Eptisicus serotina
Vagrant: one was found on Whalsay on 18th October 1991. It was sent to Aberdeen University and its identity confirmed. This was the first Scottish record of the species which has a breeding range that only extends as far north as southern England and Denmark.
Leisler's Bat Nyctalus leisleri
Vagrant: six records.
1968 - Ollaberry, north Mainland, 2nd August 1968 (sent to NMS),
1996 - East Burrafirth, west Mainland, 16th October 1996 (confirmed by Aberdeen University)
2002 - Sumburgh, south Mainland, 9th March 2002
2011 - Whalsay, 10th June
2012 - Burrafirth, Unst, 16th December
2017 - Setter, Sandwick, 17th October
This species, sometimes known as Lesser Noctule, has recently been found breeding as close as south-west Scotland.
Common Noctule Nyctalus noctula
Vagrant: three records.
1977 - Burravoe, Yell, 25th July (sent to NMS)
1986 - Asta, central Mainland, 20th August (confirmed at Aberdeen University)
1987 - Voe, central Mainland, 23rd November (sent to Surrey where its identity was confirmed although no other details are available)
There are other field sightings of large bats which may be this species: e.g. one emerged from the unfurled sail of a Swedish vessel in Scalloway Harbour in summer 1922 or 1923, and one at Burrafirth on 29th March 1980. This is the most widespread of the larger European bats, although they are absent from northern Scotland and most of Scandinavia.
Nathusius's Pipistrelle Pipistrellus nathusii
Scarce migrant, probably recorded annually, with records in all months and a peak in October. Many records are, strictly speaking, records of pipistrelle sp., but the majority of the bats examined in the hand or recorded using bat detectors have been this species. Even in the hand, separation of this species from Common Pipistrelle P. pipistrellus or Soprano Pipistrelle P. pygmaeus requires detailed examination. The first British record of this species involved one collected on Whalsay on 22nd October 1940 which was subsequently reidentified from the specimen. The next was found at Tingwall on 15th December 1987 and was the seventh British record. At that time, Nathusius's Pipistrelle was believed to occur in eastern Europe, moving south-west for the winter, and only rarely straying to Britain. It is now known to be quite regular in eastern Britain in particular, and several maternity roosts have also been located.
Common Pipistrelle Pipistrellus pipistrellus
Vagrant: one recorded on a bat detector at the Observatory, Fair Isle on 17th October 2015. Two older records, at Sumburgh, south Mainland, on 3rd October 1982 and on Unst on 26th October 1984, are considered unsafe as Nathusius's was regarded as an extremely rare vagrant and so may not have been considered. Common Pipistrelle is the only bat that is resident in Orkney.
Brown Long-eared Bat Plecotus auritus
Vagrant: four records.
1947 - Lerwick, found hibernating in factory roof, December
1972 - Reafirth, Yell, photographed, no date
1987 - Sumburgh Airport, south Mainland, 12th March
2013 - Lerwick, 17th August
This species is almost as widespread in the British Isles as the Common Pipistrelle, but it is also the most widespread species in Scandinavia.
Parti-coloured Bat Vespertiio murinus
Vagrant: ten records.
1927 - Whalsay, 31st March
1981 - Anderson High School, Lerwick, 19th November (confirmed by Aberdeen University)
1984 - Mid Yell, 16th November (confirmed by Aberdeen University)
2001 - Whalsay, 24th November
2003 - Haroldswick, Unst, 24th August
2009 - Lerwick, 23rd June
2011 - Spiggie, south Mainland, 15th June
2013 - Bardister, north Mainland, seen entering and leaving roost site, 11th-23rd December
2015 - Uphouse, Bressay, 15th June
2018 - Scalloway, 9th-15th October
This species is highly migratory, breeding in eastern Europe, including southern Scandinavia, and flying to southern Europe to hibernate. It is a vagrant to Britain and the 1927 record was the first for Britain.
Carnivora: Mustelidae (stoats & allies)
European Otter (Shetland name: Draatsi ) Lutra lutra
Common throughout the islands, but not recorded from Out Skerries, Foula or Fair Isle. About 14% of the total UK otter population is found in Shetland (approximately 900 - 1000 individuals) - it forms a very important part of the European total and is of national and international importance. As Shetland otters are isolated from those elsewhere in their range, they may also be a genetically distinct race - they are smaller and have more clearly marked white throat patches. Once thought to be indigenous to Shetland it is now known that to keep their fur waterproof they must regularly bathe in fresh water, so they are incapable of long sea-crossings. They must have been introduced to the islands for their fur, although the date of any such introduction is unknown. Otters used to caught in traps known as otter houses and the fur was sold, fetching good prices. Shetland otters are found in coastal areas, preferring low rocky coastlines with shallow water, and feeding mainly around kelp beds on inshore fish such as eelpout, rockling and butterfish. Their holts (hadds) are usually dug out of soft peaty banks near the shore.
Stoat (Mustela erminea)
Fairly common on Mainland. Probably introduced in the late 1600s in the Dunrossness area, reputedly by a king's falconer angry at not having been provided with chicks to feed hawks taken from nests in the islands (Venables & Venables 1955). They were also introduced on Whalsay in around 1900 to 'destroy rats and rabbits but they have become extinct there.
Polecat-ferret Mustela putorius x Mustela furo
Fairly common on Mainland, despite attempted eradication programmes. This widely kept hybrid, kept as a pet or used for 'rabbiting', was accidentally or deliberately released in the 1970s and 1980s.in an attempt to control the rabbit population.
There are also a few records of other species seen in the islands. Some American Mink Neovison vison were accidentally released in the 1960s and 1970s, although fortunately they never established themselves. There were frequent rumours of a Red Fox Vulpes vulpes at loose in Delting in the 1990s and on the 31st August 1996 a dog fox was found dead on the road at Olna between Voe and Brae, apparently shot at close range. Then, an Arctic Fox Vulpes lagopus was found dead at Voe on 14th February 1997. It would appear that a few animals were brought to Shetland and let loose or even transported here as carcasses, although for what reason is unclear.
Written by Mike Pennington, Paul Harvey and Kevin Osborn Updated August 2020
incorporating information provided by Shetland Biological Records Centre run by Shetland Amenity Trust