The grey seals were killed on the small island of East Linga
A fisherman has been warned he could be jailed for clubbing 21 grey seal pups to death on a remote Shetland island.
Jimmy Stewart, 47, a crewman on one of Scotland's biggest trawlers, admitted mutilating, beating and crushing the animals on 29 November.
The discovery on a beach on the island of East Linga was made by staff from Scottish Natural Heritage (SNH), who were carrying out a survey.
Sentence at Lerwick Sheriff Court was deferred.
Stewart repeatedly battered the heads of the seals with a wooden fence post.
Defence solicitor Tommy Allan told the court his client could offer no explanation why he had killed the seals.
Sheriff Graeme Napier warned Stewart that a custodial sentence was a possibility.
Sentence was deferred until 25 March.
Stewart was warned he faced jail when he returns to court
Charges against a second man also accused of being involved, John Eunson, were dropped.
SNH welcomed the conviction.
John Uttley, SNH's area manager, said: "This is a shocking case. The degree of casual cruelty shows that there is still a great deal of ignorance and prejudice about grey seals.
"Of course we hope that this is an isolated case, but it is very difficult to obtain the evidence required for a successful prosecution, and suspicions have been raised in the past. Shetland's positive image depends to a large part on its wildlife, including seals.
"These animals help to attract people and business to the islands and many people feel a strong connection with them. Conflicts do sometimes arise with people's business but there are legitimate ways of resolving these."
He added: "The brutality described in today's case towards wildlife besmirches Shetland's reputation as a place which treasures its nature and wildlife and we are pleased to see the court respond accordingly."
A Northern Constabulary spokesman said: "It was a thorough investigation into a serious case of cruelty to animals which was followed by a robust prosecution.
"As a force, we are committed to a proactive approach to wildlife crime. It will not be tolerated."
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