The Scottish SPCA has renewed its call for the annual guga hunt on the island of Sula Sgeir to be banned.
Scotland's animal welfare charity has also written to the Scottish Government and Scottish Natural Heritage (SNH), requesting that plans not to monitor the hunt are reviewed if licences continue to be issued.
Each August two thousand gannet chicks, known as gugas, are beaten to death on Sula Sgier by hunters from Ness, on the Isle of Lewis, in order to be eaten.
Responsibility for licensing the hunt has this year been transferred from the Scottish Government to SNH.
Chief Superintendent Mike Flynn said, "These birds are killed by being struck on the head with a heavy implement.
"This is an abhorrent method of slaughter which should be banned.
"The licence issued states that the birds must be killed humanely, yet there is no requirement for the hunt to be inspected and we understand SNH does not intend to do so.
"We believe it is entirely appropriate to ask for the body issuing the licence, which effectively certifies that this practice is not cruel, should ensure it is monitored and that the licence it has issued is being adhered to.
"We are concerned that many of these birds will not be killed by a single blow.
"Causing any of these birds unnecessary suffering would be an offence and as such we would expect future licences to be denied.
"If inspections are not undertaken and if it cannot be demonstrated that these birds are not suffering then we find it impossible to conclude that issuing licences can be justified."
We reject arguments that guga hunting should be granted special dispensation on the grounds of tradition.
"We appreciate that guga hunting was a way of life for the people from Ness and that gannet chicks were an essential food supply hundreds of years ago," said Chief Superintendent Flynn.
"However, brutalising animals in this way under the guise of tradition has no place in modern society."