A dozen dead little penguins have been found dumped in a bin near a popular Tasmanian coastal reserve, with authorities calling for public help to work out how they died.

The carcasses of the birds were found in a garbage bin at Low Head Coastal Reserve on Tasmania's north coast on Wednesday.

Little penguins are the smallest of all the species. ( Supplied )

Wildlife rangers collected the dead birds and took them to Mt Pleasant Laboratories for a post-mortem examination to determine the cause of death.

A tip-off from a member of the public alerted Department of Primary Industries, Parks, Water and Environment staff on Wednesday to the bin's contents.

The birds were little penguins — also known as fairy penguins — and are the smallest of the penguin species, growing to an average height of 40 centimetres and weighing an average of 1 kilogram.

Primary Industries Minister Jeremy Rockliff said the Tasmanian Government took the matter very seriously.

"Protection of our wildlife, and indeed all areas of animal welfare, are of crucial importance," he said.

Penguin spotting tours are conducted at Low Head where spectators watch the birds on their nightly journey from the surf, up the beach and to their burrows.

Anyone with information about the incident should contact the department.