A ban on the unlicensed culling of mountain hares will come into force from 1 March, the Scottish government has said.
They are being given the protection under new regulations introduced to Holyrood, which MSPs voted in favour of in June last year.
Concerns had been growing about falling numbers of the native species.
But gamekeepers said MSPs made a "grave mistake" and the move was bad for land management.
They said culls were necessary to prevent damage being caused to sensitive habitats as well as reducing the risk of a tick-borne disease spreading to grouse.
Previously a licence was only required during the closed season for shooting hares - which runs from March to the end of July.
From March this year, licences will be required throughout the whole year and it will be illegal to intentionally kill, injure or take mountain hares at any time unless one is obtained.
Public body NatureScot will oversee the new licensing arrangement.
Scottish government said licences would be issued only under certain circumstances, such as concerns for public health or protection of crops and timber.
The ban is an addition to a new law to increase sentencing for wildlife crime.
The Scottish Greens had sought greater protection for mountain hares as an addition to a new law to increase sentencing for wildlife crime.
An amendment from Green MSP Alison Johnstone was passed by MSPs by 60 votes to 19.
Maximum penalties for hunting or harming mountain hares without a licence include five years imprisonment and unlimited fines.
Conservationists had long campaigned for tougher rules on mountain hare culls.
Ecologists say numbers have been in decline since the 1950s with Scottish government figures suggesting about 26,000 hares are killed every year.
Natural Environment Minister Ben Macpherson said protecting Scotland's wild animals in their natural environment was a "key priority" of the Scottish government.
Donald Fraser, of NatureScot, added: "Mountain hares - our only native hare - are an important and valued species in the Scottish hills.
"This increased protection will help ensure healthy populations of mountain hares can be found and enjoyed in the mountains, while giving some recourse when there is a need to prevent damage being caused to saplings or sensitive habitats."
The Scottish Gamekeepers Association has described the new regulations as a "bad law" and said the views of rural working people had been ignored.
Landowners' organisation, Scottish Land and Estates, said the hares were "thriving" on Scottish moors.
In 2019, landowners groups and gamekeepers said more mountain hares had been counted on moorland managed for grouse shoots than unmanaged moorland.
The regulations are part of the Animals and Wildlife Act which will also see new licensing requirements for people breeding puppies, kittens or infant rabbits.
Legislation known as Lucy's Law will also be introduced to end unlicensed selling of dogs and cats in Scotland under the age of six months.
The ban is named after Lucy, a Cavalier King Charles Spaniel who died in 2016 after being poorly treated on a puppy farm.