Former Greens leader Bob Brown had flagged plans for an urgent injunction on logging activities in old growth forests to protect the swift parrot.

State-owned logging group Sustainable Timber Tasmania was due to undertake logging activities in parrot habitat, but Mr Brown's lawyer Ron Merkel QC told the Federal Court that it could disrupt the bird's breeding season from September to January.

STT has agreed to hold off on logging until the case can be heard by the full court, which is not expected to meet again until February.

Mr Brown said the agreement of STT to hold off logging was "a big breakthrough".

"I am surprised because it does reflect on the massive lot of swift parrot habitat at their hands," he said.

Loggers appeared to have been caught by the reality that the public won't stand for it, he said.

An STT spokesperson said the decision to postpone logging in 19 coupes was made solely to avoid costly and time-consuming injunction arguments.

Supply commitments will still be able to be met, they said.

The swift parrot is one of several endangered animals the Bob Brown Foundation is trying to protect in a larger case against STT, and the state and commonwealth governments.

Other at-risk species include the Tasmanian devil, wedge tail eagle and giant freshwater crayfish, he said.

The foundation is arguing Tasmania's regional forest agreement is invalid because it doesn't include a legally enforceable requirement for the state to protect threatened species.

Under commonwealth guidelines, any real possibility or chance of disruption to a breeding cycle is regarded as a significant impact on a species.

Mr Brown said he expected more scientists and "citizen watchdogs" out in the forests over summer to ensure native species are protected.

Australian Associated Press