Tasmania has deferred logging an area important for the breeding of the endangered swift parrot.

Forestry Tasmania will defer harvesting the coupe in the Wielangta State Forest, in the state's east, pending further monitoring of swift parrot behaviour in the area.

Resources Minister David Llewellyn said a lot of swift parrot activity had been reported in the Wielangta area.

"It has now become clear that a significant number of swift parrots will nest in Wielangta this season.

"We are keen to make sure the habitat of the parrot is conserved right through its migratory cycles."

Swift parrots breed in Tasmania between September and January after wintering on the Australian mainland.

Breeding swift parrots are largely dependent on blue gum flowers as a food source and on suitable nesting hollows within a short distance of this food source.

Most breeding occurs in the near-coastal areas of south-eastern Tasmania.

The Australian Greens estimate there are only around 1,000 breeding pairs of swift parrots in existence.

Greens leader Bob Brown lost a High Court battle in May to stop logging the 10,000 hectares of the Wielangta State Forest.

He condemned the deferment as short-sighted.

"The one-season stay of logging at Wielangta is pre-extinction blinker tactics by Forestry Tasmania," he said.

"Next year (it) will wreck their ancient nesting ground."

The Greens and conservationists have fought for years to protect the Wielangta habitat of the swift parrot.

Tasmanian Greens environment spokesperson Cassy O'Connor said Mr Llewellyn spoke about the presence of swift parrots at Wielangta as if it were a revelation.

"Of course, the Greens welcome the decision to defer logging in this particular blue gum-rich coupe at Wielangta," she said.

"But if the government is serious about protecting this species it will do more than defer logging - it will cease all forestry operations within the swift parrot's habitat range."

Ms O'Connor said the birds' blue gum habitat in Tasmania was mostly on unprotected land and quickly disappearing.