A north Queensland farmer has copped a $15,000 fine after more than 50 birds were fed corn laced with a lethal dose of poison.
The Department of Environment alleged the birds died from pesticide poisoning on a grazing and grain producing station near Cairns in 2011.
At least 10 were protected brolgas.
Station owner Osprey Australia was found guilty in the Cairns Magistrates Court on Wednesday of breaching the Nature Conservation Act.
The firm's managing director Richard Thiele, 72, was fined $15,000 but no conviction was recorded.
Tests revealed the birds died from lethal doses of pesticide found in corn which had been placed in small piles throughout the 2,300 hectare property.
Thiele's lawyer argued that anyone could be responsible for the deaths as the large property is accessible to members of the public.
Magistrate Suzette Coates said although whoever planted the poison may not have intended to harm the birds, she found there was intention to kill some kind of animal.
No motive was revealed in court.
Thiele will personally face court later this year charged with breaching the Nature Conservation Act in relation to the dead birds.
Brolgas, part of the crane species, became the official bird emblem of Queensland in 1986.
