J.D. Irving Ltd. will learn in June whether it must stand trial on charges of destroying Great Blue Heron nests under the federal Migratory Birds Convention Act.

New Brunswick Provincial Court Judge Patricia Cumming will rule on an application by Irving to strike down the act as unconstitutional because it is too vague, making compliance by logging companies impossible.

The forestry company is challenging the act after being charged with destroying the nests of several Great Blue Heron while building a logging road on its property near Cambridge Narrows in July 2006.

Federal prosecutor Paul Adams argued that the company's constitutional challenge doesn't make sense.

Irving lawyer Christopher Wayland maintained that the act was designed to cover hunting, not the destruction of bird nests during lawful forestry activities.

But, Adams said the law is clearly about more than hunting, since most of the species it protects are not game birds — citing the Great Blue Heron as an example.

The government position is that Parliament has the power to make regulations to conserve and protect migratory birds because they travel across provincial and national borders, Adams said.

He added that power can't be restricted as much as the J.D. Irving company would like.

Wayland argued the law is too broad and vague regarding nests.

Adams said it has to be broad so there is "room to manoeuvre" in order to cover as many bird species as possible.

He also argued that the law is clear: protecting nests is part of protecting migratory birds, and commercial forestry can't be allowed to destroy those nests.

During the hearing, Albert Koehl, a lawyer with Toronto-based ecojustice (formerly Sierra Legal Defence Fund), told the court that the law isn't tough enough and is rarely enforced.

"We know logging companies are worried about the provision because the provision, in our view, has always been quite clear. It says you can not destroy a migratory bird nest. But the federal government, in particular Canadian Wildlife Service, has not been taking action against logging companies," Koehl said Tuesday.

If the Migratory Birds Convention Act is upheld, a full trial on the charges will then begin.

In February 2007, a company lawyer entered not-guilty pleas on behalf of J.D Irving Ltd. and a foreman, and then filed court documents showing they would attempt to have the act itself declared unconstitutional.

The company closed the logging road in September 2006 after a Natural Resources conservation officer found six destroyed nests. It was later found that between 12 and 20 heron nests had been destroyed.