Dating back to 1621 Massachusetts, Thanksgiving is one of the biggest national holidays in America, celebrated on the fourth Thursday in November.

Shops close for the day, curtains fall across Broadway and families come together around the dinner table to give thanks for the previous 12 months.

The centrepiece of this gathering of the generations is a succulent roast turkey.

In Jimmy Hayward's computer-animated comedy, the feathered fowls strike back, attempting to change the main course of history so that they can be granted a stay of execution every winter.

Free Birds offers a surprising alternative to turkey for the Thanksgiving feast, which should appeal to both vegetarians and carnivores, but manages to vastly increase the calorie count and fat and carbohydrate contents. Considering America's battle with obesity, it seems unlikely that families will be trading in the giblets in order to pile on another couple of pounds.

The film's unlikely hero is a turkey called Reggie (Owen Wilson), who realizes that the abundance of food offered up by the farmer is merely a plot to fatten the flock.

Having caused a fuss, Reggie is kicked out of the coop and, by chance, he is chosen by the President's cherubic daughter (Kaitlyn Maher) as the one bird to be pardoned from the carving table.

Transported to Camp David where he enjoys a daily routine of pizza and trashy TV, Reggie thinks his troubles have evaporated until Jake (Woody Harrelson), founder and sole member of the Turkey Freedom Front, kidnaps Reggie and pressgangs him into a top secret mission of the utmost importance.

"We're going back to the first Thanksgiving to get turkeys off the menu," booms Jake.

Together, they break into a military facility and use a time-travelling device called S.T.E.V.E. (George Takei) - which stands for Space Time Exploration Vehicle Envoy - to head back to 1621 to spearhead a turkey uprising.

The birds immediately cross paths with colonial hunter Myles Standish (Colm Meaney) and his men, who are scavenging for food.

Cluckily, Reggie and Jake are rescued by Chief Broadbeak (Keith David) and his turkey tribe including the chief's courageous daughter Jenny (Amy Poehler), who helps the heroes from the future appreciate that, "When you're in a flock, you know you belong to something bigger."

Free Birds is light-hearted gobbledygook that lacks visual sophistication or belly laughs. Wilson, Harrelson and Poehler deliver solid vocal performances while Meaney is a lacklustre villain.

The script, co-written by Scott Mosier, is sporadically amusing, like a disclaimer caption at the beginning of the film what affirms this is a work of fiction - "Except for the talking turkeys. That's totally real."

But there's no originality or verve on screen and the plot twists and turns in obvious directions.

Parents will probably be stifling yawns.