Birdman won best feature, best lead for Michael Keaton and best cinematography at the 30th annual Film Independent Spirit Awards presented in Los Angeles on Saturday night.
Richard Linklater was named best director for Boyhood while Julianne Moore was best female lead for Still Alice.
The supporting actor awards went to J.K. Simmons for Whiplash and Patricia Arquette for Boyhood.
Laura Poitras' documentary Citizenfour, which details how she became one of the first reporters to have been contacted by Edward Snowden as the whistleblower prepared to turn over materials that would reveal the extent of the NSA's surveillance around the world, took the documentary prize.
Nightcrawler writer-director Dan Gilroy won the best first feature and best screenplay gongs.
Best international film was Ida, director Pawel Pawlikowski's drama about a young novitiate nun in 1960s Poland who, on the verge of taking her vows, discovers a dark family secret dating from the Nazi occupation.
Here is the complete list of winners:
BEST FEATURE
Birdman
Producers: Alejandro G. Iñárritu, John Lesher, Arnon Milchan, James W. Skotchdopole
BEST MALE LEAD
Michael Keaton, Birdman
BEST FEMALE LEAD
Julianne Moore, Still Alice
BEST DIRECTOR
Richard Linklater, Boyhood
BEST SUPPORTING FEMALE
Patricia Arquette, Boyhood
BEST SUPPORTING MALE
J.K. Simmons, Whiplash
BEST SCREENPLAY
Dan Gilroy, Nightcrawler
BEST DOCUMENTARY
Citizenfour
Director/Producer: Laura Poitras
Producers: Mathilde Bonnefoy, Dirk Wilutzky
BEST INTERNATIONAL FILM
Ida (Poland), Director: Pawel Pawlikowski
BEST FIRST FEATURE
Nightcrawler
Director: Dan Gilroy; Producers: Jennifer Fox, Tony Gilroy, Jake Gyllenhaal, David Lancaster, Michel Litvak
BEST FIRST SCREENPLAY
Justin Simien, Dear White People
BEST EDITING
Tom Cross, Whiplash
BEST CINEMATOGRAPHY
Emmanuel Lubezki, Birdman
JOHN CASSAVETES AWARD
Land Ho!
Writers/Directors: Aaron Katz and Martha Stephens; Producers: Christina Jennings, Mynette Louie, Sara Murphy
LENSCRAFTERS TRUER THAN FICTION AWARD
The Kill Team, Director: Dan Krauss
PIAGET PRODUCERS AWARD
Chris Chison
KIEHL’S SOMEONE TO WATCH AWARD
H., Directors: Rania Attieh and Daniel Garcia