As a children's show within writer/director Rungano Nyoni's second feature informs us, the guinea fowl is a bird known for its ability to ward off predators by gathering in groups and using its squawk to alert other birds to approaching threats. The film's protagonist, Shula (Susan Chardy), a middle class Zambian woman, can't get the childhood memory of that show out of her head. When we meet her first she's driving home from a costume party, decked out in a homemade guinea fowl costume. As Nyoni's film unspools, Shula's reasons for admiring the selflessness of the guinea fowl will become painfully clear. By a strange coincidence it's the second movie to arrive in recent weeks, following Andrea Arnold's Bird, in which a bird is employed as a metaphor for a protector against abuse.

While driving home from the aforementioned party, Shula finds the body of a middle-aged man lying on the side of the road. On close inspection she realises it's her uncle Fred. The ensuing scenes, which see a frustrated and dispassionate Shula frown as she struggles with her chaotic family members and the unreliable local police, suggest we're in for a Trouble with Harry-esque black comedy. But the laughs soon dry up as the truth about Fred's past slowly emerges.

As we meet Shula's extended family we realise they have mythologised Fred as a loveable scoundrel, a ladies man. His corpse was laid out suspiciously close to a brothel, suggesting he probably suffered a heart attack in a moment of exuberance. But while the older women weep, the younger women of the family slowly gather in support as they take the opportunity of Fred's passing to reveal his legacy of abuse.

Some of the women-directed films to emerge in the wake of the MeToo movement have hinted at the culpability of women in protecting predatory men (The Assistant; Blink Twice), but none more so than On Becoming a Guinea Fowl. The older women of Fred's family are happy to throw his victims under the bus in order to protect their family name. Fred's teenage wife, who bore his first child when she was merely 11, is cruelly dismissed as a gold digger and even blamed for his death, accused of not keeping him sufficiently well fed. This idea of a woman's place being in the kitchen echoes through the film, with Shula constantly being ordered to make breakfast or cook chicken for the mourners. The film's best scene sees an anxious Shula try to corral her uncle's various young victims while fending off countless requests to provide food for the male mourners. After confronting her father with Fred's legacy, Shula is encouraged to leave it in the past, the conversation ending with her insensitively being asked to fetch more ice cubes.

On Becoming a Guinea Fowl marks the acting debut of Zambian-British model Chardy, who comes out of the gate with one of the year's most engaging performances. Nyoni denies her leading lady any Oscar speech moments, instead forcing her to tell Shula's story largely through reactive gestures. Chardy is brilliant at portraying the unspoken frustration of being surrounded by those who have yet to catch up with your progressive ideals; Shula spends much of the film being told how she should behave, and we see the exasperation behind her eyes. The code-switching of Shula's accent serves to communicate much about her relationship with whomever she happens to be conversing with at any given time. In her most frustrated moments she speaks with a clipped British accent, as though her frustration is directed not just at her family but at Zambia itself. It's a subtle implication that she has spent time abroad and desperately wants her homeland to make the progress she's experienced elsewhere. As with Nyoni's debut, I Am Not a Witch, and the likes of Sarmad Masud and the McDonagh brothers' unflattering portraits of their ancestral homes of Pakistan and Ireland, it once again raises the thorny issue of whether a country's ills should be critiqued by a British-based member of its diaspora rather than a resident native, but as Nyoni makes all too clear here, this is a particular ill Zambia isn't yet willing to confront.

The lack of explicit confrontation in Nyoni's film may prove frustrating to viewers, but that's the point. Shula is trapped in a society unwilling to have a conversation about gender politics. The most women of an older generation can offer her is sympathy; justice simply isn't on the table. But in the sorority that develops between Shula and her uncle's young victims we're given a picture of hope, a suggestion that the young women of Zambia may be set to adopt the ways of the guinea fowl and rally together to defend themselves against predators.

Directed by: Rungano Nyoni

Starring: Susan Chardy, Elizabeth Chisela, Henry B.J. Phiri, Roy Chisha, Blessings Bhamjee