Photojournalist Rena Effendi’s father was famous in the world of butterflies; he was a lepidopterist who spent seven years hunting one species. Effendi remarks drily that seven years was longer than Rustam Effendi lasted in any of his four – possibly more – marriages. (When asked for a precise headcount of wives, his old friend answers: “God knows!”) Effendi was 14 when her father died; he had been a mostly absent presence during her childhood, and had another family while being married to her mother. At his funeral, she remembers only women around his coffin. Years later, she discovered from his Wikipedia page that he had a butterfly named after him, the rare and endangered Satyrus effendi.

This gentle, perceptive documentary follows Effendi as she searches for the elusive butterfly, which flies for just two weeks a year high in the Caucasus mountains – and chases her father’s ghost. Her mother is evasive, saying only that she would have forgiven Rustam almost anything. Effendi’s first hurdle on her mission to catch the butterfly is obtaining permission to travel to its habitat, on the border between Azerbaijan and Armenia. Effendi is Azerbaijani; her father died just as the Soviet Union teetered on the brink of collapse, after which tensions exploded between Armenia and Azerbaijan and war broke out. There is now a fragile peace.

Effendi is assisted on her search by lepidopterists; at the zoological institute in Azerbaijan, Dmitrii V Morgun tells her that butterflies all have their own characters – there are intelligent species and stupid species. Naturally the Satyrus, her father’s butterfly, is melancholic and brooding. Morgun accompanies Effendi on her search for the Satyrus; her father only took her butterfly hunting once in her childhood. It’s a moving, thoughtful film.

• Searching for Satyrus is in UK cinemas from 19 April.