Isabella Rossellini: A great actress enters the animal kingdom as a bee and a hamster

In her new film, the actress dresses up as a rodent – it's all part of her interest in maternity, she tells Geoffrey Macnab

A snowy morning in Berlin and Isabella Rossellini is sitting on the top floor of a high-rise apartment, discussing the domestic arrangements of hamsters, wasps and cuckoos. Dressed in black, Rossellini, now 60, still cuts a glamorous figure. She looks remarkably like her mother Ingrid Bergman, star of Casablanca. She has the same big eyes, high cheek bones and melancholy demeanour. It's easy to make the comparison because there is a big pile of booklets promoting a new photo book about her mum on the table in front of her: Ingrid Bergman: A Life In Pictures (which will be published later in the year.)

The reason Rossellini is discussing hamsters is that she has just made Mamas, a series of short films exploring the maternal instincts of animals. This is a follow up to her earlier Green Porno (in which the subject was mating.) The point about hamsters is that they sometimes eat their babies – although they are very good mothers otherwise. "I take classes at the university about animal behaviour and biology. I came across a book by a woman biologist called Marlene Zuk," says Rossellini, explaining her inspiration for the project.

We all assume we know what maternal instinct is. Rossellini makes the point that there is "much diversity and variety" in maternal behaviour in nature as there is in courtship strategy and lovemaking. "It's comical. I find animal behaviour to be humorous."

Mamas is indeed a funny and eccentric endeavour. To illustrate her points, Rossellini dresses up as the animals she is describing. We therefore get to see her in her hamster outfit, munching on her little ones.

"Before Darwin, our world was very religious. People saw altruism as something given by God for us to be good so that we could go to Paradise. Darwin was looking at the biological origins of altruism, which would contradict (the idea of) natural selection," Rossellini ruminates, beginning to sound more like a university lecturer than a model and actress.

Her film picks up on research from women biologists such as Zuk into self-sacrifice in the animal world. This research underlines the part that "incredible managerial skills" play in being a mother in nature. It's not all about altruism: "The example I always give is a hamster. If a hamster has too many babies she knows she cannot carry, she not only abandons them but she eats them. That means she doesn't have to go out and hunt for food for herself."

When I ask about her own mother, Rossellini seems a little startled. "Well, you know, it's hard to jump from a hamster to Ingrid Bergman." The leap from the maternal behaviour of rodents to that of one of the most glamorous stars in Hollywood history doesn't impress her. Nonetheless, she answers.

"She (Bergman) was rather an exception because she had a huge career in the Forties and Fifties when, of course, there were other actresses but it wasn't common for women to work," Rossellini reflects. "My mother acted because she wanted to act. She never saw that as a job. She always said, 'I am surprised that people wanted to pay me. I would pay them!'"

When Bergman appeared in Casablanca, she wasn't on close terms with her co-stars. "She had that funny line," her daughter recalls. "She said Humphrey Bogart didn't socialise much. He would retire to his trailer. 'I kissed him but I don't know him very well,'" Rossellini recalls Bergman saying.

Nor did her mother know how Casablanca would end. She used to pester the director Michael Curtiz, asking which man she was supposed to be in love with: "Humphrey Bogart or my husband?" Curtiz would reply unhelpfully, "We don't know yet." The script was still being revised even after filming had begun.

"It is actually the in-between that makes the film so great," Rossellini says of the uncertainty on set during the making of her mother's most famous movie. And, no, she doesn't mind too much being asked about it. "In a way, it's wonderful that there is a film that has become a bit like Beethoven's Ninth that everybody has seen. When I speak to very young people, they know my mother from Casablanca."

I ask how she reacted when she saw her mother's other films like Stromboli and Voyage To Italy, directed by her father Roberto Rossellini. Very raw, intense and disturbing dramas about troubled relationships, these were far removed from the escapism of Hollywood. When Ingrid Bergman left Hollywood to work with (and eventually marry) Rossellini, it caused a huge scandal and derailed her career. "It's as if a big actress nowadays, like Anne Hathaway, would go and make a film in Afghanistan," Bergman's daughter says.

Bergman wasn't allowed back to Hollywood for many years and became a persona non grata at the studios that once fawned over her. "It was tough. She couldn't see her first daughter from her first marriage for eight years because she wasn't allowed back to the States and the father didn't allow the daughter to travel to Europe. That was very painful. Of course, she loved making films and she had many friends – Hitchcock, Cary Grant etc. They came to Europe to visit her but it wasn't the same as continuing to work with her, which she would have liked."

In spite of Bergman's eventual "forgiveness" by Hollywood, the Oscar she won for Anastasia and the later films such as Indiscreet, Bergman never wanted to return to the US. "She got frightened of how America can turn and persecute you, so she remained in Europe where she felt, at that point, safer."

Rossellini's own childhood was more Stromboli than Warner Bros. "The first time I went to Hollywood, I was 25 years old. My background was mostly Italian." Her career is as varied as her background. She appears in independent movies. She is an author and model. She is active in wildlife conservation and is a champion of silent cinema – she is very involved in film preservation. Having just finished Mamas, she is now working on Bestiaire D'Amour, a dramatic monologue with she is co-writing with Luis Bunuel's old screenwriter Jean-Claude Carrière. This is about "love among animals" and will be told in the same comical way as Green Porno and Mamas.

She had a second new film in Berlin this week, The Zig Zag Kid, an adaptation of Israeli novelist David Grossman's picaresque coming-of-age story. True to her usual screen image, Rossellini plays a femme fatale. The film is directed by young Belgian Vincent Bal.

Like her mother, Rossellini has always stayed in touch with her European roots. When Bal invited her to appear in The Zig Zag Kid, a modestly budgeted Dutch movie, she was happy to accept.

"I live in New York but I am always delighted to come to Europe because I am European and grew up here until I was 20. I am not only Italian, I am partly Swedish. When my parents divorced, I was three years old and went to live in Paris… when I am offered a film in Europe, I come with great enthusiasm!"

This article appears in tomorrow's Radar magazine