Since getting married in 2004, she has gone by her married name of Philippa Hamilton-James for private purposes, and has also usually (but not always) been credited under that name for professional purposes too.
Although she has two piercings in each earlobe, she doesn't usually wear earrings, and has never appeared on TV wearing them.
Her children's names are Fred, Gus and Arthur.
Philippa lives in an old watermill near Bath in Somerset.
She co-presents World on the Move, a BBC Radio 4 show about animal migration.
Between 2003 and 2007, she appeared in a number of TV adverts for Lloyds Pharmacy.
Philippa was educated at Westgate School and Peter Symond's College, both in Winchester, before attending the University of Birmingham.
Her husband is Charlie Hamilton-James, who works as a BBC wildlife cameraman. They married in July 2004, and have three sons.
She supports the Recycle Now campaign, which is aimed at encouraging people to take up home composting.
She's 5'6" (1.68m) tall.
She used to have a fear of snakes, until TV hypnotist Paul McKenna cured her of her phobia on his show. Since then, she has often used his self-hypnosis tapes to help her relax.
Her nicknames are "Flipper" and "Twiglet".
In 1990, she graduated from Birmingham University with a degree in English. In 1998, she also gained a first class honors degree in Ecology and Conservation from Birkbeck College.
One of her hobbies is collecting first edition copies of old children books.
Philippa found out she was allergic to gluten at age 22.
Philippa: (On how her style has changed over the years) As a teenager in the 1980s, I really experimented with fashion and wore some pretty outrageous clothes, as did everyone back then. But, as I've grown older, I tend to stick to greys, blacks, browns and neutral colours. Also, back then, I had both of my ears pierced twice and wore a lot of those horrible huge plastic earrings that were all the rage back then. Now, I hardly ever wear earrings at all, and on the odd occasions when I do, its usually just a pair of small diamond studs or something like that.
Philippa: If there's one thing I can't stand it's fussy, frou frou fashion. I don't like being trussed up or wearing a lot of colour, but I like my clothes to feel good - tactile and comfortable. Textures and fabrics are important to me.
Philippa: A few weeks ago, it was Fred's birthday, and we hired a magician to entertain the kids at his party. Afterwards, when we asked Fred what his favourite bit of the magician's show was, he said it was 'watching Mummy get sawn in half' - The things you do for your children!!
Philippa: (On her husband's choice of gifts for her) I tend to get a new camera for Christmas and birthday and Easter! He probably buys them so I don't touch his precious photographic equipment. At least they are my toys to play with.
Philippa: I can honestly say that working with my husband is a joy. We've been working together for about 10 years and I cannot imagine (and wouldn't really want to) working with anyone else. We work really well together.
Philippa: (On the filming of her nature series Halcyon River Diaries) We invited TV cameras into our family to live with us for a whole year. What was I thinking?
Philippa: (Speaking about her home town) For me Winchester is the perfect package. It's beautiful, it's historic and the geology of the area makes its plants and countryside unique. You can walk everywhere from the shops, to the Cathedral, to the water meadows. You never feel lost or insecure and you always meet someone you know.
Philippa: (On working on Tomorrow's World) I was no techno-expert. People still think I am a gadget-freak even after all these years. I just learned things as I went along. I turned the garbled technical details into a script that people could find interesting, easy to understand, but that was still accurate. Finding a way of demonstrating a gadget so people could see clearly how it worked, while they sat and ate their tea was the challenge.
Philippa: (on being diagnosed gluten-intolerant) I was put on a strict diet for two months of no dairy foods, no alcohol, no caffeine and no wheat or grains. I took vitamin supplements and then slowly reintroduced different foods into my diet.