Nature's Epic Journeys (BBC1, 9pm)

LIZ Bonnin enters the world which has inspired films like Disney's Frozen and joins a team of wildlife experts and filmmakers in the Arctic wilderness.

Last week's opening episode brought us elephants on the move in Northern Kenya, but this week we learn about the caribou, which undertake one of the world's longest land migrations, travelling 5,000 kilometres through the frozen wilderness areas of Canada and Alaska.

It's not just the distance and the temperatures that make the journey so hazardous – the 100,000 caribou also face starving bears and wolves, frozen rivers and rugged mountains along the way.

Bonnin and a team of scientists and film-makers use the latest technology to follow the herd, offering insights into the lives of individual animals as well as tracking their journey en masse.

The presenter also explains just why it is so vital that the caribou complete their journey and reach the calving grounds before giving birth – failure to do so could spell disaster. Aerial shots of the caribou streaming through the mountains are breathtaking and there's a moment involving a curious grizzly bear and two of the programme's intrepid cameramen that will have you watching through your fingers.

Initially Bonnin may have seemed an unlikely candidate to become one of the BBC's leading wildlife experts. Although she does have a scientific background – she has a degree in biochemistry from Trinity College, Dublin – her initial career seemed more focused on entertainment.

Following a stint in the Irish girl group Chill, she went on to host shows including Channel 4's RI:SE and Top of the Pops. It was while working on a wildlife documentary in Pench National Park, in India, that everything came into a focus. She says an encounter with a tiger reignited her love for all things scientific and inspiring her to study for a Masters degree in Wild Animal Biology, specialising in tigers in Nepal.

She says: "I've always had wanderlust and I can't believe how lucky I've been to travel the world, looking at nature and helping to show people the incredible things on our planet. Science has opened up so many opportunities for me and I hope I can show young girls that it can do the same for them and far from being dry or dull, it's endlessly interesting and varied. I'm determined to explore as many places and species as I can in my lifetime."

So, Nature's Epic Journeys must be something of a dream job as it follows animals on three of the world's most breathtaking wildlife adventures, looking at how they overcome immense obstacles, from challenging terrain to hungry predators and sheer physical exhaustion.

Deepcut: Behind the Barbed Wire (BBC2, 9pm)

AS the inquest delivers its verdict into the death of young soldier Cheryl James, former soldiers who served alongside her at the notorious Deepcut barracks speak for the first time. James was found dead from a bullet wound to her head in November 1995, and was one of four recruits to die at the base in seven years. The documentary hears what life is really like behind the barbed wire, including the culture of bullying and physical and sexual abuse, which has cast a shadow over the army for more than two decades.

Killer Women with Piers Morgan (ITV, 9pm)

JOURNALIST and TV personality Piers Morgan continues his travels across the US, this time meeting two very different female murderers, both of whom killed someone they loved. First, he heads to Florida's largest female prison to visit Amanda Hutto, who is serving a life sentence for murdering her daughter. The mother was accused of deliberately drowning her seven-year-old daughter as a punishment for being naughty, with her five-year-old son testifying against her at the murder trial. Next, he journeys to Texas, where he encounters Rhonda Glover, a former beauty queen and rodeo star who gunned down her lover in cold blood after their relationship spiralled into drug-fuelled obsession and paranoia.

Viv Hardwick