Super-powered Owls: Natural World (BBC2, 8pm)

FROM the nonsense of Winnie the Pooh to the spell-binding adventures of Harry Potter, the British have always been captivated by the sight and sound of an owl – those with particularly long memories will recall Dennis Dunstable (played by Peter Denyer) demonstrating his owl call to a bewildered teacher Bernard Hedges (John Alderton) in Please Sir! Boy, did the kids have fun with that in the schoolyard.

With their charismatic faces and extraordinary head-turning ability, owls are one of our best-loved birds. Yet it's rare to catch more than a glimpse of one in the wild. These mysterious birds haunt our night, floating through the darkness with an eerie silence or distinctive cry. But how do they see in the dark? And how do they fly so silently? Through the eyes of two special barn owl chicks, bred by specialist bird handlers Lloyd and Rose Buck, and with the help of world leading scientists, Natural World reveals the magic behind owls' superpowers. Paul McGann narrates.

There's also slow-motion footage of one of nature's most ruthless and efficient killers in action as we observe a great grey owl using all its powers to seek out prey in the snow.

When the Bucks take the chicks into a school the children are in awe of the birds, but there's a lot more to the wise old owl than trying to keep old Pooh in place.

Natural World started in 1983 as a wildlife-specific spin-off to The World About Us, itself a long-running documentary strand on BBC2. The World About Us was commissioned in 1967 by Sir David Attenborough, at that time the station's controller, to promote the new colour television service to British audiences.

The programmes fall into three categories: strong, emotional stories; popular or unusual but interesting animal subjects and films offering a different, personal perspective. A typical production system involves the filmmakers being given up to 100 days in the field, but that does depend if archive material is already available.

Drugs Live: Cannabis On Trial (Channel 4, 10pm)

THE headline-hitting 2012 Drugs Live: The Ecstasy Trial, which documented the effects of MDMA on people like actor Keith Allen, novelist Lionel Shriver, a vicar and a former SAS soldier was quite a talking point. Now, C4 tackles cannabis and volunteers including newsreader Jon Snow, ex-MP Matthew Parris and former royal correspondent Jennie Bond, who will be taking skunk, hash or a placebo under controlled, laboratory conditions, while undergoing rigorous testing including MRI scans.

"I would never do it again. I can fully believe this week's figures that tell us that 25 per cent of all psychosis treated in Britain is associated with smoking skunk," says Snow, while Parris feels the experience left him stoned and stupid. "The very smell now repels me," he says.

The trial was designed by one of the world's leading experts on the effects of illegal drugs on the brain, psycho-pharmacologist Professor Val Curran, and was conducted at UCL (University College London). Former government drugs advisor, Professor David Nutt of Imperial College London, is also on-hand to offer his expert views.

Bargain Fever Britain (ITV, Regions Vary)

GETTING a good bargain is now an obsession, and this programme takes a look at the goings-on inside four major discounters - wholesale giant Costco, car supermarket Motorpoint, shoe chain Shoe Zone and Approved Food, which sells food that's out of season or past its best-before date.

We'll also meet customers and bargain hunters and hear about the lengths they will go to in order to make a saving.

First up, the challenges that discounters face are explained, from the Cardiff branch of Costco selling everything from kitchen roll to 8ft gigantic teddy bears, to the perils of trying to keep track of millions of pounds worth of stock. There's also a coupon-crazy mum, Holly, who has stockpiled 64 pizzas in her freezer.