The Weekend's Viewing: Julius Caesar, Sun, BBC4 Secrets of Our Living Planet, Sun, BBC2

Whether intentionally or not, Greg Doran's television version of Julius Caesar, broadcast when the stage production is still warm from the oven, offered an intriguing practical illustration of the difficulties directors sometimes face in putting Shakespeare on the small screen. Doran's production sets the play - very astutely - in an East African state and deploys an all-black cast.

He has supplied rationales for this decision, including Nelson Mandela's affection for the drama and the South African actor John Kani's remark that it is "Shakespeare's African play". But the truth is that his production doesn't need them. The setting is perfect for a play fraught with anxiety about democracy and dictatorship. And on stage and on screen, Doran begins with a partisan crowd celebrating a political hero.

For this scene he uses the stage production, filming inside the main theatre in Stratford and including shots of the audience in the background. The same technique is also employed for Mark Antony's famous speech to the Roman people, suggesting that there's a rationale here too. Those parts of the play that occur in a public space are filmed in the public space of the theatre. The only problem is that acknowledging the audience who were there on the night unavoidably means excluding the audience watching at home. Not completely, obviously, but there's an unmistakable, unshiftable sense of being secondary to the event. The sound is muddier and more open, the framing of shots messier. We're eavesdropping.

That feeling is only confirmed by the cut to tailor-made sequences, in which Doran films the actors in a variety of grim urban interiors. Suddenly, you have privileged access to the performers and Doran is able to choreograph his scenes for a single viewpoint, rather than a whole auditorium. He's also able to get cinematically inventive with scenes that, in the theatre, can look over-familiar. There are only so many ways Caesar can be stabbed on stage, in a hugger-mugger of assassins. On screen, though, Doran films the attack on a disused escalator and - an inventively gory touch - has Caesar cough his life blood on to the glass side panel through which we're looking. There are hazards to the sudden intimacy; not all the actors had adjusted the projection of their performance to the closeness of the camera. But generally speaking, it's alive in a way a recorded stage performance can never be. On television, we don't just want the best seat in the house, we want to feel we've got the only seat in the house.

You don't really have to pay attention to most history programmes. You can get on with something else and wait for a sharp intake of breath to alert you to the good bits. But Secrets of Our Living Planet, Chris Packham's new series, repays extended concentration. Last night, he was focusing on the nitrogen cycle, a subject that sounds a little GCSE, until you find that it is illustrated by one of the more endearing golf hazards in existence. On a Melbourne golf course, we saw early morning players trying to pick their way through a sizeable herd of kangaroos, drawn to the fairways by the rich grass that resulted from artificial nitrogen feeding. In Africa, it's the rhinos that do the gardening, champing up their own forage and then extruding the digested remains into communal middens that then fertilize the growth of even sweeter grasses. And in the cerrado of South America, maned wolves unwittingly cultivate the lobera fruit they use to supplement their diet with the help of leaf-cutter ants. The wolf uses an ant mound as a lavatory; the ant extracts the lobera seeds from its dung as food; the remains of the seed germinate and so the cycle continues. It is very elegant, and often worryingly delicate, so that just one small alteration can disrupt the whole system. No wonder Packham gets a bit excited as he unpacks it all.