Which lens for my Safari?

I'm off on my first safari this weekend. I can only take 15kg in my luggage which includes hand luggage and I have a slight problem on how much camera gear to take.

This is my kit. (weighs 6.2kg which is nearly half my weight allowance lol)

• Canon 7 D

• 24-70m L 2.8f

• 50m 1.8f

• 17-55m 4-5.6f

• 55-250m 4f IS

Obviously I will take the long zoom, but I was wonder if it's worth me taking my heavy L lens. It's a great lens and I can get some good pictures with it, but I'm thinking it's zoom is big enough to even get a decent shot anyway, what do you fellow safari people think?

My thoughts are the 55-250m and 50m and 17-55m. The 50m is pretty light anyway.

I'm off to Tanzania and then Zanzibar afterwards for a beach holiday so I want to get some nice shots there too.

Any helpers here?