Well I'm going to carry on breaking all the imaginary rules because it's really pictures of the week this time, and all four go together on the topic of endurance.
The image above comes first just because it's a bit more of an attention grabber than the one that I really want you to look at. Sat up there on top of a rocky outcrop in Antarctica is a chinstrap penguin.
Whilst I like the image above - it's nice and there's quite a nice diagonal from rock to penguin to distant peak - it's by no means an absolute humdinger banker of a favourite of mine, and on it's own doesn't tell much of a story. But it is more immediately recognisable as a penguin than the image below (and everyone likes a penguin picture for grabbing their attention - right?!).
So the real story actually starts with the image below. Now if you happen to be reading this on your phone, internet fridge or a small screen on something, then for your visual assistance let me tell you that that tiny dark outline is also a chinstrap penguin, and those faint lines trailing off around him are made by (happy) penguin feet. This chap is looking a little lost, and if you can't tell - again for your information he's a very, very (very) long way away from the camera.
Now in the next image you can see him in a bit more context. A fellow tourist (let's call him Bob) is obligingly pointing at yonder penguin from the mountainside we're both stood on. The penguin is there - follow Bob's outstretched arm and you can just make him out as teeny tiny dot (he's there on the ice, directly below the last floating iceberg on the right). Bob and I are, at a very rough guess, about 200-250 metres (650-820 feet) up this mountain - admiring the view. For photography settings fans these two images were taken at the "polar" opposite ends of an 18-200mm lens.
Well it turns out that our lost penguin isn't really lost at all. Instead he's stood there, presumably drawing breath after a spot of lunch and a refreshing dip in the sub-zero water dodging leopard seals and killer whales. Now you do know that penguins can't fly don't you? So what he's also doing (again I presume) is contemplating his long, long, long climb up to meet the rest of his colony, perched here, high up on the side of this mountain.
Our pygoscelis antarcticus (please don't tell me these posts aren't educational) friends here are about two foot tall, so to scale, it must be like a human climbing all the stairs of the Empire State Building, opening the door at the top and then finding someone's stuck the Gherkin on top and that that needs climbing too. And then doing that every time we fancied a lie down in bed after a spot of dinner back at ground level. No wonder the penguins have given up using the downstairs privy.
I'm sure you've all seen countless examples of penguins incredible endurance on the TV or in the cinema. Well chinstraps don't quite have the Hollywood looks and glamour of their towering cousins the emperor penguin, or the comedy eyebrows (and Robin William's vocals) of Lovelace the Rockhopper - but I'd like to say "hurrah!" for the chinstrap penguin - and these images hopefully show an example of their own efforts.
Ultimately, they endure that enormous climb for a safe place to raise their young, far away from seals and other most of their other predators. But come on, for that climb to really, really be worth it you'd have to assume that the local school has got an outstanding ofsted report ...