Attack of the killer penguins

While mainly on a fish diet the penguins enjoyed the occasional human as well.

It is great! Very interesting, thank you Paul. To think that Penguins of that size once roamed earth, is quite amazing. I wouldn't like to come across one in a dark alley!
Do you think the reason it may have gone extinct was that due to its large size (and thus larger SA:V ratio), it was unable to expel body heat fast enough in the stifling equatorial climate? It sounds quite convincing, but maybe there is more to it...any ideas?

Could this be the [monster] penguin you are talking about Paul?
http://www.abc.net.au/news/newsitems/200602/s1573054.htm

Over 100kg...wow

They would have to have eaten bigger fish. I would have thought that they'd had a hard time keeping up with the agile small fish they prey on nowadays. Possibly the disappearance (or decrease in abundance) of these larger fish (prey of the giant penguins) brought about their extinction? 

I've heard that penguin colouration is very effective camouflage underwater. Their tummies tend to be white, meaning that when you are underneath one in the water (looking up at it) it blends in well with the sky which is light. And when you are looking down on a penguin from above, the dark background of the deeper ocean matches the dark black coat on a penguin's back. Also, Orcas still hunt penguins do they not? They hunt just about everything in the ocean except humans actually...well within reason (no brittle stars or sea cucumbers).

Each pod of orcas (mainly depending on geographical location, which governs the abundance and presence of prey items) has become specialised in catching its own regular prey. For example, in Norway, there are no seals or penguins, so the orcas have become expert sardine hunters. I'd imagine you've heard of the bubble tunnel technique? Also, off the coast of Argentina, where the beaches tend to have very steep shores, and where seals are in high demand, the orcas have become specialised in catching seals in the shallows and beaching to catch them. In the Croziers Islands in the South Indian Ocean, King Penguins and Elephant seals are everywhere, so they've adapted to prey upon both. Canada (eg.Vancouver Bay) has a large abundance of salmon at certain times of the year, and this is precisely when the orcas arrive too.
Note that each has not lost its ability to prey upon other prey items,  -orcas are incredibly versatile in both diet and hunting method- it's just that they have become niche predators in each particular area of their vast range. Amazing hey?
Sorry to detract from the whole penguin thing...I mentioned penguins in there once...

My guess would be that an Orca could adapt very well to just about every oceanic environment. I don't think catching prey would be there problem, more the temperature and environmental variation. Say, we are detracting from Paul's topic here - shall we create a topic on Orcas?

What is an Orca? It linguistically reminds me of an Orc but I believe you are speaking of something else...

I have been talking about the killer whale, called orca. but if you are talking about middle earth orcs... that is another creature entirely!

Gaelic orc means "young pig" and Norse �rkn means "seal" .but I like their image of the Orc as misshapen humanoids with brutal, warmongering, sadistic, yet cowardly tendencies. No offence to Orcs of course!