...but have been around 56 million years.

Including this GIANT ancient penguin Icadyptes salasi

He was 5 ft tall and lived in the tropics of South America.

"Paleontologists have constructed a model of a prehistoric penguin that stood almost 4 feet 6 inches tall when it lived in what is now New Zealand, approximately 25 million years ago." [wired]

"Penguins seem to have no special fear of humans.

however some scientists think Penguin populations "may decline by 60% by 2099."

Emperor Penguin population: 595,000 (2009)

This species has been uplisted to Near Threatened because it is projected to undergo a moderately rapid population decline over the next three generations owing to the effects of projected climate change. However, it should be noted that there is considerable uncertainty over future climatic changes and how these will impact the species.