In turn, the Adelie penguins split off from the other members of the genus around 19 million years ago, and the chinstrap and Gentoo finally diverged around 14 million years ago.
Very fetching Gentoo penguins |
We will likely need to reclassify the gentle Gentoos into a species complex of four morphologically similar but separate species: the northern gentoo penguin (P. papua sensu stricto), the southern gentoo penguin (P. ellsworthi), the eastern gentoo penguin (P. taeniata), and the newly-described South Georgia gentoo penguin (P. poncetii).
We find breeding colonies of gentoo penguins on ice-free surfaces either directly on the shoreline or far inland.
They prefer shallow coastal areas and often nest between tufts of grass. In South Georgia, breeding colonies are 2 km inland.
In colonies farther inland, where the penguins nest in grassy areas, they shift location slightly every year because the grass will become trampled over time.
Gentoos breed on many sub-Antarctic islands. The main colonies are on the Falkland Islands, South Georgia and the South Sandwich Islands, and Kerguelen Islands; smaller colonies are found on Macquarie Island, Heard Islands, Crozet Islands, South Shetland Islands, and the Antarctic Peninsula.
Their breeding populations number well over 600,000 birds. Once a breeding pair decide that their romance is a go, they stay together for life.These lovelies breed monogamously and infidelity is frowned upon. Punishment is banishment from the colony — strict but these birds know how to draw a firm line in the pebbles.
Nests are usually made from a roughly circular pile of stones and can be quite large — up to 20 cm (7.9 in) high and 25 cm (9.8 in) in diameter. The chosen rocks are prized and jealously guarded.
Just who owned which pebble is the subject of many noisy debates — some escalating to nasty physical altercations between disagreeing parties. "That rock is mine. Mine!"
The pebbles are especially prized by the females, to the point that a male penguin can woo his lady love and secure a lifetimes' devotion by proffering a particularly choice stone — not unlike some human females.