A lone adult king penguin stands among a crowd of chicks on sub-Antarctic Marion Island.
Chris Oosthuizen, from the University of Pretoria, took the overall prize in the British Ecological Society's Capturing Ecology photo competition, showing off flora and fauna from across the planet.
"Although the global population of king penguins is large, populations inhabiting islands around the Antarctic face an uncertain future," he said.
"Global climate change may shift the oceanic fronts where they feed further away from breeding sites, forcing penguins to travel farther to reach their foraging grounds."
Oosthuizen took the photos while spending a year on the remote island, part of the Prince Edward Islands, conducting research on seals and killer whales.