Our Yellow-Eyed Penguins in Trouble

According to a new study, New Zealand’s iconic yellow-eyed penguin (hoiho) may be locally extinct by 2043, Kendra Pierre-Louis writes for Popular Science.

The study, published in the journal PeerJ, reports breeding penguins declined by 76 per cent between 1996 and 2015. And while climate change is a factor, it’s unclear if it’s the most important one.

The penguins in question make their home in the Otago Peninsula. This self-proclaimed wildlife capital of New Zealand is home to fur seals, sea lions, and the aforementioned yellow-eyed penguin. The penguins are benthic foragers (they find their sustenance at the sea floor) so they spend a lot of time scrounging for food in the impossibly blue waters of the South Pacific.

Thomas Mattern, ecologist at the University of Otago and lead author of the new study, and his team, used population data recorded at Kumo Kumo Whero from 1937 to 1948, and from 1982 and 2015 at Boulder Beach, one of the yellow-eyed-penguin’s mainland strongholds, to assess the impact of various factors on declining populations. Using this technique, he was able to attribute roughly a third of their decline to warming temperatures likely related to climate change.

But what about the remaining two-thirds?

Mattern thinks gillnets are likely one of the easily ignored factors. Gillnets are hung vertically in the water with to trap fish. The holes in the net are tailored to the size of the fish they seek to catch, but fish aren’t the only animals getting caught.

“The penguins don’t see them, they get entangled in them, and then they drown,” Mattern says.

“The penguins that are really struggling these days are the ones that live closest to humans. The closer the species live to humans, the greater their problems.”

Original article by Kendra Pierre-Louis, Popular Science, May 16, 2017.

Photo by Matt Binns.