Penguin puzzle as major breeding ground deserted
For the past three years, virtually nothing has hatched at Antarctica’s second biggest breeding grounds for emperor penguins and the start of this year is looking just as bleak, a new study has found.
Usually 15,000 to 24,000 breeding pairs of emperor penguins flock yearly to a breeding site at Halley Bay, considered a safe place that should stay cold this century despite global warming.
But almost none have been there since 2016, according to a study in Thursday’s Antarctic Science. The breeding pair population has increased significantly at a nearby breeding ground but the study’s author said it was nowhere near the number missing at Halley Bay. ‘‘We’ve never seen a breeding failure on a scale like this in 60 years,’’ said study author Phil Trathan, head of conservation biology at the British Antarctic Survey. ‘‘It’s unusual to have a complete breeding failure in such a big colony.’’
Normally about 8 per cent of the world’s emperor penguin population bred at Halley Bay, Trathan said.
Black-and-white with yellow ears and breasts, emperor penguins are the largest penguin species, weighing up to 40kg and living about 20 years. Pairs breed in harsh winter conditions with the male incubating their egg.
Scientists blame the sharp decline on climate and weather conditions that break apart the ‘‘fast ice’’ – sea ice that is connected to the land – where the
‘‘We’ve never seen a breeding failure on a scale like this in 60 years.’’
emperor penguins stay to breed.
They incubate their eggs and tend to their chicks – one per pair – on ice. After breeding and tending to the chicks, the penguins move to the open sea.
In 2016 and 2017, there was no breeding in Halley Bay and last year there was just a bit, the study found.
The nearby Dawson-Lambton breeding area, which had been home to a couple of thousand pairs, increased to 11,117 pairs in 2017 and 14,612 pairs in 2018, the study said.
While that was encouraging, it did not make up for all that was lost at Halley Bay, Trathan said.
‘‘Not everybody has gone to Dawson Lambton yet,’’ he said.
What was troubling wasn’t that part of the colony had moved to Dawson-Lambton, it was that scientists thought of Halley Bay as a climate change refuge in one of the coldest areas of the continent ‘‘where in the future you expect to always have emperors’’, Trathan said.
David Ainley, a marine ecologist and penguin expert, worried that some people would be more alarmed than they needed to be because many of the penguins didn’t disappear, but just moved. While not as scary as it might sound initially, with climate change ‘‘long term, it’s another question as alternate breeding sites likely will become harder to find’’, said Ainley, who was not part of the study.
The study made sense, and sometimes dramatic environmental change could cause a breeding failure like this, said Stephanie Jenouvrier, a penguin expert at Woods Hole Oceanographic Institution, who wasn’t part of the study. –AP