By Steve Williams From Care2

Satellite data shows that a major emperor penguin breeding ground at Halley Bay, located on the Brunt Ice Shelf in the Antarctic, is now virtually deserted. What happened, and will the emperor penguins return?

Publishing in the science journal “Antarctic Science“, researchers from the British Antarctic Survey report that Halley Bay was once considered a vital “safe breeding ground” for the emperor penguins. Despite global warming, it was predicted to stay at a temperature the penguins favored, at least for the foreseeable future. The region usually sees some 15,000 to 24,000 birds flock to the site in order to hatch their young, about eight percent of the emperor penguins’ total global population.

But satellite data reviewed by the research team reveals that in 2016 virtually none of the penguins showed up to breed, a trend that persisted through 2018, where only a handful of chicks were hatched on the site.

“We’ve never seen a breeding failure on a scale like this in 60 years,” study author Phil Trathan told the Associated Press. “It’s unusual to have a complete breeding failure in such a big colony.”

WHAT CAUSED THIS DESERTION OF HALLEY BAY?

While not related directly to rising temperatures, scientists believe it is down to climate change.

In 2016 scientists recorded an early decline in what is known as “fast ice”, which connects sea ice to the land. Emperor penguins use this ice as they incubate and then care for their chicks. When they are at a sufficient stage of development, usually coinciding with the breakup of the ice, the young penguins and parents will then take to the seas.

If the ice breaks up before the young penguins develop their adult plumage they will not have the tools—specifically, the feathers—necessary to swim.

The researchers conclude that the early breaking of the ice, which they believe to be a result of storms in October and November fragmenting the thinner-than-average ice, led to the penguins discounting Halley Bay as a viable breeding ground.

WHERE DID THE PENGUINS GO?

There is some good news. A secondary breeding ground, known as the Dawson-Lambton breeding area, used to be a refuge for just a few thousand emperor penguins. However, in 2017 the numbers had increased to 11,117 pairs, and in 2018 the study counted 14,612 pairs. That’s a significant increase and almost certainly means that a proportion of the Halley Bay penguins have made their way to Dawson-Lampton.

Yet this represents only a relatively small proportion of the number of penguins from Halley Bay. More may yet arrive at Dawson-Lampton, but it is unclear how many will ultimately find their way to this spot.

Of further worry is that scientists had believed Halley Bay would remain a safe-haven for emperor penguins for the foreseeable future, at least in terms of temperatures. To an extent they were right—the harsh conditions that the emperor penguins are adapted to do persist at Halley Bay, but the scientists hadn’t been able to account for the early ice break-up being a factor.

To an extent, the scientists are puzzled as to why the colony has not regenerated at Halley Bay, and they caution that we not be overly concerned, as it may be that the emperors will eventually return.

WHAT CAN WE LEARN FROM HALLEY BAY’S EMPEROR PENGUINS?

This may underscore how even relatively robust animals, like emperor penguins, can be extremely sensitive to certain environmental factors that, in turn, can change their breeding patterns. This is something that can have an impact on their survival as a species.

Emperor penguins are classed as “near-threatened“, meaning that while they are not considered in danger just yet and that their population is, for the moment, stable, they are not totally in the clear. The loss of a breeding ground is significant, then, even if some of the penguins are going elsewhere.

The fate of the Halley Bay site is not itself the most pressing issue here. As the BBC notes it could have been lost anyway, thanks to the impending Brunt Ice Shelf split. The critical piece is that the emperor penguins could be so keenly affected by something we hadn’t previously envisioned being a problem.

Climate change is sometimes spectacular in the problems it creates, but other times it is more subtle. It seems in this case it is the subtle signals we need to look out for in order to monitor and save animals in the Antarctic.

Photo credit: Getty Images.

For more on this story go to; https://www.care2.com/causes/where-have-halley-bays-emperor-penguins-gone.html