New Magellanic penguin colony discovered in Argentina

ARGENTINA – Wildlife Conservation Society (WCS) researchers have announced the discovery of a new colony of Magellanic penguins on a remote island in Argentina.

A Magellanic penguin on Isla de los Estados.
Credit: Ulises Balza. 

The penguins were found on the eastern side of Isla de los Estados off the eastern tip of Tierra del Fuego at the southernmost end of the South American continent.

Researchers made the discovery while surveying a known colony of rockhopper penguins that they had been tracking by remote cameras for two years.

When the researchers eventually accessed an unexplored area of the rockhopper colony, they discovered the telltale nesting burrows of Magellanic penguins hidden in tall grasses.

Single male Magellanic penguin numbers rising at Punta Tombo

ARGENTINA – Like most of their stout-bodied, flippered kin, Magellanic penguins spend much of their lives in the ocean. From late autumn through winter and into spring in the Southern Hemisphere, these South American penguins swim off the coast of southern Brazil, Uruguay and northern Argentina in search of anchovies, sardines and squid.

A young male Magellanic penguin.
Photo: Natasha Gownaris

But as spring turns to summer, they swim thousands of miles south and congregate in big coastal colonies. There, males and females pair off, breed and attempt to rear one or two newly hatched chicks. One of the largest breeding colonies for Magellanic penguins is at Punta Tombo in Argentina, where University of Washington (UW) biology professor P. Dee Boersma and her team at the Center for Ecosystem Sentinels have studied the penguins since 1982. They have documented a population decline at Punta Tombo of more than 40 percent since 1987, along with a rising male-to-female ratio, and have spent years trying to pinpoint its cause.

In a paper published on 2 January 2019 in the journal Ecological Applications, Boersma and UW postdoctoral researcher Natasha Gownaris report that juvenile females are more likely to die at sea, which has caused a skewed sex ratio of nearly three males to every female, as well as population decline. Their study incorporated more than 30 years of population data collected by UW researchers – including banding and studying individual penguins – into models of population dynamics.

After a bad winter in the ocean, female Magellanic penguins suffer most, study shows

ARGENTINA – Every autumn in the Southern Hemisphere, Magellanic penguins leave their coastal nesting sites in South America. For adults, their summer task – breeding, or at least trying to – is complete. Newly fledged chicks and adults gradually head out to sea to spend the winter feeding. They won’t return to land until spring.

Adult Magellanic penguin and chicks
Credit: Dee Boersma/Center for Ecosystem Sentinels

Yet life for these birds when they winter offshore is largely a mystery to the scientists who study Magellanic penguins – and who advocate for their conservation amid declining population numbers.

“The winter period is something of a black box for us in terms of understanding Magellanic penguins,” said Ginger Rebstock, a University of Washington (UW) research scientist.

“We know the least amount about this part of their year.”

But research by Rebstock and P. Dee Boersma, a UW professor of biology and founder of the Center for Ecosystem Sentinels, is starting to pry open that black box and discover how Magellanic penguins from one nesting site, Punta Tombo in Argentina, fare during the winter months.

Twenty-eight years of natural selection in Magellanic penguins

Magellanic penguin at Punta Tombo showing its metal band.
Credit: Dee Boersma

ARGENTINA  –  Biologists of all stripes attest to evolution, but have debated its details since Darwin’s day. Since changes arise and take hold slowly over many generations, it is daunting to track this process in real time for long-lived creatures.

“We know that evolution occurs – that species change,” said Dee Boersma, a University of Washington (UW) professor of biology.

“But to see this process in long-lived animals you have to look at generations of individuals, track how traits are inherited and detect selection at work.”

Boersma studies one particularly intriguing long-lived species, the Magellanic penguins of South America. She has spent 34 years gathering information about their lifespan, reproduction and behaviour at Punta Tombo, a stretch of Argentine coast that serves as their largest breeding site.

Boersma and her colleagues combed through 28 years’ worth of penguin data to search for signs that natural selection  –  one of the main drivers of evolution  –  may be acting on certain penguin traits. As they report in a paper published on 21 September in The Auk: Ornithological Advances, selection is indeed at work at Punta Tombo.

New protected areas for Argentina's Magellanic penguins

Adult Magellanic penguin and two chicks begging for food.
Photo credit: Dee Boersma

ARGENTINA – They live far from the North Pole, but Christmas came early for the stout-bodied, black and white Magellanic penguins of Patagonia's Punta Tombo region. On 3 December, the legislature for Chubut province established a new marine protected area off Punta Tombo, which would help preserve the feeding grounds for about 500,000 Magellanic penguins that make their home along this rocky stretch of Argentine coast.

"This is really exciting. We've long wanted to see the waters around Punta Tombo protected," said University of Washington (UW) biology professor Dee Boersma, who has been studying the Magellanic penguins there for more than 30 years.

Climate change blamed for penguin deaths

Rain wets the down of a chick still
too young to have the waterproofing
its parent has.
Credit: D Boersma/U of Washington

ARGENTINA - Climate change has been documented repeatedly as an indirect cause of penguin deaths by reducing their food sources. Now it is killing chicks from the world's largest colony of Magellanic penguins directly through drenching rainstorms and, at other times, heat, according to new findings from the University of Washington (UW).

Too big for parents to sit over protectively, but still too young to have grown waterproof feathers, downy penguin chicks exposed to drenching rain can struggle and die of hypothermia in spite of the best efforts of their concerned parents. And during extreme heat, chicks without waterproofing can't take a dip in cooling waters as adults can.