Parents don't pick favorites, at least if you're a Magellanic penguin

Date:  February 14, 2019

Source:  University of Washington

Parenthood can be a struggle, particularly for families with multiple children in need of care, nurturing, protection and attention. But a weary mom or dad may find solace in the reassurance that all parents with several offspring face a similar challenge -- even the non-human variety.

Researchers at the University of Washington wanted to know how Magellanic penguin parents in South America balance the dietary demands of multiple chicks. As they report in a paper published Jan. 23 in the journal Animal Behaviour, when a Magellanic penguin parent returns to its nest with fish, the parent tries to feed each of its two chicks equal portions of food, regardless of the youngsters' differences in age or size.

This finding surprised the team, since parents across the animal kingdom, including other penguin species, often allocate resources unequally to their chicks based on factors like offspring age, body condition, health and behavior, said senior author P. Dee Boersma. Boersma, a UW professor of biology and director of the Center for Ecosystem Sentinels, has for more than three decades studied penguins at Punta Tombo, a coastal region in Argentina that hosts one of this species' largest breeding colonies.

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Why the number of single male Magellanic penguins is rising at this breeding colony

Date:  January 3, 2019

Source:  University of Washington

The number of single male Magellanic penguins is rising at this breeding colony. Here's why.

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.

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 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 Jan. 2 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. Boersma and Gownaris' models show that juveniles have much lower survival rates than adults in all years, a common phenomenon in seabirds. In addition, among both juveniles and adults, females are less likely to survive than males, but this sex bias is much larger among juveniles. Adult females seem to fare worst in years when overall survival is low, suggesting they are more vulnerable than males to disruptions in the food supply during the nonbreeding season.

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First test-tube baby penguin says hello to the world

By Eric PfeifferAugust 13, 2014 10:26 AMThe Sideshow

Officials hope the first penguin hatched via artificial insemination at SeaWorld in San Diego will help make strides …

To science, she’s simply known as “184.” But on the empirical cuteness scale, the world’s first test-tube penguin scores a “100.”

The still unnamed baby Magellanic penguin was hatched at SeaWorld in San Diego 12 weeks ago, but the first images of her were released to the public this week.

She’s the first penguin to be born using artificial insemination, a technique researchers say will help them increase diversity in the captive penguin population and help their studies of the creatures.

“The goal of our research center is to study a species’ reproductive biology, to learn as much as we can about that and use this to not only monitor the health of not only our zoological populations but wild populations as well,” said Sea World’s reproductive center Scientific Director Dr. Justine O’Brien.

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