Roadside Science

Exploring science from the roadside and beyond

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Field Notes

Whether I’m in my parents’ backyard in suburban Philadelphia or deep in Acadia National Park, I’ve found that if I stay outside long enough, something strange and wonderful will appear. As a field biologist, I log a lot of time outdoors and so I’m often treated to such sightings. Below are just a few of the plants and animals I came across this summer that made me drop my datasheets and jump for my camera. All of these photos were taken along the side of a road or in someone’s backyard. Continue reading

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When evolution hits a wall: Crested penguins and the two-egg problem

Royal penguins on Macquarie Island

Royal penguins on Macquarie Island (Photo credit: Wikipedia)

The royal penguin begins the path to reproduction much like many other birds. A male selects a nest site, a female joins him, and an egg is laid. But then, within about four days of laying that first egg, and right around the time a second, much larger egg is laid, the royal penguin pair gives their first egg the boot. They remove it from the nest with beak or foot and divert all energy into caring for the second egg. Over ninety-nine percent of these first eggs never hatch.

The royal penguin is one of six species of crested penguin (genus Eudyptes) that all neglect their first egg. Although this first egg is smaller than the second (as much as nearly 60% smaller, depending on the species), there is a living embryo inside. Given two chances to produce chicks each year, why do crested penguins only take the second chance? And if they only ever rear the second egg, why put energy into producing egg number one in the first place?

Researchers puzzled over these questions for over fifty years. Biologists R. Will Stein and Tony D. Williams of Simon Fraser University believe they may now have some answers. In a paper published this month in The American Naturalist, Stein and Williams explain that crested penguins only have enough energy to raise one chick per year. They continue to lay two eggs anyway because evolution is essentially stuck. Continue reading