Age is more than a number -- In barn owls, it reveals how susceptible one is to climate change

Jan 10, 2007
Age is more than a number -- In barn owls, it reveals how susceptible one is to climate change
Young barn owls waiting for the return of a parent with prey. Credit: Courtesy Alex Labhardt.

Fluctuations in weather and the environment affect survival and reproduction of animals. But are all individuals within a population equally susceptible? Theory on the evolution in age-structured populations suggests not – those life stages that are more important for overall fitness should be less susceptible to environmental variation than other life stages.

Empirical support for this prediction is rare because detailed data need to be collected over many years, and true variation tends to be inflated through the way in which natural populations are sampled.

In the January issue of The American Naturalist, Res Altwegg (University of Cape Town and University of Victoria), Michael Schaub (Swiss Ornithological Institute and University of Bern), and Alexandre Roulin (University of Lausanne), examined temporal variation in survival and reproduction of barn owls in western Switzerland that had been observed over the past fifteen years. Using recently developed statistical tools, they were able to show that those fitness components that experienced stronger selection were indeed less variable over the years.

"Our results help explain why certain age classes are more susceptible to adverse weather, and they will help us understand how climatic variation affects populations of organisms in nature. This is important for predicting the effect of climate change on populations," the authors said.

Citation: Altwegg, Res, Michael Schaub, and Alexandre Roulin, "Age-specific fitness components and their temporal variation in the barn owl." The American Naturalist: January 2007.

Source: University of Chicago

Explore further: Brother of Hibiscus is found alive and well on Maui

add to favorites email to friend print save as pdf

Related Stories

Google searches hold key to future market crashes

8 hours ago

A team of researchers from Warwick Business School and Boston University have developed a method to automatically identify topics that people search for on Google before subsequent stock market falls.

Recommended for you

Molecular gate that could keep cancer cells locked up

5 hours ago

In a study published today in Genes & Development, Dr Christian Speck from the MRC Clinical Sciences Centre's DNA Replication group, in collaboration with Brookhaven National Laboratory (BNL), New York, ...

The 'memory' of starvation is in your genes

8 hours ago

During the winter of 1944, the Nazis blocked food supplies to the western Netherlands, creating a period of widespread famine and devastation. The impact of starvation on expectant mothers produced one of the first known ...

User comments : 0