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: The influence of the Isthmus of Panama in the evolution of freshwater shrimps in America

add to favorites email to friend print save as pdf

Related Stories

NASA issues 'remastered' view of Jupiter's moon Europa

8 hours ago

(Phys.org) —Scientists have produced a new version of what is perhaps NASA's best view of Jupiter's ice-covered moon, Europa. The mosaic of color images was obtained in the late 1990s by NASA's Galileo ...

Dish restores Turner channels to lineup

8 hours ago

Turner Broadcasting channels such as Cartoon Network and CNN are back on the Dish network after being dropped from the satellite TV provider's lineup during contract talks.

LiquidPiston unveils quiet X Mini engine prototype

13 hours ago

LiquidPiston has a new X Mini engine which is a small 70 cubic centimeter gasoline powered "prototype. This is a quiet, four-stroke engine with near-zero vibration. The company said it can bring improvements ...

Recommended for you

Dogs hear our words and how we say them

1 hour ago

When people hear another person talking to them, they respond not only to what is being said—those consonants and vowels strung together into words and sentences—but also to other features of that speech—the ...

Amazonian shrimps: An underwater world still unknown

3 hours ago

A study reveals how little we know about the Amazonian diversity. Aiming to resolve a scientific debate about the validity of two species of freshwater shrimp described in the first half of the last century, ...

Factors that drive sexual traits

4 hours ago

Many male animals have multiple displays and behaviours to attract females; and often the larger or greater the better.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.