Mauritius kestrels show long-term legacy of man-made habitat change

Feb 20, 2014
This is a Mauritius kestrel. Credit: Samantha J. Cartwright

The widespread loss of forest to sugarcane fields on the island of Mauritius has forced kestrels living there to survive by speeding up their life histories, according to a report published online on February 20 in the Cell Press journal Current Biology. By getting an earlier start, the birds are managing to have just as many offspring, even though they die sooner.

Those changes to the kestrels' life history are apparently driven entirely by their early life experiences, the researchers say.

"This adaptive, plastic response is a testament to how resilient this species is," says Samantha Cartwright, a postdoctoral researcher from the University of Reading and lead author on the study. "It has narrowly avoided extinction in the 20th century and is now persisting in a landscape very different from what it would have originally evolved to occupy."

The kestrels' future remains in doubt, given that less than two percent of the native forest that once covered Mauritius remains today. Kestrels already can't live at all on many parts of the island, most of which has been converted to agricultural land.

In 1974, Mauritius kestrels were labeled "the rarest birds in the world," with only four individuals living in the wild. They are now the most intensively monitored wild tropical raptors in the world, which made them a good case study for questions about the effects of habitat change.

This is the Mauritius Kestrel habitat. Credit: Samantha J. Cartwright

The researchers analyzed 23 years of longitudinal data on the Mauritius kestrel to find that females born in territories affected by habitat change shifted investment in reproduction to earlier in life at the expense of late life performance. They also had lower survival rates as young adults.

"We found that birds from both types of habitat still ultimately produce the same number of offspring in a lifetime," Cartwright says. "The strategy is a good one: breeding when younger compensates for the increased risk of dying sooner."

While the birds may be making it for now, Cartwright emphasizes that their shifted life history should serve as a warning about the extent to which human activities have already influenced wild species.

This shows Mauritius kestrels. Credit: Samantha J. Cartwright

"Taken together, our results suggest that human activities can have a persistent effect on the life histories of wild organisms through natal environmental effects," the researchers write. "Given the ubiquity of human-induced habitat change, the patterns we report could be widespread but remain poorly documented due to the short-term nature of most studies that attempt to quantify only the immediate impact of on fitness traits."

Explore further: Freshwater and ocean acidification stunts growth of developing pink salmon

More information: Current Biology, Cartwright et al.: "Anthropogenic natal environmental effects on life histories in a wild bird population." dx.doi.org/10.1016/j.cub.2014.01.040

Related Stories

Warmer temps push tropical birds up and off mountains

Feb 19, 2014

(Phys.org) —Many tropical mountain birds are shifting their ranges upslope to escape warming temperatures, but tropical species appear to be more sensitive to climate shifts than species from temperate ...

Recommended for you

Can pollution help trees fight infection?

4 hours ago

Trees that can tolerate soil pollution are also better at defending themselves against pests and pathogens. "It looks like the very act of tolerating chemical pollution may give trees an advantage from biological ...

Stink bugs have strong taste for ripe fruit

6 hours ago

The brown marmorated stink bug has a bad reputation. And for good reason: every summer, this pest attacks crops and invades homes, causing both sizable economic losses and a messy, smelly nuisance—especially ...

Iceland whaling season underway despite protest

8 hours ago

Icelandic whaling boats have left port to begin the 2015 whaling season, authorities said on Monday as more than 700,000 people signed a petition calling for an end to the hunt.

Study suggests there are only two tiger subspecies

14 hours ago

(Phys.org)—A team of researchers with affiliations to institutions in Germany, Denmark and the U.K. has concluded after extensive research, that there are really only two subspecies of tigers, as opposed ...

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.