Some animals, it seems, are going on a diet, while others have expanding waistlines.
It's likely these are reactions to rapidly rising temperatures due to global climate change, speculates Prof. Yoram Yom-Tov of Tel Aviv University's Department of Zoology, who has been measuring the evolving body sizes of birds and animals in areas where climate change is most extreme.
Changes are happening primarily in higher latitudes, where Prof. Yom-Tov has identified a pattern of birds getting smaller and mammals getting bigger, according to most of the species he's examined. The change, he hypothesizes, is likely a strategy for survival. Prof. Yom-Tov, who has spent decades measuring and monitoring the body sizes of mammals and small birds, says that these changes have been happening more rapidly.
His most recent paper on the topic, focused on the declining body sizes of arctic foxes in Iceland, appeared in Global Change Biology.
Radical changes in body size
Animal populations in a wide variety of geographical areas-― birds in the UK, small mammals in the arctic, and most recently foxes, lynx and otters in cold Scandinavian regions-― are adapting to a shift in rising temperatures. Where temperature changes are most radical, such as those at higher latitudes, Prof. Yom-Tov has measured the most radical changes of these animals' body size over time.
"This change can be seen as an early indicator of climate change," says Prof. Yom-Tov. "There is a steady increase of temperatures at higher latitudes, and this effect whether it's man-made or natural is having an impact on the animals living in these zones."
In his most recent paper, Prof. Yom-Tov and his Tel Aviv University colleague Prof. Eli Geffen report that arctic foxes are being influenced by changing water currents in the oceans. These changes, likely a result of climate change, affects the foxes' food supplies. Hydrologists are confounded
|Contact: George Hunka|
American Friends of Tel Aviv University