We studied geographical and temporal body size trends among 169 adult museum specimens of the Eurasian otter (Lutra lutra) collected in Sweden between 1962 and 2008, whose sex, year of collection, and locality were known. Skull size and body mass increased significantly in relation to the year of collection, and skull size (but not body mass) was significantly and negatively related to latitude, contrasting Bergmann's rule and the trend found for Norwegian otters. Latitudinal differences in body size between the two countries may be due to differences in food availability. The temporal increase in body size among Swedish otters resembled that observed for Norway otters, though Swedish otters are smaller with respect to their Norwegian counterparts. Latitude and year represent a combination of environmental factors, including ambient temperature in the year of collection as well as the number of days of ice coverage. We replaced the above factors with mean annual temperature or the number of days of ice coverage, and found that each of these factors explains a similar proportion of the variation in body size as did latitude and year. We hypothesize that this temporal increase in body size is related to a combination of factors, including reduced energy expenditure resulting from increasing ambient temperature, and increased food availability from longer ice-free periods.
How to translate text using browser tools
1 November 2010
Recent Changes in Body Size of the Eurasian Otter Lutra lutra in Sweden
Yoram Yom-Tov,
Anna Roos,
Peter Mortensen,
Øystein Wiig,
Shlomith Yom-Tov,
Thrine M. Heggberget
ACCESS THE FULL ARTICLE
It is not available for individual sale.
This article is only available to subscribers.
It is not available for individual sale.
It is not available for individual sale.
AMBIO: A Journal of the Human Environment
Vol. 39 • No. 7
November 2010
Vol. 39 • No. 7
November 2010
ambient temperature
body size
Eurasian otter
food availability
global warming
Ice coverage
Lutra lutra
