The Salamander effect …

Widespread rapid reductions in body size of adult salamanders in response to climate change.

Nicholas M. Caruso, Michael W. Sears, Dean C. Adams and Karen R. Lips.

From the abstract …

We compared historic and contemporary size measurements in 15 Plethodon species from 102 populations (9450 individuals) and found that six species exhibited significant reductions in body size over 55 years. Biophysical models, accounting for actual changes in moisture and air temperature over that period, showed a 7.1–7.9% increase in metabolic expenditure at three latitudes but showed no change in annual duration of activity. Reduced size was greatest at southern latitudes in regions experiencing the greatest drying and warming.

The biophysical model was a computer model of course which can be summarised thus …

To estimate activity, humid operative temperatures (Teh) were calculated for each minute of the day as:

display math              (1)
display math                                                  (2)

… otherwise known as the salamander equation ! Global warming = smaller salamanders.

The literature is far from unanimous on the effect of warming and drying on salamanders. If you would prefer them to get bigger try this paper instead …

Bruzgul J. E., Long W. & Hadly E. A. BMC Ecol., 5. 7 (2005).  Reported in Nature …

Fossil hunters in Yellowstone National Park have discovered an unusual way to record the effects of climate change. Specimens from the past 3,000 years suggest that salamanders have grown bigger as the climate has warmed, and may continue to change as temperatures rise and lakes dry up.

During development, tiger salamanders (Ambystoma tigrinum) can metamorphose and head for land rather than staying in the water. And warmer climes have made salamanders on land outgrow their water-based relatives, says Elizabeth Hadly of Stanford University in California. Hadley and her colleagues examined almost 3,000 salamander vertebrae from the park’s Lamar Cave in Wyoming.

The difference is particularly pronounced in the warmest period of Yellowstone’s history, between 1,150 and 650 years ago, the researchers add. Hotter conditions allow for more abundant food and faster growth rates, they suspect, and such effects are expected to be less marked in the water, where temperature changes are smaller.

Global warming = bigger salamanders.

Let’s just say climate change = altered salamanders.