Indiana Bat Numbers Down 72% 2005-11; By 2060, Climate Likely Means No Reproduction In Current Range

[hatrack]

Jan. 28, 2013 — Research by U.S. Forest Service scientists forecasts profound changes over the next 50 years in the summer range of the endangered Indiana bat. In an article published in the journal Ecology and Evolution, Forest Service Southern Research Station researchers Susan Loeb and Eric Winters discuss the findings of one of the first studies designed to forecast the responses of a temperate zone bat species to climate change.

The researchers modeled the current maternity distribution of Indiana bats and then modeled future distributions based on four different climate change scenarios. "We found that due to projected changes in temperature, the most suitable summer range for Indiana bats would decline and become concentrated in the northeastern United States and the Appalachian Mountains," says SRS research ecologist Loeb. "The western part of the range (Missouri, Iowa, Illinois, Kentucky, Indiana, and Ohio) -- currently considered the heart of Indiana bat maternity range -- would become unsuitable under most climates that we modeled. This has important implications for managers in the Northeast and the Appalachian Mountains as these areas will most likely serve as climatic refuges for these animals when other parts of the range become too warm."

In general, bat species in temperate zones such as Indiana bats may be more sensitive than many other groups of mammals to climate change because their reproductive cycles, hibernation patterns, and migration are closely tied to temperature. Indiana bat populations were in decline for decades due to multiple factors, including the destruction of winter hibernation sites and loss of summer maternity habitat.

Due to conservation efforts, researchers saw an increase in Indiana bat populations in 2000 to 2005, but with the onset of white-nose syndrome populations are declining again, with the number of Indiana bats reported hibernating in the northeastern United States down by 72 percent in 2011. The study predicts even more declines due to temperature rises from climate change, with much of the western portion of the current range forecast to be unsuitable for maternity habitat by 2060.

"Our model suggests that once average summer (May through August) maximum temperatures reach 27.4°C (81.3°F), the climatic suitability of the area for Indiana bat maternity colonies declines," says Loeb. "Once they reach 29.9°C (85.8°F), the area is forecast to become completely unsuitable. Initially, Indiana bat maternity colonies may respond to warming temperatures by choosing roosts that have more shade than the roosts that they currently use. Eventually, it is likely that they will have to find more suitable climates."

EDIT

http://www.sciencedaily.com/releases/2013/01/130128191233.htm

[dixiegrrrrl]

1. Is it not possible the bats have moved into a different climate area?

We have watched the change in bird migration down here over the last 5 years
along with reports that the same birds are now observed further north of us.

[happyslug]

2. In appears the Indiana Bat habituate in only a few caves.

http://en.wikipedia.org/wiki/Indiana_bat

23% of those caves are in the State of Indiana. Thus the problem, if the general temperature gets to high, they will have to travel to far away from their winter cave. Some of these caves in are Pennsylvania, and being in the Appalachian Mountains will not get as hot as fast. Thus the idea of the bats "retreating" to the Appalachians, is more a situation that the caves in Indiana gets to be to far from areas where the bat can survive while the caves in the Appalachians would still be in areas below the temperature that these bats can NOT tolerate.

[dixiegrrrrl]

3. thank you for your detailed answer.

[happyslug]

4. I live in Johnstown, south of Indiana PA, and these bats are a big issue here.

Thus, I know they exist in this area, in various caves and former mines. Every so often the local paper carry a story about them, thus I know a little bit more then the Wikipedia Article states but I have to defer to bat experts as to any real facts on these bats.