The more you know.
Pennsylvania Snowshoe Hares Make Front Page News!
The following article is copied without permission from:
PENNSYLVANIA Outdoor News-August 18, 2017-
Pa. snowshoe hares are cool customers
by Jeff Mulhollem-Editor
University Park, Pa.--
Snowshoe hares in Pennsylvania, - at the southern end of the species' range - show adaptations in fur color and characteristics, behavior and metabolism, to enable them to survive in less wintry conditions than their far northern relatives, according to a team of researchers in Penn State's College of Agricultural Sciences.
These evolved, organic survival strategies, they say, suggest snowshoe hares possess at least a limited ability to adjust to a warming climate.
Understanding adaptations of non-hibernating mammals to cope with extreme cold and snow - and then, the lack of those conditions - is important because climate-induced changes in winter temperatures and snow cover are predicted to become more pronounced in the future, noted team member Duane Diefenbach, adjunct professor of wildlife ecology.
Animals living in the Arctic and Boreal regions - especially those adapted to survive harsh winter - are particularly vulnerable because these regions are experiencing the greatest change in winter conditions, said Diefenbach, leader of Pennsylvania Cooperative Fish and Wildlife Research Unit at Penn State.
"Understanding how a species has adapted to the different winter temperatures experienced across their range can offer insight into how a species might respond to future changes in winter conditions," he said.
Striking examples of that variability were documented by Diefenbach's team in findings published online in the Canadian Journal of Zoology.
They compared winter coat characteristics and heat production of snowshoe hares in Pennsylvania's Pocono Mountains, Monroe County, to hares in Canada's Yukon, in the southwestern Kluane region to investigate how hares might respond to changing environmental conditions. [for more information on the Yukon's Kluane Region see, HARE-RAISING ENCOUNTERS by Mark O'Donohue and Susan Stuart listed on this blog]
The study also investigated how hares in Pennsylvania altered movement rates and resting spot selection to cope with variable winter temperatures.
To accomplish the analysis, data from a study of Yukon snowshoe hares collected in 2007 by research team member Michael Sheriff, assistant professor of mammalogy and ecology, was contrasted with information collected from 70 Pennsylvania hares trapped in 2014-15 by lead researcher Laura Gigliotti.
Some were fitted with radio collars that monitored location, movement and animal temperatures.
A master's degree student in wildlife and fisheries science when the research was done, Gigliotti is now a doctoral degree student at Clemson University.
The researchers discovered that hares in Pennsylvania had shorter, less-dense and less-white winter coats than their northern counterparts, suggesting lower coat insulation. Hares in the southern population had lower coat temperatures, indication that they produced less heat than those in northern population.
In addition, hares in Pennsylvania did not select resting spots that offered thermal advantages, instead selecting locations offering obstruction from predators.
Hare - movement rates were related to air temperature, with the smallest movements occurring at the lower and upper range of observed ambient temperatures - the animals did not move much in winter when it was very cold or very warm.
Snowshoe hares are ideal to investigate the potential for species to alter winter adaptations in response to climate change, explained Gigliotti, because unlike other small mammals the hibernate, group huddle, or use nests as means of coping with cold temperatures, hare remain active on the surface throughout winter.
And they are active at night when temperatures are typically the lowest.
"Snowshoe hares also have well-documented morphological and physiological adaptations to cope with winter, such as an increase in fur density -- in addition to their coat color change -- and a low metabolic rate," she said. "Hares also have a broad geographic range, which permits comparison of winter adaptations from populations that experience very different conditions."
Pennsylvania hares were, on average, significantly larger than hares in the Yukon, Gigliotti pointed out, and to their surprise, researchers found specimens that did not completely molt, or change coloration from brown to white, in winter.
That development, of course, helps hares camouflage and elude predators in winters with scant snowfall.
"We trapped three hares in January that were almost completely brown, and it's the first time that has been recorded in eastern North America," she said. "There are hare populations in the Cascades in Washington that don't molt completely, but that had not been documented elsewhere.
Researchers, right now, can only speculate over what time scale Pennsylvania snowshoe hares' adaptations to warmer winters have occurred, and the don't know, yet, whether genetic modifications are triggering the changes. But, in tandem, the adaptations may allow hares to survive warming long term, Gigliotti hopes.
"Our results indicate that snowshoe hares may be able to adapt to future climate conditions via changes in pelage characteristics, metabolism and behavior," said Gigliotti, "Unfortunately, we don' know if they can adapt as quickly as climate change is occurring."
The Pennsylvania Game Commission supported this research.
Animals living in the Arctic and Boreal regions - especially those adapted to survive harsh winter - are particularly vulnerable because these regions are experiencing the greatest change in winter conditions, said Diefenbach, leader of Pennsylvania Cooperative Fish and Wildlife Research Unit at Penn State.
"Understanding how a species has adapted to the different winter temperatures experienced across their range can offer insight into how a species might respond to future changes in winter conditions," he said.
Striking examples of that variability were documented by Diefenbach's team in findings published online in the Canadian Journal of Zoology.
They compared winter coat characteristics and heat production of snowshoe hares in Pennsylvania's Pocono Mountains, Monroe County, to hares in Canada's Yukon, in the southwestern Kluane region to investigate how hares might respond to changing environmental conditions. [for more information on the Yukon's Kluane Region see, HARE-RAISING ENCOUNTERS by Mark O'Donohue and Susan Stuart listed on this blog]
The study also investigated how hares in Pennsylvania altered movement rates and resting spot selection to cope with variable winter temperatures.
To accomplish the analysis, data from a study of Yukon snowshoe hares collected in 2007 by research team member Michael Sheriff, assistant professor of mammalogy and ecology, was contrasted with information collected from 70 Pennsylvania hares trapped in 2014-15 by lead researcher Laura Gigliotti.
Some were fitted with radio collars that monitored location, movement and animal temperatures.
A master's degree student in wildlife and fisheries science when the research was done, Gigliotti is now a doctoral degree student at Clemson University.
The researchers discovered that hares in Pennsylvania had shorter, less-dense and less-white winter coats than their northern counterparts, suggesting lower coat insulation. Hares in the southern population had lower coat temperatures, indication that they produced less heat than those in northern population.
In addition, hares in Pennsylvania did not select resting spots that offered thermal advantages, instead selecting locations offering obstruction from predators.
Hare - movement rates were related to air temperature, with the smallest movements occurring at the lower and upper range of observed ambient temperatures - the animals did not move much in winter when it was very cold or very warm.
Snowshoe hares are ideal to investigate the potential for species to alter winter adaptations in response to climate change, explained Gigliotti, because unlike other small mammals the hibernate, group huddle, or use nests as means of coping with cold temperatures, hare remain active on the surface throughout winter.
And they are active at night when temperatures are typically the lowest.
"Snowshoe hares also have well-documented morphological and physiological adaptations to cope with winter, such as an increase in fur density -- in addition to their coat color change -- and a low metabolic rate," she said. "Hares also have a broad geographic range, which permits comparison of winter adaptations from populations that experience very different conditions."
Pennsylvania hares were, on average, significantly larger than hares in the Yukon, Gigliotti pointed out, and to their surprise, researchers found specimens that did not completely molt, or change coloration from brown to white, in winter.
That development, of course, helps hares camouflage and elude predators in winters with scant snowfall.
"We trapped three hares in January that were almost completely brown, and it's the first time that has been recorded in eastern North America," she said. "There are hare populations in the Cascades in Washington that don't molt completely, but that had not been documented elsewhere.
Researchers, right now, can only speculate over what time scale Pennsylvania snowshoe hares' adaptations to warmer winters have occurred, and the don't know, yet, whether genetic modifications are triggering the changes. But, in tandem, the adaptations may allow hares to survive warming long term, Gigliotti hopes.
"Our results indicate that snowshoe hares may be able to adapt to future climate conditions via changes in pelage characteristics, metabolism and behavior," said Gigliotti, "Unfortunately, we don' know if they can adapt as quickly as climate change is occurring."
The Pennsylvania Game Commission supported this research.
A hare hunters perspective.
by The High HareMan
First, the High HareMan is not a
creationist in the broad sense of the term. (Creationism is the religious belief that the universe and life originated "from specific acts of Divine creation," as opposed to the scientific conclusion
that they came about through natural process.)
However, when it comes to the snowshoe hare, the High HareMan believes the varying hare or snowshoe hare (lepus Americanus) was designed by the Architect of the Universe or by The Creator hundreds of thousands or possibly millions of years ago and remains today, basically, just it was and has been for all those eons. There is no “natural process” here. The “process” by which the snowshoe hare changes color in winter was not created by evolution and Darwin had nothing to do with any of it. The snowshoe hare could not have survived from the get-go if it were not for his white in winter. The process of changing color in winter was designed by The Creator.
However, when it comes to the snowshoe hare, the High HareMan believes the varying hare or snowshoe hare (lepus Americanus) was designed by the Architect of the Universe or by The Creator hundreds of thousands or possibly millions of years ago and remains today, basically, just it was and has been for all those eons. There is no “natural process” here. The “process” by which the snowshoe hare changes color in winter was not created by evolution and Darwin had nothing to do with any of it. The snowshoe hare could not have survived from the get-go if it were not for his white in winter. The process of changing color in winter was designed by The Creator.
Second, "Our results indicate that snowshoe
hares may be able to adapt to future climate conditions via changes in pelage
characteristics, metabolism and behavior," said Gigliotti,
"Unfortunately, we don' know if they can adapt as quickly as climate change
is occurring."
The High HareMan is
a “climate change” denier. I do not deny
the possibility of global warming or climate change. I deny the possibility that man, especially me personally, can do
anything about it and the poor snowshoe hare cannot “adapt” to warming temperatures
and lack of snow-cover. In the
Pennsylvania Game Commission’s own words: “Cold temperatures and ground color
have nothing to do with the pelt's color change. It results totally from phototropism—in other
words, it depends on light. As days get shorter in fall, for instance, a hare's
eyes receive light for shorter and shorter periods; this stimulates the
pituitary gland, located at the base of the brain. During molt, the pituitary
shuts off pigment production in the new fur, which therefore grows in white. In
spring, lengthening days trigger the reverse of this process,” so says the
Pennsylvania Game Commission @ PGC > Education > Wildlife Notes Index > Snowshoe Hare.
I don’t see the length of the day changing any time soon.
Nowhere in the article or in the abstract of the study was there any mention of phototropism or photoperiodism.
I don’t see the length of the day changing any time soon.
Nowhere in the article or in the abstract of the study was there any mention of phototropism or photoperiodism.
Third, I can
believe animals can vary in coat or fur (pelage) production from one climate to
the next even though the animals are of the same species. Beaglers know that beagles
living in the south or indoors will have less thickness in their coat
(pelage) than those living in the far north.
“Hare - movement rates were related to air
temperature, with the smallest movements occurring at the lower and upper range
of observed ambient temperatures - the animals did not move much in winter when
it was very cold or very warm.”
All hare
hunters know the illusive snowshoe hare are very hard to find in winter when
the weather conditions are warm with little snow. On the other hand, we have found the colder
the weather the more the hare will be on the move.
"We trapped three hares in January that
were almost completely brown, and it's the first time that has been recorded in
eastern North America," she said.
I would sooner believe there to be something
deficient in the hare’s diet or something wrong with the hare’s the
pituitary.
In conclusion: Global warming may come and go but the
illusive and majestic, and, yes, omnipotent snowshoe hare will persist as it
has for thousands or millions of years, The Creator willing.
