"The USDA(Dept. of Agriculture) Conservation Reserve Program (CRP) pays a yearly rental payment in exchange for farmers removing environmentally sensitive land from agricultural production and planting species that will improve environmental quality"........."CRP is a voluntary program that contracts with agricultural producers so that environmentally sensitive agricultural land is not farmed or ranched, but instead used for conservation benefits".............. "CRP participants establish long-term, resource conserving plant species, such as approved grasses or trees (known as “covers”), to control soil erosion and improve water quality".............."In return, FSA provides participants with rental payments and cost-share assistance"............"Contract duration is between 10 and 15 years and was signed into law by President Ronald Reagan in 1985"..................."CRP is the largest private-lands conservation program in the United States"............"Thanks to voluntary participation by farmers and land owners, CRP has improved water quality, reduced soil erosion, and increased habitat for endangered and threatened species".............."This is espcially true in light of modern agriculture's large monoculture fields which grow a lot of corn and soybeans, planted annually"............"Soil, nutrients, groundwater, pollinators, wildlife diversity, and habitat (among other things) can be lost when crop yields are maximized"............."Prairie strips are composed of native perennial plants and located across hillslopes"............"The stiff stems and abundant, fibrous roots of the native plants slow down water and allow it to soak into the soil, causing less soil erosion"..................."The native plants also provide habitat for wildlife"................"Conservation Reserve Program (CRP) contracts through the USDA's Farm Service Agency can greatly reduce the cost of establishing prairie strips"............."Overall, this is one of the most economical best-practice conservation steps farmers can take"

https://phys.org/news/2019-01-prairie-farmland.html

Prairie strips transform farmland conservation

January 30, 2019, American Society of Agronomy

Modern agriculture's large monoculture fields grow a lot of corn and soybeans, planted annually. The outputs from row crops can be measured both in dollars paid in the market and also in non-market costs, known as externalities. Soil, nutrients, groundwater, pollinators, wildlife diversity, and habitat (among other things) can be lost when crop yields are maximized.

Prairie strips are composed of native perennial plants and located across hillslopes. The stiff stems and abundant, fibrous roots of the native plants slow down water and allow it to soak into the soil, causing less soil erosion. The native plants also provide habitat for wildlife. Credit: Lynn Betts

Now it appears that prairie strips have an extraordinary power to change this pattern.

A prairie strip is much what it sounds like: a strip of diverse herbaceous vegetation running through a farm's rowcrops. In the American Midwest, chances are the soil that now supports crops was once covered in prairie before cultivation. Prairie plants are a mixture of native grasses, wildflowers, and other stiff-stemmed plants. They have deep roots that draw water and nutrients from far below the surface. They are perennials, returning to grow each spring.

"Research shows that areas of native prairie planted in the right places in a farm field can provide benefits that far outweigh losses from converting a small portion of a crop field to prairie," said Lisa Schulte Moore of Iowa State University. "For example, when we work with farmers to site prairie strips on areas that were not profitable to farm, we can lower their financial costs while creating a wide variety of benefits."

Prairie strips are composed of a diverse plant community and can be designed to provide an abundance of flowers blooming from early spring through late fall. This is crucial to conserving pollinators and other beneficial insects. Credit: Sarah Hirsh

Schulte Moore is a team member with STRIPS: Science-based Trials of Rowcrops Integrated with Prairie Strips. STRIPS showed that converting just 10% of a row-cropped field to prairie strips:

• reduces soil loss by 95%,
• reduces overland water flow by 37%, and
• reduces the loss of two key nutrients (nitrogen and phosphorus) from the soil by nearly 70% and 77%, respectively.

It also leads to greater abundance and diversity of beneficial insects, pollinators such as bees and monarch butterflies, and birds. Going from zero to 10% prairie provided far more than a 10% increase in the measured benefits.

"Some of these benefits can impact our pocketbooks but are not accounted for by typical financial markets," said Schulte Moore. These include ecological benefits such as flood control, cleaner water, and carbon from the atmosphere stored.

Farmer and farmland owner collaborators gather with the STRIPS team to share knowledge about the science and practice of prairie strips. Credit: Matt Stephenson

Market benefits also exist: more productive soil in the fields can, in time, translate into better yields, fiber and honey production, forage for livestock, and hunting leases.

The STRIPS research began in Iowa in 2007. Because of promising scientific results, five years later the researchers began working with farmers to introduce prairie strips onto commercial farms. While the research results have been more variable in these more complicated settings, the findings are encouraging and cooperating farmers are liking what they see.

The plantings require a modest investment in site preparation and seed planting. Maintenance tasks include some mowing in the establishment years and spot treatment for weeds. So far, the researchers have not seen competition between the prairie plants and crops that impact yield.

Conservation Reserve Program (CRP) contracts through the USDA's Farm Service Agency can greatly reduce the cost of establishing prairie strips. Overall, Schulte Moore said, this is one of the most economical best-practice conservation steps farmers can take.

Still, lack of stable financial rewards for establishing and maintaining prairie strips is a barrier to widespread adoption. "Finding ways to return economic value to farmers and farmland owners is crucial," Schulte Moore said. She is now focused on developing marketable products from prairie strips, such as renewable energy sources from prairie biomass. That would help make what is already a solid investment into a can't-lose proposition.

 Explore further: Strips of prairie plants slow loss of soil, nutrients and water from ag fields, double biodiversity

"Landscape corridors are among the most important conservation strategies in the face of global changes such as habitat fragmentation, habitat destruction, and climate change"..............."Corridors are habitats that are typically long relative to their width, and they connect fragmented patches of habitat".................."They can vary greatly in size, shape, and composition"............"The main goal of corridors is to facilitate movement of individuals, through both dispersal and migration, so that gene flow and diversity are maintained between local(animal and plant) populations".............."By linking populations throughout the landscape, there is a lower chance for extinction and greater support for species richness"..........."Corridors work by increasing connectivity between patches that are isolated by human habitat fragmentation, caused primarily by urbanization, agriculture, and forestry"............."Plants and animals can use corridors for both dispersal and migration, two key movement patterns for species persistence".............."The human-dominated habitats surrounding most natural areas(including National and State Parks and Preserves) present barriers that plants and animals are unable or highly reluctant to move through"................ "These inhospitable places may have higher abundances of predators, lower resource availability, or reduced shelter"............."When a corridor is present, however, it provides an unbroken path of suitable habitat that can provide safe passage for animals or plants without being hindered as they travel through agricultural or urban landscapes"............."This connectivity is key to population persistence, as it promotes gene flow between populations and supports higher species diversity"

http://conservationcorridor.org/2019/01/how-wide-should-a-corridor-be/

How wide should a(Wildlife) corridor be?

Conservation Corridor; January 19, 2019

It’s one of the most common – and simplest – questions when it comes to landscape connectivity: what is the best width for a corridor? When connecting large landscapes, is 10 or 20 meters a wide enough path for species to move? Larger animals need larger corridors, but exactly how much larger? And what about species with very high or very low mobility, like birds or plants?

So just how wide should a corridor be? According to Northern Arizona University ecologist Paul Beier, the answer is straightforward enough: a corridor should be 2 kilometers wide.

A lone Wolf using a wildlife corridor to seek out a mate
and create a pack of its own

In his most recent essay, Beier reviews the limited research into corridor width, and acknowledges that this is one of the most frequent questions he is asked. His recommendation of a 2 km width stems from the need to consider several issues.

First, some species need more than one generation to traverse the corridor to the next protected patch, and therefore need a corridor big enough to accommodate their home range. A 2 km wide corridor could accommodate the majority of possible terrestrial mammals likely to become “corridor dwellers”.

Mother Black Bear aMnd cubs using Wildlife corridor

Second, edge effects can negatively impact individuals that are forced to live or move near the boundaries of a corridor. A 2 km wide corridor could effectively create enough space to eliminate edge effects within a majority of its area.

Last, the widest possible corridor in general provides the opportunity to incorporate more human recreational use. This may not be the primary focus of the corridor, but is often a selling point when leveraging political and economic support. A corridor 2 km wide can also support not only the focal species, but species that were not originally considered when the corridor was designed and implemented as well.

The Wildlands Network seeking to link up North America's open space

Few other studies have explicitly addressed the question of how wide a corridor should be, and they mostly do it at a small scale. For example, one study intended to determine the minimum corridor width for streams concluded that there was no one standard width that could effectively maximize biodiversity conservation. Another study on voles concluded that the best corridor width was 1 m wide, but it only tested corridors up to 3 m wide. A study on dispersal behavior of frogs and salamanders provides a useful method for determining optimal corridor width, but without providing explicit values.

A detailed map of the hoped for Western Wildway Network corridor

For now the question of corridor width remains, with the most applicable answer coming from Beier’s 2 km rule of thumb. Land managers, stakeholders, conservation planners, and communities in general would benefit from more research, more discussion, and better consensus to the answer of this challenging question.

Resources

Beier P. 2018. A rule of thumb for widths of conservation corridors. Conservation Biology. DOI: 10.1111/cobi.13256.

Determining corridor width (January 2015)

Spackman SC and Hughes JW. 1995. Assessment of minimum stream corridor width for biological conservation: species richness and distribution along mid-order streams in Vermont, USA. Biological Conservation 71(3): 325-32.

Andreassen HP, Halle S and Ims RA. 1996. Optimal width of movement corridors for root voles: not too narrow and not too wide. Journal of Applied Ecology 33: 63-70.

January 15th, 2019

http://conservationcorridor.org/corridor-toolbox/

ADAPT AND OVERCOME is the response of many mammals to the presence of us human animals..............U. of Berkeley research reveals what many of us have come to witness ourselves----"mammals are 1.36 times more nocturnal in response to human disturbance".................."An animal that naturally split its activity evenly between the day and night, for example, would increase its nighttime activity to 68 percent around people".............."Eighty-three percent of the case studies examined showed some increase in nocturnal activity in response to disturbance"................."The findings were consistent across species, continents and habitat types"................."Antelope on the savanna of Zimbabwe, tapir in the Ecuadorian rainforests, bobcats in the American southwest deserts – all seemed to be doing what they could to shift their activity to the cover of darkness"................."The pattern also held across different types of human disturbance, including activities such as hunting, hiking, mountain biking, and infrastructure such as roads, residential settlement and agriculture"................."Animals responded strongly to all activities, regardless of whether people actually posed a direct threat".............."It seems human presence alone is enough to disrupt their natural patterns of behavior"..............."People may think our outdoor recreation leaves no trace, but our mere presence can have lasting consequences"

https://www.njherald.com/20180614/to-avoid-humans-more-wildlife-now-work-the-night-shift

To avoid humans, more wildlife now work the night shift

By KAITLYN GAYNOR
University of California, Berkeley

Posted: Jun. 15, 2018 

For their first 100 million years on planet Earth, our mammal ancestors relied on the cover of darkness to escape their dinosaur predators and competitors. Only after the meteor-induced mass extinction of dinosaurs 66 million years ago could these nocturnal mammals explore the many wondrous opportunities available in the light of day.

Raccoon in tree

Fast forward to the present, and the honeymoon in the sun may be over for mammals. They're increasingly returning to the protection of night to avoid the Earth's current terrifying super-predator: Homo sapiens.

My colleagues and I have made the first effort to measure the global effects of human disturbance on the daily activity patterns of wildlife. In our new study in the journal Science, we documented a powerful and widespread process by which mammals alter their behavior alongside people: Human disturbance is creating a more nocturnal natural world.

Coyote on the hunt in the dark

Many catastrophic effects of humans on wildlife communities have been well-documented: We are responsible for habitat destruction and overexploitation that have imperiled animal populations around the world. However, just our presence alone can have important behavioral impacts on wildlife, even if these effects aren't immediately apparent or easy to quantify. Many animals fear humans: We can be large, noisy, novel and dangerous. Animals often go out of their way to avoid encountering us. But it's becoming more and more challenging for wildlife to seek out human-free spaces, as the human population grows and our footprint expands across the planet.

Global increase in nocturnality

My collaborators and I noticed a striking pattern in some of our own data from research in Tanzania, Nepal and Canada: animals from impala to tigers to grizzly bears seemed to be more active at night when they were around people. Once the idea was on our radar, we began to see it throughout the published scientific literature.

It appeared to be a common global phenomenon; we set out to see just how widespread this effect was. Might animals all over the world be adjusting their daily activity patterns to avoid humans in time, given that it is becoming harder to avoid us in space?

 Deer wander the evening roadway

To explore this question, we conducted a meta-analysis, or a study of studies. We systematically scoured the published literature for peer-reviewed journal articles, reports and theses that documented the 24-hour activity patterns of large mammals. We focused on mammals because their need for plenty of space often brings them into contact with humans, and they possess traits that allow for some flexibility in their activity.

We needed to find examples that provided data for areas or seasons of low human disturbance – that is, more natural conditions – and high human disturbance. For example, studies compared deer activity in and out of the hunting season, grizzly bear activity in areas with and without hiking, and elephant activity inside protected areas and outside among rural settlement.

Based on reported data from remote camera traps, radio collars or observations, we determined each species' nocturnality, which we defined as the percentage of the animal's total activity that occurred between sunset and sunrise. We then quantified the difference in nocturnality between low and high disturbance to understand how animals changed their activity patterns in response to people.

Red Fox out for an evening stroll

Overall, for the 62 species in our study, mammals were 1.36 times as nocturnal in response to human disturbance. An animal that naturally split its activity evenly between the day and night, for example, would increase its nighttime activity to 68 percent around people.

While we expected to find a trend toward increased wildlife nocturnality around people, we were surprised by the consistency of the results around the world. Eighty-three percent of the case studies we examined showed some increase in nocturnal activity in response to disturbance. Our finding was consistent across species, continents and habitat types. Antelope on the savanna of Zimbabwe, tapir in the Ecuadorian rainforests, bobcats in the American southwest deserts – all seemed to be doing what they could to shift their activity to the cover of darkness.

Bobcat hunting at night

Perhaps most surprisingly, the pattern also held across different types of human disturbance, including activities such as hunting, hiking, mountain biking, and infrastructure such as roads, residential settlement and agriculture. Animals responded strongly to all activities, regardless of whether people actually posed a direct threat. It seems human presence alone is enough to disrupt their natural patterns of behavior. People may think our outdoor recreation leaves no trace, but our mere presence can have lasting consequences.

Future of human-wildlife coexistence

We don't yet understand the consequences of this dramatic behavioral shift for individual animals or populations. Over millions of years, many of the animals included in our study have evolved adaptations to living in the daylight.

Sun bears, for example, are typically diurnal and sun-loving creatures; in undisturbed areas less than 20 percent of their activity occurred at the night. But they increased their nocturnality to 90 percent in areas of the Sumatran forest where intensive forest research activity created a disturbance.

Such diurnally adapted animals may not be as successful at finding food, avoiding predators or communicating in the darkness, which could even reduce their survival or reproduction.

Gray Fox under the cover of darkness

However, because our mammalian ancestors evolved under the cover of darkness in the time of the dinosaurs, most mammal species possess traits that allow for some flexibility in their activity patterns. As long as animals are able to meet their needs during the night, they may actually thrive in human-dominated landscapes by avoiding daytime direct encounters with people that could potentially be dangerous for both parties. In Nepal, for example, tigers and people share the exact same trails in the forest at different times of day, reducing direct conflict between humans and these large carnivores. Dividing up the day, through what researchers call temporal partitioning, may be a mechanism by which people and wildlife can coexist on an ever more crowded planet.

An increase in nocturnality among certain species may also have far-reaching consequences for ecosystems, reshaping species interactions and cascading through food webs. In California's Santa Cruz Mountains, coyotes are becoming more nocturnal in areas with human recreation. By analyzing coyote scat, scientists have linked this behavioral change to dietary shifts from diurnal to nocturnal prey, with implications for small mammal communities and for competition with other predators.

Puma walking a game trail in the night hours

Working on this study reminded me that people aren't alone on the planet. Even if we don't see large mammals while we're out and about during the day, they may still be living alongside us, asleep while we are awake and vice versa. In areas where threatened species live, managers may consider restricting human activity to certain times of the day, leaving some daylight just for wildlife.

And it is likely that we need to preserve wilderness areas entirely free of human disturbance to conserve the most vulnerable and sensitive mammal species. Not all animals are willing or able to just switch to a nocturnal lifestyle around people. Those that try to avoid human disturbance entirely may be most vulnerable to the consequences of the expanding human footprint.

This article was originally published on The Conversation.

"Signs of an increasing black bear population in Tennessee are evident through re-colonization into their former range, including the Cumberland Plateau"..........."More evidence of an increasing bear population is from the high volume of bear calls TWRA receives and responds to"............... "Last year, TWRA wildlife officers in east Tennessee investigated over 1,000 incidents involving black bears".................."While it is hard to put an exact number on Tennessee’s total bear population, it is estimated at about 7,000 animals"............... "TWRA is conducting a black bear population study with the states of Georgia, Kentucky, North Carolina and South Carolina to get a better estimate of bear numbers across the southern Appalachians"................."The Researchers are utilizing a mark/recapture method to identify and estimate black bear densities"......................."The study, which should be completed by next summer, involves DNA analysis of bear hair collected from study sites"....................."This year(2018), Tennessee hunters harvested a record 759 black bears last year breaking the previous record of 589 set in 2011"..............."While 2018’s record harvest may stabilize bear numbers in certain areas, it will not stabilize the population as a whole and it will continue to grow, just at a slower rate"...............“Taking 759 bears out of a population of about 7,000 animals equates to approximately 11% of the total population"............“It would take a harvest of about 20% to stabilize the population at its current level"

https://www.tn.gov/twra/news/2018/11/5/tennessee-on-way-to-record-bear-harvest0.html

Tennessee on Way to Record Bear Harvest

Monday, November 05, 2018 

MORRISTOWN, Tenn. --- Just more than halfway through the 2018 black bear hunting season, Tennessee hunters have already harvested 551 black bears since the season opened Sept. 22. The record of 589 black bears was set in 2011.

Tennessee annual Bear kill levels by year

TWRA Black Bear Program Leader Dan Gibbs points towards a spotty acorn crop this year to account for the high harvest. Simply put, the more that bears have to move in search of food, the more susceptible they are to being located by hunters.  In 2011, biologists say there was a mast failure of acorns in the Great Smoky Mountains National Park forcing bears to leave protected areas and onto the national forests or private lands where they could be hunted.  For example, Sevier County, which borders a large boundary of the GSMNP, accounted for about 20 percent of the total bear harvest that year.  Gibbs also mentions that the high harvest so far this year reflects an increasing black bear population.

 While it's hard to put an exact number on the total number of bears in Tennessee, it's estimated to be at about 7,000 animals.  TWRA is conducting a black bear population study with the states of Georgia, Kentucky, North Carolina, and South Carolina to get a better estimate of bear numbers across the southern Appalachians. "We are basically utilizing a mark/recapture method to identify and estimate black bear densities," says Gibbs. Tennessee's part of the study should be completed by the summer of 2019.

Tennessee Black Bear locations on map below

Cumberland Plateau indicated in Red and Yellow

Other signs of an increasing black bear population are evident through re-colonization into their former range, including the Cumberland Plateau. As a result, TWRA created a new Bear Hunting Zone in several Cumberland Plateau continues and has seen an increase in harvest since the first archery only season opened in 2014. In fact, archery hunters in Fentress County took 50 black bears with archery equipment this year alone. All hunting segments in the Cumberland Plateau area have concluded this year, however, a few hunts still remain in other Bear Hunting Zones in East Tennessee. One still hunt (without the use of dogs) remains from Nov. 17-20 in Bear Hunt Zones 1-3 followed by a segment with the use of dogs Nov. 26-Dec. 15 in BHZ 1; Nov. 26-Dec. 20 in BHZ 2 and Nov. 26-Dec. 9 in BHZ 3. The final segment of the 2018 black bear hunting season will be held Dec. 27-30 and is only open in BHZ 3.  So far, Cocke County leads the state with 92 bears harvested followed by Monroe County with 89 and Blount County with 67

For more details about black bear hunting in Tennessee, refer to page 36 of the Tennessee Hunting and Trapping Guide at https://www.tn.gov/content/dam/tn/twra/documents/huntguide.pdf

Harvest reports and biological data for Tennessee's big game species can be researched online at:

https://hunterstoolbox.gooutdoorstennessee.com/?reportId=210#Harvest_Reports

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https://ag.tennessee.edu/news/Pages/NR-2018-05-Appalachianbearstudy.aspx

University Study of Black Bears Spreads to Western North Carolina

​University of Tennessee Continues Monitoring Black Bear Populations Across the Southeast

5/31/18 ;

Kristy Keel-Black

University of Tennessee student and SACBS research field manager Sam Millman (center, crouching) explains the sample collection procedure to other participants in the 2017 Southern Appalachian Cooperative Bear Study (SACBS), a research program collecting population data of Appalachian black bears. SACBS is currently in its second and final year in which research technicians, students and volunteers are working to collect hair samples of black bears in North Carolina. ​Photo by K. Keel-Blackmon, courtesy UTIA.

Regional Black Bear Study Area

"In Winter, wildlife can succumb to frostbite and hypothermia, just like people and pets. In the northern United States, the unfurred tails of opossums are a common casualty of cold exposure"...................."Every so often an unusual cold snap in Florida results in iguanas falling from trees and manatees dying from cold stress"............."Animal species have their own equivalent to what us human animals experience as that unpleasant biting mixed with pins-and-needles sensation that urges us to warm up soon or suffer the consequences"................"Many animals have evolved behaviors to help them beat the cold: migration, herding, denning, burrowing and roosting in cavities are all good defenses"................ And some animals experience physiological changes as winter approaches, building fat reserves, growing thicker fur, and trapping an insulating layer of air against the skin beneath the fur or feathers"..............."Some warm-blooded animals exhibit torpor: a state of decreased activity"..............."They look like they are sleeping" ............"Hibernation is a prolonged version of torpor"......................."Another secret weapon in mammals and birds during long periods of cold exposure is brown adipose tissue or "brown fat," which is rich in mitochondria"................"Even in people, these cellular structures can release energy as heat, generating warmth without the muscle contractions and energy inefficiency involved in shivering, another way the body tries to heat up"..............."This non-shivering heat production probably explains why people in Anchorage can contentedly wear shorts and t-shirts on a 40 degrees Fahrenheit spring day"

https://phys.org/news/2019-01-winter-miserable-wildlife.html

Is winter

 miserable for

 wildlife?

January 18, 2019 by Bridget B. Baker

While the weather outside may indeed get frightful this winter, a parka, knit hat, wool socks, insulated boots and maybe a roaring fire make things bearable for people who live in cold climates. But what about all the wildlife out there? Won't they be freezing?

Squirrel in Winter snow

Credit: tim elliott/Shutterstock.com

Anyone who's walked their dog when temperatures are frigid knows that canines will shiver and favor a cold paw – which partly explains the boom in the pet clothing industry. But chipmunks and cardinals don't get fashionable coats or booties.

In fact, wildlife can succumb to frostbite and hypothermia, just like people and pets. In the northern United States, the unfurred tails of opossums are a common casualty of cold exposure. Every so often an unusual cold snap in Florida results in iguanas falling from trees and manatees dying from cold stress.

Avoiding the cold is important for preserving life or limb (or, in the opossum's case, tail) and the opportunity to reproduce. These biological imperatives mean that wildlife must be able to feel cold, in order to try to avoid the damaging effects of its extremes. Animal species have their own equivalent to what human beings experience as that unpleasant biting mixed with pins-and-needles sensation that urges us to warm up soon or suffer the consequences. In fact, the nervous system mechanisms for sensing a range of temperatures are pretty much the same among all vertebrates.

One winter challenge for warm-blooded animals, or endotherms, as they're scientifically known, is to maintain their internal body temperature in cold conditions. Interestingly though, temperature-sensing thresholds can vary depending on physiology. For instance, a cold-blooded – that is, ectothermic – frog will sense cold starting at a lower temperature compared to a mouse. Recent research shows that hibernating mammals, like the thirteen-lined ground squirrel, don't sense the cold until lower temperatures than endotherms that don't hibernate.

Some animals find a protected spot to wait out the worst of it, like this chipmunk. Credit: Michael Himbeault, CC BY

So animals know when it's cold, just at varying temperatures. When the mercury plummets, are wildlife suffering or just going with the icy flow?

One solution: Slow down and check out

Many cold-climate endotherms exhibit torpor: a state of decreased activity. They look like they are sleeping. Because animals capable of torpor alternate between internally regulating their body temperature and allowing the environment to influence it, scientists consider them "heterotherms." During harsh conditions, this flexibility offers the advantage of a lower body temperature – remarkably in some species, even below the 32 degrees Fahrenheit freezing point – that is not compatible with many physiologic functions. The result is a lower metabolic rate, and thus lower energy and food demand. Hibernation is a prolonged version of torpor.

Torpor has energy conservation benefits for smaller-bodied wildlife in particular – think bats, songbirds and rodents. They naturally lose heat faster because the surface area of their body is large compared to their overall size. To maintain their body temperature within normal range, they must expend more energy compared to a larger-bodied animal. This is especially true for birds who maintain higher average body temperatures compared to mammals.

Unfortunately, torpor is not a perfect solution to surviving frigid conditions since it comes with trade-offs, such as a higher risk of becoming another animal's lunch.

The large ears of a fennec fox would be a liability in a cold climate like where the arctic fox lives. Credit: Jonatan Pie/Unsplash and Kkonstan/Wikimedia Commons, CC BY

Adaptations that help

Unsurprisingly, animals have evolved other adaptations for weathering the winter months.

Wildlife species at northern latitudes tend be larger-bodied with smaller appendages than their close relatives closer to the tropics. Many animals have evolved behaviors to help them beat the cold: herding, denning, burrowing and roosting in cavities are all good defenses. And some animals experience physiological changes as winter approaches, building fat reserves, growing thicker fur, and trapping an insulating layer of air against the skin beneath the fur or feathers.

Nature has devised other neat tricks to help various animals deal with conditions that people, for instance, would be unable to endure.

Have you ever wondered how geese can appear to stand comfortably on ice or squirrels in snow in their bare feet? The secret is the close proximity of the arteries and veins in their extremities that creates a gradient of warming and cooling. As blood from the heart travels to the toes, the warmth from the artery transfers to the vein carrying cold blood from the toes back to the heart. This countercurrent heat exchange allows the core of the body to remain warm while limiting heat loss when the extremities are cold, but not so cold that tissue damage occurs. This efficient system is used by many terrestrial and aquatic birds and mammals, and even explains how oxygen exchange occurs in the gills of fish.

Carp in a partially frozen pond are doing fine. Credit: Starkov Roma/Shutterstock.com

Speaking of fish, how do they not freeze from the inside out in icy waters? Luckily, ice floats because water is most dense as a liquid, allowing fish to swim freely in not-quite-freezing temperatures below the solidified surface. Additionally, fish may lack the cold-sensing receptor shared by other vertebrates. They do, however, have unique enzymes that allow physiologic functions to continue at colder temperatures. In polar regions, fish even have special "antifreeze proteins" that bind to ice crystals in their blood to prevent widespread crystallization.

Another secret weapon in mammals and birds during long periods of cold exposure is brown adipose tissue or "brown fat," which is rich in mitochondria. Even in people, these cellular structures can release energy as heat, generating warmth without the muscle contractions and energy inefficiency involved in shivering, another way the body tries to heat up. This non-shivering heat production probably explains why people in Anchorage can contentedly wear shorts and t-shirts on a 40 degrees Fahrenheit spring day.

Of course, migration can be an option – though it's expensive in terms of energetic costs for wildlife, and financially for people who want to head closer to the equator.

As a species, human beings have the ability to acclimate to an extent – some of us more than others – but we're not particularly cold-adapted. Maybe that's why it's hard to look out the window on a frigid day and not feel bad for a squirrel hunkered down as the winter wind whips through its fur. We may never know if animals dread winter – it's difficult to gauge their subjective experience. But wildlife do have a variety of strategies that improve their ability to withstand the cold, making sure they live to see another spring.

Provided by: The Conversation