What's living under the ice?

            It’s one of my fondest memories of childhood, ice skating on the one-acre pond in my backyard in North Kingstown. We often skated several times each day – before school, after school and even after dinner, thanks to the lights my father installed to illuminate the area. And weekends were for skating parties, hockey games and general silliness on the ice.

            That’s also when I first began to wonder about the creatures that were living in the water beneath the ice. Occasional spots of clear ice seemed to serve as a window into the underwater world, and I never ignored an opportunity to lie on the ice to see what was there.

I often saw very little, just mud and leaves and floating sediment. But every once in a

Cartoon by David Chatowsky

while, something else came into view – mostly aquatic insects, fairy shrimp, tiny fish and, once, a giant snapping turtle. I’ll never forget lying face-to-face with that snapper, wondering if he was frightened of me and worrying that he was as cold as I was.

            To this day I still think about that turtle every winter. I had assumed that most turtles bury themselves in the mud and hibernate through the cold months, but apparently not all do. Snapping turtles are particularly cold tolerant and well known for remaining active beneath the ice, though even they reduce their metabolism and move very slowly.

            Peter Paton, a reptile and amphibian expert at the University of Rhode Island, said that he has seen wood frogs, spotted turtles, and spotted salamanders swimming under the ice on occasion. It’s more likely to happen, he said, during cycles of melting and refreezing, especially during rainy periods in late winter. That’s when many frogs and salamanders begin to move from the land to the ponds in search of a mate. When temperatures plunge at night and the ponds refreeze, it may lock the animals in, but they seem to survive just fine.

            Aquatic creatures that cannot live on land – like fish, fairy shrimp and insect larvae – are locked beneath the ice, too, but they’ve evolved to live through such conditions and thrive. For some, the cold, icy conditions are a necessary trigger for the next stages of their growth and development.

            And as any ice fisherman will tell you, there are plenty of fish that remain active beneath the ice. That’s because there is still plenty of food available to sustain them: crustaceans keep creeping along, algae still bloom, plants still photosynthesize when enough light penetrates the ice, and tiny zooplankton continue to swim, feed, and reproduce.

            The larval form of dragonflies, stoneflies and mayflies are among a very few aquatic insects that remain active beneath the ice throughout the winter. Some can even live a short time encased in ice, which is especially helpful when shallow ponds freeze all the way to the bottom. And when the ice eventually melts and reaches a certain temperature, the bugs transform into their adult form and fly away.

            Which is what I’d like to do about now – fly away south. My ice skates no longer fit, our ponds seldom freeze thick enough to skate on any more, and general silliness on the ice is no longer as attractive as it once was. But I’d relish another opportunity to go face-to-face with a snapping turtle lurking beneath the ice.

This article first appeared in the Independent on February 15, 2018.

Hydrothermal vents speed development of deep-sea skate eggs

            A team of scientists from the University of Rhode Island and the Charles Darwin Research Station exploring the seafloor northwest of the Galapagos Islands in 2015 made an unexpected discovery. Large numbers of egg cases of a deep-sea skate – relatives of sharks and rays – were observed adjacent to the hot water emitted from hydrothermal vents, which the scientists said the skates use to accelerate the development of the embryos.

                It is the first time such behavior has been recorded in marine animals. The discovery is published this week in the journal Scientific Reports.

                Brennan Phillips, URI assistant professor of ocean engineering, was leading the operations team of remotely-operated vehicle operators during the expedition to explore the underwater

Robotic arm picks up Pacific skate egg from ocean floor (Ocean Exploration Trust)

mountains around the Galapagos. He said they didn’t recognize the significance of the aggregation of skate eggs until much later.

                “We were on a really deep dive in a hydrothermally-active rift valley, with walls 30 meters tall on either side, and the ROV was meandering back and forth looking for vents,” Phillips explained. “We started noticing all these egg cases, and we recorded their location and collected a few but then just kept going.”

                Later, when the egg locations were analyzed and compared to hydrothermal vent locations and recorded water temperatures, the scientists concluded that the eggs were likely intentionally placed by the skates where the water was warmer than average.

                In total, 157 mobile-phone-sized egg cases were observed, which DNA analysis revealed to be from the Pacific white skate (Bathyraja spinosissima). About 58 percent of the egg cases were found within 20 meters of a black smoker, the hottest kind of hydrothermal vent, and 89 percent of the egg cases were laid in water that was hotter than the background temperature of 2.76 degrees Centigrade.

                “The eggs weren’t right next to the active vents, because the water can get so hot – hundreds of degrees – that it would kill them,” Phillips said. “We found most of them in the lukewarm water not far from the vents and near some extinct vents.

                “The kicker is that we showed our data to a bunch of shark experts, and they had seen anecdotal evidence of shark and ray egg cases near hydrothermal vents, but they never had the data to put the story together,” he added.

                Several land animals have been recorded laying their eggs in similar situations. A rare bird native to Tonga, the Polynesian megapode, often nests in volcanically-heated soils, for instance. Fossils of some sauropod dinosaurs of the Cretaceous era are believed to have done so as well.

                This isn’t the first time Phillips has observed unexpected behaviors by shark family members in heated water. In 2014, he investigated an underwater volcano near the Solomon Islands in the western Pacific Ocean, where he watched several species of shark swim right through the bubbling hot water in the volcano’s crater.

                “Our cameras caught images of schools of sharks, smaller fish and even jellyfish living in the hot acidic plume,” he said at the time. “This presumably toxic environment supports a whole community of life, even though every once in a while it blows up.”

                Coupled with his hydrothermal vent observation, Phillips believes that sharks, rays and skates – which evolved about 500 million years ago – have adapted to the unusual conditions.

                “Seafloor volcanism comes and goes, and it is often one of the causes of mass extinctions,” he said. “It’s interesting to me that we’re seeing sharks and skates thriving around volcanoes and vent sites, like they’re especially resilient and have evolved to withstand the hot water environment.”

Beach birds: Geology's link to avian abundance

            One of the rarest breeding birds in the Northeast finds the beaches of Rhode Island particularly appealing in summer – not for swimming and sunbathing, of course, but for nesting and feeding.  Piping plovers, sparrow-sized pale shorebirds listed as threatened on the U.S. endangered species list, breed more densely in Rhode Island than anywhere else in their Atlantic coastal range.

About 90 pairs of the birds – up from just 10 in the 1980s – can be found laying eggs and raising their chicks on a half dozen beaches in the state, from Goosewing Beach in Little Compton to Moonstone Beach in South Kingstown and Napatree Point in Westerly. They choose

Piping plover nest at Napatree Point (Peter Paton)

those particular beaches for reasons of geology as much as for any other characteristic. According to ornithologist Peter Paton, they seek ocean-facing beaches where crashing waves create a sizable wrack line of seaweed and other debris for feeding; wide unvegetated beaches that give them plenty of visibility to watch for approaching predators; and sand that frequently blows over the dunes to create washover fans for nesting habitat.

“Piping plovers are particularly adapted to open beach areas created by storms,” said Paton, a professor of natural resources science at the University of Rhode Island. “When Hurricane Sandy came through and pushed sand back into the dunes behind the beaches and created big sand fans, that provided them with prime nesting habitat.

“But if the storms and sea level rise push beaches farther and farther into vegetated upland areas,” he added, “or if there’s no place for the beaches to move, it could be a serious issue for them.”

            The plover/geology connection doesn’t stop there, however. The plumage of the birds is sand colored, allowing them to more easily blend in with their environment when they are wandering the beach looking for food or when incubating their eggs. And their nest is generally placed in an area of sand with scattered small cobblestones, because the eggs are camouflaged to look like the stones.

            Least terns, gull-like birds that are also on the endangered list, choose the same beaches as the plovers for nesting, and for similar reasons. American oystercatchers do, too, though their preferred nesting habitat isn’t nearly as narrowly defined. The large black-and-white shorebird with a bright orange beak seeks open undisturbed sandy beaches near shellfish beds for feeding. Several other bird species raise their young in the vegetated dunes adjacent to beaches, like spotted sandpipers and savannah sparrows, and even more birds prefer nearby salt marshes.

            The link between birds and geology isn’t one that many birders or geologists spend much time thinking about, but the link exists nonetheless. What the birds seek in the geology of their preferred beach varies from species to species. The grain size of the sand matters to some birds, as does the slope of the beach, whether it has an adjacent coastal pond, and how protected it is from waves and storm surge.

            Luckily, Rhode Island’s beaches are highly variable, providing many of the elements required by a wide variety of birds for feeding and nesting. Unlike the shoreline of New Jersey or the Outer Banks of North Carolina, where the beaches are much the same for hundreds of miles, a short walk on an Ocean State beach often turns up considerable geologic diversity. And that diversity is the result of the region’s glacial history.

            “One characteristic of our glacial shorelines is the heterogeneous sediment types and land forms that intersect the shoreline,” said Bryan Oakley, a coastal geologist and assistant professor at Eastern Connecticut State University, who has studied the Rhode Island coastline for nearly a decade. He noted that the region is dominated by two types of sediment: till, which consists of what he calls “a poorly sorted mixture of everything from clay to gravel deposited directly by the ice sheet,” and stratified deposits of sand, gravel and silt from the rivers and lakes formed by the melting glacier.

            “Till produced things like Green Hill and Quonochontaug and Point Judith, boulders without a lot of sand in front of them,” Oakley explained. “The Matunuck Headlands from Cards Pond to East Matunuck is comprised of stratified deposits. The beaches themselves might not look too different – you’ve got a pile of sand with a dune behind it – but what you find further down differs from place to place. There are differences in grain size that relates to the underlying glacial geology.”

            Considerable variability exists among the beaches in Narragansett Bay as well. According to Janet Freedman, a geologist with the Rhode Island Coastal Resources Management Council, the sand and sediment in bay-facing beaches are often a bit muddier than those on the south shore due to a division in the glacial ice sheet that deposited finer grain sediment, mica schists and sandstone on beaches in the bay. “Along the south shore the glacial material is more granitic, and that is more of a coarser grain size,” she said. “A beach is just a pile of sediment,” added Oakley. “If you have a source of sand and gravel suitable for the wave and tidal energy at the site, you’ll have a beach. The difference in the bay is that there are lots of shoreline protection structures, so the beaches are armored to some degree, more so than we see on the south shore.”

            From a bird’s perspective, all of that geologic variability means a wide variety of food is likely hidden in the sediments waiting to be eaten. While just a handful of bird species nest on the state’s beaches, dozens more visit throughout the year – especially during migration – to bulk up on the tiny invertebrates that fill nearly every nook and cranny of the coastline.

            Although few research studies have been conducted about the creatures that live in the sand on New England beaches, Tim Simmons has become a local expert on the topic. A retired biologist who worked for many years for the Massachusetts Natural Heritage and Endangered Species Program, he has spent much of his career studying beach tiger beetles and other associated species in Massachusetts. He calls beach sand “an incredible ecological niche” for tiny amphipods, beetles, flies and other invertebrates.

            “People don’t see how alive a beach is,” he said. “They compare it to a desert, but that’s far from what it is.”

            Simmons said that some amphipods and beetles choose to live in the fine sands because that’s where they find it easiest to burrow beneath the surface. Others choose coarser sands where there are larger spaces between the grains, while still others prefer the saturated sand closest to the waterline.

            “There are a whole lot of things in there that you can’t really even see unless you’re wearing polarized sunglasses,” he said. “I remember watching shorebirds feasting on something, but I couldn’t see what. Every time a wave came up and went back down, the birds ran in to grab something. Turns out it was the larvae of a polychaete worm. The birds could see them but I couldn’t until I put on my sunglasses.”

            Because the composition of the sand on many beaches changes from season to season and storm to storm, many of the invertebrates that live in the sand must be prepared to move when the conditions change or when their food supply shifts.

            “Some beaches that are perfect habitat for some species in the summer are rocky and full of boulders in winter with nowhere for the creatures to hide,” Simmons said. “In the mud at inlets to coastal ponds, you get a different suite of species than in the sand. But then when washover fans carry beach sand over the mud, the mud creatures have to pack up and move.”

            Those that can’t move fast enough get washed away or become food for something else. The predatory tiger beetle that Simmons studies is capable of rapid movements and can often detect vibrations caused by the eroding beach in time to emerge from their burrow and escape to a safer location. They move from season to season, too, traveling to the dunes in winter and back to the sand near the wrack line in summer.

            “There’s also a grasshopper that’s almost completely bound to dune blow-outs, where a storm has blown out the vegetated face of a dune and created a bowl-shaped depression,” he said. “As juveniles, they’re flightless and hop around, and birds often forage there for them in the early morning.”

            The wrack line is another beach ecosystem that changes daily and where another unique suite of creatures can be found. A 2004 study by a URI graduate student recorded an abundance of species that spend at least part of their lives in the wrack line. Some eat the decomposing seaweed or use it as cover from predators and extreme temperatures, others lay their eggs there, and wolf spiders make daily migrations from the dune grass to the wrack to prey upon amphipods.

Shorebirds of many varieties – from piping plovers and ruddy turnstones to whimbrels and semipalmated sandpipers – eat anything and everything they can find in the wrack.

A visit to Napatree Point further illustrates this link between birds and geology. The mile-long sandy peninsula extending southwest from Watch Hill in Westerly has experienced dramatic changes in the last 100 years – from being the site of 39 homes prior to the 1938 hurricane to a somewhat pristine barrier beach today that shifts with almost every storm.

Riding out the peninsula on an ATV, Janice Sassi, manager of the Napatree Point Conservation Area, pointed out the wide sandy beach on the ocean-facing side, where waves crash loudly and piping plovers are often observed feeding on flies and amphipods in the wrack line during the breeding season. It’s here that wintering and migrating sanderlings adroitly chase the receding waves to quickly grab larval crabs that briefly expose themselves to filter feed, then the birds dash shoreward to avoid getting their ankles wet as the next wave approaches. Closer to the point, where seaweed-covered boulders divide the shrubby dunes from the sea, purple sandpipers forage for arthropods and mollusks amid the plant material on the waist-high rocks.

On the opposite side of the dunes, just 75 yards away, a narrow beach faces the quiet Little Narragansett Bay, where thousands of migrating shorebirds feed on horseshoe crab eggs deposited beneath the sand at the high tide line in May and June; where the region’s highest concentration of oystercatchers forage in the adjacent mussel beds; and where about 40 other species regularly search for a meal among the rocks, seaweed and sand during migration, including northern harriers that hunt for mice and voles in the dunes in winter and nesting osprey that hunt for fish wherever they can find them in summer.

“There are so many birds here in the summer and during migration that it’s like you’re at the mall during the holidays,” said Sassi, noting that she and her volunteers work hard to ensure that the hordes of boaters and beach-goers that also visit Napatree in summer do not disturb the birds.

Bryan Oakley said that while the sand is not likely much different on one side of the peninsula or the other, the wave energy is certainly lower on the bay side, making for better habitat for many species of birds and their prey. The calmer water on the bay side is also home to abundant minnows of several varieties, the perfect meal for the terns that nest nearby.

“As often as I’m here, it’s different every single time,” Sassi said. “The light is different, I see something different, and yet the birds are always here. Where else can you go where you have bay on one side, ocean on the other, you have a lagoon, the dunes are allowed to migrate as they’re supposed to, and you have shrublands and all kinds of wildlife. To realize that the geology plays such a role in attracting the birds is amazing.”

This article first appeared in the Winter 2018 issue of the magazine 41 North.

Staving off the winter chill

            My feet get uncomfortably cold very easily. If I spend even a short time outside in freezing conditions, even while wearing insulated boots, my toes go numb and my feet start to ache. I think it’s a genetic thing. My parents used to complain about their cold feet while standing around various ice rinks while I was playing hockey as a kid. And now I have the same problem.

            Yet ducks, geese and a number of other birds are apparently unbothered by the cold as they stand on ice-covered ponds in their bare feet. What do they have that people don’t have? It’s one of the most common questions I get about birds at this time of year. Why don’t they rock back and forth, stomp their feet, or use any number of other strategies that humans employ to keep their feet warm?

            The answer, according to University of Rhode Island ecologist Scott McWilliams – my go-to guy for all bird physiology questions – has a lot to do with blood circulation. The birds have

Cartoon by David Chatowsky

what McWilliams calls a counter-current heat exchange system between the veins and arteries in their legs. As warm arterial blood flows down their legs toward their feet, it passes near the cold blood in their veins that is returning from their feet. The blood going down to their feet warms up the blood that’s going back up, and as it does so, the blood going down drops in temperature. As a result, the blood that flows through their feet is quite cool – just warm enough to avoid frostbite. By reducing the difference in temperature between their feet and the ice, the ducks lose little heat through their feet.

            “It’s a common solution to the problem of keeping your body core warm and not having to expend a ton more energy trying to keep your entire body warm, including your extremities,” McWilliams said.

            Ducks also have downy, waterproof feathers and a thick layer of body fat to keep them warm in freezing conditions. If the weather gets extremely cold and the birds feel the chill, they have several additional options. They can stand around on one foot while tucking the other foot in their feathers to keep it warm, or they can fluff up their feathers to trap more of their body heat, which provides an insulating blanket around their bodies.

            Like almost all other birds that live in a cold climate for at least part of the year, ducks can also slow their metabolism to conserve energy. For tiny birds like kinglets, this strategy can save as much as 20 percent of their daily energy budget.

            Birds also have something called brown fat, which is designed to produce heat through a biochemical process, much like humans do by shivering. And then there’s McWilliams’ favorite strategy – huddling. Many small birds will gather together in tight groups during chilly nights to share their body heat.

            While I understand how these physiological adaptations enable birds to survive most winters unscathed, it still amazes me that the adaptations do the trick when temperatures remain well below freezing for weeks at a time, like that two week stretch around  New Years. It’s especially impressive that tiny birds like chickadees make it through such cold snaps.

            Still, if birds can spend the whole winter outside, why can’t I last for more than an hour or two? Maybe I need to grow some downy feathers. Or brown fat.

This article first appeared in the Independent on January 18, 2018.

Rare Breed: Lou Perrotti protects less-than-cuddly species

            In the concrete block cellar of the building that houses the moon bears and snow leopards at Roger Williams Park Zoo is a brightly lit room where unrecognized visitors are welcomed with a mesmerizing clatter produced by some of the 16 Eastern timber rattlesnakes that reside there. Heated to 82 degrees, the room is lined with large, clear plastic cages along two walls, each containing an adult rattlesnake about four feet in length, two of which are believed to be pregnant. A vertical rack containing 12 plastic tubs stands against a third wall, each home to a juvenile rattler less than half the length of the adults.

            The snakes are unexpectedly attractive and strikingly patterned, some colored in yellows and browns while others are dressed in smoky gray and white. One adult male displayed a yellow triangular head with chocolate brown chevrons along the length of his golden back,

Lou Perrotti and New England cottontail. (Photo by James Jones)

which blended into a velvety black tail that didn’t stop rattling during the entire 15-minute visit.

            Lou Perrotti, 53, director of conservation at the zoo and an expert snake handler since his junior high school days, says the rattlesnakes are usually silent when their regular zookeepers attend them. “But new faces get the full treatment,” he adds.

            The subterranean room is a captive rearing center for New England’s only native rattlesnake, an endangered species that disappeared from Rhode Island in the 1960s and whose few remaining colonies in the Northeast are declining precipitously due to habitat loss and poaching. A newly-discovered fungal disease that causes skin lesions and blisters on their faces is contributing to the high mortality rate.

            When Perrotti heard about the disease, he recruited the veterinarians at the zoo to study how prevalent it was in New England. They found it everywhere they surveyed. So he partnered with the U.S. Fish and Wildlife Service to launch a captive breeding effort. By taking rattlesnakes from healthy populations and breeding them at the zoo so their offspring can be released into the wild, Perrotti and his colleagues are augmenting snake populations that are barely sustaining themselves.

“And then we decided that creating a new population would be awesome,” he says. Biologists identified a small island in the Quabbin Reservoir in central Massachusetts as the ideal location. “We thought the site was brilliant. It has plenty of habitat, plenty of food, it’s off limits to humans. It just made sense to create a secure population there.”

It didn’t turn out that way. When the public got wind of the plan, their vocal objections – which Perrotti says were based on little more than fear and speculation – quickly scuttled the project.

“We were doing what we thought was the best thing to keep this endangered animal on the planet,” Perrotti says. “We can’t only protect the cute and cuddly animals. They all deserve to be protected. This project was....

Continue reading this article in the January issue of Rhode Island Monthly magazine.

Climate change, plastics combine to create rising tide of marine invasive species

            A large buoy that washed ashore on the coast of Belgium in October – trailing a 10-foot rope that was covered in hundreds of goose barnacles, crabs and shrimp – has been traced to an offshore lobster boat based in Point Judith, R.I.  The discovery of the buoy and attached marine life illustrates one of many ways that non-native marine life finds its way to distant shores. And one local scientist believes it’s a vector for invasive species that will become more and more common as climate change produces increasingly severe storms that will toss sturdy plastic debris into the ocean.

            Aaron Fabrice, 20, who describes himself as a beachcomber, citizen scientist, conservationist and nature guide, located the buoy on a beach in the town of De Panne, on the northwest coast of Belgium, on Oct. 8. He said the discovery was “like a dream” as he and a

Aaron Fabrice with buoy from Rhode Island found in Belgium (Diederick D'Hert)

friend counted 39 Columbus crabs, native to the Sargasso Sea near Bermuda, nestled between hundreds of goose barnacles. He claims it is “the largest observed stranding [of Columbus crabs] on the Belgian coast ever.”

Fabrice also found numerous skeleton shrimp on polyps on the barnacles, a species he said is commonly found attached to floating debris.

After collecting samples of the crabs for the Royal Belgian Institute for Natural Science, Fabrice posted photos of the buoy to beachcombing and lobstering message boards showing the unique combination of letters and numbers printed on it. Two months later, he learned that it belonged to Rhode Island lobsterman Roy Campanale Jr. of Narragansett, who acknowledged to Fabrice that he lost the buoy off his boat Mister Marco sometime in 2016.

“We did not expect that North American floating objects would wash up on our coast,” wrote Fabrice in an email message. “Normally floating objects from North America wash up in Cornwall, U.K., or Brittany, France. There must have been an Atlantic seawater bubble coming through the channel in the North Sea.” 

According to Jim Carlton, an ecologist at Williams College who studies marine invasive species, debris from North America shows up on the coast of Europe fairly regularly, and it is often colonized by a wide variety of marine life. He said that goose barnacles and Columbus crabs are oceanic species that cannot live in the coastal zone, so they are unlikely to become established in Belgium and affect native species.

But, he added, it could be that there were species from North America that were buried within the barnacle-crab community.

Carlton has studied the transoceanic dispersal of marine life in great detail. Last fall he published a paper in the journal Science about the nearly 300 species of Asian marine life he and his colleagues found on debris along the U.S. West Coast that they traced to the 2011 earthquake and tsunami in Japan.

He said that natural disaster provided a greater opportunity for the dispersal of species across the Pacific than ever before because of all the plastic objects that make up modern daily life. Before plastic became ubiquitous, most storm-tossed marine debris consisted of wood, vegetation and other biodegradable materials that would disintegrate before it made it across the oceans.

“That got us thinking that the story of ocean rafting has shifted rather remarkably in the last half century,” Carlton said. “The plastic rafts at sea now are very enduring. They’re not degrading and dissolving. Animals can go on a much longer voyage now than they could have historically when they were drifting on a piece of vegetation.”

The implication is quite dramatic. Carlton believes that the tsunami-caused invasion of species from across the Pacific is only a hint of what is to come. As increasingly severe storms – the result of the changing climate – hammer coastlines around the world, more and more marine species will find their way across the oceans on plastic debris, ultimately causing a homogenization of the world’s coastlines.

“Imagine the amount of debris that came off the Caribbean islands during the hurricanes last fall – many hundreds if not thousands of buildings and all of their contents were swept into the ocean,” he said. “The climate models and evidence strongly suggest that we’re going to be entering a world of more of these cyclonic systems, making ocean rafting potentially one of the major new vectors for invasive species.”

The article first appeared on EcoRI.org on January 18, 2018.

Extreme cold puts animals to the test

            The extreme cold of the past two weeks has Rhode Islanders avoiding the outdoors as best as they can and loading on extra layers when they must go outside. Which raises the question of how wildlife will fare during this unusually cold period.

            Local biologists agree that most species of wildlife that spend their winters in Rhode Island are well adapted to weather the cold. They have evolved numerous strategies to deal with the conditions, from hibernation and torpor to thick fur coats and layers of fat.

Birds, for instance, have developed a number of adaptations that enable them to survive the extreme cold. According to Scott McWilliams, a physiological ecologist at the University of

Rhode Island, ducks can stand on ice for hours at a time and swim around in the icy water without suffering frostbite in their feet thanks to a counter-current heat exchange system in their legs. The warm blood flowing down to their feet warms up the cold blood flowing back to their core, and the blood in their feet is so cold that the difference between their foot temperature and the ice ensures that they lose little heat through their feet.

Birds also huddle together to stay warm, fluff up their feathers to provide an insulating layer around them, and lower their body temperature to save energy.

But not all birds are prepared for the cold.

“Most sensible birds will migrate to warmer places, thereby avoiding having to contend with the cold,” McWilliams said. Some of those that stick around, however, “ are less well-insulated or otherwise poorly adapted to living in cold places." 

He points to the Carolina wren, a southern species that has expanded its range northward in recent decades. Southern New England is at the northern part of its range, and during extreme and extended cold spells in Rhode Island, many of the birds do not survive. That was the case during the winter of 2015, when the state had a record snowfall and the state’s Carolina wren population declined. When favorable weather returns, however, the wren population bounces back again until the next severe winter.

Cold-blooded creatures like reptiles and amphibians – animals that cannot regulate their own body temperature – are also well prepared for extreme cold. Wood frogs, for instance, have what some scientists call antifreeze in their blood that enables their tissues to freeze solid without harmful effects. In some winters, the frogs experience several freeze-thaw cycles.

Herpetologist Scott Buchanan said that adult painted turtles, snapping turtles, and spotted turtles are also extremely cold tolerant and will likely fare well. But some painted turtle hatchlings, which overwinter in their nest cavity, may die if the temperatures are extreme for an extended period of time.
"The invasive red-eared slider, on the other hand, is less tolerant of extreme cold - both the adults and hatchlings," Buchanan said. "Hatchlings, which also overwinter in the nest, are more vulnerable to these cold periods and would exhibit a greater rate of mortality than painteds or snappers.
"From a conservation perspective, this would be a good thing, as it would slow down the invasion," he added.

Wildlife that lives in the upper layer of the soil or in the grass at the surface may be particularly vulnerable to extreme cold, especially cold temperatures without a thick layer of snow to serve as insulation. David Gregg, director of the Rhode Island Natural History Survey, speculates that the dearth of leaves on the ground – thanks to two years of gypsy moth defoliation – may mean there will be less insulation for species that hibernate in the forest floor, such as box turtles and salamanders.

“Low temps and thin snow is also probably tough for small mammals like voles, which tunnel around in the grass,” Gregg said before this week’s blizzard. “Of course, that might make life easier for owls and hawks that need to be able to find voles.”

He also wonders about the impact of the cold weather on aquatic mammals when all of the local ponds are frozen solid. During the week before New Year’s, he twice observed a muskrat wander up from a nearby frozen river to scratch for food in his lawn.  And in the winter of 2015, a river otter emerged from the same frozen river to forage in his compost pit.

Charles Brown, a wildlife biologist with the Rhode Island Department of Environmental Management, isn’t worried about those aquatic mammals, however. He said the range of muskrats, river otters and beavers extends far to the north in Canada, where they likely experience much longer periods of extreme cold than they do in southern New England.

“So around here, they’re probably living the easy life,” he said.

Those animals typically gravitate to areas of moving water, like dams and spillways, during extreme cold, Brown said, and otters can even chew holes in the ice to gain access to pond water.

Brown is more concerned about how big brown bats will fare. He said that most bat species that spend time in Rhode Island migrate to caves to hibernate or travel south to warmer climates to avoid the winter conditions. Big brown bats are the only species that lives in the state all year. And even those should survive without much difficulty.

“We’ve had some pretty cold winters in the past, but rarely have I ever seen any evidence of bats dying from exposure,” he said.

The big picture, according to Gregg, is that the creatures that winter in the state do so for a reason, and there’s probably a logical reason for those that don’t survive the chill.

“I think that hard cold like this helps to hold back the northward expansion of southern species, like fire ants, kudzu and lizards,” he said. “The kind of animals and plants we think of as typical here are either helped or hurt in the appropriate ways by cold, so the net effect is good even though there are animals and plants that go up and others down.”

This article first appeared in EcoRI.org on January 7, 2018.