Monday, January 22, 2018

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.

Friday, January 19, 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.

Thursday, January 18, 2018

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 on January 18, 2018.

Sunday, January 7, 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 on January 7, 2018.