Forecast calls for a snowy owl winter

            It’s looking more and more like the winter of 2017-18 is going to be a big year for snowy owls in southern New England. Large numbers of the iconic white birds have been observed throughout the Upper Midwest and Northeast since late November, and many have turned up in Rhode Island.

            Project SNOWstorm, a volunteer-based snowy owl tracking organization, is predicting that the attractive birds will invade much of the northern tier of the United States this winter. Hundreds of birds have already been sighted, including some as far south as North Carolina, Oklahoma and Missouri.

            Scott Wiedensaul, director of Project SNOWstorm, said it’s difficult to predict how many birds will travel to the area or how long they will stay. “There’s a little bit of voodoo and black magic in all of this,” he told Audubon magazine. But the signs point to it being a good year for snowy owl watching.

            Rhode Island has so far had visits by at least 17 snowy owls in recent weeks, according to Rachel Farrell, a member of the state’s Avian Records Committee. University of Rhode Island ornithologist Peter Paton reported seeing seven snowy owls on Block Island last week, and local birdwatchers have reported additional owls at Sachuest Point National Wildlife Refuge in Middletown, East Matunuck State Beach in South Kingstown, along the shores of the Narrow River in Narragansett, and elsewhere. One was even photographed perched on a chimney in a residential neighborhood in Providence, and another Providence bird – or perhaps the same one – was located at the headquarters of Save the Bay.

Just one or two snowy owls usually visit Rhode Island during a typical winter.

Snowy owls spend most of their lives in the Arctic feeding on lemmings on the tundra. But Farrell said that about every four years, when lemming numbers are high, the owls lay more eggs than usual. Many of the birds that hatch from those eggs end up migrating south in winter after being forced from their Arctic habitat by adult owls due to the reduced availability of food in the deep snow.

“It’s all due to the population cycling of lemmings,” she said. “They’re a boom or bust animal.”

Canadian scientists reported that snowy owls successfully raised an especially large number of young birds last summer.

This year’s irruption of snowy owls into the U.S. is not unprecedented. Four years ago, the the country experienced the largest influx of snowy owls since at least the 1920s, when several thousand owls spent the winter south of the Canadian border. Some traveled to places they had never before been reported, including Jacksonville, Fla., and Bermuda. More than 400 were observed in Pennsylvania alone, a state that seldom records more than 10 in a year.

            The birds that visit Rhode Island are usually found on beaches, farm fields and airports, which mimic their tundra homes, where they search for mice and voles. Owls that spend time in coastal locations often hunt for wintering ducks, something they don’t often eat on their breeding grounds.

            As exciting as it is to see a snowy owl, they can also be a nuisance and a safety hazard at airports. Paton and fellow URI professor Scott McWilliams will attempt to capture and relocate any owls that show up at Quonset State Airport and other undesirable locations this winter.

            The large number of snowy owls visiting the area is not necessarily a sign that the breeding population is growing, however. Farrell said that the population of snowy owls breeding in North America has declined by about 64 percent since 1970, though scientists are not sure why.

Unlike so many other rare birds that occasionally turn up in southern New England, snowy owls are easy to identify. Weighing in at about six pounds, it is the heaviest owl species in North America, and its white plumage and piercing yellow eyes make it unmistakable. Adult males may be pure white, the perfect camouflage for a bird that spends much of its life in a snowy environment. Younger birds are much more visible, with contrasting gray barring on their white bellies and wings that make them stand out as they perch on fence posts, beaches and snow-covered fields.

The Audubon Society of Rhode Island advises that those interested in going in search of snowy owls in the area should bring along binoculars or a spotting scope and stay at least 200 feet away from the birds, as the owls can be skittish. It also recommends staying quiet and refraining from making sudden movements that may frighten them. The owls are already rather stressed after their long migration and their efforts to find food in unfamiliar places, and rambunctious humans will add to their stress.

            “We still don’t know the magnitude of this year’s irruption yet,” concluded Farrell. “But it has already been fairly substantial. And it started a little earlier than the last one, so that may be a good sign for what’s to come.”

This story first appeared on EcoRI.org on December 14, 2017.

Changes to ecology of Narragansett Bay worry fishermen

            Narragansett Bay has experienced dramatic changes over the last century, from being a dumping place for sewage and industrial pollutants to a near paradise for recreational swimming and boating. But changes continue to occur, whether from the warming climate, invasive species, fluctuating wastewater effluent or other factors.

            As University of Rhode Island oceanography professor Candace Oviatt told an audience of fishermen, scientists and students last week, “I don’t think I’ve ever seen an average day on Narragansett Bay. The bay is always changing. Every year is different. Whether we like it or not, the bay is going to keep changing.”

            Oviatt’s comments were part of a daylong symposium sponsored by Rhode Island Sea Grant aimed at creating a dialogue between fishermen – many of whom are worried that the

Narragansett Bay photo by Frank Carini/EcoRI News

bay has gotten so clean that there is little food left for fish to eat – and scientists whose research tells a sometimes confusing story of how the changing bay ecology might give that erroneous impression.

            While most of the scientists claim that their research suggests that the biomass of fish and other creatures living in Narragansett Bay has changed little through the years, almost all said the composition of species that call the bay home has changed dramatically.

            A weekly fish trawl survey in two locations in the bay conducted since 1959 illustrates those changes. According to Jeremy Collie, the URI oceanography professor who directs the trawl, in the early years of the survey most of the species collected in the nets were fish and invertebrates that live on or near the bottom, like lobster, winter flounder, tautog, cunner and hake. Those species also happen to prefer cooler water.

            In recent years, the species that prefer warmer waters and that live higher in the water column have dominated the trawl survey results, including butterfish, scup and squid.

            “Very few species are standing still or swimming in place,” said Collie, noting that similar patterns have taken place in estuaries throughout the Northeast. “All are either increasing or decreasing. And some have had really big changes.”

            One of the major drivers of change in the bay is nutrient levels, primarily nitrogen and phosphorous, which largely come from discharges from wastewater treatment plants. Those nutrients stimulate the growth of plankton, which are fed upon by fish and a wide variety of marine invertebrates. But when nutrient levels are too high, it can cause harmful algae blooms and oxygen depletion in the water, which can lead to massive fish kills like the one that occurred in Greenwich Bay in 2003.

            Stricter discharge regulations for wastewater treatment plants since the mid-2000s has reduced nutrient levels significantly, leading to much clearer and cleaner water, especially in the upper bay. But it has prompted some fishermen, including lobsterman Al Eagles, to worry that Narragansett Bay has become “a dead bay.” Their concerns are in part because the decline of popular species like winter flounder and lobster seemed to occur at the same time that discharge regulations were tightened.

            Oviatt acknowledged that nutrient levels in the upper bay have declined by 50 percent since 2004, which resulted in a 33 percent decrease in “primary production” – the growth of plankton, especially algae. This has significantly decreased the size of the annual winter/spring plankton bloom that occurs throughout the bay and serves as the base of the food web, when it sinks to the bottom and is fed upon by crabs, fish and other species.

            “When we have a short winter/spring bloom, or no bloom, we have low input of organic matter to the sea floor,” Oviatt said. “The consequence is lower biomass to the benthos [seafloor] and pelagic fish dominating the bay.”

            She said this partly explains Collie’s findings that the species composition in the bay has shifted from bottom species to species living higher in the water column.

            “Are there fewer fish in the bay? I don’t think so,” she said. “We’ve had a dramatic decrease in the bottom community, which started in the 1990s. Our decapods [crustaceans like lobsters and crabs] have basically left the bay.”

            Oviatt said that nutrients in the bay are still three times higher than they were before Europeans colonized New England, but just a few decades ago, when more sewage was being discharged into local waters, nutrient levels were up to five times higher than in pre-colonial times.

            “Wastewater treatment facilities are still the major contributor of nutrients to the bay,” she said.

            Yet Oviatt and others said that decreases in nutrients from wastewater plants aren’t the only reason for the changes to marine life in Narragansett Bay.

            Robinson Fulweiler, a professor at Boston University who studies nutrients in the bay, said that the warming climate is causing some species to move northward to cooler waters and other species to arrive here from the south. And other factors complicate the situation.

            Responding to a question about the “best” level of nutrients in the bay, she said it depends on what you’re looking for. “The estuary a purist wants to go back to is not likely the one that fishermen might want.”

This article first appeared on EcoRI.org on December 10, 2017.

Spotted turtles in trouble in Rhode Island

            A University of Rhode Island doctoral student who surveyed the state for freshwater turtles and studied their habitat preferences found that the once-common spotted turtle is in trouble, due largely to habitat disturbance.

            Scott Buchanan, a New Jersey native working in collaboration with URI Associate Professor Nancy Karraker, repeatedly visited 88 different wetlands in the state over three years and captured nearly 2,000 turtles of four different species. Just 50 were spotted turtles, a species considered by the state to be of high conservation concern and a candidate for the U.S. endangered species list.

            “Throughout their range, populations of spotted turtles have declined extensively, and we can certainly say with a good deal of confidence that’s also the case in Rhode Island,” said

Spotted turtle (Photo by Scott Buchanan)

Buchanan, who graduates from URI later this month. “I found that they are associated with wetlands in forested landscapes, which means they are susceptible to development, forest fragmentation, wetland alteration and other human disturbances.”

            Buchanan said that the largest populations of spotted turtles he found were in locations where human disturbance has been minimal. “So now it’s a matter of managing those landscapes in an appropriate way,” he added.

            Habitat alteration is not the only conservation concern the species faces, however. The illegal collection of wild turtles for the pet trade is also a problem.

            “Spotted turtles will command a formidable sum in the pet trade, which is unfortunate,” Buchanan said, noting that he encountered people during his research who had captured spotted turtles they intended to bring home to keep as pets but released them at his insistence. “It’s really easy for someone to deplete an entire population of them very quickly.”

During his turtle surveys, Buchanan also found a non-native turtle called a red-eared slider in more wetlands than he found spotted turtles. The slider is a species commonly purchased at pet stores and frequently released into the wild after their owners no longer wish to care for them. He said that wetlands close to human populations, especially those with easy access from roads, are the most likely place to find red-eared sliders in Rhode Island.

“They’re an especially detrimental invasive species,” he said. “It’s a good bet that all the sliders we found are turtles that were bought at pet stores. We don’t know if they’re reproducing in the wild.”

Eastern painted turtles and common snapping turtles, the two most common species of freshwater turtles in Rhode Island, were found in abundance during Buchanan’s turtle surveys.

“They were everywhere, with no strong pattern as to where we might find them across different landscape types,” he said.

What can be done to protect the region’s declining spotted turtle populations?

“It would mean protecting and preserving wetlands, especially forested wetlands, including small wetlands like vernal pools where they sometimes overwinter,” Buchanan said. “It would also mean minimizing fragmentation of the landscape surrounding those wetlands. And it’s also really important that we protect the turtles themselves from illegal collection. That’s an increasing concern among conservation biologists.”

As Buchanan prepares to graduate from URI, he will share his data with a region-wide team of biologists collecting information about the three turtle species being considered for inclusion on the U.S. endangered species list – spotted, wood and Blanding’s turtle.

“The habitat information we collected could help determine where populations of spotted turtles occur and help protect and appropriately manage those populations into the future,” he said.

What do plants hear?

            Plants and trees are seldom considered to have acute senses – at least not like those of many mammals. But scientists at the University of Western Australia discovered that plants have far more complex senses than previously believed, and they can even detect and respond to the sound of moving water.

            In a study led by Associate Professor Monica Gagliano, pea plants sensed sound vibrations from running water moving through pipes or in the soil, and the plant’s roots responded to that sound by moving toward the source of water. The study also revealed that plants avoid other sounds by moving away from them.

            The researchers put pea plants into containers with two tubes at the base, giving them a choice of directions for their roots to grow. They then exposed the plants to a series of sounds beneath each tube, including white noise, running water, and a recording of running water.  They found that the plants could tell where the source of the water was and their roots grew toward the water.

            “It was surprising and extraordinary to see that the plant could actually tell when the sound of running water was a recording and when it was real, and that the plant did not like the recorded sound,” said Gagliano, adding that when moisture was readily available in the soil, the plants did not respond to the sound of running water.

How the plants accomplish this feat is unknown. “The detection of acoustic vibrations, which are vibrations of mechanical nature, is likely to involve the same sensory systems plants use to detect touch – and they’re really good at that,” she said. “If correct, this would possibly involve touch genes and mechanoreceptors because sound is a touch-at-a-distance kind of phenomenon.”

These findings may explain how and why tree roots invade sewer pipes and could lead to the development of soundproof materials for pipelines.

“This would not only improve the sewer systems but reduce exorbitant repair and maintenance costs to municipalities worldwide and make the use of toxic chemicals currently used to clear the roots from the sewer system unnecessary, hence reducing environmental pollution and contamination,” Gagliano said.

The study also raises questions about the implications of noise pollution on plants. Might the increasingly noisy environment be drowning out the ability of plants to hear moving water? Gagliano calls that an open question that should be investigated.

“In animal communities, both in terrestrial and marine environments, these kinds of questions have been raised and the current available studies are showing that these effects are indeed serious and detrimental,” she said. “Based on our findings, it is reasonable to expect that this would be the case for plants, too. Acoustic pollution could mask important acoustic information and make life and survival for plants more difficult. And we have no idea of the long-term consequences of this form of anthropogenic disturbance to plant life.” 

This article first appeared in the fall 2017 issue of Northern Woodlands magazine.

It's bug versus bug in fight against invasive species

            The mixed hardwood forest on the edge of the town of Dalton in western Massachusetts looks healthy to the untrained eye, but the researchers from the University of Massachusetts who visited the site every few weeks last summer are anything but untrained. They quickly noted the small holes made in some trunks by foraging woodpeckers and distinguished them from the even smaller holes made by wood-boring insects. And staring into the canopy they observed that many of the trees were in the early stages of decline.

Consisting primarily of ash and red maples, the forest is owned by the nearby city of Pittsfield to protect its public drinking water supply. But it also serves as a living laboratory to test a variety of methods for controlling the emerald ash borer, an iridescent green beetle native to China that has killed hundreds of millions of ash trees in the eastern and central United States, Ontario and Quebec.

The invasive beetle was discovered near Detroit in 2002 and slowly expanded in all directions, reaching New York in 2008, Massachusetts in 2012 and New Hampshire a year later.

Spathius galinae, a parasitoid of emerald ash borer. (Jian Duan USDA)

While it hasn’t yet been found in Vermont or Maine, it is only a matter of time before trees there will also start dying. The beetle is expected to kill almost all mature ash trees in the region in the next decade or two.

But that isn’t stopping researchers from trying to control the invasive beetle and find a way to protect future generations of the trees from succumbing. While several trees in the Dalton forest have been injected with a systemic pesticide to test whether adjacent trees will benefit from the treatment, the forest is primarily the site of a series of biological control experiments to determine if the emerald ash borer’s natural enemies in the Far East might succeed at keeping the insect in check here as well.

As UMass research fellow Ryan Crandall wandered the forest, he carried with him two prescription medicine bottles capped with a fine mesh. Inside the bottles were coffee filters embedded with emerald ash borer eggs, and inside the eggs were the larvae of Oobius agrili, a tiny parasitic wasp that is one of several insects that scientists hope will do in the U.S. what they do in China – control emerald ash borer populations so native ash trees can continue to thrive.

Crandall and his assistant, Sebastian Harris, were seeking the perfect trees on which to hang the medicine bottles – ash trees that aren’t too far gone yet but that exhibit numerous woodpecker holes suggesting the trees are infested with emerald ash borers. Most of the larger trees they examined were already near death, but eventually the researchers selected a couple of smaller specimens and proceeded to hammer nails in their trunks and hang the pill bottles on the nails. Soon, they hoped, the parasitic wasps would emerge and seek out more emerald ash borer eggs in which to lay their own eggs.

Although Crandall and Harris spent just 30 minutes at the Dalton site, they were far from finished for the day. They had five more stops to make at similarly infested forests in Massachusetts, New York and Connecticut, where they left behind a total of 1,400 emerald ash borer eggs parasitized by Oobius agrili....

Continue reading the rest of this article in the fall 2017 edition of Northern Woodlands magazine.

Nocturnal feeder visitors

            Before construction was even finished on my house many years ago, I had already put up several birdfeeders in the backyard, and I’ve been keeping them filled throughout the colder months of the year ever since. If you haven’t put out your feeder for the year yet, it’s definitely time. In addition to the regular winter visitors, I have high hopes that this will be one of those unusual years when we’ll have some rarities from the far north dropping by, like redpolls, evening grosbeaks and red crossbills.

            But don’t think that it’s just birds and squirrels that are attracted to birdfeeders. A wide variety of other creatures are, too. And if you get into the habit – as I have – of briefly turning on

the back porchlight and glancing at the feeders before going to bed at night, there is an excellent chance that you will spy some unexpected neighbors dropping by for a bedtime snack.

            I first started paying attention to my nocturnal feeder visitors when I noticed that large

Cartoon by David Chatowsky

quantities of birdseed was disappearing during the overnight hours when I assumed all the seed-eating birds were asleep. It wasn’t long before I discovered a parade of wildlife scavenging spilled seed from beneath the feeders and a few adept critters climbing on the feeders and knocking more seed to the ground.

            A pair of gray foxes were the first night-time animals I noticed in the illuminated area around my feeders. Slightly larger than their more common red cousins, gray foxes sport a conspicuous black tip to their tail and a black “mane” running atop their tail’s entire length. When I turned on the light, they glanced toward it and then went back to slurping up sunflower seeds from the ground.

            My continued vigilance with the backyard light occasionally turns up at least two different striped skunks that must live nearby, one with a wide white stripe down its back and tail and another whose white stripe is thin, crooked and mottled with black. In all my years of watching, I’ve seen just one opossum, and it just strolled through the light without stopping to eat any seeds.

            My favorite nighttime visitors have been flying squirrels, three of them with big ears, huge eyes and a thick flap of fur between their front and hind legs allowing them to soar from tree to tree. They frequently chase each other around the feeders and then play peek-a-boo behind a tree trunk when they see my face in the window. Like several of the more common daytime birds, the flying squirrels take one seed at a time and disappear into the forest to eat it before returning for another morsel.

            Lately, my feeders have been regularly assaulted by a family of five raccoons. When I flicked on the light the other night, I saw one tugging at a big chunk of suet, another was hanging upside-down on a tube feeder sucking out the seeds, and a third was on the ground gobbling up what the tube sucker had spilled. The other two animals were perched comfortably above the feeders high in a tree, probably digesting a big meal compliments of yours truly.

            But I’m not complaining. My nocturnal visitors are highly entertaining, and I’m happy to have them. Besides, it could be worse. At least no bears have found my feeders. Yet.

This article first appeared in The Independent on November 16, 2017.

Scientists seeking insights into saw-whet owl migration

Nearly every evening between mid-October and Thanksgiving, when the weather conditions are promising for bird migration, Scott Comings sets up a series of nearly-invisible nets on Block Island and plays a recording of the call of the saw-whet owl, the smallest owl to be found in Rhode Island. His aim is to capture as many of the birds as possible, place bands around their legs, and learn what he can about the migratory habits of the diminutive owl.

            Comings, the associate director of the Rhode Island office of The Nature Conservancy, is among a growing cadre of biologists and ornithologists from throughout the coumtry who have been banding saw-whet owls regularly since the early 2000s to get an idea of the bird’s

Saw-whet owl (Megan Lorenz)

movement patterns and population distribution. The effort, dubbed Project OwlNet, began in Pennsylvania in 1997 and now includes several hundred researchers at more than 350 different sites.

            “Before this started, there was a big question about how they move through the area, so it became a concerted effort to see if we could crack this problem,” said Comings, who calls the birds “a really majestic species” despite being just 8 inches tall. “It’s a species that has always captivated me. It’s something you don’t normally see, so that pushes me to want to do more, to learn more, and to go deep into the night trying to catch them instead of sleeping.”

            Peter Paton, professor of natural resources science at the University of Rhode Island, is another of the Project OwlNet collaborators. He has been banding saw-whet owls since 2000 at locations in Richmond, South Kingstown and Hope Valley.

            “It’s as effective to set up the nets at my house as it is at more remote areas,” he said. “It turns out you can put a net out almost anywhere and still do a good job of catching the birds.”

            In a typical year, he catches more than 100 owls, and some nights when the winds are just right, he may catch a dozen or more in just a few hours. Comings catches similar numbers of owls, though one year he banded more than 200 of the birds.

            In the eastern United States, saw-whet owls primarily breed in northern New England and New York and in the Appalachian Mountains, and they winter as far south as North Carolina. According to Rachel Farrell, a member of the Rhode Island Avian Records Committee, saw-whet owls have been documented as breeding in Rhode Island just six times since 1952. Two of those records occurred in the last two years and were documented as part of the Rhode Island Breeding Bird Atlas, which is managed by ornithologist Charles Clarkson.

            “It seems like the species is maintaining a small but persistent breeding population in the state,” Clarkson said.

            But many more saw-whet owls migrate through Rhode Island. Those that are captured by Comings and Paton are revealing interesting details about their migration patterns.

            “We have a much better idea of their migratory pathways,” said Paton. “We’ve also learned that they’re much more common than people used to think. And we see an annual variation in their numbers.”

Paton said that the number of saw-whet owls migrating through the Northeast rises and falls every other year based largely on the number of acorns and other seeds produced by trees in the area. When trees produce large numbers of acorns, they provide abundant food for small mammals like mice and voles, whose populations then skyrocket. When the small mammal numbers increase, saw-whet owl numbers grow, because the owls eat the mammals and can produce more chicks.

Most of the owls caught in Rhode Island fly to the mid-Atlantic states.

“We know that because we’re starting to build a database of where the birds have been caught and where they’ve ended up,” explained Comings. “I’ve had birds I’ve caught recaptured by others in New Jersey, Massachusetts and Maryland, and I caught birds that had previously been banded in Cape May, New Jersey, and Massachusetts.”

Paton has similar records. “One year I caught a bird at my house in Richmond, the next year it was caught in northern Maine, and a week after that it was caught at Audubon’s Eppley refuge in West Kingston.”

One of the more unusual findings from Project OwlNet is that birds migrating for the first time often take a different route than older birds who have previous migration experience. First time migrants tend to be caught along the coast, while adult birds are more likely to follow an inland migratory route.

“The older birds know better when to fly; they’re a little more savvy,” Comings said. “If you’re an adult bird and this isn’t your first rodeo, you know to wait for a northeast wind, which takes you on an inland route. If you’re a young bird, you know you’re supposed to go on a north wind, but if it’s from the northwest it pushes you toward the coast. Almost all the saw-whet owls I catch on Block Island are young ones.”

So far, this year has been a quiet one for saw-whet owl migration. Through the first week of November, Paton had captured only one owl, and Comings hadn’t fared much better.

“It’s been really slow this year because the winds haven’t been right,” Comings said. “But there’s still time. I’m just waiting for that one big night.”

This story first appeared on EcoRI.org on November 16, 2017.