Monday, February 29, 2016

Wacky winter weather confounding plants and animals

The weather this winter in southern New England has been far from typical, and it is having serious implications for wildlife and natural history phenomena. The official temperature at T.F. Green Airport on February 1 reached 66 degrees, a record high for the date, but two weeks later on Valentine’s Day it plunged to minus-9, the coldest temperature in Rhode Island in more than three decades. A week later, it was back in the 60s again. And on February 24, the National Weather Service issued a severe thunderstorm warning, the first time it has ever done so in February. That follows a warmer than usual January and record warmth in December.
            The periods of warm weather in February triggered daffodils, crocuses and other early-blooming flowers to sprout a month or more before they usually do. Wood frogs and spring peepers were observed hopping across roads and chirping loudly in vernal pools in many locations during the last week of February, which is also several weeks earlier than usual. And Keith Killingbeck, a professor of botany at the University of Rhode Island, noticed a red maple tree with flower buds expanding almost two months early on February 25.
Crocuses blooming in Providence (photo by Frank Carini/EcoRI)
If the weather remains warm, these plants and animals shouldn’t experience any ill effects. But what will happen if the deep freeze returns, as it often does in March?
“Early spring plants are pretty tolerant of cold temperatures,” Killingbeck said, “but it depends on how cold it gets and how long those cold temperatures last.  It’s in the realm of possibility that flowers could pop open, bloom and get zapped by a long, cold frost and be toast for the season. A lot of trees are susceptible, too. That’s a lot of energy the plants and trees expend for nothing.”
Killingbeck said that such an event would not affect the survival of the plants, but it eliminates an entire year of reproduction.
Frog and salamander reproduction could be affected, too. In a typical year, evening rains in mid- to late March trigger wood frogs, spring peepers and spotted salamanders to migrate from their wintering locations among the leaf litter and in shallow burrows to temporary pools and small ponds, where they mate and lay their eggs. But the warm weather in late February triggered some to begin their migrations several weeks early. The return of winter conditions in March could jeopardize any eggs that have already been laid.
Lou Perrotti, director of conservation programs at Roger WilliamsPark Zoo and an expert on reptiles and amphibians, said that wood frogs are especially cold hearty and will hunker down until the weather is just right. “The males arrive [in their breeding ponds] first and start calling the girls down, but if it is too cold they will not call and the girls will not move,” he said. “So breeding won’t happen until the temperatures and precipitation are optimal.”
It’s not unusual for a thin layer of ice to form on amphibian breeding ponds after the frogs and salamanders have laid their eggs, according to URI herpetologist Peter Paton. Some eggs may die as a result, he said, but those submerged below the surface should survive. And the adult frogs are usually able to avoid being trapped under the ice by exiting the pond.
Paton does worry, however, about repeated cold and warm spells in March. Wood frogs and spring peepers survive the winter by slowing their metabolism, dropping their body temperature, and allowing the water in their bodies to freeze solid. They survive unharmed thanks to the production of a concentrated sugar solution that acts as an anti-freeze to protect their organs.
“But I don’t know how many times they can withstand freezing and thawing in one season,” he said. “They might not do well if they have to keep doing it.”
Plants and amphibians aren’t the only wildlife that seems to be a bit confused by the weather. On February 25, David Gregg, executive director of the Rhode Island Natural History Survey posted a video on Facebook of a group of bees swarming around his bird feeder. He said it appeared as if the bees were licking the sunflower seeds.
“I understand that one of the concerns about global warming is the mismatch between bees and flowers,” he said. “The bees are active because the weather’s warm, but there aren’t any flowers out yet for them. So maybe that causes them to go after alternative food courses such as my bird seed."
Climate change may well be playing a role in the unusual weather this year, but also playing a role is this year’s strong El Nino, which changes weather patterns in complex and unpredictable ways.
"This overriding element of global warming is impacting everything on our planet,” said Killingbeck, “and then on a little less universal scale, the El Nino year on top of that is messing with certain pockets of the globe as well.”
But he said that all is not lost for this year. At least not yet.
“We’re at a critical time right now,” he said. “It all depends on what happens in the next month. It could still get back to normal. If we get back to more seasonable temperatures in March, the plants should do what they usually do in spring. Or we could have 70 degrees in March and all bets are off.
“But just because we’ve had a wacky winter doesn’t necessarily mean we won’t have a normal spring,” he concluded.

This article first appeared in EcoRI on February 29, 2016.

Friday, February 26, 2016

Sandhill cranes becoming regular visitors to Ocean State

            If you happen to spot a four-foot tall, gray bird in Tiverton this winter, you’re not alone in thinking that it looks out of place.  A lone sandhill crane has spent the entire winter in fields around the Seapowet Marsh, and the bird has drawn considerable attention from birdwatchers and other sharp-eyed observers. First spotted in October, it has been seen in the vicinity almost every day for more than four months.
            Sandhill cranes are common birds in the western United States and Canada. They breed in the tundra and prairie regions of Canada and Alaska, as well as in a few scattered locations in the Rocky Mountains, and migrate south in large numbers to winter in California, New Mexico and Texas. A non-migratory flock lives year-round in central Florida.
Sandhill crane in Tiverton, R.I. (Photo by Butch Lombardi)
            Cranes may have been common migrants through the Northeast in the 17th and 18th centuries, but not in the last century or so. They are prone to wander, however, especially in the fall, and in recent decades small numbers have been observed along the East Coast, including in Rhode Island, where every few years a bird or two has stopped off for a few days or migrated through the region. But according to Rachel Farrell, a member of the Rhode Island Avian Records Committee, the birds have become annual visitors in the last five or six years and are staying for longer and longer periods.
            Farrell said the increasing frequency of sandhill cranes visiting the Ocean State probably has to do with the species’ eastward range expansion. Cranes were reported breeding for the first time in Pennsylvania in 1998, Maine in 2000, Vermont in 2002, New York in 2003, Massachusetts in 2007 and New Hampshire in 2014. Cranes are not yet confirmed breeders in Rhode Island, though there is speculation that a pair spent last summer on private property in West Greenwich where access to birdwatchers was prohibited.
            Scientists believe there were fewer than 20 breeding pairs in all of New England in the last couple years. Observers tracked a flock of 29 sandhill cranes – both adults and young – traveling through five states in the Northeast during a one-week period in November 2014, beginning in Maine and ending in eastern Pennsylvania. This may have been the first documentation of the migratory route of cranes nesting in northern New England. Small numbers of cranes have also been seen regularly during migration at the cranberry bogs in Carver, Mass.
            But records of sandhill cranes breeding in and migrating through the region doesn’t make this winter’s observation of the bird in Tiverton any less remarkable. While they can survive challenging environmental conditions, they typically spend the winter more than 1,000 miles south of Rhode Island in a much warmer climate.
            “They’re hardy birds, but staying the whole winter is unusual,” said Farrell, who speculates that the Tiverton bird is probably one of those that breeds somewhere in northern New England. “It’s likely a local bird, but no one can really say for sure.”
            Peter Paton, an ornithologist and professor of natural resources science at the University of Rhode Island, notes that “they’re long distance migrants, so this bird may be a bird that strayed from its normal route, which happens sometimes. It’s like it short-stopped its migration and decided to stay.”
            Paton recalls a similar situation two years ago near the URI campus when a sandhill crane, which may have been injured, was observed for most of the winter feeding in a cornfield off Route 138. Late in the season it was joined by a second bird before they both departed the region.
            Is it likely that the sandhill crane in Tiverton will eventually find other cranes and breed, or is this bird destined for a solitary life unconnected to others of its species?
            Paton is optimistic.
            “I thought the bird in Kingston was never going to find anybody, but sure enough another bird showed up and they left together,” he said. “As cranes become more and more common in the region, the chances are greater that they’ll find others of their species and not be loners for the rest of their life.
            “There aren’t a ton of cranes in this neck of the woods, so it’s amazing how they find each other,” Paton added. “It’s one of the mysteries of nature.”
 This article originally appeared in EcoRI on February 26, 2016.

Tuesday, February 23, 2016

New wildlife refuge to benefit shrub-lovers

            Rhode Island has an abundance of gorgeous coastal vistas and a huge expanse of mature interior forest. In between, however, is a swath of habitat that gets little attention but which is becoming increasingly important, so much so that it may soon become part of a new national wildlife refuge.
The habitat that biologists call “early succession” is the intermediate step between a meadow and a forest, where thickets of berry-laden shrubs, vines and other low-growing vegetation are interspersed with young trees barely tall enough to be called trees. It’s a habitat that five or six dozen species of birds, mammals, insects and other wildlife depend upon for foraging and breeding. And sadly, it’s a habitat that is rapidly declining.
            The wildlife that lives in this shrubby habitat – including ruffed grouse, whippoorwills, New England cottontails, box turtles and monarch butterflies – is often forced to move around a great deal. That’s because 10 or 15 years after the habitat is in an ideal state, it matures into a full-fledged forest and is no longer the ideal habitat it once was for these species. By then, the young trees have grown, the flowering shrubs have been shaded out, and the thicket no longer exists.
New England Cottontail photo by USFWS
            Historically, the habitat for these shrub-loving species was created naturally by beavers damming streams (which eventually killed neighboring trees) or by storms or wildfires. But humans suppress wildfires and trap beavers, leaving very little territory left for the animals. The abandonment of agricultural fields in the last century created a great deal of this early succession habitat, but by now that has become re-forested, too.  Or been developed.
            Artificially creating these thickets often requires cutting down patches of forest and letting them naturally regenerate into shrubby habitat before they become forest again. But plans to cut down anything more than a small handful of trees often run into tremendous public opposition. Most biologists agree that as long as the right trees in the right forest are cut, it can benefit numerous shrub-loving species that are declining precipitously. The wildlife sometimes need the boost after their old habitat has matured into forest and too little new habitat is created to sustain their populations.
Luckily, however, southern Rhode Island has an abundance of naturally occurring thickets that provide feeding grounds and breeding sites for many of these animals. Much of the habitat at the Sachuest Point, Trustom Pond and Ninigret National Wildlife Refuges is this “maritime scrubland” community that tends to remain shrubby for longer periods.
Now the federal government is looking to incorporate more of this habitat into a new refuge called the Great Thicket in parts of seven states. According to Charlie Vandemoer, refuge manager of the Rhode Island National Wildlife Refuge Complex, efforts are underway to identify areas where conserving shrubland and young forest could make a big difference for wildlife.  

The U.S. Fish and Wildlife Service hopes to acquire 3,200 acres for the refuge in southern Rhode Island from willing sellers over the next three decades, and it is seeking public comment on their plans until March 4. It’s an exciting proposal that seeks to permanently protect habitat for species that otherwise get little attention. I, for one, have sent them a letter to endorse the project. And while we’re waiting for the new refuge to become established, we can all plant patches of native shrubs on our own properties to aid the declining species.

This article first appeared in The Independent on February 18, 2016.

Tuesday, February 9, 2016

Bats wintering in Rhode Island: Seeking refuge from white nose syndrome?

            Several species of bats that spend the summer in Rhode Island have experienced dramatic declines in their populations due to white nose syndrome, the fungal disease discovered in 2007 that infects bats in the caves and mines where they hibernate for the winter.  Little brown bats, for instance, the most abundant species in the region prior to the outbreak and the species most likely to be found breeding in attics and barns during the summer, have declined by about 90 percent in the Northeast, and northern long-eared bats have lost more than 98 percent of their population.
            Perhaps the only good news that has resulted from the disease is that bat biologists have been forced to think out-of-the-box for ways to protect the remaining populations of bats. They’ve begun to re-think the concept of hibernation caves – called hibernacula – in hopes of discovering previously unknown locations where bats may be spending the winter.
            Until very recently, it was not believed that many bats wintered in Rhode Island. Those species that migrate, including hoary, silver-haired and red bats, head south well before the winter freeze. And those that hibernate underground – like little brown, northern long-eared and tri-colored bats – were all thought to migrate to caves and mines in New Hampshire, Vermont, and New York. And they do. But, it turns out, not all of them.
            After a biologist in New Hampshire discovered bats hibernating in abandoned man-made structures along that state’s coast, Charlie Brown, the wildlife biologist responsible for bat conservation for the Rhode Island Department of Environmental Management, began to seek out sites where the animals may be over-wintering in the Ocean State.
Little brown bats with white nose syndrome (USFWS)
            “To my knowledge, no effort had been made previously to survey those kinds of sites,” Brown said. “But it got us thinking about what constitutes a hibernaculum. Instead of caves and mines, are there alternative sites that bats might use that we haven’t noticed in the past? And might these places be the last holdouts for the species?”
            Beginning in 2011, Brown began identifying possible facilities, most on state-owned land, that might have the appropriate conditions.
            “Bats are finicky about their environment. Those that typically use subterranean structures to hibernate require a stable environment with high humidity and low temperatures consistently around 35 to 40 degrees in winter,” Brown explained. “There can’t be much airflow through the structure that might change those conditions.”
            He said the bats also require a location that is undisturbed by frequent human visitation.  “Every time they’re aroused, they burn calories,” Brown said.
            After several years of using a headlamp and flashlight to explore abandoned structures throughout the coastal regions of Rhode Island, Brown has identified four structures where small numbers of bats have been found hibernating. A total of less than 100 bats have been recorded at the four sites, with big brown bats the most common species detected. Northern long-eared and tri-colored bats have also been observed.
            Peter August, a biologist at the University of Rhode Island who has studied tropical bats, isn’t surprised that Brown has discovered big brown bats overwintering in Rhode Island. He said that species typically hibernates within 30 miles of their summer roost. “We just don’t notice them here because they’re hibernating,” he said. “If we continue to have warm weather like we have, I wouldn’t be at all surprised if people start seeing bats flying around outside this winter.” Finding the other two species, however, is a surprise.
            Brown banded eight of the hibernating big brown bats he discovered, and four of them returned to the same site the following year, which suggests they have a degree of site fidelity. But the small numbers of bats he has found so far may indicate that the structures do not provide optimal conditions for hibernation. And Brown has no idea how long they may have been in use.
“We don’t see skeletons of bats that would suggest that 10 years ago there were many more using these sites than today,” said Brown, who won’t reveal the location of the sites in order to reduce the likely hood of disturbance. “I assume that these facilities became appropriate as hibernacula at some point, maybe because they were abandoned recently or are not used in the same way any more.”
            The DEM biologist will continue searching smaller structures this winter in hopes of finding additional bats.
            “We’d like to find more sites. Bats may use cisterns, sewage systems, military-type structures, summer homes, and other places we haven’t looked at yet,” he said. “We’ve looked at most of the larger structures, but we’re sure there are other smaller places out there.”
            As exciting as it is to find a diversity of hibernating bats in Rhode Island, Brown isn’t convinced that these sites are protecting local bats from white nose syndrome, even after tests of samples collected last year from the structures and from the bats themselves all came back negative.
            “The fungus was not detected, but we can’t say it’s not there,” Brown said. “Given that the bats move around the landscape and interact with bats from infected caves, it’s hard to imagine that our area hasn’t been affected or that we’re insulated from it. That would be nice, but we don’t know that yet.”
            Those who observe a bat in a home or other structure in winter are encouraged to contact Brown at 401-789-7481 or He also monitors maternity colonies in the summer months and asks those with large numbers of bats in their attics or barns in the summer to contact him. And if you find a bat in the living space of your home, he recommends contacting the Rhode Island Department of Health for a health screening, as bats are known to carry rabies and other diseases.

This article first appeared on EcoRI News on February 9, 2016.

Thursday, February 4, 2016

Absence of sea ducks attributed to weather, climate

            Rhode Island’s south shore is typically a haven for wintering sea ducks. It’s not unusual to observe flocks of hundreds of eiders and scoters and dozens of harlequin ducks grouped together feeding amid the crashing waves. But not this year. At the usual places where observers go to look for the birds – like Brenton Point, Sachuest Point, Beavertail, and the Charlestown Breachway – duck numbers are alarmingly low.
            Many of the active birders in the region repeatedly scour the coastline looking for the usual flocks of sea ducks, but they are reporting just a few handfuls of the birds, which is not nearly what they have come to expect.
According to Scott McWilliams, an ornithologist at the University of Rhode Island, there are multiple possible explanations for the absence of sea ducks in the area, explanations that involve the warm weather in December, environmental changes due to global warming, and even behavioral preferences among the different species of birds.
Black scoter by Alan D. Wilson
The three species of scoters – surf, black and white-winged – are attired in black plumage with white markings on their head and variable amounts of orange on their beaks. They often flock together with common eiders, which are black and white with a pale greenish tinge behind the head and neck. And the most sought-after of the sea ducks, the harlequin, is an attractive combination of slate blue, chestnut and white in patterns reminiscent of their namesake character. None of the five species seem to mind the blowing wind and cold temperatures of the New England winter, and harlequins especially seem to prefer the surf zone.
McWilliams isn’t worried, however, that duck populations have suddenly declined in Rhode Island waters this winter. Instead, he believes the birds are simply spending the winter elsewhere.  He said that the warm temperatures early in the winter likely played a role. Rather than migrate all the way from their breeding grounds in Canada, the birds probably took advantage of the warm weather in December and lingered along the coast of the Canadian Maritimes, Maine and Massachusetts, where many of them likely remain.
That’s almost certainly true of common eider. “Once they find a spot they like, they stay there,” McWilliams said. “Each bird tends to spend the entire winter within a very small area. So the 200 eider that you see one day at the Charlestown Breachway are the same 200 eider that will be there every day of the winter.”
Black scoters, on the other hand, are wanderers.  McWilliams and his colleagues have tagged a number of scoters and eiders to track their activity as part of a region-wide study of bird movement patterns, and they found that black scoters appear to move around based on local environmental conditions. “So they may be here in Rhode Island waters for a few weeks and then take a jaunt to the Chesapeake Bay for a few weeks, and then maybe return,” he said. “They probably pay close attention to changes in the environment and move around based on the conditions.”
The colder weather in January has prompted some eiders and scoters to move further south to their more typical wintering locations in recent weeks, but McWilliams said that most haven’t gotten much beyond Cape Cod just yet. And most may not make it to Rhode Island at all this year.
Rhode Island seldom has large numbers of wintering white-winged scoters, so this year’s numbers aren’t far off from an average year. McWilliams said that most white-winged scoters spend the winter off Cape Cod, and based on the data from birds he has tagged, they are in their usual places this year.
One other element that may be confounding the situation is climate change. The URI researcher said that increasing temperatures and the longer ice-free season in northern waters may mean that many species of coastal seabirds are finding open water further and further north. Scientists studying biological activity in northern waters say that food appears to be readily available to seabirds that choose to spend the winter months to the north. So the birds may not have to travel as far south as they used to in winter. Since migration is the most dangerous time in a bird’s life, many may choose to cut the trip short and spend the winter to the north of their usual range.
So the dearth of sea ducks in Rhode Island waters this winter may be a sign of things to come, McWilliams said. Bird watchers in the region might have to get used to seeing fewer seabirds in local waters in winter. On the other hand, it may also mean that more birds that migrate to points south of Rhode Island may end up wintering in the local area instead.

The article first appeared on EcoRI on January 30, 2016.