Thursday, November 24, 2016

Flock together

            It’s difficult to drive very far in Rhode Island without eventually stumbling upon a flock of wild turkeys. They’re seemingly everywhere – and strangely enough, they appear especially visible during the Thanksgiving season.
            In my wooded neighborhood, a flock of a dozen turkeys regularly makes the rounds of the homes with overflowing birdfeeders and weedy gardens. And they’re not shy. They parade down my driveway in single file, strutting and squawking and making a fuss, then battle over whatever morsels the songbirds have spilled from my feeders. If I open the window, they barely acknowledge me – unless I announce myself with a high-pitched gobble. To which they respond in kind, as if we’re playing a raucous game of call and response.
            This year, for the first time, four turkey mommas brought their 27 babies – officially called poults – to my yard every few days all summer long. And now they’re all grown up. Or at least most of them.
            The turkey babies that visited my yard survived at a much greater rate than was the case with most turkey broods in Rhode Island this year. According to Brian Tefft, the Rhode Island Department of Environmental Management biologist who keeps track of the state’s turkey population, the average number of turkey poults to survive until fall this year was just 2.7 per hen, which is below the 10-year average of 3.2 and just half of last year’s rate.
            Nonetheless, Rhode Island’s wild turkey population is a conservation success story. The birds were eradicated from the region by hunters in the 1700s, and it was nearly 200 years before they returned, thanks to reintroduction efforts by DEM. State biologists captured 29 turkeys in Vermont in 1980 and released them in Exeter. Another 105 birds were released in the 1990s in Tiverton, Little Compton, Burrillville, West Greenwich and Scituate. By 2001, about 6,000 turkeys were roaming nearly every community in the state.
            The birds even made it to Aquidneck Island, where Tefft said self-sustaining flocks are often seen in Portsmouth and Middletown, especially near the airport and Norman Bird Sanctuary. “Whether they walked over the bridge or flew over, we don’t know,” he said, noting that a Middletown flock became a short-term nuisance a decade ago when they exhibited a variety of anti-social behaviors, including attacking children getting of a school bus.
            Mark Pagliarini, education coordinator at Norman Bird Sanctuary, said a flock of 7 or 8 turkeys visits the sanctuary regularly, and he often sees other flocks in the neighborhoods near Easton’s Pond and Albro Woods. He said the abundant farmland and golf courses on Aquidneck Island means there is plenty of suitable habitat for wild turkeys to thrive on the island.
            “We don’t have an over-abundance of them, so you aren’t guaranteed to see them every time you go looking for them, but they’re still here in good numbers,” he said. “And they’re a good source of food for our coyotes.”
            According to Tefft, the wild turkey population in Rhode Island has declined to about 3,500 birds in recent years for unknown reasons. Almost every state from Maine to Virginia has experienced similar declines. He said the number of poults that survive to adulthood has been below average most years in the last decade.
            “For our population to really grow to their former numbers, we need multiple years of above average production,” he said.
            Spring and early summer weather is an important factor in poult production. When the chicks hatch in May and June, they are especially susceptible to hypothermia if they get wet from a heavy rain storm. They are also unable to fly into the trees to roost at night until they are about 3 weeks old, so they are vulnerable to predators on the ground.
            “We’re also looking at food sources – if acorn production is poor or there’s a hard winter, then the hens might not be so fit to raise a family in spring,” Tefft said.
            Hunting appears to be a non-factor in the sustainability of Rhode Island’s turkey population. Just 100 to 125 turkeys – males only – are harvested by hunters each year. Tefft calls those numbers “biologically insignificant.”
            Mortality in winter doesn’t appear to be much of a factor, either. University of Rhode Island ornithologist Scott McWilliams said that one research study found that wild turkeys can survive in temperatures as low as -50 degrees. Another study of winter survival indicated they can live 2 to 3 weeks without eating if snow and ice make food inaccessible.
            Whatever it is that is keeping turkey numbers from booming like they did in the 1990s isn’t likely to result in serious declines, especially as the climate warms and our winter weather places less stress on the birds.
            “We probably didn’t grow the turkey population this year,” concluded Tefft. “But it probably at least remained stable.”

This article first appeared in the Newport Mercury on Nov. 23, 2016.

Tuesday, November 22, 2016

Wildlife-killing feral cats pose environmental threat

            A new book examining the complicated issue of cats and wildlife has re-opened a difficult discussion that has long pitted animal welfare organizations against biologists, birdwatchers and the environmental community. And the position taken by authors Peter Marra and Chris Santella is doing little to make that discussion any easier.
            You can tell by its title, Cat Wars: The Devastating Consequences of a Cuddly Killer, that the authors don’t pulling any punches. Marra, who directs the Smithsonian Migratory Bird Center, and Santella, a journalist, argue that drastic action is necessary to curb the massacre of birds and small mammals caused by feral cats and housecats that are allowed to go outside.
            After reviewing thousands of reports, pet-owner surveys, cat regurgitation studies, academic research and other data, they calculated what they say is a conservative estimate – cats kill up to 22 billion small mammals, 4 billion birds, 822 million reptiles and 299 million amphibians in the United States each year.
            “More birds and mammals die at the mouths of cats than from wind turbines, automobile strikes, pesticides and poisons, collisions with skyscrapers and windows, and other so-called direct anthropogenic causes combined,” they write.

            What’s more, the authors say that feral cats are also a hazard to human health. Feral cat colonies where humans provide food attract raccoons, skunks, foxes and coyotes, too, easing the spread of rabies. Cats also carry a variety of diseases that can be transmitted to humans, from a bacterium that causes a life-threatening infection in cat scratches and bites to a parasite that can cause birth defects when pregnant women are exposed to cat feces.
            The authors call feral cats an invasive species and say the only answer to solving the problem is what is euphemistically called “trap and remove,” which means capturing the animals and euthanizing them.
            “No one likes the idea of killing cats,” they write. “But sometimes, it is necessary.”
            It is unclear how many feral cats live in Rhode Island, but all the interested parties agree it’s too many. Estimates range as high as 250,000, though state veterinarian Scott Marshall says it’s probably closer to “tens of thousands.”
He established a Feral Cat Working Group in 2010 after receiving innumerable complaints about the animals. The group, which includes members from animal welfare groups, academia, environmental organizations, and public health agencies, hired a student from the Tufts University School of Veterinary Medicine to census known feral cat colonies in the state. She found 302 colonies, mostly in urban areas, with a total of about 4,000 cats.
It is believed there are many more colonies than those she surveyed, plus thousands of uncounted cats that are not part of established colonies and an estimated 60,000 housecats whose owners let them go outside.
“Cats are a serious problem for wildlife,” said Marshall. “Their hunting instinct isn’t diminished by feeding them. A pet cat that is fed at home still brings birds and rodents home. We can’t deny that they’re having an impact on wild birds, rodents and to a lesser extent reptiles. They kill whatever they can get.”
According to Marshall, feral cats live very short lives. Their life expectancy is less than two years. Half don’t make it out of kittenhood, 75 percent don’t survive one year, and 85 percent die before their second birthday.
“People don’t realize that when animals are dying young in large numbers, they have a miserable life and a miserable death,” he said. “They’re struck by cars, exposed to parasitism, die of exposure, get ripped to shreds by predators. They don’t live good lives.”
He agrees with the authors of Cat Wars that, unfortunately, the best solution is euthanasia.
“Given the tools we have, that’s the only way to solve it,” Marshall said. “If a male contraceptive were available, that could be effective, but right now nothing else works.”
Most of the animal welfare groups in Rhode Island disagree. Vehemently.
They argue instead for a method called “trap, neuter and return,” or TNR, in which feral cats are captured at colonies, brought to clinics to be spayed or neutered, and returned to their colony. Advocates say it is the most humane alternative to euthanizing the animals, and because the cats can no longer reproduce, the colonies will eventually disappear.
Gil Fletcher, a member of the Feral Cat Working Group who runs a cat rescue organization called PawsWatch, acknowledges that not all of the animal welfare groups agree with the “return” component of TNR, and because there are numerous small grassroots groups advocating for feral cats, there is considerable tension among them. But, he wrote in an email, “it goes without saying that any form of large scale lethal approach to reducing the free-roaming cat population (trap and euthanize, hunting, targeted poisoning, etc.) is an anathema to this group.”
Fletcher is pushing for municipal governments to adopt the TNR approach, because the feral cat problem is one he equates with other community concerns addressed with taxpayer funds, like anti-littering campaigns and roadside beautification efforts.
While he barely mentions the impact of cats on wildlife – other than to disagree with the cat predation numbers Marra and Santella claim – he says that “the cat people” and “the wildlife people,” as he calls them, all seek to remove free roaming cats from the outdoor environment. Their “interest, motivation and their presently-favored means are poles apart, but the end goal is the same,” he said. “By all logic, they should be natural allies.”
Part of the reason they aren’t, according to Marshall and the scientific community, is that there is no evidence that TNR works. In practice, feral cat colonies managed with TNR don’t get smaller and disappear. Instead, the populations remain mostly the same and the animals continue to kill wildlife. To be successful, at least 80 percent of the cats in a colony must be spayed or neutered, and the colonies must be constantly monitored as new animals arrive.
“TNR seems to be the panacea that animal welfare groups endorse, but there’s virtually no evidence that it’s effective,” Marshall said. “Everybody wants it to be effective, but it’s very labor intensive, expensive, and ultimately it’s ineffective. Unless people can shut down new inputs into the colonies, it’s doomed to fail.”
The one thing Marshall and Fletcher agree on is that it will be nearly impossible to address the issue of feral cats in Rhode Island without public support for whatever strategy is chosen. And they say that the public won’t support a widespread euthanasia effort.
“The science would say that cats should be removed from the environment, but emotions run very high and there is no public support for removal,” he said. “I personally don’t like the idea of tolerating their existence, because in my opinion the lives and deaths they experience are far less humane than trapping and removing them.”
The authors of Cat Wars, however, are less concerned with the sad lives of feral cats and more concerned for the welfare of wildlife and the environment. They say that of all the threats to birds that are directly or indirectly caused by humans, cats are the easiest problem to fix, especially when compared to complex issues like climate change.
“To me, this should be the low-hanging fruit,” said Marra in Smithsonian Magazine. “but as it turns out, it might be easier stopping climate change than stopping cats.”

This article first appeared in on November 22, 2016.

Saturday, November 19, 2016

War on marine invaders seems a losing battle

            On a cool Friday morning last month, a dozen curious Rhode Islanders lay down on the pier at Point Judith Marina to collect some of the squishy and crunchy creatures that were growing on the side of the docks. Using rusted metal spatulas, they scraped the unknown life into small aquarium nets and saved it in plastic tubs, then spent half an hour trying to identify what they had retrieved.
            With the exception of a few blue mussels, almost nothing was recognizable. There were sea squirts and shrimp-like things, seaweeds and green crabs, and just about everything was covered in a mushy yellow-brown mat called a colonial tunicate.
Almost none of it was native to New England waters. In fact, most it came from the other side of the planet.
Colonial tunicate
Marine invasive species are a growing problem. According to Kevin Cute of the CoastalResources Management Council, who led the marina program sponsored by RhodeIsland Sea Grant, there is little that can be done about them. Once a new species arrives, it’s almost impossible to get rid of it.  So prevention is the key, he said.
But preventing marine organisms from showing up where they don’t belong is harder than you would think. Most arrive in the ballast water of ships, which pump entire marine ecosystems from one part of the world into their hulls to improve the ship’s stability, and then they discharge it into water bodies far from where they originated.
Since the biochemistry of Narragansett Bay is far different from that of the South China Sea, for instance, most microscopic organisms cannot survive in both places. But a few hardy specimens endure the journey, latch onto a hard surface like a rock or marina dock, and start to reproduce. And it’s nearly impossible to stop them.
The colonial tunicate that covered most of the other creatures at Point Judith Marina that day originated in Japan, showed up in Maine in 1993, and has been spreading along the East Coast ever since. With no known predators, it grows aggressively, fouls fishing and aquaculture gear, and smothers shellfish and other creatures living on the seafloor.
Cute and a team of CRMC staff and volunteers conduct monthly sampling for marine invasive species at five sites around Narragansett Bay to keep an eye on the known invaders and to watch for new arrivals. But, he said, “there are so many variables – storm events, changing temperatures and salinity, predation, competitors – if I came back next week there could be very different species here.”
Various regulatory agencies are doing what they can to restrict the arrival of new organisms. Ships entering U.S. waters are now required to dump their ballast water at least 200 miles from shore. And some ships must install on-board chemical or ultraviolet systems for treating their ballast water before discharging it – though many in the shipping industry are fighting these regulations.
So while it is getting more difficult for new species to make it to our shores, dealing with the species that are already here is a never-ending battle. The colonial tunicate is an especially challenging one to manage. It’s already affecting Narragansett Bay’s eelgrass beds, which Cute calls the most important habitat in the bay because it is a valuable nursery area for fish.
“We’re playing ecological roulette with invasive species,” Cute said. “They’re wiping out dinner for all of us.”

This article first appeared in the Independent on November 17, 2016.

Friday, November 4, 2016

Block Island project finds falcon migration route

During the peak of this year’s fall raptor migration season, scientists from the Biodiversity Research Institute in Maine completed a five-year effort to monitor the movement of falcons on offshore islands along the East Coast. And most of their effort was focused on Block Island, which the researchers say is among the most important stop-over sites for migrating falcons.
Their aim was to capture peregrine falcons and affix them with satellite tracking devices to map the birds’ movements so scientists can better understand their migration routes, how they use the coastline, and how they may be affected by offshore wind farms.
Rick Gray with a merlin.
The findings so far have been somewhat unexpected.
BlockIsland is perfectly situated as a jumping off point for birds migrating south, according to Rick Gray, one of the researchers leading the project. It attracts an abundance of songbirds – the primary food of peregrine falcons – and it is situated between Long Island, Nantucket and Martha’s Vineyard, which the birds also visit during migration.
“We’re very excited that we found this gem of a site,” said Gray. “Falcons are coastline migrants, so Block Island is an ideal location for this kind of study.”
Since 2012, Gray and his colleagues have captured more than 550 falcons on Block Island and attached transmitters to 38 peregrines and 80 merlins – the latter a smaller cousin of the peregrine. The scientists hid in a portable blind at the edge of a bluff on Lewis Farm on Block Island, a site where the birds are regularly observed soaring on thermals and hunting for food. When a falcon was lured into a series of nets, the researchers conducted a health assessment of the captured bird, collected blood and feather samples, fit it with a transmitter, and released it.
The first surprise the researchers discovered was that falcons often make long flights far out over the ocean.
“When the birds leave Block Island, they typically hug the coast to the Outer Banks [of North Carolina] and then do long overwater flights to Florida and the Bahamas,” Gray said, noting that the birds then continue on to wintering grounds in the Caribbean and Central and South America. “One of the first males we tracked in 2014 was a total outlier, though. It left Block Island and went straight out into the ocean. We’re convinced it was hunting pelagic birds following ships.”
Another somewhat surprising finding was that the researchers have caught just four adult female peregrine falcons during the five years of the study, and they haven’t seen even one adult male. Almost all of the birds they capture on Block Island are young birds migrating for the first time, and almost all are of a subspecies that breed in the Arctic, not the subspecies that breeds in the northeastern United States.
Gray said that little is known about the migration route of adult male peregrines – few have been captured at any bird banding location on the East Coast – and the small number of adult females tracked have followed the coastline closely throughout their migration.
“Migration routes are probably learned. On their next migration, the young birds are probably not going to do an oceanic flight,” explained Gray. “It’s the same with ospreys. Hatch-year birds do crazy oceanic flights, and the next year they don’t. They only do that long overwater flight one time. I wouldn’t be surprised if it’s the same thing with peregrines.”
            Mortality of falcons on their first migration is quite high, probably in part because of the long routes they take over the ocean. But the researchers say they also do not appear to be very cautious during their first migration.
            “We found one of our transmitters underneath an eagle nest on Assateague Island in Virginia,” said Gray. “Our thought is that the bird had probably killed something and wasn’t paying attention and was taken by an eagle.”
            Having wrapped up their study of peregrine falcons this year, Gray said that the researchers hope to focus more on merlins in coming years. They hadn’t expected to see so many merlins on Block Island, so in 2014 and 2015 they began attaching them with a small device called a nanotag that provides a GPS reading when the birds fly by one of the many antennas set up along the East Coast to monitor bird migration.
            “This is the first time that merlins have been tracked anywhere, and their track is very similar to peregrine migration,” Gray said. “They do over-ocean flights, but not as great distances as the peregrines. We don’t have the ability yet to see exactly where they go over the ocean, but they’re definitely using the coastline the same way as peregrines.”
            The falcon research project is supported in part by the Rhode Island office of The Nature Conservancy, which hopes to use what is learned in future land protection and wildlife management efforts.
“The raptor research at Lewis Farm is producing cutting edge scientific discoveries, giving us a more comprehensive view of raptor migration than ever before,” said the Conservancy’s Clair Stover. “By supporting and hosting the Biodiversity Research Institute, The Nature Conservancy and others in the conservation field are learning more about raptors and their migrations, and as a result, we are able to better manage and protect nesting, stopover, and wintering habitats that are key to the species’ success.”

This article first appeared on on Nov. 2, 2016.