Monday, February 18, 2019

Trail cam provides unexpected wildlife insights

            Few of us probably spend as much time as we would like enjoying the outdoors. We just have too many other responsibilities – work, chores, meal prep, family time – to make extra time for relaxing and observing the natural world around us.
I likely spend more time than most staring out the back window at the trees and lawn and bird feeders – more time than I care to admit – and still I wish I could do it more. Because for every minute I’m not watching, there is probably an animal doing something interesting that I’m missing.
That’s why I was especially excited to receive a motion-activated trail camera for Christmas a couple years ago. It allows me to document the comings and goings of wildlife when I’m not paying attention to those activities myself. And the images the camera provides are insightful.
            For instance, deer are much more abundant in my area than I ever imagined. I typically see a deer or two wandering the woods and fields along my road about every other month, and
yet my camera detects deer strolling through the forest behind my house almost daily. And it’s not always the same animal, either. I’ve had pictures of six-point bucks, speckled fawns, groups of three and four antlerless deer, and one unique individual with a distinctive mark on its rump.
            The photos aren’t exactly magazine quality images, however. More often than not they just show a deer’s backside as it walks away from the camera, or a close-up of an ear or nose as the animal investigates the camera. Once, though, it captured a late-night shot of a deer on its hind legs, apparently trying to nibble on some leaves over its head.
            The camera often captures images of other forest dwellers as well. Fishers are apparently regular visitors to my yard, as are coyotes, raccoons and red and gray foxes. I almost never see those animals except as images on the trail cam.  
Most often, the pictures show one of these creatures dashing across the path where I’ve set up the camera, but sometimes they’re doing something more interesting. They occasionally seem to pause and stare right into the camera, as if they’re posing. Or they’re sitting down and scratching an itch or chewing on a morsel they’ve just discovered.
The most fun images are those that I can’t quite figure out at first glance. They test my identification skills when all that’s visible is a distant furry blob or a tail just disappearing from view.
Fast moving animals are especially challenging, because they often just look like a digital blur. Is that night-time image – showing a long streak that appears to be well-above ground level – an owl or a flying squirrel? Or maybe it’s just a falling branch. Is that hazy long-tailed thing a fox or coyote? I enjoy sharing those images with friends on Facebook to help ID the animals.
And then there are the pictures that seem to show nothing at all. Maybe the movement of a leaf or branch triggered the camera. Or maybe some creature is there after all but it’s too well camouflaged for me to see it.
As fun as it is to watch backyard wildlife remotely via a trail cam, the best picture it captured was of an abominable snowman. At least that’s what I call the winter shot of my wife strolling through the woods trying to avoid the camera.

This article first appeared in the Newport Daily News on February 16, 2019.

Friday, February 15, 2019

He caught the natural history bug

            The artifacts scattered around David Gregg’s office provide a good idea of what he does for a living. Among the items are a crayfish preserved in a jar of alcohol, two coyote skulls, numerous large dead moths awaiting identification in a plastic container, framed invasive insects, a deer head hanging on a wall, illustrations of butterflies, and a foot-long, eight-inch diameter tree stump he quizzes visitors to identify. (Spoiler alert: The stump is bittersweet, an invasive vine that apparently grows much larger than most people think it does.)
            Gregg is the executive director of the Rhode Island Natural History Survey, and what he calls his “cabinet of curiosities” represents many of the issues, programs and challenges he
David Gregg starting the annual BioBlitz (EcoRI News)
regularly addresses as one of the Ocean State’s leading voices for the study and conservation of Rhode Island’s wildlife and other natural resources.
He describes the Survey as somewhat of a social organization where “people who have been bitten by the bug of natural history” can connect with like-minded individuals.
“There are many ways to discover things about the world around you, but for people who are oriented toward identifying animals and plants and learning about them, the Survey is an excuse to get together,” he said. “And that makes it valuable, because otherwise we would never get together and talk about what we know.”
The group was founded following a 1994 ecological research conference at the University of Rhode Island, when many of those in attendance recognized how productive a gathering it had been and wanted to keep the exchange of information going. Based at URI’s East Farm, the Survey is celebrating its 25th anniversary this year with a fall conference on “Climate Change and Rhode Island’s Natural History Future” and a monthly citizen science event. This month’s event is a bird census on Feb. 15 as part of the world-wide Great Backyard Bird Count.
Gregg caught the natural history bug – literally – as a young teen in Falmouth, Mass., when he tried to capture a butterfly that had landed on his shoe. He had already been somewhat interested in nature, but that moment led him to start a butterfly collection using a net he made out of cheesecloth.
After collecting as many butterfly species as he could find around town, he switched to moths. “I got all the colorful moths in my collection, and all the rest were brown and I couldn’t make heads or tails of them,” he recalled. “So then I switched to beetles, then to grasshoppers.”
The lure of insects was their endless variety and interesting physiological adaptations, Gregg said.
But he also had a curiosity about archaeology, and when he was considering a career, archaeology eventually won out. He said archaeology “is about discovering a mystery and finding out what it means. I also liked the outdoorsness of it, the expedition aspect, the cadre of people thrown together in remote locations and having to stay focused on what they do. It’s the same thing in natural history.”
 Gregg ended up earning graduate degrees in archaeology at Oxford University and Brown University, then worked at Brown’s Haffenreffer Museum of Anthropology before becoming director of the Spellman Museum of Stamps and Postal History.
By then he had rekindled his interest in entomology and joined the board of the Natural History Survey. He accepted the leadership post at the Survey in 2004.
He describes the job is a balancing act between gathering information about rare and invasive species to support conservationists’ need for scientific information – a mission “that doesn’t pay very well,” he noted – and administering complex ecological monitoring projects involving multiple partners and numerous funding agencies.
“The state can build a highway or an airport, but it can’t do a project with six funders and lots of partners,” Gregg said. “We can do that.”
For instance, the Rhode Island Department of Environmental Management used federal funds to hire the Natural History Survey to implement a project to assess the health of salt marshes and freshwater wetlands around the state. The Survey is also leading a coyote ecology research project with numerous partners and funding from the U.S. Fish and Wildlife Service.
“These are the kind of projects that wouldn’t get done unless we did them,” said Gregg. “These are the projects that are every other organization’s fourth priority.”
Along the way, Gregg still finds time for insects. He has shifted his attention in the last two years to ants as a leader of a statewide effort to document all of the species of ants found in Rhode Island.
“I’ve been working on moths since I was 14, and I think I have a better understanding of ants after two years than I do of moths after 40,” he said.
In the coming year or two, Gregg’s focus at the Natural History Survey will be on the establishment of a new database of everything known about the biodiversity of Rhode Island, preparing an updated publication of the state’s vascular plants, and ensuring the group’s finances are stable.
But his favorite activity is the Survey’s annual Bioblitz, which brings together as many as 200 biologists, naturalists and volunteers for a 24-hour period to document every living organism at a particular property. This year’s event is a return to Roger Williams Park, where the first Bioblitz was held 20 years ago.
“Bioblitz is an expedition to discover things in a particular place, and you bring together people with all of the different skills and talents you need to look at all of the different aspects,” he explained. “But they’re not just random people. They’re really nice people having a great time because this is what they love. Bioblitz is social – it’s not just science – and that’s the key. You get to meet people that can show you the cool things you don’t notice the rest of the year.”

This article first appeared on EcoRI.org on February 15, 2019.

Monday, February 4, 2019

Hawks increasingly feed on birds at backyard feeders

            For at least two decades, many people who provide seed to feed the songbirds in their backyard have provided anecdotal evidence of an increase in the number of bird-eating hawks that visit their feeders. Now, an analysis of 21 years of data collected by Cornell University has confirmed those observations by noting that Cooper’s and sharp-shinned hawks – which prey primarily on songbirds – have been colonizing urban and suburban areas during winter due to the availability of prey at bird feeders.
            According to Jennifer McCabe, a postdoctoral researcher at the University of Wisconsin in Madison, whose study focused on birds in the Chicago area, many hawk species had declined
Cooper's Hawk (stock)
significantly by the middle of the 20th century because of hunting and pesticide use. Populations of most hawks, including the Cooper’s and sharp-shinned, have rebounded since then – largely due to legal protections and the banning of particularly harmful pesticides – enabling the birds to colonize areas that they had previously ignored.
            In a research paper published in November in the Proceedings of the Royal Society B, McCabe found that the two hawk species, which look similar and are collectively called Accipiters for their genus name, occupied about 26 percent of the area in and around Chicago in the 1990s. Two decades later they were found in nearly 67 percent of the area.
            Birders in Rhode Island have also reported anecdotal evidence of an increase in Accipiter numbers in recent decades, especially Cooper’s hawks. Rachel Farrell, a member of the Rhode Island Avian Records Committee, has noted several Cooper’s hawks nesting in Providence in recent years, and she calls their presence at feeders in winter “commonplace, unremarkable, and therefore not generally reported [any more] from suburban areas.”
            “In the beginning years of our study, sites were occupied around the fringe of the city, and through time they moved into the inner city,” said McCabe of her study site in Chicago. “The main driver for this colonization is prey abundance. They seem to be cuing in on feeders that have a lot of birds. That’s the driver that keeps the hawks there – prey abundance at feeders.”
            Her findings were initially counterintuitive, because Accipiters nest in forested habitats. Their narrow wings and long tail enable them to maneuver quickly through densely forested landscapes and chase down small birds, a behavior the larger soaring hawks like the common red-tailed hawk cannot do. The soaring hawks typically feed on slower-moving rodents.
            “We did our study in winter, so the birds weren’t concerned about finding the perfect tree for nesting,” McCabe said. “They were more concerned about survival.”
            The relative absence of tree cover in urban areas and the abundance of pavement and other impervious surfaces did not seem to discourage the hawks from colonizing cities, she said. In fact, the more tree cover a site had, the less likely it was to attract Accipiters in winter. The key factor was prey availability. As long as there were bird feeders attracting an abundance of small songbirds to the area, the hawks moved in.
            The data for the study comes from Project Feederwatch, a citizen science project in which participants periodically count the birds and bird species at their feeders. Sponsored by the Cornell Lab of Ornithology and Bird Studies Canada, the program began in 1987 and now includes more than 20,000 volunteers from across North America.
            Since bird feeding is among the most popular pastimes in the United States, with some surveys finding that more than 40 percent of households participate, it is likely that the Accipiters that have colonized urban and suburban areas will not go hungry.
The effect the hawks are having on the population of common feeder birds like sparrows, chickadees, titmice and nuthatches has not been measured, but it is unlikely they will be impacted in the long term. They may even receive a boost, since other studies have found that urban Accipiters primarily target invasive city birds like pigeons, starlings and house sparrows, potentially easing competitive pressures on native species.
A study of the recolonization of Britain by sparrowhawks, which also feed on birds, provides additional insights. When sparrowhawks were extirpated from Britain, it became less necessary for their primary prey – house sparrows – to be vigilant for the predators.
“Over 30 years, they lost this anti-predator behavior,” McCabe said, “and when the hawks came back, they ended up decimating the house sparrow population.”
Whether North American feeder birds’ vigilance for predators declined following the eradication of hawk populations half a century ago is uncertain. But even if they did, it’s not likely to last long.
“If the birds lost their anti-predator behavior, they’ll regain it pretty quickly now that the hawks are back,” McCabe said. “People’s backyards won’t be picked clean by hawks.”

This article first appeared on EcoRI.org on February 2, 2019.