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Archive for July, 2010

Bubble Rock

Perched on South Bubble Mountain, Bubble Rock is one of Acadia National Park's most popular destinations (SERC Institute/P. Morgan). This large, granite boulder is what geologists call an "erratic," and has been deposited by glaciers thousands of years ago. The word "erratic" derives from the Latin word meaning "to wander," which sums up the history of these glacial deposits.

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A powerful symbol of hope that gracefully towers towards the heavens. Almost alien in appearance, the gigantic body and spinning head of the wind turbine could be the clean energy alternative of the future.

Whoosh. Whoosh. Whoosh. The long blades capture wind energy and start rotating. This motion spins a shaft leading from the hub of the rotor to a generator. The generator turns that rotational energy into electricity that can be used to power homes and businesses.

Whoosh. Whoosh. Whoosh. Bang. A bat flies into the wind turbine. To say “ouch!” would be an understatement.

A researcher handles a brown bat (NPS photo).

During their migration paths, bats often encounter wind turbines. Most of them successfully avoid wind turbine blades, detecting them through echolocation (a type of biological sonar). So, why all of the concern? The trouble starts when bats encounter the pressure changes around the wind turbine; these pressure changes cause pulmonary lesions in almost all bats that encounter them, resulting in frequent internal hemorrhaging and eventually death. As a result, scientists are concerned about how wind turbines are affecting bat populations.

I know, I know–for something with as much promise as wind power, it’s hard to focus on negative ecological consequences. In fact, the Maine Governor’s Task Force on Wind Power Development has recommended that the installation of wind turbines should be “aggressively” pursued along the coast of Maine. After working so diligently to start the move towards clean energy, are they really going to stop pursuing wind power because of bat populations?

More research is needed. Timothy Divoll of the BioDiversity Research Center has spent the last few years looking at how the installation of wind turbines will affect Maine bat populations. Using acoustic sampling technology (to collect data on bat species and abundances), mist netting (to capture bats and see if acoustic technology and species identification are correctly matched), and banding (to see if bats return to same areas during migration), Divoll hopes to gain data about the species and abundances of bats coming through four different zones throughout Maine. This information can eventually help scientists and policy makers decide where to place wind turbines so that they do not obstruct bat migration paths and/or have minimal impacts on bat populations.

In this way, insightful research and careful decision making can help avoid an impossible dilemma: cleaner energy via wind turbines, or protecting the fascinating bats of Maine. So it doesn’t have to be bat versus wind turbine. I am optimistic that, with enough forethought, we can have both.

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We had a productive, though breezy, morning on July 22nd with lots of good news to share from the islands!

The Least Tern colony on Lovells is quite active with numerous chicks present.  We decided not to enter the colony site since chicks were running around everywhere (!) but observed at least 26 adult terns present.  Several adults appeared to still be incubating nests, but most were feeding and tending young (see attached pics).    We also observed 5 Common Terns on Lovells, including one fully fledged juvenile still begging its parent for a handout (teenagers are all the same regardless of species).  Although we know these Common Terns did not breed on Lovells they were quite territorial – maybe they are prospecting new sites for next season?

We were prevented from visiting Snake due to a surprise LNG delivery, but did visit the Hingham Harbor Islands after receiving a report of an American Oystercatcher pair with chicks on Sarah Island.  We saw no sign of AMOY on Sarah, but did see one pair flying around the area between Ragged and Button.  We did not observe any chicks present, but sometimes they are pretty sneaky.

We landed on Sheep Island where we found 3 pair of AMOY.  One pair had a fledged chick and one of the adults from this pair was banded there in 2009 (yellow band – ‘CK’).  The other two pairs were very active and territorial, but we did not observe chicks or nests.  In addition to AMOY, Sheep also has very active gull and wading bird colonies; young Glossy Ibis were readily visible.

A visit to Hangman turned up little except gull chicks, though there were a number of eider and one White-winged Scoter in the area.  We finished the morning with a quick pass by Rainsford.  The AMOY pair that had been incubating on the tern nesting beach was not present there, but we did find a pair on the rocks by the landing beach.  No chicks appeared to be present with them, but we’ll take a closer look next week.

(See Bob Stymeist’s excellent photos from the trip at http://www.flickr.com/photos/rstymeist/4818840410/)

-Carol

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When I first heard about ecological change from a nature documentary, I immediately jumped from my living room couch and ran outside. I was ten years old and I wanted to personally witness how we, humans, were affecting our environment.

Yup... still blue. (L.Weisenfluh, July 2010)

The sky was still blue. Birds were still cheerfully chirping. Rollie pollies were still… rolling? Ants were still… being ants? And better yet, I was still comfortably warm in my apple tree sweater outfit (complete with leggings and all) on a crisp fall day.  The house had always been here. And the car? Definitely nothing new. My young and naive mind translated these brief observations into a rather unscientific hypothesis: ecological changes…hmmph…where?

Ten years later, and I have finally figured out that one’s perception of the environment is all relative–that is, based on one’s very own baseline observations of the environment. In other words, if you don’t know know about something’s past, then how can you know if it’s changing?

Take, the passenger pigeon, for example. Right–I know, passenger pigeon? What? But that’s exactly point. During the 19th century, passenger pigeons would literally flood the skies. Accounts tell of migratory flocks of up to two billion passenger pigeons passing overhead, occasionally taking hours to pass.  And so, people started to hunt them. What’s one less passenger pigeon from a billion? Well, folks, passenger pigeons are no longer with us, having been hunted to extinction. If I have never seen one, then how am I to know that it ever existed? This very predicament brings me to my main point: it’s all relative.

How can ecologists scientifically prove that ecological change is occurring without baseline data? As a result, some of the most compelling studies that convincingly imply climate change result from comparisons between data collected years ago and present day data.

Dr. Bryan Windmiller and Glen Mittelhauser of Hyla Ecological Services, Inc., and Maine Natural History Observatory (respectively) are doing  this same kind of work, aiming to compare their own data on freshwater invertebrate communities to baseline data gathered by  William H. Procter more than sixty years ago.

Dragonfly larvae are one type of freshwater invertebrate (USGS photo).

In a recent study, the researchers surveyed twelve freshwater wetlands in Acadia National Park to determine freshwater invertebrate species composition and abundances. By comparing this newly compiled data set to the data collected by William H. Procter, scientists will be able to glean how the ecology of freshwater wetlands has changed over the past sixty years. This also means that we might be able to see how past events, like the Great Fire of 1947, changed the ecology of aquatic insect community compositions.

But is 60 years a good enough baseline to signify ecological change? It’s a start. For now, we have to take what we can get–we are lucky to have such a thorough collection as Procter’s–and look at ecological change of freshwater invertebrate communities over the past 60 years.

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Branches snap. We push apart webs with the force of our faces, hands and shoulders; the spiders scramble. A few birds sing from the tops of red cedars and pines, as we crush fallen, dead trees with the weight of our shoes.

It’s a few hours into the afternoon and deep in the forest we cut our own paths through thicket, bog, and high grass. We listen for crunching–the promise of footsteps in a wilderness less frequented by humans. We pause at every rocky area or uprooted tree to search for dens; we scan the ground for scat; and look for bare patches on bark with rolled out sides…all signs of the creature we just can’t seem to find. The forest is so vast, our eyes get lost searching the canopy.

Porcupines are generally not elusive, but today they remain undercover.  Dr. Linda Ilse, a part time professor at the University of Maine in Orono, doesn’t seem discouraged; for more than twelve years she’s studied the North American Porcupine, Erethizon dorsatum, and is comfortable with the unpredictability of fieldwork. And anyway, variation holds its own significance. It helps Dr. Ilse answer her central question: what habitat do porcupines prefer? Since the 1930s and 1940s, the porcupine’s range has shifted. So far, data from recent studies shows that wet, marshy areas are uninhabited by porcupines. A number of reasons are possible–perhaps the creatures don’t like walking on the springy moss.

Dr. Ilse carries a GPS which she refers to as a virtual Hansel and Gretel bread crumb track. Every move we make is recorded and by the end of the day, she hopes to cover an area of ground graphically similar to a soft-cornered “M”. She’s already covered other land around Schoodic and marked points for return trips, when she’ll come back to gather more precise data (like tree measurements) on the areas with evidence of porcupine activity.

“It’s tough. It’s a thankless job–but somebody’s gotta do it,” she says, crawling under a fallen tree branch.

She pauses to analyze the pile of animal droppings on the ground–scat. But whose? Deer, rabbits, moose, bobcats, and porcupines coexist in these forests. Dr. Ilse informs us that porcupine scat is similar to deer’s, but slightly more curved on the end and lighter in color. Furthermore, porcupine scat is usually spread out over an area, instead of piled up. She picks a piece up, and crumbles it between her fingers–if it’s very fibrous, it could be porcupine.

Porcupines are strictly herbivores, and a large portion of their diet consists of tree bark. They may remain in one tree for a couple days at a time, stripping away the inner bark with their teeth. Where patches of bark have been stripped away, new growth curls inwards around the perimeter of the damaged spot.

We stand looking at some tree damage when we hear loud rustling behind us…could it be? Lauren looks in the distance and YES! Porcupine of the day spotted high in a tree. We walk over and Dr. Isle marks a point on the GPS. This is a place to return to.

Generally, porcupines do not kill trees, although bark stripping does weaken the trees vascular system (which is in charge of transporting nutrients and water from the roots to the leaves). Girdling–the process of completely removing a strip of bark around a tree’s circumference–can kill the tree, but porcupines often move up and down branches, not around them. In response to porcupine gnawing, a damaged tree will seep a protective layer of sap (sort of like the human bodies response to send blood platelets to plug a cut in the skin), which remains on the tree for years and looks like as a frozen, translucent stream.

Under a damaged tree you’ll usually find a scattering of droppings, similar to the ground layer of a porcupine den. Porcupines don’t build their own dens, but seek out sheltered places like uprooted trees or rocky areas. A female porcupine remains pregnant for seven months until giving birth to a single baby, and outside of its den will often stash the baby under fallen trees or in thicket to protect it while she feeds. Although a baby’s quills are soft and wet at birth, they harden within only a couple hours!

After hours of walking through thick brush, my legs lose coordination. I begin making less precise movements, practically flailing my body in the forward direction. I try to save energy by using roots as steps and branches as hand holds. Porcupines also consider energy conservation when seeking out a tree to climb. No sense in trying to climb a tree without a built-in ladder… Many of the trees in the forest begin their leafy layers way at the top, but they at least have branch stubs that wind around the lower trunk like a spiral staircase. Porcupines prefer to scale these than trees with bare trunks.

After seven hours, we break through the boundary leading to the road. We smell of dirt and cedar. Dr. Ilse checks the GPS and tells us we walked only under 3 miles….We all agree to tell the other stat: we covered an area of 77 acres.

I think back to something Dr. Ilse said earlier when I asked her why she got involved in studying porcupines. Out in the field doing other research, she said she felt some sort of presence, that there was something in the forest watching her, and she wanted to study whatever it was. The forest does have eyes–hundreds of thousands of them; total, we only had eight. As we squinted and scanned, searching for the brown, needled bodies, perhaps the porcupines were there, looking down on us…sitting quietly, munching on tree bark, watching the evening sun illuminate the forest floor.

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Today, as I opened yet another research proposal for summarizing, I had a startling revelation:

We know surprisingly little about our environment. (gasp)

As a ecology student, professors tell us about the most riveting studies in the field. We learn about climate change and biodiversity. We learn about phenotypic plasticity, and predator-prey interactions. Mind you, it is fascinating stuff. And when immersed in such cutting-edge research, it is easy to forget how little we really know. But out here, my experiences with ecology research are unfiltered. I am learning and writing about the stuff that hasn’t made it  into the textbooks. In fact, most of the research I am summarizing are survey studies.

Surveys? To study ecological processes? Yes, surveys–monitoring study sites and taking inventory. Let me explain. Ecologists study the interactions that occur in the environment. And by interactions, I mean everything from a bear eating a fish for dinner to anerobic bacteria adding a carbon group to mercury to form methylmercury. Before studying one of these intricate ecological processes, a scientist must first determine what exactly is in the environment–in other words, you have to survey the environment.

It may sound like a simple question, something you answer just by glancing around. But a detailed and accurate report of the diversity and abundances of species located in a specific region is hard to obtain. Animals do not typically follow a 9-5 schedule. They don’t show their faces just because you are ready with your camera, they don’t sing , grunt, or howl just because you are passing by with your audio recorder. Therefore, to record animal activity in a certain area, researchers often install stationery sound recorders or motion/light-sensitive cameras. These pieces of equipment are the eyes and ears of the project, observing and recording animal movement, feeding, nesting, mating, etc. The data collected serves as an inventory of the animals present. After surveying an area, ecologists can begin to make inferences as to the specific ecological processes occurring in the monitored ecosystem; surveying is an ecologist’s first step to understanding an ecosystem. After all, how can understand how and why an ecosystem operates if we don’t know anything about the animals–the building blocks–of the system?

And that’s why I say we know so little about our world. So many of the research proposals that I read daily call for surveys of Acadia NP’s flora and fauna. And that’s not a bad thing in any way. Inventory and monitoring work may not have the obvious “Wow!” factor of the experiments and projects that fill textbooks, but these initial efforts to explore and understand are essential; these are the projects that gather hoards of baseline data for future researchers to use for comparisons and trend analyses. And all this survey research helps me remember that ecology is a relatively new and blossoming field. I read about bats and freshwater mussels and freshwater fish and freshwater insects… all sorts of populations that need to be surveyed so that scientists have baseline data–so that they have some idea of which bats and how many mussels are out there.

Lesson learned? I am no longer the naive high schooler who closed her biology textbook believing that scientists know everything about this planet.

In fact, quite the contrary.

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Located in Tremont on the southwestern side of Mount Desert Island, the Bass Harbor Head Light sits on the side of a cliff, warning incoming boats of Bass Harbor Bar and signaling an entrance to Blue Hill Bay. It is attached to a small house that is home to a local Coast Guard family (L. Weisenfluh, July 2010)

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