A key research paper from National Park Service and Colorado State scientists has been published in Trends in Ecology and Evolution.  The paper, which got a lot of press when it was first made available online in the fall, introduces two key new metrics for measuring the effects of noise on animals.  The first, “alerting distance,” is the distance at which sounds can be heard: these may be sounds made by a species to alert others to danger, or sounds made by predators (which prey animals want to hear, so as to take cover).  The second, is “listening area,” the full area around an animal in which it can hear other animals’ calls, footsteps, and wingbeats.  A key insight offered by this approach is that even moderate increases in background noise (from nearby roads, airplanes, or wind farms) can drastically reduce an animal’s listening area.  The paper, which was free while in pre-press, is now available only to subscribers to the journal or other academic journal services; an article published in Park Science magazine and free to view online introduces much of the same material (be sure to click on the links to the figures, as they illustrate the concepts very well): see the article here, and check out the entire special soundscapes issue of Park Science here.

A very good article in the Aspen Times introduces the research, and includes many extremely insightful quotes from the researchers.  Go read the whole article! Three bits that are especially worth keeping mind are:

• “The male sage grouse, in its mating displays, produces high-frequency popping sounds and swishing sounds,” Fristrup said. “It also uses a low-pitch hooting sound, which carries the farthest from the display area as a long-distance advertisement. The danger is, it doesn’t take a lot of noise to substantially reduce the range at which females or other males could hear that low-frequency hoot. So the attraction radius of the display ground could contract substantially with the inability to hear a hoot.” The authors note that some species can reduce the effects of masking by shifting their vocalizations. This is especially true when members of a species are communicating with each other. However, when the sounds a species depends on emanate from another species (such as a mouse burrowing under the snow, which an owl needs to hear as it hunts), there is less room for compensation.
• Carnivores like lynx, who sit at the top of the food chain, can be particularly sensitive to habitat degradation of any type — including auditory — since each individual requires a huge hunting territory. “If one part of the range of a top-level predator is compromised, it may not take much to squeeze it out,” Fristrup said.
• Contrary to what one might expect, noise is not always more disruptive when it’s louder. Snowmobiles or cars, for example, might be less disruptive to elk or deer than a hiker or cross county skier would be. “There’s pretty good evidence that so-called quiet use can disturb wildlife. If it’s a noisy source, the animal perceives it a long way off and can track its progress. There are no surprises, and it can go on feeding or doing whatever else. A quiet sound, like a snowshoer’s footstep, is only perceptible when it is very close, potentially startling the animal,” Fristrup said.

To read AEI’s detailed lay summary of the research paper, published here in December, see this link.

Zion National Park is gearing up to begin incorporating soundscape planning into their management priorities.  Park Superintendent Jock Whitworth has announced two open houses in March on the topic, and public comments are being accepted until April 9 as part of an initial information-gathering stage.  This will inform the drafting of a Soundscape Management Plan Environmental Assessment, which will aim to to link soundscape management to the existing park management direction, and “ensure that natural soundscapes are protected for present and future generations.”

Zion NP. Photo: David Iliff

To participate in the public comment process, see this National Park planning page.

You can also learn more about the Park Service’s efforts to protect natural soundscapes by visiting the NPS Natural Sounds Program website, and by reading this 2007 review of Park Service soundscape management by sound consultant Nick Miller.

This one slipped past me when it happened last June, but it’s well worth noting now.  Complicating assessments of the risks of bird deaths at wind farms is the fact that two-thirds of migrating bird species migrate mainly at night; Cornell’s Bioacoustics Research Program, which has already done groundbreaking work in elephant communication and underwater listening systems, has proposed that combining their autonomous recording devices with radar data could provide the missing information on exactly when and where concentrations of migrating birds may exist near proposed wind farms.

A compelling animation highlights the large-scale patterns: The color-coded radar map illustrates areas of precipitation over the coasts as well as vast movements of tens of millions of birds, bats and insects across the entire country. In the densest areas, the color-scales indicate movement of 2,000 birds per cubic kilometer. ”You’re talking about a massive movement of birds overnight,” said post-doctoral fellow Andrew Farnsworth.

Radar imagery of night-migrating birds, bats, and insects

Although radar data can show the magnitude, location, timing, speed and direction of migration patterns and provide information on key stopover sites, they do not identify types of birds or accurate flight altitudes, Farnsworth said. But combining radar data with data from flight call recordings and tracking tags on birds could allow researchers to identify many species in key areas. Bioacoustics program director Chris Clark added that recorders are cost effective, can be automated for many months at remote sites, provide data on many species simultaneously, increase the probability of tracking secretive and endangered species, and could allow regulatory agencies to develop computer models to assess risks to birds from wind turbines. He acknowledged, however, that using such acoustic technology could produce a massive “data crunch”; a single microphone over a three-to-four-month period can record 120 to 140 gigabytes of data, so data from several hundred microphones would be too much to process without advanced software. Also, researchers would need to better recognize the wide variety of flight calls and learn to integrate data from radar with those from acoustics and tracking tags, he added. More research is needed, Clark stressed, to determine at what altitudes species tend to fly and whether birds sense turbine blades and avoid them.  Read full account of the presentation in the Cornell Chronicle, with link to the radar map animation.

In the most promising development yet in using acoustics to deal with the spread of bark beetles in the American and Canadian west, researchers at Northern Arizona University have found that some beetles can be disrupted by playback of other beetle sounds. The tiny insects make squeaking noises as they tunnel through trees; the researchers have been manipulating the beetle sounds, which are above human hearing, and playing them back to the insects. The results drive them buggy: They attack each other, scamper in circles rather than straight lines and have tried to gnaw their way through Plexiglas covering a cross section of a tree in a lab in Flagstaff, Ariz.

A great article in The Missoulan included these tidbits from NAU researchers Richard Hofstetter and Reagan McGuire, Skye Stephens, an entomologist with the Colorado State Forest Service, and David Dunn, a sound artist who discovered and first recorded the beetle sounds:

“One of the questions is if we could effectively remove them from a particular tree or set of trees, where do they go, what happens to them?” Stephens said. “I’m very excited to see what happens next” with the research. Hofstetter and McGuire are eager to run tests on the ground to answer questions like that. Working with Dunn, they have applied for a patent on a device that pumps in noise to throw off the beetles’ destructive course. Hofstetter said the sounds are at a frequency that shouldn’t bother other species. The work has been a side project for the professor, who has struggled to scrape together funding for the research. McGuire is volunteering his time. ”We’re hoping it’s going to lead to a whole new field,” Hofstetter said.

David Dunn, who has traveled the world collecting sounds of nature for his compositions, first started recording the inner life of trees in 2004. He took the kind of small microphone used in greeting cards to record and play, fastened it to a recycled meat thermometer and inserted it into the tree. While concerned about the dying trees and what they signal about climate change, Dunn has become intrigued by the beetles, “an absolutely fascinating form of life. I fell in love with them,” Dunn said. “But then we’re watching them cannibalize each other. I always think, ‘How bad is this karma?’

“But if something really positive about forest health comes of it, perhaps it’s worth the price.”

Dunn’s CD, The Sound of Light in Trees, was released by EarthEar; 100% of all sales revenues are donated by Dunn and EarthEar to support the Acoustic Ecology Institute.  See more on the CD and beetle project on AEI’s website.

Ongoing research in Stellwagen Bank National Marine Sanctuary is providing ever more compelling visualizations of shipping noise and the much quieter calls of whales in the area. Scientists from Woods Hole Oceanographic Institute, NMFS, and Cornell have deployed networks of sound recorders, which allow them to track individual whales and ships and see how their sounds interact.  The Sanctuary, which contains the shipping lanes into Boston harbor, is one of the more urbanized ocean environments to be closely studied thus far.  Here, we see four panels; the top left is wind noise, bottom left is right whales, and the right hand ones show that two ships completely drown out the whales as they pass through the area. “Every day, five to six large ships move into and out of Boston, and their acoustic footprint can last for hours.” says Cornell’s Chris Clark. “As a result, the Right whales trying to make a living off Boston are losing about 80 percent of their opportunities to keep in contact every day, day after day, month after month, year after year.”

From Sciencemag.com; click to read source article

“Right whales are long-lived animals. When they were kids and teenagers, their world was normal,” Clark says. “Acoustic habitat loss is a stressor and there are multiple stressors on a species.” His team has found that the whales often no longer bother answering calls from their peers. In this world of constant noise, they wouldn’t be heard anyway. ”Their social network is constantly ripped apart,” says Clark. “In one area, noise levels are now 105 decibel where they should be 75.” Other researchers from the Right Whale Consortium found that the animals show dramatic loss in vital body fat: In some individuals, the blubber layer is thinner than normal, hinting at the possibility that they no longer find enough food due to the noise.

At conferences over the past year, project scientists have shared compelling animated sequences showing similar patterns; so far, only still images are available online. UPDATE! A recent article on this work in the journal Science (from which the Clark quotes above were drawn) has a link to a good video (note: the video has minimal interpretation. I find the upper left graph most compelling: it shows the whale call (in blue), loud near the whale and fainter as the cone spreads out; the red disc is the noise from the ship, gradually getting louder than the whale calls, until it drowns out the whale everywhere except very nearby). For more on this important research, see this recent article which contains two stills from a different animation, this section of the Stellwagen website on the passive acoustic monitoring program,  this movie which visualizes the movements and sounds of two nearby and some more distant humpback whales, and hear this local radio piece on the Stellwagen research.

The most recent issue of the Marine Ecosystem and Management newsletter (download here) has several features that offer a good sense of current efforts to adopt Marine Spatial Planning (MSP) and its related management principle, Ecosystem Based Management (ESB).  The lead article centers on reports from Massachusetts, Norway, and Germany, each oriented toward the relationship between MSP and ESB.  Shorter pieces include interrviews on related topics and direct readers to recent management plans, proposals, and reports by the US Federal Government, the State of Massachusetts, and Papahanaumokuakea Marine National Monument in Hawaii.  For more on MEAM programs and publications, see the MEAM website.

The final EIS in the Navy’s multi-year effort to get its training activities into legal compliance with NEPA requirements is heading for the finish line.  Adding to the drama, however, is the fact that the Navy is pushing to introduce active sonar training into the Gulf of Alaska—while previous EISs at other training ranges proposed continuing sonar training at or near levels that have been taking place for years, the Alaskan proposal would bring sonar training for the first time into Alaskan waters rich with marine mammal habitat.  While the Alaskan range where sonar training would take place is relatively small compared to many of the other ranges on the east and west coasts of the continental US, it is within dozens of miles of key whale habitat, and locals have expressed much concern at public hearings.  For more detail, see these links to Alaskan newspaper coverage.

Meanwhile, as the Navy completes the EIS, it has also applied for the Incidental Harassment Authorization from the National Marine Fisheries Service, which announced in early February its intention to issue a Letter of Authorization to permit Navy activities as planned from December 2010 to December 2015.  The Navy estimates that its covered activities will take individuals of 20 species of marine mammals (15 cetaceans and 5 pinnipeds) through Level B behavioral harassment. ”Further, the Navy requests authorization to take 3 individual beaked whales (of any of the following species: Baird’s beaked whale, Cuvier’s beaked whale, Stejneger’s beaked whale) annually by serious injury or mortality.” See the Navy’s IHA application here, and NMFS notice of intent to issue the LOA here.

The latest in AEI’s ongoing series of comprehensive special reports on key topics is finally done!

This one is modeled on AEI’s acclaimed annual reviews of science and policy developments in ocean noise, but focuses for the first time on wind farm noise issues.  The 30-page report covers new research, public concerns, and industry trends over the past year.

Read the report in the embedded pdf reader below, or download a pdf copy.  Click on to below the fold for a table of contents and the report’s brief Introduction.

Read the rest of this entry »

This came out in December, but I forgot to post about it then.  The National Park Service’s science magazine has published an entire issue devoted to the NPS’s soundscape studies and programs.

A couple strolls through Cathedral Grove on a quiet morning in winter when visitation is typically low. Signage at the entrance to this area reminds visitors that they are in a quiet zone. (NPS Photo/Lou Sian)

Articles include:

• Measuring and monitoring soundscapes in the national parks
• Integrating soundscapes into NPS planning
• Conserving the wild life therein–Protecting park fauna from anthropogenic noise
• Soundscapes monitoring and an overflight advisory group: Informing real-time management decisions at Denali
• Soundscape management at Grand Canyon National Park
• Generator noise along the US-Mexico border
• A program of research to support management of visitor-caused noise at Muir Woods National Monument

And, as they say, much, much more!  See the issue online here; from there, you can read every article in full. Note that the html views break each article into several separate pages, but you can also view in a “printer-ready” format that loads the entire article into a FlashPaper format, or you can view or download the full articles as pdfs.

Very cool collection of various approaches to sound mapping, recently posted at Weird Vibrations.  Here’s the first post, sharing their overview of several sound mapping models, including collaborative documentary, composition, preservation, and policy-oriented.  And here’s a follow-up post of others sent in by readers.  And to go one step further, here’s a delicious link from a commenter, to his own collection of sound maps.  And, oh, what the heck: here’s the current list of sound maps from AEI’s main site!

Paris Sound Map (click to read 1st post)

Those of you who were attracted to this particular post topic may well also enjoy checking by Weird Vibrations this week, where they’ve just begun an “open thread” on Acoustic Ecology, centered around their upcoming reviews of Gordon Hempton’s One Square Inch book, and a book on sound weapons; the initial questions posed are promisingly provocative: “ First, is understanding sound as an ecosystem practical? In other words, can this formulation help us deal with noise in a just fashion? How does the ecological metaphor sit with you? Second, does acoustic ecology’s focus on “natural” preservation make it essentially conservative? This is a charge that’s latent (if not explicit) in some recent Sound Studies work that foregrounds technology. What do you think?”

In the best overview I’ve yet seen of efforts to solve the “problem” of electric cars being so quiet, the New York Times Wheels blog provides a tour of the the apparently burgeoning of field sound design for these future (and increasingly, present-day) vehicles.  Most designs plan to incorporate sounds that will alert nearby pedestrians of a car nearby, but will only emit sound when the car is slow-moving (above 12 or 15 mph, tire noise will be sufficient).

A speaker embedded in the bumper of a Fisker Karma (click to read NY Times blog post)

Among the key questions is whether electric car owners will be able to customize their car’s “voice,” ala cell phone ring tones, or if they should be standardized.  So far, individual auto companies are each pursuing their own standard sounds, which could presumably become part of the “look and feel” of the car’s branding.  A Nissan engineer quoted in a September article from Bloomberg,  says that “we decided that if we’re going to do this, if we have to make sound, then we’re going to make it beautiful and futuristic.” The company decided on a high- pitched sound reminiscent of the flying cars in “Blade Runner,” the 1982 Ridley Scott film. “We wanted something a bit different, something closer to the world of art,” said the Nissan designer.  At least one acoustic design company has turned its attention to becoming the “go to” company for automakers facing this 21st century problem.  The Times blog and its accompanying article are both great reads on this fascinating – and for some anti-noise activists, frustrating – topic.

I’ve just finished reading what must be the most exciting research paper I’ve seen this year, barely nudging out a similar paper addressing terrestrial noise impacts. A small group of researchers, with Chris Clark of Cornell as the lead author, took a giant step forward in addressing the impacts of ocean noise on the communication ranges of whales.  They came up with a clear and strikingly rigorous set of new metrics that will allow researchers and ocean planners to have a much more practical picture of how numerous noise sources combine to create cumulative impacts on acoustic habitat.  The new approach centers on the “Communication Space” of individual animals, as well as groups, and provides an intuitively obvious way to both imagine and assess the effects of ocean noise – measuring the area in which an animal can hear or be heard by others of its species.

My formal “lay summary” of this paper is reprinted in full below the fold, and I encourage anyone with a deep interest in ocean noise to read through that five-paragraph overview, or to download the paper yourself.  The key takeaway for those of you with a more casual interest in these issues is that in the test case that they used to illustrate their new approach, the researchers found that shipping noise has dramatically different impacts on different species, even though all three species they studied are low-frequency communicators.  In the area off Boston Harbor that they investigated, the critically endangered right whale is by far the most affected by shipping noise: on a day when two ships passed through the area (the average is often six), right whale Communication Space was reduced by an average of 84% over the course of the day, with several hours in which they could hear and be heard in an area less then 10% of that which would be expected without shipping nearby. Since right whales call back and forth to find each other as they form groups for feeding, this is truly worrying (though the key question of how a reduced communication range actually affects animals remains unanswered).  Fin whales and humpbacks were far less dramatically affected, with their Communication Spaces reduced by just 33% and 11% respectively.

These first examples focus on the effects of low-frequency shipping noise on low-frequency communication by large whales, but this approach can easily be used to address mid- or high-frequency noise sources (sonars, airguns) and higher frequency animal sounds such as those used for echolocation, opening a vast and exceedingly useful new doorway for biologists and ocean managers, as well as the general public, to appreciate the impacts of human sounds in the sea.   (click through for complete lay summary)

Read the rest of this entry »

An ongoing research project from the National Park Service Natural Sounds Program is about to publish a groundbreaking paper that outlines the many ways that even moderate increases in human background noise can create major impacts on animals.  The study proposes a new metric for use in bioacoustics research, the “effective listening area.”  This is the area over which animals can communicate with each other, or hear other animals’ calls or movements; as might be expected, animals focus especially on listening for sounds at the very edges of audibility, so that even a small increase in background noise (from a road, wind farm, or regular passing of airplanes) can drown out sounds that need to be heard.  The authors note analyses of transportation noise impacts often assert that a 3dB increase in noise – a barely perceptual change – has “negligible” effects, whereas in fact this increased noise reduces the listening area of animals by 30%. A 10dB increase in background noise (likely within a few hundred meters of a road or wind farm, or as a private plane passes nearby) reduces listening area by 90%.

In addition to introducing this important new metric, the paper provides a good overview of previous research that has addressed the impacts of moderate noise on various animals, including bats, antelope, squirrels, and birds.  The paper will be published next year, though an “in press” version is available for download.  A recent BBC article also covered this important new work.  A full detailed lay summary of this paper, as previously published on AEI’s science research page, appears below the fold: Read the rest of this entry »

As surely as winter follows autumn, Yellowstone National Park’s annual rite of tussling over snowmobile use has arrived just on time.  After issuing a proposed 2-year winter use plan in September, and opening its arms to receive a round of public comments that likely mimic those received during the previous three attempts to settle this issue, the Park Service issued its interim rule on Friday, and on Monday, the State of Wyoming challenged it in federal court.  With the winter season due to open in December, the now-unsettled situation is a familiar one.  Improving the situation over previous years, however, Wyoming says it will not ask for an injunction to stop implementation of the new rule on the eve of the winter season, since outfitters are basically prepared for the lower numbers already.

Photo: Bob Zellar, Billings Gazette

This time, the number under dispute is 318.  That’s how many snowmobiles the new interim rule calls for; the last full NPS EIS recommended the same in 2008, though the Bush administration intervened and proposed instead that 540 be allowed.  That, of course, spurred environmental groups to challenge the rule, which was overturned by a DC federal court.  The NPS is headed back to the drawing board, and is planning a 2-year EIS process to try to resolve the issue, with the current proposed interim rule to be in place for the next two winters. Wyoming has called for NPS to revert instead to a 2004 winter use rule that allowed 720 machines per day; this rule began a tradition of spurring dueling rulings from federal courts in DC and Wyoming—the DC court saying that the number is too high to fit with NPS science findings, and WY court saying that the limits are too low—which the 2008 EIS was trying to resolve.  Yikes!

Rather than try to recount the whole sordid mess up to now, if you’re a glutton for punishment I invite you to peruse the AEIews archives or Special Report on the issue.  For local news coverage of this round in the mother of all snowball fights, see this article in the Jackson Hole Daily, and this commentary by a local environmental group urging snowmobile advocates to turn their sights toward National Forest lands around Yellowstone where, in fact, winter snowmobile enthusiasts spend the vast majority of their motor-sled time.  This AP article provides a concise history, up to this September when Federal Judge Clarence Brimmer decided that he had no standing to intervene to derail the new interim rule and impose the 2004 limit of 720 snowmobiles (in a legal thread separate from this week’s challenge, Wyoming has asked the regional Federal Appeals court to allow or urge Brimmer to address this claim UPDATE 11/24: The Appeals Court denied the appeal, agreeing with Brimmer that the original issue is moot now that NPS has issued its temporary plan).  In the meantime, let’s all pray for snow and some modicum of sanity to quiet this decade-long dispute in the next couple of years!

The newly-formed Fiji Islands Voyager Society was christened at the start of the South Pacific Pageant this week, with the dawn launch of the canoe Uto Ni Yalo (Heart of Souls).   In June of next year,  a flotilla of canoes will sail from Fiji to Hawaii to advocate the protection of our ocean environment and rekindle traditional voyaging, sailing and navigational skills.

Warriors launch canoe from beach (click for Fiji Times article)

Representing the Pacific Voyaging movement, Rawiri Patekere from New Zealand, said people of the Pacific had been the innocent victims of ocean noise pollution for years. ”And the time has come for the Pacific to unite, stand firm while they voice their concerns,” Mr Patekere said. ”The sea has been crying for years and it is time to answer that call for help.”  Recalling the words of his grandfather, he said, “when you paddle your canoe, paddle quietly.”   Director Letila Mitchell says the Wasawasa Dawn Festival celebrates Pacific Culture, and that “the Ocean Noise project will raise awareness to help stop the increase in noise pollution being brought about through shipping.”   Read more at these three Fiji news outlets.

Just a quick note to say that I did the first major update to AEI’s Special Report on wind farm noise today.  I added several key new pieces that will be familiar to regular readers of this blog.  The report aims for AEI’s typical sweet spot of providing a comprehensive yet concise overview of all the key issues, presented in a balanced way, with links to source material and advocates on all sides of the issue. The report can be viewed online here, or downloaded as a 33-page pdf here.