Recording the Sounds of Disappearing Glaciers

by Thomas Rex Beverly – a nature field recordist based in Philadelphia.

IMG_3031I spent my summer exploring the lush soundscapes of northern Montana in Glacier National Park. This was my first time recording in the Rocky Mountains and I was excited to test my field recording skills in the expansive coniferous forests and glacial valleys.

A Conservation Approach to Field Recording

I approach field recording as an act of conservation, so I wanted to capture the sounds of this stunning natural cathedral while these glaciers still remain. Of the 150 glaciers reported in 1850, only 25 remain in Glacier National Park and they could all could melt within 30 years (Wines, 2014). Given this urgency, I wanted to capture the soundscape of these stunning valleys. This ecosystem will never sound the same when the glaciers disappear.

IMG_3152.jpgTo be clear, I did not record any glacial ice or snow on this trip. The goal of this trip was to capture sounds of the flora and fauna in the glaciers’ surrounding ecosystems. A warming environment causes glaciers to melt, native species to migrate, and vegetation to die out or move to higher elevations. As the flora and fauna react to the temperature changes, the soundscape will undoubtedly change as well. It is my hope these libraries will serve as a small snapshot of this beautiful environment and preserve its unique soundscape for years to come.

Common Loons

One of my first goals upon arriving in Glacier National Park was to find Common Loons (Gavia immer) to record. The first time I heard one of their magical calls, it was as a distant echo across a large glacial lake. For a moment, I thought was hearing a wolf! When I realized the sound came from a loon, I was astounded that a bird that’s only the size of a large duck can make such a haunting and resonant call.

IMG_3045.jpgLoons can be found in pairs on small boreal lakes of North America. I learned they are active around dawn like most other birds, but will also call sporadically throughout the night. In order to get a clear loon recording, I found their nest on the lake and sat near it as close as possible to the water. This made for ideal listening as the loons’ wails resonated across the still water. Enjoy listening to some of their wails, yodels, and tremolos below:

Ruffed Grouse

After a few days focused on recording loons, I was excited to explore the rest of the park. Fortunately, I found several great spots to capture lively and unique ambiences. Soon, though, I started to hear a low thrumming sound in my recordings, like the sound of a distant lawnmower. Dismissing it as an electric generator, I turned off the recorder. “No big deal.” I thought to myself, “Generators ruin recordings all the time.” I packed up my equipment and decided to find a new spot to record.

“The generator kept following me.”

I tried five different locations, but I couldn’t get away from the hum of the generator. Frustrated, I thought I might have overlooked an industrial drilling site nearby. My entire trip would be ruined because of one incessant generator!

I went to the park ranger station to inquire about the generator hum and played the recording for the ranger on duty. Without hesitation, he exclaimed, “Oh! That’s a Ruffed Grouse!”

The park ranger went on to explain that a male grouse will attract a mate by perching on top of a hollow log and beating his wings to create a bass pulse.  To the male grouse, the log is a natural amplifier, but to the untrained ear, this all happens to sound like a generator revving up.

I was so used to avoiding man-made sounds in my nature recordings that I didn’t even think this sound could have been an animal! All hope was not lost. From then on, I stopped trying to avoid the Ruffed Grouse. Instead, I honed my microphones in on the bass thumps and brought their beautiful drumming into focus in my recordings. I even found a perfect spot at the end of a large glacial lake where the thumps were amplified by the water’s surface and carried across the lake like the loon calls!

For more information about the Ruffed Grouse, check out this video of Ruffed Grouse drumming from the Cornell Lab of Ornithology:

*Note – the bass thumps from the Ruffed Grouse is all below about 100 Hz, so it can easily be low cut out of the recording if you don’t want it in your project.


Natural Silence

Airplanes are the bane of field recordists’ lives. Luckily, air traffic in northern Montana is relatively light, as Glacier National Park’s location is away from most of the major air routes in between major North American hubs. Because of this ideal location, I was able to capture extremely long dawn choruses, that magical moment when the sun begins to rise, and all kinds of birds wake, calling into the dawn air. The majority of the NR: Active Nature library is contained in four extended dawn choruses with clips ranging from 30 to 50 minutes. This is exceedingly rare to find anywhere in the continental United States. Gordon Hempton talks at length about this in his book One Square Inch of Silence. Enjoy listening to some of those lively dawn choruses in the Northern Rockies: Active Nature demo below:


On this trip, I took every single piece of recording gear I own. While I’ve done a lot of nature recording in West Texas and New Mexico, during most of those sessions I had a house as a home base and made daily excursions to record.

This trip was my first extended, car-based field recording road trip and I found that taking all my gear was nearly unmanageable. As a result of worrying about temperature, humidity, and general care of the gear, I made fewer recordings this trip. However, since this trip, my mindset has become:

“Bring less gear. Hear more.” 

As a field recordist, I want to be fully present in the environment I am recording. I find it much easier to clear my mind and meditate if I have less gear bogging me down. I have started asking myself, “Could I get a replacement overnighted if this item broke?” In most cases, the answer is “yes.” As a result, I have packed lighter for more recent recording trips. Here is a list of used and unused gear from my Northern Rockies trip:

Unused Gear Used Gear
Sennheiser MKH 50/30 Sound Devices 702
Rycote MS Blimp Sennheiser MKH 8040 pair
GoPro and lots of accessories Rycote ORTF Blimp
DPA 4060s and accessories Manfrotto Stand
Zoom H6 and accessories MacBook Pro
Anker Battery
SD Card Reader
Aquarian Audio H2a-XLR hydrophone

Looking forward, I would rather take one set of microphones and find twenty magical places to record, than bringing three sets of mics to over-record a few easily accessible locations. With less gear, I can listen to the environment to find the perfect recording spot. Enjoy listening to some of the perfect spots in the Northern Rockies: Quiet Nature demo below:

Lessons Learned

  1. Minimalism: Bring less gear. Hear more.
  2. Talk to the local experts: I found a nesting pair of loons much faster by asking for help. A ranger pointed me toward a specific lake, and I was able to record enough calling loons for a whole library! Also, if I hadn’t asked a ranger for help I would still think that the drumming of the Ruffed Grouse was made by generators!
  3. Northern Summers: Summer days are fairly long in Northern Montana. I was pleasantly surprised to find that while other visitors to Glacier National Park would stay up past the setting sun at 10:00 pm, they would not get up for the early sunrise at 4:30 am. This was incredibly helpful for recording dawn choruses. I was able to record pristine dawn choruses in locations relatively close to other campers while they slept through the entire dawn!
  4. Spectrogram Spot Checking: I had issues with very faint generators in my recordings during this trip (not Ruffed Grouse, but actual electric generators). I’ve started quickly zooming into a range of 0-1000 Hz on the spectrogram to check for these distant machine sounds. This is much faster than checking for them by ear and then those recordings can quickly be excised or minimized with software such as iZotope’s RX. This is also a good practice in Ruffed Grouse territory, so their thumps are not confused with man-made sounds.
  5. Humidity in the Car: Humidity is a frequent problem I encounter when recording from the inside of a car, cables running out through a cracked window to the remote microphones. The window is gaff-taped to keep bugs out. One human can exhale a lot of humidity overnight. It quickly builds up on gear and windows. Keeping a battery-powered humidity sensor in the makes it easy to know when the defroster needs to be run to remove humidity.
  6. Car Engine Cooling: If you are going to sit in your car while recording, make sure you arrive at least 1-2 hours prior to recording to give all the metal in your engine and transmission time to cool. Otherwise, you will get aggravating pings every few minutes as the metal cools. Though you can also run cables far enough from the car that the pings won’t be heard, this would take at least 150+ feet of cable. I generally don’t carry enough cable to do runs that long, so I prefer to arrive early and let the car cool instead.
  7. Use dry bags instead of hard shell electronics cases: I now keep my valuable recording gear in dry bags. The dry bags are durable and perfect when paired with desiccant packs. Pelican cases are wonderful (I have several), but they shout, “I have lots of expensive gear in this case” and draw too much attention for my tastes. Dry bags look like camping gear, are much less bulky, and further help in my goal of minimalist field recording.
  8. Always keep a recorder in the tent at night: Before I even got to Glacier National Park, I encountered wildlife worth recording. On my way to Montana, I made a pit spot in North Dakota, setting up my tent for the night at a campground. I was woken up at two o’clock in the morning by something licking the picnic table in my campsite. My first reaction was panic – “BEAR!”. I had stored all my food properly in the bear box. Maybe something had been spilled on the table by a previous camper. I decided to wait it out in the tent. Five minutes slowly went by, then ten minutes, then twenty. Still, the licking continued. I finally got the nerve to unzip the tent and look out…and a 1,500-pound bison was staring right at me, less than twenty feet away! Somewhat relieved it wasn’t a bear, I decided my best move was to slowly re-zip the tent and stay still. If I startled the giant beast, he could still trample my tent without hesitation. After another agonizingly slow twenty minutes of table-licking, the bison finally lumbered off into the night. I’d left my gear in the car, so sadly I was unable to record this visit. I’ll never forget those fantastic grunting and licking sounds! Lesson learned: always keep a recorder in the tent at night.


Carbon Neutral

On the long drive home to Philadelphia, I thought about ways to reconcile the conservationist activity of recording soundscapes with the environmental impact of traveling to recording sites. Even my fuel-efficient sedan generates carbon dioxide that contributes to climate change. I calculated that my drive from Philadelphia to Montana generated one ton of CO2. I decided to purchased carbon credits for one ton of CO2 and make the trip carbon neutral. Now I was not only preserving the soundscapes of the glacial habitats of Glacier National Park, but I could also offset the carbon footprint of the recording process and slow the melting of this unique natural habitat!

Upcoming Projects

I am constantly learning from each new environment I visit. I know the deserts of the Southwest well and explored them extensively in my High Desert Series. Now I’ve gained experience in the coniferous forests and glacial valleys of the Northern Rockies. Next, I’m off to the temperate rainforests of the Pacific Northwest. I’m sure to be challenged by rain and humidity in yet another environment, the Olympic Peninsula, which receives over two hundred inches of annual rainfall in some places. As always, I’m excited to explore a new ecosystem with my microphones and capture the wonderful sounds nature has to offer.

Buy Northern Rockies SFX

All Northern Rockies Libraries are on sale through 2/7/2018.

Northern Rockies Series.jpg


Wines, Michael. “Climate Change Threatens to Strip the Identity of Glacier National Park.”The New York Times, The New York Times, 22 Nov. 2014,


One thought on “Recording the Sounds of Disappearing Glaciers

  1. Nice story Tom, I enjoyed the perspective of audio problems/solutions compared to my video experiences. I look forward to hearing your Olympics tracks.


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