Do wolf howls change with the seasons?

A wolf from Yellowstone's Druid Pack mid-howl (Photo: NPS Photo)
A wolf from Yellowstone’s Druid Pack mid-howl (Photo: NPS Photo)

Recently, the Acoustic Atlas entered into a new partnership with the National Park Service and its publication Yellowstone Science. Over the next two years, radio reporter and science editor Jennifer Jerrett will be producing a podcast series featuring new scientific research in the park. These podcasts will be jointly featured by the Park Service and the Acoustic Atlas, along with many of Jerrett’s Yellowstone field recordings.

Look for these fascinating stories and sounds in the coming months. Meanwhile, take a listen to Jerrett’s story this week for the national radio program Living on Earth. It features researchers Doug Smith and John Theberge, who are investigating how wolf howls may change with the seasons. “People come from all over the world to see and hear wild wolves in Yellowstone,” reports Jerrett. “And this latest research into wolf ecology, communication, and behavior, offers an opportunity to move further, beyond seeing and hearing, to take another tiny step closer toward understanding the mind of the wolf.”

Listen to the full story on PRI’s Living on Earth.

Can robins hear worms?

American Robin. Photo by Brocken Inaglory. Creative Commons Attribution Share Alike 4.0 International license.
American Robin. Photo by Brocken Inaglory. Creative Commons Attribution Share Alike 4.0 International license.

Next time you see a robin on your lawn, take a look at how it catches worms. At times it will appear to cock its head and listen to the ground. Naturalists have suspected since the 1800s that robins can actually hear worms moving beneath the soil. Years ago, two Canadian biologists devised a series of experiments to test the theory. Continue reading “Can robins hear worms?”

NPS maps the nation’s quietest places

Noise map from the National Park Service.
Sound map courtesy of the National Park Service.

The National Park Service has released a new map showing human-caused noise levels at parks across the nation. Yellowstone National Park shows up as one of the quietest parks, according to CityLab, which reported on the map presented at last week’s meeting of the American Association for the Advancement of Science (AAAS) in San Jose, California. The map is based on 1.5 million hours of sound level measurements conducted by the agency’s Natural Sounds and Night Skies division.  In the coming months, the library’s Acoustic Atlas will be collaborating with the National Park Service to record sounds and sound-related stories from Yellowstone and surrounding areas.

View the map at Science magazine. 

Read an abstract of the presentation by the National Park Service.

 

Voices of Yellowstone National Park

There are some great winter images and sounds of Yellowstone National Park in this video (click on the link below) from the National Park Service. See how the agency has identified natural sounds as a protected resource at parks throughout the United States:

yellowstone_indepth_screenshot

You can hear many recordings from Yellowstone on the library’s Acoustic Atlas. 

The hawk

Juvenile Red-tailed Hawk, courtesy of USFWS; photographer: Keenan Adams
Juvenile Red-tailed Hawk, courtesy of USFWS;
photographer: Keenan Adams

You might notice that many of the sounds on the library’s Acoustic Atlas are credited to Kevin Colver. Kevin is one of the pre-eminent wildlife recordists in the United States. He is co-author of the Stokes Field Guide to Bird Songs: Western Region and has captured the calls of just about every bird known to occur in the West. He is also responsible for one of the most famous animal sound recordings ever made. Continue reading “The hawk”

Squeaky snow

Snowflake macro shot, january 2012. Glass background with backlight. Photo by Alexey Kljatov. Available through a Creative Commons Attribution-NonCommercial 2.0 Generic license.
Snowflake macro shot, january 2012. Glass background with backlight. Photo by Alexey Kljatov. Available through a Creative Commons Attribution-NonCommercial 2.0 Generic license.

Have you ever wondered why snow sometimes squeaks underfoot?

When you step on snow, you put pressure on it. Pressure causes heat. At temperatures above 14 degrees Fahrenheit, the pressure from your boot heats up the snow below it and melts it. This causes the snow to “flow” on a minuscule amount of liquid, making a relatively quiet sound. According to the University of Wisconsin-Madison website WxWise, this is how ice skates work. The pressure from the skates melts some of the ice, and the skater slides along the liquid.

But if the air temperature is below 14 degrees Fahrenheit, the pressure from your step does not create enough heat to melt the snow, and the ice crystals rub against each other, making a squeaking sound.

Here is the sound of my shoes sliding and crunching on packed snow when the temperature outside was 13 degrees Fahrenheit:

 

Winter bat recordings

By U.S. Fish and Wildlife Service Headquarters [CC BY 2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons.

Bats are known as warm weather creatures, but did you know that they can be active throughout the winter? Biologists at the Montana Natural Heritage Program along with a coalition of partners have been monitoring bats year-round and have recorded their echolocations during some of the year’s coldest months.

The MSU Library’s new Acoustic Atlas received this January 4th, 2013 recording of a Big Brown Bat near the Continental Divide on the Big Hole River in southwest Montana. The original recording was above the range of human hearing, but was slowed down by 70% to make it audible.

Very little is known about bat behavior during the winter. Bats are much less energetic this time of year, but some species like the Big Brown Bat and Western Small-footed Myotis are known to venture out in search of water and may even be foraging during portions of the winter as well.

Biologists are monitoring bats in Montana to increase their understanding of both winter and summer roosts and baseline activities during typical hibernation periods. They hope to understand the health of Montana’s bat populations and assess potential threats such as white-nose syndrome. That disease has not yet reached Montana, but is devastating bat populations across North America.

Visit the Acoustic Atlas to hear the sounds of a wide range of animal species from Montana and the Western United States.