By Ashley Archer
All of those animal sounds you hear when walking through a forest, like birds calling, frogs croaking, and insects chirping, are used by wildlife to communicate a variety of messages. In addition to sounds that are within the hearing range of your typical human, some wildlife species communicate in the range that we can’t hear. In order to use these sounds to study wildlife, we need help from an acoustic monitor.
Scientists have successfully used acoustic monitors to collect data on wildlife populations. These monitors are able to record sounds within a wide range of frequencies including those outside of our hearing range. This non-invasive technique is being used more and more by wildlife biologists and scientists because we can evaluate species presence in an area (occupancy) and potentially document change over time related to modifications of habitat or other changes that might impact a species. Much of the research using this technology has focused on surveying for bat species by identifying the unique characteristics of their calls, but newer applications include monitoring amphibian populations using their unique breeding calls and determining songbird diversity in a forest stand.
The northern flying squirrel also uses calls to communicate among individual squirrels. This species produces unique high-frequency calls that have led to the use of non-invasive acoustic monitoring for this species. We used acoustic monitors this past summer in the Spruce Mountain Grouse Management Area Project near Spruce Knob Lake and in areas near Davis to survey for northern flying squirrels and compare their detection to vegetation and habitat characteristics. Refining this technique will allow for larger areas of forest to be monitored reducing the need for direct handling of flying squirrels as well as reducing the cost and effort needed to study this rare species.
Check out these audio snippets that researchers used when conducting this flying squirrel research in the Spruce Mountain project area this past summer