Music of the Night
Christina Collins | December 2019
It was about 12:00 a.m. on a warm night in late spring and I was creeping along in my car on the Blue Ridge Parkway on the backside of Grandfather Mountain in North Carolina. I had all of the windows down and the volume on my radio turned all way up. I wasn’t listening to what most people would consider music but is music to my ears. I was playing the mating call of the Northern Saw-whet owl. I have been fascinated by birds since a child and have loved these owls since learning about them many years ago. I knew they live in the area and since moving to Boone, I’ve been determined to hear and eventually, see one.
Northern Saw-whet owls (Aegolius acadicus) are the one of the most abundant owl species in the United States and are the smallest species of owl found on the east coast. These owls stand about 7 inches tall and have rounded, large heads with no ear tufts, yellow irises, chestnut-brown body, and a white underbelly with chestnut-brown spots or hatching. There are two subspecies of Northern Saw-whets, A. acadicus which breeds across Canada, parts of the West coast and in the southern Appalachian Mountains and A. brooksi which is only found on the Queen Charlotte Islands, British Columbia.
There is an isolated subpopulation of Northern Saw-whet owls that lives on Grandfather Mountain and I was hoping to hear their elusive hoots this night. Their hoots are high pitched, monotoned and sound like a repetitive tooting. As I drove slowly down the Parkway I would play the call through my car speakers then turned it down and anxiously listen. If I didn’t hear anything, I moved forward 300 feet or so along the forest edge and repeated the process. The call of the male Northern Saw-whet can be heard from about one half a mile away, but I wanted to be cautious. I didn’t want to miss out on hearing an owl calling back to me.
These small owls are considered forest specialists and rely heavily on coniferous trees for their habitat. The Northern Saw-whets in the Southern Appalachians specifically like Red spruce and Frasier fir as their habitat. These trees are considered to be glacial relics and are rare in the southeast because as the ice sheets retreated the trees could only survive at elevations over 4,400 feet. This meant that the only areas the trees remained after the ice fully retreated was on the higher peaks of the Appalachian Mountains. The combination of tree species and elevation make Grandfather Mountain an ideal home for the Northern Saw-whet owl.
The spruce-fir forest is the second most endangered ecosystems in the United States which is problematic for the Northern Saw-whet owls residing in these forests. Habitat loss and fragmentation are two of the main threats to the Northern Saw-whet. Though the species is able to hunt in forest edges, edges leave fewer perching locations, have less prey and make them more accessible to larger predators such as the Great horned owl. In the Southern Appalachian region approximately 90% of the virgin spruce-fir forests have been logged, clear-cut or slash-burned. Additionally, the introduction of the balsam wooly adelgid (Adelges piceae), an exotic pest accidentally introduced on imported trees from Europe, began to kill the spruce-fir trees in the 1970’s. Combine the effects of logging, clear-cutting, and slash-burn with the introduction of an exotic pest and you are left with patches of habitat on the peaks of mountains.
The owls in the Southern Appalachians are isolated to islands of habitat on the peaks of these mountains. As global temperatures continue to rise, the spruce-fir trees they rely on will migrate up in elevation in search of cooler temperatures. At some point they will not be able to move up any further. A friend of mine is an employee of Grandfather Mountain Stewardship Foundation, the private side of the mountain, and she is part of an initiative to help save the spruce-fir habitat on the mountain. The goal of this initiative is to plant more Red-spruce trees on the mountain in hopes to save this precious ecosystem and the little owls that need them to survive.
The Northern saw-whet owl is currently being affected by two of the nine planetary boundaries. Climate change and land use change. The concept of planetary boundaries was put into place to keep humans in check. This set of boundaries that we should not cross is like a “keep off the grass” sign. It is not the end of the world if you step on the grass but if many people continuously step the grass, it will eventually die. The nine planetary boundaries act in the same way, they are a set of guidelines we should stick to but if we do not, it will not start an apocalypse. At least not immediately. Humans have already overstepped our own limits on three of these nine boundaries. One of which is affecting the Northern saw-whet owl. Climate change, if unchecked, will have harmful effects on the species by forcing the spruce-fir forests further up in elevations. The other planetary boundary that is affecting the Northern Saw-whets is change in land-use. Fragmenting and clearcutting alter the suitability of a forest to the owls. Humans have not crossed this boundary yet, but we are dangerously close.
If global temperatures do continue to rise and the spruce-fir trees migrate so far up in elevation that they go extinct in the Southern Appalachians, so will the Northern saw-whet owl. I never did hear an owl calling back to me that night this summer. I went back out one more time a few weeks later, again playing the mating call in hopes of hearing an owl call back to me. Unfortunately, I did not hear one that night either though. Now that fall has settled in, I know that I will have to wait until next spring to hear that sweet music.
Sources
Hinam, H. L., & St. Clair, C. C. (2008). High levels of habitat loss and fragmentation limit reproductive success by reducing home range size and provisioning rates of Northern saw-whet owls. Biological Conservation, (2), 524. Retrieved from http://search.ebscohost.com.proxy006.nclive.org/login.aspx?direct=true&db=edscal&AN=edscal.20169934&site=eds-live&scope=site
Johnsgard, P. A. (1988). North American owls: Biology and natural history. Washington: Smithsonian Institution Press. 231-237.
Marks, J. S., Nightingale, A., & McCullough, J. M. (2015). On the Breeding Biology of Northern Saw-whet Owls ( Aegolius acadicus). Journal of Raptor Research, 49(4), 486–497. https://doi-org.proxy006.nclive.org/10.3356/rapt-49-04-486-497.1
Milling, Timothy C.; Rowe, Matthew P.; Cockerel, Bennie L.; Dellinger, Timothy A.; Gailes, Johnny B.; Hill, Christopher E. (1997). Population densities of northern Saw-whet Owls (Aegolius acadicus) in degraded boreal forests of the southern Appalachians. In: Duncan, James R.; Johnson, David H.; Nicholls, Thomas H., eds. Biology and conservation of owls of the Northern Hemisphere: 2nd International symposium. Gen. Tech. Rep. NC-190. St. Paul, MN: U.S. Dept. of Agriculture, Forest Service, North Central Forest Experiment Station. 272-285.
Noss, R. F., LaRoe, E. T., & Scott, J. M. (1995). Endangered ecosystems of the United States [microform] : a preliminary assessment of loss and degradation / by Reed F. Noss, Edward T. LaRoe III, and J. Michael Scott. Washington, D.C. : U.S. Dept. of the Interior, National Biological Service, 1995. Retrieved from
http://search.ebscohost.com.proxy006.nclive.org/login.aspx?direct=true&db=edsgpr&AN=edsgpr.000448013&site=eds-live&scope=site
Rockström Johan, Steffen Will, Noone Kevin, Persson Åsa, Chapin F. Stuart III, Lambin Eric,
Lenton Timothy M., et al. “Planetary Boundaries : Exploring the Safe Operating Space for Humanity.” Ecology and Society 14, no. 2 (2009). http://search.ebscohost.com.proxy006.nclive.org/login.aspx?direct=true&db=edsjsr&AN=edsjsr.26268316&site=eds-live&scope=site.
Christina Collins | December 2019
It was about 12:00 a.m. on a warm night in late spring and I was creeping along in my car on the Blue Ridge Parkway on the backside of Grandfather Mountain in North Carolina. I had all of the windows down and the volume on my radio turned all way up. I wasn’t listening to what most people would consider music but is music to my ears. I was playing the mating call of the Northern Saw-whet owl. I have been fascinated by birds since a child and have loved these owls since learning about them many years ago. I knew they live in the area and since moving to Boone, I’ve been determined to hear and eventually, see one.
Northern Saw-whet owls (Aegolius acadicus) are the one of the most abundant owl species in the United States and are the smallest species of owl found on the east coast. These owls stand about 7 inches tall and have rounded, large heads with no ear tufts, yellow irises, chestnut-brown body, and a white underbelly with chestnut-brown spots or hatching. There are two subspecies of Northern Saw-whets, A. acadicus which breeds across Canada, parts of the West coast and in the southern Appalachian Mountains and A. brooksi which is only found on the Queen Charlotte Islands, British Columbia.
There is an isolated subpopulation of Northern Saw-whet owls that lives on Grandfather Mountain and I was hoping to hear their elusive hoots this night. Their hoots are high pitched, monotoned and sound like a repetitive tooting. As I drove slowly down the Parkway I would play the call through my car speakers then turned it down and anxiously listen. If I didn’t hear anything, I moved forward 300 feet or so along the forest edge and repeated the process. The call of the male Northern Saw-whet can be heard from about one half a mile away, but I wanted to be cautious. I didn’t want to miss out on hearing an owl calling back to me.
These small owls are considered forest specialists and rely heavily on coniferous trees for their habitat. The Northern Saw-whets in the Southern Appalachians specifically like Red spruce and Frasier fir as their habitat. These trees are considered to be glacial relics and are rare in the southeast because as the ice sheets retreated the trees could only survive at elevations over 4,400 feet. This meant that the only areas the trees remained after the ice fully retreated was on the higher peaks of the Appalachian Mountains. The combination of tree species and elevation make Grandfather Mountain an ideal home for the Northern Saw-whet owl.
The spruce-fir forest is the second most endangered ecosystems in the United States which is problematic for the Northern Saw-whet owls residing in these forests. Habitat loss and fragmentation are two of the main threats to the Northern Saw-whet. Though the species is able to hunt in forest edges, edges leave fewer perching locations, have less prey and make them more accessible to larger predators such as the Great horned owl. In the Southern Appalachian region approximately 90% of the virgin spruce-fir forests have been logged, clear-cut or slash-burned. Additionally, the introduction of the balsam wooly adelgid (Adelges piceae), an exotic pest accidentally introduced on imported trees from Europe, began to kill the spruce-fir trees in the 1970’s. Combine the effects of logging, clear-cutting, and slash-burn with the introduction of an exotic pest and you are left with patches of habitat on the peaks of mountains.
The owls in the Southern Appalachians are isolated to islands of habitat on the peaks of these mountains. As global temperatures continue to rise, the spruce-fir trees they rely on will migrate up in elevation in search of cooler temperatures. At some point they will not be able to move up any further. A friend of mine is an employee of Grandfather Mountain Stewardship Foundation, the private side of the mountain, and she is part of an initiative to help save the spruce-fir habitat on the mountain. The goal of this initiative is to plant more Red-spruce trees on the mountain in hopes to save this precious ecosystem and the little owls that need them to survive.
The Northern saw-whet owl is currently being affected by two of the nine planetary boundaries. Climate change and land use change. The concept of planetary boundaries was put into place to keep humans in check. This set of boundaries that we should not cross is like a “keep off the grass” sign. It is not the end of the world if you step on the grass but if many people continuously step the grass, it will eventually die. The nine planetary boundaries act in the same way, they are a set of guidelines we should stick to but if we do not, it will not start an apocalypse. At least not immediately. Humans have already overstepped our own limits on three of these nine boundaries. One of which is affecting the Northern saw-whet owl. Climate change, if unchecked, will have harmful effects on the species by forcing the spruce-fir forests further up in elevations. The other planetary boundary that is affecting the Northern Saw-whets is change in land-use. Fragmenting and clearcutting alter the suitability of a forest to the owls. Humans have not crossed this boundary yet, but we are dangerously close.
If global temperatures do continue to rise and the spruce-fir trees migrate so far up in elevation that they go extinct in the Southern Appalachians, so will the Northern saw-whet owl. I never did hear an owl calling back to me that night this summer. I went back out one more time a few weeks later, again playing the mating call in hopes of hearing an owl call back to me. Unfortunately, I did not hear one that night either though. Now that fall has settled in, I know that I will have to wait until next spring to hear that sweet music.
Sources
Hinam, H. L., & St. Clair, C. C. (2008). High levels of habitat loss and fragmentation limit reproductive success by reducing home range size and provisioning rates of Northern saw-whet owls. Biological Conservation, (2), 524. Retrieved from http://search.ebscohost.com.proxy006.nclive.org/login.aspx?direct=true&db=edscal&AN=edscal.20169934&site=eds-live&scope=site
Johnsgard, P. A. (1988). North American owls: Biology and natural history. Washington: Smithsonian Institution Press. 231-237.
Marks, J. S., Nightingale, A., & McCullough, J. M. (2015). On the Breeding Biology of Northern Saw-whet Owls ( Aegolius acadicus). Journal of Raptor Research, 49(4), 486–497. https://doi-org.proxy006.nclive.org/10.3356/rapt-49-04-486-497.1
Milling, Timothy C.; Rowe, Matthew P.; Cockerel, Bennie L.; Dellinger, Timothy A.; Gailes, Johnny B.; Hill, Christopher E. (1997). Population densities of northern Saw-whet Owls (Aegolius acadicus) in degraded boreal forests of the southern Appalachians. In: Duncan, James R.; Johnson, David H.; Nicholls, Thomas H., eds. Biology and conservation of owls of the Northern Hemisphere: 2nd International symposium. Gen. Tech. Rep. NC-190. St. Paul, MN: U.S. Dept. of Agriculture, Forest Service, North Central Forest Experiment Station. 272-285.
Noss, R. F., LaRoe, E. T., & Scott, J. M. (1995). Endangered ecosystems of the United States [microform] : a preliminary assessment of loss and degradation / by Reed F. Noss, Edward T. LaRoe III, and J. Michael Scott. Washington, D.C. : U.S. Dept. of the Interior, National Biological Service, 1995. Retrieved from
http://search.ebscohost.com.proxy006.nclive.org/login.aspx?direct=true&db=edsgpr&AN=edsgpr.000448013&site=eds-live&scope=site
Rockström Johan, Steffen Will, Noone Kevin, Persson Åsa, Chapin F. Stuart III, Lambin Eric,
Lenton Timothy M., et al. “Planetary Boundaries : Exploring the Safe Operating Space for Humanity.” Ecology and Society 14, no. 2 (2009). http://search.ebscohost.com.proxy006.nclive.org/login.aspx?direct=true&db=edsjsr&AN=edsjsr.26268316&site=eds-live&scope=site.