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Eastern Screech-Owl
(Megascops asio)
By Liz Yaslik NYC Ecology Wiki
About the Owl
Small in size among other “eared” owlsNocturnal raptorUsually red or gray in colorFound in suburban and rural areasNon- migratory (stays relatively close to
home area)
Flickr Photo by Bobtravis
Habitat
Found in suburban and rural areasCavity nester but do not create the cavities
themselvesLives in many parks in New York CityWilling to use nest boxes placed in parks
Screech Owl in Nest Box
Flickr Photo by Gilintx
Central Park Reintroduction
Native to Central Park for decadesDecrease in population from 1930s-1950sNew York City Urban Park Rangers worked to
reintroduce the owl into the park1998- NYCUPR released 6 owls into Central
Park -the owls were not equipped with monitoring
devices2001 & 2002- NYCUPR released 32 owls into
Central Park- 30 of the owls were equipped with radio
transmitters
New York City
Central Park
Flickr Photo by Jimbowen0306
Central Park Reintroduction
Released owls were found to have 23% survival rate
Suggests that about 77% of owls died or left the area
Owl deaths due to lack of food, predation, impact with objects, or rodenticide poison
2003- None of the 7 owls released in 1998 were found
7 owls from the 2001-2 release remained in the park
Flickr Photo by Dobak
Tracking the Owls
Owls were banded and equipped with radio transmitter backpacks
One month after 2001 release, 12 of 17 birds equipped with radio backpacks had been separated from backpacks
By 2003 all transmitter batteries had diedCentral Park bird watchers contacted
researchers about sightingsCall surveys using owl calls Collecting owl pellets to locate
Eastern Screech Owl Sightings Since 2001
Map Created By Liz Yaslik using Google Earth
Problems with Reintroduction
Most of the owls had slipped out of transmitter packs
Batteries of packs diedA decrease in bird watchers could lead to a
decrease in bird sightings, not necessarily a decrease in owls
Possible Causes of Owl Decrease
Lack of males or females, slowing reproduction rates
Poor weather conditionsIncrease in owl predatorsCollision of owls with other structuresHabitat or cavity destruction/competitorsFewer bird watchers
Red Phase Eastern Screech Owl
Flickr Photo by rbs10025
Importance of Reintroduction
Maintain biodiversity in New York CityNecessary for park ecosystemCreate breeding pairs
Click to play virtual tour
Personal Observations
Relatively difficult to track the owlsRadio transmitters are not reliableMost owls left Central Park area, the owls
may know which areas are best
Recommendations
Since 77% of reintroduction population left the area, discontinue reintroduction
Research why owls choose other areasKeep track of number of males and femalesCheck availability of owl habitats, add more
nest boxes if necessaryTrack the owls’ available food sources and
reproduction rates
Bibliography
Bibliography Andrle, Robert F. 1987. The Atlas of Breeding Birds in New York State. Ed. Janet R. Carroll. Ithaca: Cornell University Press. Audubon New York. Audubon Sharon: Resident Animals, Our Resident Screech Owls. http://www.audubon.org/local/sanctuary/sharon/plant_animal/EasternScreechOwl.html. Belthoff, James R. 1993. Home Ranges of Adult and Juvenile Eastern Screech-Owls: Size, Seasonal Variation and Extent of Overlap. J. Raptor Res. 27: 8-15. DeCandido, Robert. 2002. "The Screech-Owls of Central Park." Birder's World 16, no. 6: 58. Academic Search Complete, EBSCOhost (accessed March 1, 2009). DeCandido, Robert. 2005. History of the Eastern Screech-Owl (Megascops asio) in New York City 1867-2005. Urban Habitats 3.1 (2005): 1-17. Gehlbach, F.R. 1995. Eastern screech-owl (Otus asio). In Poole, A. & F. Gill, (Eds.) The birds of North America (No. 165). Philadelphia: Academy of Natural Sciences; Washington, DC: American Ornithologists' Union. Nagy, Christopher. “The Eastern Screech Owl Reintroduction Program in Central Park, New York City: Habitat, Survival, and Reproduction” (M.S. Biology Thesis, Fordham University, 2004), 1-46. New York City Department of Parks and Recreation. The Daily Plant: Screech Owls Return to Central Park. http://www.nycgovparks.org/parks/prospectpark/dailyplant/11498. Robbins, Chandler S., Bertel Bruun, and Herbert S. Zim. 1966. A Guide to Field Indentification: Birds of North America. New York: Golden Press. Sibley, David A. 2001. National Audubon Society: The Sibley Guide to Bird Life and Behavior. Eds. Elphick, Chris, John B. Dunning Jr. New York: Alfred A. Knopf, Inc.