Eastern Screech-Owl

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.