Tyto alba

Barn Owls are strictly nocturnal and are seldom observed during the day unless disturbed. At night, they utter a weird, drawn-out harsh, unmelodious crythat is easily recognizable as well as startling. Thus, they are more common than many people are aware even in urban and suburban areas. Prey remains in cast food pellets of Barn Owls are highly reliable indicators of local small mammal populations. Pellets have been used extensively to study small mammal population dynamics, the economic importance of these owls, and in educational programs in schools.

DISTRIBUTION: Barn Owls are rare to locally common residents through most of Texas except in the eastern forested area and above 1500 m (5,000 ft) in the mountains of the Trans-Pecos ecoregion where they are local and rare (Lockwood and Freeman 2004). They occupy a broad range of open area habitats from urban to rural. In winter they roost in the dense foliage of junipers in open field areas (RCT).

SEASONAL OCCURRENCE: Barn Owls are year-round residents in Texas. Breeding has been reported in all months, based on eggs collected between November 13-May 16 and young in nests as early as November 13 (Oberholser 1974); clutches have been initiated every month except November and December in South Texas (Otteni et al. 1972) and clutches laid in every month except February and June in the southern Post Oak Savannah (RCT). During the latter unpublished 6-year study (1979-1984), a captive bird produced a total of 72 eggs in 17 clutches: 1 clutch in November, December, January and March; 2 clutches in April, May, August, September and October and 3 clutches in July.  These results suggest most breeding is initiated from  April to October in Texas (RCT). The breeding cycle is about 4 months in length (Marti 1992); so in Texas, 2 broods per year are easily possible and sometimes 3 broods per year are produced (Wilmer and Patrick 1987).

BREEDING HABITAT: Barn Owls nest in cavities in a variety of sites, e. g., trees, cliffs, caves, riverbanks, church steeples, chimneys, barn lofts, football stadiums, hay stacks, and nest boxes. The nest consists of a cup of shredded regurgitated food pellets (Marti 1992) and molted feathers (RCT). A captive Barn Owl produced 17 clutches over 6 years, ranging in size from  3-6 eggs, mean = 4.2, 1-4 clutches per year, mean = 2.8 (RCT).STATUS: Barn Owls have highly variable clutch sizes (2-11) laid at 2-3 day intervals with incubation beginning with the first egg and a prolonged breeding season. Therefore, they are highly adapted to maximizing annual productivity in favorable years. For example, in South Texas, the hatching success of eggs averaged 54.9% (2.7 chicks per nest, average clutch of 4.9 eggs) over a 7-year period, while an average of 2.5 chicks per nest were raised in years of prey abundance, compared with 1.0 chicks per nest during years of prey scarcity (Otteni et al. 1972).

Analysis of Christmas Bird Count data for Texas (Stewart 1980) showed an increase percentage of counts reporting Barn Owls: 8.3% (1952-1956) and 23.6% (1975-1977). However, during the later period there were about 3 times as many counts; so, the population may have been relatively stable. North American Breeding Bird Survey data for Texas (Sauer et al. 2005) are too few to provide reliable trend data.

Literature cited.

Lockwood, M. W. and B. Freeman. 2004. The TOS handbook of Texas birds. Texas A&M. University Press, College Station.

Marti, C. D. 1992. Barn Owl (Tyto alba).The Birds of North America, No. 1 (A. Poole, P. Stettenheim, and F. Gill, eds.). The Birds of North America, Inc., Philadelphia,PA.

Oberholser, H. C. 1974. The bird life of Texas. University of Texas Press, Austin.

Otteni, L. C., E. G. Bolen, and C. Cottam. 1972. Predator-prey relationships and reproduction of the barn owl in southern Texas. Wilson Bull. 84: 434-438.

Sauer, J. R., J. E. Hines, and J. Fallon. 2005. The North American Breeding Bird Survey, results/analysis 1966-2005. Version 6.2.2006. USGS Patuxent Wildl. Res. Cnt., Laurel, Maryland. http://www.mbr-pwr.usgs.gov/bbs/bbs.html.

Stewart, P. A. 1980. Population trends of Barn Owls in North America. Amer. Birds 34: 698-700.

Wilmer, M. C. and R. E. Patrick. 1987. Continuous breeding at a Barn Owl nest in Texas. Southwest. Nat. 32: 402-403.