Seiurus aurocapilla is a large, thrushlike warbler, that is approximately 5.75 - 6 inches (14 -- 15 cm) long and has a mass of approximately 21 grams. It is olive to olive-gray above and white below, with bold black spotting on the underparts aligned into rows. Adult S. aurocapilla has a bold white eye-ring, thin blackish malar stripe, and blackish lateral crown stripes bordering a dull orange central crown stripe. The eye of S. aurocapilla is large and thrushlike, and the legs are pinkish, stout, and long. Males and females have similar plumage. Immature S. aurocapilla are less brightly colored, often with broader olive crown stripes. (Dunn & Garrett, 1997; Van Horn & Donovan, 1994)
Seiurus aurocapilla breeds throughout much of the eastern United States and Canada. Along the east coast, S. aurocapilla ranges from southeastern Newfoundland in Canada to northern North Carolina. In Canada, it can be found as far west as central and northern Alberta and as far north as James Bay in the east and southern Northwest Territories in the west. In the United States, S. aurocapilla ranges west to central Minnesota down to western Arkansas, extending in some places west to central Montana and Colorado. Seiurus aurocapilla winters in Mexico, Central America, and the Caribbean, although on some occasions will overwinter in the southeastern United States west to Texas. (Dunn & Garrett, 1997; National Geographic, 1999)
Seiurus aurocapilla is found in mature deciduous or mixed broadleaf-conifer forest with little undergrowth, and occasionally pine forests. Breeding habitats are relatively dry uplands or slopes, although they have been noted to breed in bottomland forests and swampy areas. An abundance of leaf litter on the forest floor is essential for foraging and nest building. Seiurus aurocapilla requires relatively large contiguous forest tracts for breeding. (Ehrlich, Dobkin, & Wheye, 1988; Dunn & Garrett, 1997)
Seiurus aurocapilla generally breeds in mature deciduous or mixed broadleaf-conifer forest tracts with little undergrowth, but will occasionally breed in pine forests. Seiurus aurocapilla requires relatively large contiguous forest areas for breeding. The male S. aurocapilla displays above and near the female; often the male pursues the female in a wild courting flight, singing throughout the flight. The male ascends 10--60 feet (3--21 meters) above the treetop level and hovers and flutters with spread wings and tail while singing. The nest of S. aurocapilla is built in the open, on leaf-covered floor of deciduous woods or just above the ground in a clump of low plants or shrubs. Often the nest is placed next to an opening in the forest. The nest is shaped like a Dutch oven, and is the source of the common name "ovenbird." It is built of dried grass, leaves, moss, other vegetative matter, and hair. The nest is well camouflaged with leaves, branches, and other litter placed on the roof. The entrance is a small slit on the side of the nest. Eggs are white with brown and gray markings, and about 0.8 inches (2 cm) long. Seiurus aurocapilla occasionally has two broods, and even three when spruce budworms are abundant. Females incubate the eggs and flushes only when approached closely and then will perform a distraction display. (Ehrlich, Dobkin, & Wheye, 1988; Dunn & Garrett, 1997; Zach & Falls, 1975)
Seiurus aurocapilla usually walks (rather than hop or fly) alone on the forest floor among the leaf litter, often wagging its tail and bobbing it head while walking. It often does not flush when approached, instead remaining quiet on the forest floor. When agitated, it will raise its crest slightly, showing the orange color of the median crown. When flushed, it usually flies upward to a branch. Seiurus aurocapilla is far more often heard than seen; its song a loud, ringing, distinct teacher, teacher, teacher call. The song is delivered from a perch up to 30 feet above the ground, and occasionally from the ground. Male S. aurocapilla uses song to delineate territories, while females rarely sing. Territory size decreases as prey density increases. During the breeding season, S. aurocapilla is generally monogamous, although multiple mates have been documented. It winters in the southeastern United States and the Neotropics. (Ehrlich, Dobkin, & Wheye, 1988; Dunn & Garrett, 1997; Smith & Shugart, 1987; Van Horn & Donovan, 1994)
Seiurus aurocapilla eats insects, spiders, snails, and worms, primarily while walking on the floor of deciduous of mixed broadleaf-conifer forest among the leaf litter and fallen logs. In spruce budworm outbreaks, S. aurocapilla will feed in trees. Seeds and other vegetation sometimes make up part of its fall and winter diet. Seiurus aurocapilla will search for food based on prey distribution. It will learn where there are areas of high prey density and repeatedly revisit those sites. (Ehrlich, Dobkin, & Wheye, 1988; Dunn & Garrett, 1997; Van Horn & Donovan, 1994)
Seiurus aurocapilla is well studied by scientists in North America, partly due to its need for large mature forest tracts. Birdwatchers will travel to rural areas with large forest tracts to observe S. aurocapilla. (Dunn & Garrett, 1997)
Due to its need for large continuous forest tracts, S. aurocapilla is sensitive to forest fragmentation of its breeding habitat and wintering grounds. In breeding grounds, fragmentation of forest decreased suitable breeding sites and increases cowbird parasitism, to which S. aurocapilla is very susceptible. Towers, windows, and other human structures take a large toll on migrating S. aurocapilla. (Ehrlich, Dobkin, & Wheye, 1988; Dunn & Garrett, 1997; Link & Hahn, 1996)
Several subspecies of Seiurus aurocapilla are generally recognized, reflecting minor variations in the color of the upperparts. However, these subspecies are controversial. The subspecies S. a. furvior, found in Newfoundland, and S. a. cinereus, found in the western part of its range, are generally recognized. Authorities do not often recognize the subspecies S. a. canivirens, found in southern Appalachia. (Dunn & Garrett, 1997)
Jacob Foster (author), University of Michigan-Ann Arbor, Terry Root (editor), University of Michigan-Ann Arbor.
Dunn, J., K. Garrett. 1997. A field guide to warblers of North America. NY: Peterson Field Guide Series, Houghton Mifflin Co..
Ehrlich, P., D. Dobkin, D. Wheye. 1988. The birder's handbook: A field guide to the natural history of North American birds. NY: Simon & Schuster Inc..
Link, W., D. Hahn. 1996. Empirical Bayes estimation of proportions with application to cowbird parasitism rates. Ecology, 77 (8): 2528-2537.
Smith, T., H. Shugart. 1987. Territory size variation in the ovenbird - the role of habitat structure. Ecology, 68 (3): 695-704.
Van Horn, M., T. Donovan. 1994. Ovenbird (Seiurus aurocapillus). The Birds of North America, 88: 1-22.
Zach, R., J. Falls. 1976. Ovenbird (Aves - Parulidae) hunting behavior in a patchy environment - an experimental study. Canadian Journal of Zoology, 54 (11): 1863-1879.