Plumages, Molts, and Structure

Ovenbirds have 9 functional primaries, 9 secondaries (including 3 tertials), and 12 rectrices. Geographic variation in appearance slight. The following plumage descriptions pertain to the widespread North American subspecies S. a. aurocapillus; see Systematics: Geographic Variation for specifics on variation in two other recognized subspecies in western North America and Newfoundland. No geographic variation in molt strategies reported.

Following based primarily on detailed plumage descriptions of Ridgway (1902), Bent (Bent 1953b Bent, A. C. (1953). Life Histories of North American Wood Warblers. Bulletin of the United States National Museum 203. Close ), Roberts (1955), Eaton (1957a, 1957b), Taylor (1972), Oberholser (1974), Curson et al. (1994), Cramp and Perrins (1994), and Dunn and Garrett (1997); see Taylor (1973), Donovan and Stanley (1995), and Pyle (1997a) for age-related criteria. Definitive Plumage is essentially assumed following Preformative Molt.

Natal Down

Present May-Jun. Coloration of natal down described as dark gray by Hann (Hann 1937 Hann, H. W. (1937). Life history of the Ovenbird in southern Michigan. Wilson Bulletin 49:146-237. Close ) and pale sepia brown by Dwight (Dwight 1900c Dwight, J., Jr. (1900). The sequence of plumages and moults of the passerine birds of New York. Annals of the New York Academy of Sciences 13:73–360. Close ). See Breeding: Young birds for more information.

Juvenile (First Basic) Plumage

Present only briefly on each individual from Jun-Aug; lost quickly following fledging. See Curson et al. (1994, plate 17) for an illustration. Head, neck and upperside cinnamon brown, the lateral stripes faintly present on crown; scapulars and back with indistinct darker streaks; upperwing and tail similar to adults but median and greater secondary coverts tipped pale cinnamon forming indistinct wingbars; tertials tipped cinnamon (Taylor 1973b Taylor, W. K. (1973b). Aging of Ovenbirds by rusty-tipped tertials and skull ossification. EBBA News 36:71-72. Close ); underparts pale cinnamon with faint olive brown streaks on sides; abdomen and undertail coverts tinged yellowish white.

Formative Plumage

"First Basic" or "Basic I" plumage of Pyle (1997a) and previous authors. Present Sep-Aug. Similar to Definitive Basic Plumage but plumage may average slightly more faded, sex for sex and seasonally (see below); outer retained juvenile outer primaries and rectrices narrower and more pointed (Donovan and Stanley 1995); contrasts occur between replaced formative secondary coverts and retained juvenile primary coverts, the latter averaging brownish and wearing to thinner by spring; retained juvenile tertials with cinnamon tips when fresh, sometimes wearing off by spring. Ridgway (Ridgway 1902 Ridgway, R. (1902). The birds of North and Middle America. Part II. United States National Museum Bulletin 50, part 2. Close ) noted that buff-tinged feather tips on the malar stripe and sides may be indicative of Formative Plumage but confirmation and reliability of this required.

Definitive Basic Plumage

Present Sep-Aug. Upperparts plain, dull olive green, the crown with 2 narrow, lateral stripes of black bordering a broader median stripe of tawny ochraceous feathers which are tipped with pale olive, especially on occiput; supercilium region slightly tinged grayish olive, grading into a paler hue in the auricular region; orbital ring whitish; lores grayish white; inner webs of remiges and rectrices grayish brown (Ridgway 1902 Ridgway, R. (1902). The birds of North and Middle America. Part II. United States National Museum Bulletin 50, part 2. Close ), about 5% of birds showing indistinct pale spots extending over 1 mm onto inner webs of rectrices. Underparts white with dusky submalar streak, the chest and sides heavily streaked with black; flank streaking narrower and less distinct; axillars and underwing coverts pale olive yellow. In general, light feather edges are lost by wear which brightens plumage by spring. Sexes similar but females have slightly duller plumage and paler median crown stripe by season, on average. Differs from Formative Plumage in that basic outer primaries and rectrices broader and more truncate; secondary and primary coverts uniform in wear and color; tertials without cinnamon tips when fresh.

Molt and plumage terminology follows Humphrey and Parkes (1959) as modified by Howell et al. (2003, 2004). Ovenbird appears to exhibit a Complex Basic Strategy (cf. Howell et al. 2003, Howell 2010), including complete prebasic molts and a partial preformative molt but no prealternate molts (Stone 1896; Dwight 1900c Dwight, J., Jr. (1900). The sequence of plumages and moults of the passerine birds of New York. Annals of the New York Academy of Sciences 13:73–360. Close ; Oberholser 1974; Cramp and Perrins (1994); Curson et al. 1994; Dunn and Garrett 1997; Pyle 1997a, 1997b; Fig. 3). Reports of a limited prealternate molt of head feathers in Dec-Apr (Cramp and Perrins 1994, Pyle 1997) may be based on protracted prebasic or preformative molts and requires verification. Definitive molt cycle commences with Second Prebasic Molt.

Prejuvenile (First Prebasic) Molt

Complete, May-Jul, in the nest. On days 0 and 1 the juvenile primaries and secondaries appear as dark lines beneath the skin and by day 3 these feathers begin to emerge. Rectrices appear as a transverse line by day 5. On day 8 juvenile primaries project 20 mm and juvenile rectrices 2-3 mm from sheaths and breast and abdomen feathers more than half of full length (Hann 1937 Hann, H. W. (1937). Life history of the Ovenbird in southern Michigan. Wilson Bulletin 49:146-237. Close ).

Preformative Molt

"First prebasic" or "Prebasic I" molt of Pyle (1997a) and previous authors. Partial, Jun-Aug, on or near nest site (can commence before fledging). Includes body feathers and most or all secondary (lesser, median, and greater) upperwing coverts but rarely (if ever) the tertials or greater alula and no primary coverts or other flight feathers.

Definitive Prebasic Molt

Complete, Jun-Aug, on or near breeding grounds, although study is needed on the relationship between breeding territories and molting grounds. Primaries replaced distally (p1 to p9), secondaries replaced proximally from s1 and proximally and distally from the central tertial (s8), and rectrices probably replaced distally (r1 to r6) on each side of tail, with some variation in sequence possible.

Bill And Gape

Maxilla dark brown, culmen much paler.

Iris

Brown.

Legs And Feet

Pale pink

Table 1. Ovenbirds collected in Sep and Oct, 1969 and 1970, from a tower kill in Orange Co., FL weighed (g): adult males, 22.5 (17.8–27.5 range); immature males, 23.5 (15.7–27.4 range); adult females, 21.7 (18.4–25.8 range); and immature females, 22.5 (16.4–27.8 range; Taylor 1972).

No significant variation in size across the range of this species.