Sounds

Vocalizations

Development

Songs are learned. Morrison-Parker (1977) captured 2 hatch-year males in fall; one, tape-tutored with songs of many species (including conspecific), produced the 2 Field Sparrow song types with which it was tutored. The other male, isolated from taped recordings, never progressed beyond subsong before its death at about 1 yr of age. In addition, Nelson (1992) recorded 2 males in plastic song, an intermediate stage typical of the song learning process. Liu and Kroodsma (1999) followed song development in caged hatch-year birds exposed to song from live tutors: subsong began at about 2 wk of age and ceased in early fall. Subsong resumed in December and developed into plastic song with increasing daylength; crystallization occurred January-February. Most birds imitated the song of their hatch year tutors, then modified their songs in the following spring to more closely match spring tutors or peer neighbors.

Sensitive periods for learning: No data.

Learning from another species: Short (1966) observed a male singing Chipping Sparrow (S. passerina) song. One juvenile caged without access to adult tutors, but kept in a holding room with sedge wrens (Cistothorus platensis), incorporated sedge wren notes into part of its song (Liu and Kroodsma 1999).

Vocal Array

Songs and calls: Unless noted, descriptions of calls follow Morrison-Parker (1977); descriptions of song types follow Nelson and Croner (1991). A note is a continuous tracing on an audiospectrogram.

Seep Call (Fig. 2)—single note, given by both sexes while foraging together or within flocks of migrants. When repeated, intervals between calls usually exceed 0.5 s. Possibly functions to maintain contact between individuals.

High-pitched Seep Call—given between members of a mated pair during courtship and nest construction.

Trill Call (Fig. 2)—rapidly repeated series of notes given by a male before landing near a female, in territorial interactions, or when attracted by song playback. In territorial context, “trills” often alternate with songs (DAN). Duration 0.5–2.0 s. Function unclear, possibly appeasement.

“Rapid high-pitched trill” call—given by males during copulation.

Cricket Call—similar to a low-pitched cricket stridulation, given by brooding female as male approaches with food for nestlings.

Chip Call (Fig. 2)—given by both sexes in presence of predators or human observers. Rate of calling appears to depend on the proximity of the stimulus. Probably functions to alert mate or offspring to threat from terrestrial predators.

Ti-ti-ti Call—rapid series of syllables given by females in precopulatory display (MC).

Zeeeeeee Call—high, thin whistle used as a hawk alarm call (Walkinshaw 1945).

Eeeeeeee Call—screeching sound heard in attacks on cowbird models and snakes at the nest and when handled (DEB).

Simple Song (Fig. 2)—the common familiar song. Begins with long, often down-slurred whistles with slow or little frequency modulation, followed by one or more rapid trills of shorter notes. Mean intersong interval 16–19 s, Mar–Jul in Indiana; mean interval in Aug (26 s) significantly longer (Morrison-Parker 1977). Given “spontaneously” by territory-holding males; appears to function in long-distance advertisement.

Complex Song (Fig. 2)—uncommon. Order of short and long notes the opposite of Simple Song; Complex Song begins with a trill of short notes, followed by longer down-slurred notes. Complex Songs are longer than Simple Songs and often alternate between phrases of short and long notes. The short notes in Complex Song differ from those in Simple Song by having two or more parts with rapid frequency modulation. Complex Song is given by males commonly in the dawn chorus and during territorial interactions. Appears to signal heightened aggressive tendencies. Playback of Complex Song in the center of a territory elicits stronger response than Simple Song playback.

Phenology

Males begin singing on arrival in spring and continue until paired. Song uncommon after pair formation but resumes at reduced rates once incubation begins or if the nest is lost. Ceases in late Jul or Aug (Nelson and Croner 1991).

Daily Pattern Of Vocalizing

In early spring, males are relatively quiet at dawn and on cold days. As days grow warmer, the highest song frequency occurs at dawn, with mean song rates about twice those occurring later in the morning (Nelson and Croner 1991).

Places Of Vocalizing

Song almost exclusively occurs within territory boundaries. Male usually perched at or near the top of the tallest vegetation in the area of the territory where song is occurring (MC).

Repertoire And Delivery Of Songs

Males arriving on territory for the first time in early spring often sing 2 or more Simple Song types, then selectively retain the one song type that best matches one of their neighbors (Nelson 1992).

Social Context And Presumed Functions Of Vocalizations

See Vocal array and Behavior sections.

Duetting: Not reported.

Countersinging: Males countersing with Simple Songs after the dawn chorus (Nelson and Croner 1991).

Recognition of neighbors and species: Many males have Simple Song types similar to those of one or more of their neighbors (Nelson 1992). Simple Songs of familiar and unfamiliar males are discriminated (Goldman 1973) using frequency cues (Nelson 1989a). Species recognition of Simple Song is based on a weighted combination of frequency, number of phrases or parts in the song, durations of notes and internote intervals, and frequency-time structure of the notes (Nelson 1988, 1989b).

Nonvocal Sounds

None reported.