Sounds

Development

Peep Call. Young peep quietly during and after hatching, apparently as contact note with adult and possibly siblings (MAS). Audible to 15 m; duration about 0.5 s.

Wheee Call. A loud, harsh distress note by chicks when disturbed or captured; lasts ≤1 s. Also described as pwee-oo; considered a stronger version of within-egg call (Williamson 1946).

Vocal Array

Vocalizations not analyzed outside breeding season; need further study. During migration, birds give a far-carrying, soft, whistled cur-lee (Snyder 1957); a cur-lew note, reported by Bent (1929) as more frequent in spring than fall; and 2 low, straight whistles when a flock is alighting (Mackay 1892). These calls are not reported on breeding areas. Migrating birds also utter a tittering call: 5–7 rolling, twittering pip s (Snyder 1957, MAS), also described as a rapid, tittering titti-titti-titti-titti-titti-tit, with syllables consistent in length and emphasis (Witherby et al. 1940). In wintering areas in Central America, birds give a series of piping or tittering whistles, whee hee-hee-hee-hee-hee, and a whirr-i whirr-ip, the latter heard more often in spring than in fall or winter (Howell and Webb 1995). On mudflats in Panama, a series of piping whistles occur with aggressive interactions on feeding territories (but not recorded on breeding grounds), as well as Scolding Trill Calls (see below); trills that may be Low Trill Calls (see below) also occur (EPM, MAS). In Nigeria, N. p. phaeopus gives cour-lee, Low Trill (Bubbling) Call, and tittering call (Cramp and Simmons 1983).

Vocalizations on breeding grounds in North America described and analyzed by Skeel (1976a, 1978); described by Williamson (1946) on Faeroe Is., Denmark. From arrival until shortly after hatching, 12 adult and 2 chick calls described (see Development, above, for description of chick calls; also see Fig. 3 and Skeel 1978). Calls during fledging and onset of migration need study. The following account follows arrangement in Skeel 1978 and Cramp and Simmons 1983 .

Low Whistle Call (Fig. 3A). A soft, low, mournful whistle, lasting ≤1.6 s, usually uttered 2–5 (up to 20) times. In early spring, heard throughout day and only as part of Aerial Display Song (see below). Later in summer, heard from birds too high to be seen. Described by Williamson (1946) as koo .

Low Trill (Bubbling) Call (Fig. 3B, C, and D). A steady, melodious call composed of 1–3 phrases, the final phrase being a trill of low-frequency elements. When 1 phrase, almost invariably a trill; when 2 or 3 phrases, first part of some or all phrases is a whistle or vibrato similar to Low Whistle Call. Final trill consists of 17–80 elements. Single-phrase call lasts up to 6.5 s; 3-phrase call approaches 8 s. Described as koo given from ground (initial whistle phrase; Daukes 1933); low, mournful teeeeu and bubbling trill (Witherby et al. 1940); and whinny (Williamson 1946).

Aerial Display Song (Fig. 3A–D). Composed of Low Whistle Call repeated up to 20 times, followed by 3-phrase Low Trill Call. Principally a component of male self-advertising Aerial Display (see Behavior: sexual behavior, below). In Manitoba, no vocalizations during bird’s climb; song begins 2–10 s after onset of glide component. On Faeroe Is., Low Whistle Call (koo notes) is more frequent than silence during climb (Williamson 1946).

Whining Call (Fig. 3E). A single, loud, scream-like whistle, lasting 0.5–2.3 s, increasing in intensity, then ending abruptly. Can be uttered softly; occasionally followed by Low Trill Call. In nesting areas, initially uttered throughout the day every 10–60 s for bouts of ≥10 min. Also described as a melancholy, long-drawn whistle, wee-ee (Williamson 1946). A possible variation, a cur-eeee call preceded by several short whistles, was uttered by 1 bird of a pair in foraging area upon arrival of another pair (B. McCaffery pers. comm.).

Chase Call. A rapid series of short, highly variable notes, including whistles and buzzes, lasting 2–4 s. Uttered early in breeding season by a bird in close aerial pursuit of another in non-nesting areas; probably associated with incipient territorial behavior.

Settling Call. A very soft whistle, given as bird settles on its nest; similar to a human sigh. Occasionally followed by Low Trill Call.

Whit Call. A short whit, heard twice: once when 1 of a pair flew low over observer and once when female watched newly hatched chicks shakily leave nest. Probably a general anxiety call.

Aerial Predator Alarm Call (Fig. 3F). A relatively high, loud trill of 4–8 short, abrupt, uniform elements; the only trill with no harmonics. Heard exclusively prior to or when chasing an aerial predator; bird dives downward toward intruder, then calls ≤3 times on upward swoop (see Behavior: predation, below).

Ground Predator Alarm Call. A loud trill of 24–44 short elements, uttered as bird flies low along ground toward human intruder 50–250 m from nest. Often followed by, and later replaced by, Scolding Trill Call.

Scolding Trill Call. Composed of a rapid succession of loud, short elements. Graded sound: 3 types, difficult to distinguish without experience or sonograms. Up to 35 elements in Type I (Fig. 3G) and Type II (Fig. 3H), up to 12 in Type III (Fig. 3I). As call changes from Type I to III, its frequency becomes higher, with elements longer and fewer, and intervals shorter; change reflects an increasing state of excitement or anxiety in bird. Also described as krek, krek, krek (Bent 1929); qück, qück (Witherby et al. 1940); and quick, quick, quick or kwok, kwok kwok, and in extreme excitement, a harsh, screaming bark, quak, qua-quak (Williamson 1946).

Parental Contact Call. A low, gurgling tremolo of 8–19 notes; call lasts about 1–2 s. Given by both adults from hatching of first chick until chicks are ≤ 1 wk old, perhaps older. Sometimes uttered prior to brooding; given regularly as adult moves with feeding chicks.

Copulation Call. A weak, low tu-tu-tu-tu given by male.

Phenology

Aerial Display Song is given when male establishes territory in late May and early Jun, soon after arriving on breeding grounds; less frequently in mid-Jul at dusk and dawn (Skeel 1978). All other vocalizations are given by both sexes throughout breeding season. Use of Whining Call drops sharply just prior to nesting; of Aerial Predator Alarm Call after onset of nesting. Ground Predator Alarm Call is uttered early in breeding season or during initial visits to territory by observer; replaced by Scolding Trill Calls.

Daily Pattern Of Vocalizing

No data.

Places Of Vocalizing

Aerial Display Song is uttered by male during Aerial Display (see Behavior: sexual behavior, below) at height of 150–300 m. Low Trill Call, when not part of Aerial Display Song, is given from ground or perch, or as bird glides to land. Whining Call is uttered from ground, usually from a hummock or ridge (MAS); also heard from 1 bird of a pair in fluttery slow motion just above ground (B. McCaffery pers. comm.). Scolding Trill Call is uttered as bird flies toward human intruder up to 250 m from nest; also from ground or low perch (usually dwarfed spruce or tamarack).

Repertoire And Delivery Of Songs

No data.

Social Context And Presumed Functions Of Vocalizations

From Skeel 1978 except where noted. Aerial Display Song, which ceases after onset of nesting, probably functions primarily in mate attraction. Song with accompanying Aerial Display (see Behavior: sexual behavior, below) is not performed by all males; it occurs less frequently where the incidence of returning birds (likely established pairs) is high. Probably unpaired males display. Aerial Display may also mark area, part of which becomes male’s territory, for inspection by potential mate; nesting success varies with habitat (see Behavior: predation, below). Competing male may be repelled; little overlap in area traced by Aerial Displays (MAS). Resumption of song in mid-Jul may be triggered by shortening day length.

Low Trill Call, the most common vocalization, is uttered day and night throughout breeding season: from on or near ground, from incubating and off-duty bird, at nest-relief, and usually as bird glides to land. Appears to serve as contact between birds of a pair, and serves general locative function among birds.

Prior to and during nesting, Whining Call appears to be a contact or warning call associated with establishing territory, and an antagonistic call during disputes. Often uttered upon landing following Aerial Display; sometimes prior to, during, or after an aggressive encounter on or off territory.

Aerial and Ground Predator alarm calls are given in pursuit of a potential predator; they function as alarms to other birds, and possibly distract predators that prey on eggs.

Scolding Trill Call, directed toward a human intruder, also functions as an alarm and may distract intruders: Type I is uttered in low-intensity situations (e.g., after an observer enters blind near nest); Type II, the most common, is uttered in all situations of disturbance near a nest; and Type III is uttered when a bird is extremely excited, and always in association with Distraction Display (see Behavior: predation).

None described.