Sounds

Generally highly vocal inside and outside breeding season, but little detailed information. Utterances best known from breeding grounds, particularly advertising or in defense of nest territory from conspecifics and potential egg and/or chick predators. “Repertoire” or variety of calls large, some even described as “singing” (Trevor-Battye 1895), but many considered to be variations of the same vocalization (in context of function) rather than individual context-specific calls (Cramp and Simmons 1983). Male more vocal than female. Vocalizations on summer grounds best described by Bergman (1946), and those in feeding groups postbreeding, with less detail, by Groves (1978), Burger et al. (1979), and Fleischer (1983). Numerous descriptions of ground and flight calls in literature (e.g., Feilden 1879; Manniche 1910; Forbush 1912; Bent 1929; Bird and Bird 1940, 1941; Salomonsen 1950; Dement’ev and Gladkov 1951; Hall 1960; see also Vocal array, below). Calls of adults best summarized in Cramp and Simmons 1983 .

Development

Numerous sounds from chicks prior to fledging, likely parent-chick Contact Calls, becoming more distinct after fledging as “panic” or “alarm” notes within small flying groups, but few described or analyzed (for summary, see Vocal array below). Distinct differences in strength and intensity of individual calls between age cohorts; adults dominant over immatures on migration and wintering grounds (Groves 1978).

Vocal Array; Social Context And Presumed Functions

Vocal and noisy, limited variety with great variation in intensity relative to season and situation. Main calls of adults and young described by Bergman (1946) and aptly summarized in Cramp and Simmons 1983 . Major adult calls: Contact Rattle, a short tremolo/staccato chuckle or twittering metallic kitititit, given throughout the year, mostly outside breeding season when in flocks along shore (Witherby et al. 1940), in feeding groups (Thompson 1973), and sometimes in flight (Cramp and Simmons 1983), but also on breeding grounds as extended “purring rattle” (see Fig. I in Cramp and Simmons 1983: 622) by birds in flocks or individual in aerial pursuit of predator, or as staccato, rolling cackle/rattles: “ cut-i-cut-cut ” and “ tuk-i-tuk ” (Sutton 1932); Alert Call, all used to “warn” and “alarm,” given on ground, throughout the year, as a sharp, metallic “ teuk ” or “ keu ” (Sutton 1932, Witherby et al. 1940) or in flight as a loud, irregularly repeated “ teu ” (see Fig. II in Cramp and Simmons 1983: 622), also described as “ kliu,” “ tche,” “ shia ” (Bergman 1946, Paget-Wilkes 1922, Stoll 1931, respectively), and “sharp whistle” to silence feeding flocks (Thompson 1973); and Chattering-Alarm Call, mainly on breeding grounds, most pronounced in male, described as a strong metallic “ TITwoooTITwoooRITitititititititititit …” (see Fig. III in Cramp and Simmons 1983: 622) with ending a rolling chatter (not as fast as Contact Rattle), sometimes described as a song (Trevor-Battye 1895, Witherby et al. 1940, Bannerman 1961), though characteristics variable within individual bird and overall function uncertain. Much additional study required on precise functions of all major calls.

Other adult calls described include: Scrape Call, long series of “ pri pri pri ” notes (Bergman 1946); Chick Call, variable intensity and volume, mostly quiet series monosyllabic notes similar to Scrape Call but emphasis on “r,” used to summon young or maintain contact (Bergman 1946); Distraction-Display Call, low clicking sounds made in crouch-run posture to lead predators away from nest or young (Bergman 1946, Parmelee et al. 1967); also loud “bill-snapping” noises made during attacks on predators (Blair 1961) and gentle, quiet “ chup ” or “ wik ” sounds (often inaudible at 30 m) emitted within foraging flocks. Calls of young less diverse: As chicks, chiefly “ si-i-i ” (early) and “ virr virr ” (later) sounds for parental contact, and lengthy shrill “ i-i-i-i-i ” notes in distress (Bergman 1946); once fledged, a high-pitched “ twit-twit-twit ” (Savile and Oliver 1964).

Phenology

Most pronounced on breeding grounds during settlement period from late May to mid-Jun: associated with territorial displays and aggressive encounters, pair formation, and courtship prior to incubation. Sentinel alert/alarm calls, predator scolding, and aerial pursuit, and other territorial-defense and anti-predator behaviors that include vocalizations continue through incubation period. Vocalizations less frequent and conspicuous thereafter, but after hatching, alert/alarm calls often more intense and loud. Outside breeding, “chatter/gabbling” vocalizations almost continuous when feeding in groups and mixed-species flocks, sometimes highly aggressive in context: e.g., individual feeding distance (<30 cm; Thompson 1973), foraging or aggressive behavior (Groves 1978), aggressive behavior in migration (Burger et al. 1979), winter flocking or foraging (Fleischer 1983), winter flocking (Metcalfe 1986), or flocking or aggressive behavior (Metcalfe and Furness 1987).

Daily Pattern

No systematic quantitative records available. During breeding, evident early before egg-laying and incubation by regular patrols around nesting territory by male giving loud flight calls between specific “territorial advertisement” sites, mainly elevated vantage locations or “lookouts,” top of large rocks or boulders, where extended Chattering-Alarm Call or other vocalizations follow; aggressive calls associated with territorial aerial chases and ground encounters frequent throughout settlement period, initiated by intruder landing or flying over resident male’s territory. Frequency of calls much reduced once territorial boundaries established and incubation under way (Bergman 1946, Nettleship 1967). During migration and winter, “chattering” and aggressive calls predictable within daily patterns of flocking and foraging (e.g., Bent 1929, Burger et al. 1979, Groves 1978, Fleischer 1983, Harrington and Flowers 1996). Further study required, particularly on breeding grounds regarding territoriality and breeding density.