Sounds and Vocal Behavior

Development

Young nestlings produce low, soft peeps (pipsee) while in the nest, especially in response to the arrival of parents or other disturbance (Brown and Amadon 1968 Brown, L. H., and D. Amadon (1968). Eagles, Hawks, and Falcons of the World. McGraw-Hill, New York, NY, USA. Close , Preston 2000 Preston, C. R. (2000). Red tailed hawk. Mechanicsburg, PA: Stackpole Books. Close ). Between leaving the nest and attaining independence, juveniles utter loud, persistent hunger calls (klee-uk) in rapid sequence. These calls are accompanied by rhythmic wing fluttering upon approach by parents (Fitch et al. 1946b Fitch, H. S., F. Swensen, and D. F. Tillotson (1946). Behavior and food habits of the Red-tailed Hawk. Condor 48:205–217. Close ).

Array of Sounds

Among adults, the most familiar vocalization is a 2–3 s hoarse scream, kee-eeee-arrr (Figure 4) , that rises gradually then descends near the end. Cry often signals irritation or a defensive response when its territory is entered by an intruder or perceived threat (Brown and Amadon 1968 Brown, L. H., and D. Amadon (1968). Eagles, Hawks, and Falcons of the World. McGraw-Hill, New York, NY, USA. Close ). Duration, pitch, and general quality of the scream vary greatly, presumably with age, gender, and circumstance. Often described as having a “steam-whistle” quality, (e.g. Brown and Amadon 1968 Brown, L. H., and D. Amadon (1968). Eagles, Hawks, and Falcons of the World. McGraw-Hill, New York, NY, USA. Close ). Usually produced by soaring birds, it is also uttered from a perch or during active flight. Given frequently in sequence during territorial disputes (Fitch et al. 1946b Fitch, H. S., F. Swensen, and D. F. Tillotson (1946). Behavior and food habits of the Red-tailed Hawk. Condor 48:205–217. Close , Brown and Amadon 1968 Brown, L. H., and D. Amadon (1968). Eagles, Hawks, and Falcons of the World. McGraw-Hill, New York, NY, USA. Close ) and occasionally in response to human intrusion. Nestlings utter a softer version of the scream. During courtship flight, a sharp, shrill chwirk is produced by one or both mates (Figure 4). Several of these chirps are uttered at intervals of about a second (Fitch et al. 1946b Fitch, H. S., F. Swensen, and D. F. Tillotson (1946). Behavior and food habits of the Red-tailed Hawk. Condor 48:205–217. Close ). Mates also utter a low, nasal gannk when near one another.

Phenology

No information available.

Daily Pattern

No information available.

Places of Vocalizing

Vocalizations occur most often near nest during breeding season (biased by prevalence of studies associated with breeding) and during aerial territorial displays (Bent 1937b Bent, A. C. (1937). Life histories of North American birds of prey, Part 1. U.S. National Museum Bulletin no. 167. Close , Palmer 1988f Palmer, R. S. (1988f). "Red-tailed Hawk." In Handbook of North American birds, Vol. 5, Part 2, 96-134. New Haven, CT: Yale Univ. Press. Close , Preston 2000 Preston, C. R. (2000). Red tailed hawk. Mechanicsburg, PA: Stackpole Books. Close ).

Social Context and Presumed Functions

See above.

None known with a communicative function.