The prevalent use of soaring could be explained because it confers multiples advantages such as exploration, better detection of prey or intruders, territorial displays or courtship, and thermoregulation. Perching behavior could also have conferred the advantage of access to the interior of forest remnants, allowing better exploitation of such prey patches. The Harris's Hawk's prevalent tendency to perch could be explained by its stereotyped sit-and-wait foraging mode. Within each season, time budgets for soaring differed markedly throughout the day. Soaring was the most frequent flight mode throughout the year (46−87% of total flying time, N = 628.5 min). Six flight modes were identified: gliding, cruising, soaring, hovering, diving and parachuting. Harris's Hawks perched more often during mid-morning (09:00−11:00 h) and midday (12:00−14:00 h) in winter, during mid-morning and mid-afternoon (16:00−17:00 h) in spring and autumn, and during mid-morning and late-afternoon (19:00−21:00 h) in summer. Except in winter, perching activity exhibited a daily, bimodal pattern. Harris's Hawks perched more often during winter and autumn (83−95% of total time hawks were observed, N = 11,940 min), and flew more often during spring and summer (21.6−33.6% of total time hawks were observed). Perching was the prevalent activity within each season and day. The time spent in a particular activity was measured using the focal-animal sampling method. During nine months, we surveyed the activities of Harris's Hawks (Parabuteo unicinctus) for a total of 199 hours over 22 observation days in a coastal forested area of central Chi-le. Knowledge about activity patterns of raptors in different habitats is important to understanding their behavioral flexibility and adaptive ability. Our results corroborate previous findings that the Whitetailed Kite is a rodent-specialist predator and suggest that in our study area it behaves as an opportunistic predator (i.e., capturing rodent prey in proportion to their availability). ![]() The frequency of rodent prey species in the pellets was positively correlated to rodent prey abundance in the environment, as measured using live-trapping surveys (rs = 0.83, P = 0.05). The geometric mean weight of vertebrate prey was also similar among seasons (27.0–28.6 g). Rodents were important in the diet in all seasons (frequency 5 88.6–100%, biomass 5 98.8–100%), and the ranking of rodent prey species in the diet was virtually the same for all seasons (x2 = 4.6, P = 0.05). longipilis) were the most common prey (47.5% and 32.4% of all prey by frequency, respectively 40.3% and 38.9% by biomass, respectively). Olivaceous field mice (Abrothrix olivaceus) and long-haired mice (A. Kites’ diet was determined based on pellets (N = 209) and consisted of rodents, insects and birds (95.6%, 13.8% and 0.6% of all consumed individual prey ). In 2004–05, we evaluated seasonal variation in the diet of White-tailed Kites in a suburban area of Concepcio´n, southern Chile.
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