DISCUSSION
Aerial and Foraging Behavior.—Edible-nest and Glossy swiftlets performed fly/glide, foraging
attempts (twist, fly-pause, roll, flutter, and tailwing-open), call, follow, preen, defecate, and carry nest material in decreasing order. When breeding seasonality of the Edible-nest Swiftlet based on Sankaran and Manchi (2008), and Manchi (2009) was considered, temporal variations in activities of the two species near caves used for breeding appeared to be related to timing of breeding. Swiflets at Chalis-ek had chicks and eggs in the nest during April and May, and were more active near breeding sites. Edible-nest Swiftlets near caves used for breeding were inactive between 0700 and 1700 hrs, and 0800 and 1400 hrs, respectively, during early and late nest construction periods. Not requiring nest material might have led Edible-nest Swiftlets to spend most of the time exploring potential foraging areas away from breeding sites. Commencement of egg-laying during February followed by incubation, and brooding and feeding nestlings led to increased activity of Edible-nest Swiftlets near breeding sites. The active period of Edible-nest Swiftlets declined after May (Fig. 1), which was attributed to fledging occurring from most nests and avoidance of extreme weather
conditions (Medway 1962). Medway (1962) reported wider foraging ranges
of Edible-nest Swiftlets in the non-breeding season, leading to changes in activity near
breeding sites. Swiftlets at Chalis-ek, traveled away from the caves even during the preincubation period, possibly due to non-availability of food near caves. Food availability for swiftlets depends on the density and diversity of insects which in turn depend on weather conditions (Johnson 1969). Glossy Swiftlets were more active in early and late morning hours, but did not have significant diurnal variations in activities (Fig. 2). Asynchronous breeding in the Andaman and Nicobar Islands by Glossy Swiftlets may have resulted in no variation in diurnal activities
DISCUSSIONAerial and Foraging Behavior.—Edible-nest and Glossy swiftlets performed fly/glide, foragingattempts (twist, fly-pause, roll, flutter, and tailwing-open), call, follow, preen, defecate, and carry nest material in decreasing order. When breeding seasonality of the Edible-nest Swiftlet based on Sankaran and Manchi (2008), and Manchi (2009) was considered, temporal variations in activities of the two species near caves used for breeding appeared to be related to timing of breeding. Swiflets at Chalis-ek had chicks and eggs in the nest during April and May, and were more active near breeding sites. Edible-nest Swiftlets near caves used for breeding were inactive between 0700 and 1700 hrs, and 0800 and 1400 hrs, respectively, during early and late nest construction periods. Not requiring nest material might have led Edible-nest Swiftlets to spend most of the time exploring potential foraging areas away from breeding sites. Commencement of egg-laying during February followed by incubation, and brooding and feeding nestlings led to increased activity of Edible-nest Swiftlets near breeding sites. The active period of Edible-nest Swiftlets declined after May (Fig. 1), which was attributed to fledging occurring from most nests and avoidance of extreme weatherconditions (Medway 1962). Medway (1962) reported wider foraging rangesof Edible-nest Swiftlets in the non-breeding season, leading to changes in activity nearพันธุ์อเมริกา Swiftlets ที่ Chalis เอก การเดินทางจากถ้ำแม้ช่วง preincubation อาจเป็นเพราะไม่ใช่-มีอาหารใกล้ถ้ำ อาหารว่างสำหรับ swiftlets ขึ้นอยู่กับความหนาแน่นและความหลากหลายของแมลงซึ่งจะขึ้นอยู่กับสภาพอากาศ (Johnson 1969) Swiftlets มันถูกใช้งานมากขึ้นในเวลาเช้าก่อน และหลัง แต่ไม่มีรูปสำคัญ diurnal ในกิจกรรม (Fig. 2) พันธุ์แบบอะซิงโครนัสในอันดามันและเกาะนิโคบาร์ โดย Swiftlets มันอาจทำให้ไม่เปลี่ยนแปลงในกิจกรรม diurnal
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