ML644845736

觀察細節

Clearly a swift with sickle-shaped, long wings, forked tail (mostly closed). Long phases of gliding, with bursts of wing beating, generally flying at high speed. When gliding, wings appeared to be held somewhat down. Similar size and shape to Common Swift. All dark from below, except for a white throat patch that stood out even at quite some distance. Otherwise beneath generally brownish-black, primaries and secondaries from below with hints of dark grey when seen close up, contrasting somewhat with the slightly darker coverts. From above a white rump patch clearly visible. Scaly belly also distinguishes it from Common Swift. No vocalisation. Observation and photos submitted to SBRC