School of Life Sciences The Chinese University of Hong Kong Sha Tin 999077 N.T China;
Swift and Swallow Research Group The Hong Kong Bird Watching Society 7C V Ga Building 532 Castle Peak Road Lai Chi Kok Kowloon Hong Kong 999077 China;
School of Life Sciences The Chinese University of Hong Kong Sha Tin 999077 N.T China;
School of Life Sciences The Chinese University of Hong Kong Sha Tin 999077 N.T China;
School of Life Sciences The Chinese University of Hong Kong Sha Tin 999077 N.T China;
Diet; DNA barcoding; House swift; Urbanisation threat;