The feasibility of using transrectal ultrasonography for imaging the in situ morphology of the reproductive tract of females of several large nondomestic and endangered species was studied. Two black (Diceros bicornis) and 1 white (Diceros simus) rhinoceros, 2 Asian (Elaphus maximus) and 2 African (Loxodonta africana) elephants, 4 banteng (Bos javanicus), 1 gaur (Bos taurus), 1 giraffe (Giraffa camelopardalis), and 1 bactrian camel (Camelus bactrianus) were examined. Real-time ultrasonic images were obtained for the following structures: 1) rhinoceros—corpus luteum, ovarian