{"fact":"Crows pay attention to more than just alarm calls. This study used \"Hey\" as a human vocalization, and \"tchak\" as a jackdaw contact call, demonstrating that crows differentiate familiar and unfamiliar individuals even from these simple calls.","context":"Five women familiar to the crows and five women unfamiliar to the crows were recorded saying \"Hey,\"… For the jackdaw stimuli \"tchak\" contact calls from five familiar and five unfamiliar birds were recorded.","source":"Claudia A. F. Wascher; Georgine Szipl; Markus Boeckle; Anna Wilkinson, You sound familiar: carrion crows can differentiate between the calls of known and unknown heterospecifics, 10.1007/s10071-012-0508-8","index":332}