INDIVIDUAL HUMANS AS DISCRIMINATIVE STIMULI FOR CATTLE (BOS-TAURUS)

Holstein-Friesian dairy cattle were tested for their ability to use in dividual humans as discriminative stimuli for the performance of an op erant response. Nine animals demonstrated their ability to tell people apart by successfully learning to confine their responding to the pre sence of a handler who reinforced a nose press response (S+ handler), while not responding in the presence of a handler who never reinforced a response (S- handler). During test sessions where (1) the order of handler presentation, and (2) both handler presentation and trial dura tion varied randomly, response rates of all cattle were significantly higher(p < 0.005) in the presence of the S+ handler. Further, the cows ' behaviour in the presence of each handler during 15 s pre-trial peri ods reflected the underlying Pavlovian component of this discriminatio n: cows typically showed orienting and reaching behaviour towards the S+ handler, while avoiding looking at or reaching towards the S- handl er. The ability of these animals to differentiate individual humans, e ven under less formal reinforcement contingencies, has far-reaching as sociative implications for the management of dairy cattle (whether in agricultural or research settings), where the pairing of hedonic stimu li with individual humans may affect handling, productivity, and physi ology. (C) 1998 Elsevier Science B.V. All rights reserved.