“…cephalopods (Hochner et al, 2006;Wollsen et al, 2009;Alves et al, 2013), amphibians, fish 35 , reptiles such as lizards and snakes, birds such as woodpeckers (Tebbich et al, 2001), jays (Clayton, 2007;Emery & Clayton, 2008;Watanabe et al, 2014), crows (Hunt, 1996;Hunt & Gray, 2003a;Hunt & Gray, 2003b;Taylor et al, 2012) and parrots (Auersperg et al, 2012;, mammals such as elephants (Moss, 1988), cetaceans Krützen et al, 2014), caniforms, feliforms, rodents, and, evidently, apes (chimpanzees and bonobos, gorillas, orangutans, and gibbons) and monkeys (baboons, macaques) (Goodall, 1964;deVore, 1965;Nishida, 1968;Premack, 1971;Fouts, 1973;Terrace, 1979;Patterson & Linden, 1981;SavageRumbaugh et al, 1985;Savage-Rumbaugh et al, 1986;Wallman, 1992;McGrew, 1992;Parker & Gibson, 1990;van Schaik & Knott, 2001; LadyginaKohts & de Waal, 2002;de Waal, 2006;van Schaik et al, 2003;Hobaiter & Byrne, 2011;Boesch, 2012;Schrier et al, 2013, etc.). Because these studies-numerous, well-documented and grounded in well-designed and carefully executed observations and experiments-are relatively recent, they are to be found mostly in research papers, the syntheses being still rare and more cautious in making firm statements than the original research 36 .…”