Cognitively advanced animals are usually assumed to possess better self-control, or ability to decline immediate rewards in favour of delayed ones, than less cognitively advanced animals. It has been claimed that the best predictor of high such ability is absolute brain volume meaning that large-brained animals should perform better than small-brained ones. We tested self-control ability in the great tit, a small passerine. In the common test of this ability, the animal is presented with a transparent cylinder that contains a piece of food. If the animal tries to take the reward through the transparent wall of the cylinder, this is considered an impulsive act and it fails the test. If it moves to an opening and takes the reward this way, it passes the test. The average performance of our great tits was 80%, higher than most animals that have been tested and almost in level with the performance in corvids and apes. This is remarkable considering that the brain volume of a great tit is 3% of that of a raven and 0.1% of that of a chimpanzee.Significance statementThe transparent cylinder test is the most common way to test the ability of self-control in animals. If an animal understands that it only can take food in the cylinder from the cylinder’s opening and controls its impulsivity, it passes the test. A high level of self-control has been demonstrated only in cognitively advanced animals such as apes and corvids. Here, we demonstrate that the great tit, a small song bird that is very good at learning, performs almost in level with chimpanzees and ravens in this test.Electronic supplementary materialThe online version of this article (10.1007/s00265-018-2529-z) contains supplementary material, which is available to authorized users.

Motor inhibition refers to the ability to inhibit immediate responses in favour of adaptive actions that are mediated by executive functions. This ability may be an indication of general cognitive ability in animals and is important for advanced cognitive functions. In this study, our aim was to compare motor inhibition ability of two closely related passerines that share the same habitat. To do this, we tested motor inhibition ability using a transparent cylinder task in blue tits in the same way as we previously tested great tits. To test whether the experience of transparent objects would affect the performance of these species differently, both in the present experiment using blue tits and our previous one on great tits, we divided 33 wild-caught individuals into three different treatment groups with 11 birds each. Before the test we allowed one group to experience a transparent cylindrical object, one group to experience a transparent wall and a third group was kept naive. In general, blue tits performed worse than great tits, and unlike the great tits, they did not improve their performance after experience with a transparent cylinder-like object. The performance difference may stem from difference in foraging behaviour between these species.

Studies of animal cognition struggle frequently with the question of how representative results from small samples are for a species. A recent article by Farrar et al. (2021), in this journal, highlights some of the major problems and suggests some solutions to these with cautionary examples drawn from the animal cognition literature. One such example comes from a study of inhibitory control in the great tit, Parus major, by the authors of this commentary. Although we recognize, and agree, that there are issues regarding representativeness in studies of animal cognition, we disagree with the use of our inhibitory control study as a cautionary example. Here, we explain why we think that our study is representative of Great tit inhibitory control. In fact, some of our arguments as to why our study is representative are in agreement with suggestions by Farrar et al (2021), e.g., comparing individuals with different levels of previous experiences in the cognitive paradigm under investigation. Moreover, we also add to Farrar et al.’s (2021) conclusion on how to approach studies with ambiguous representativeness by highlighting the importance of recognizing and discussing methodological differences in studies of cognitive ability. In summary, we do not argue against the valid points laid out by Farrar et al (2021), but discuss important nuances of the representativeness issue to also consider and, most importantly, add an additional point of scrutiny to account for in comparative animal cognition research.