Absolute numerousness judgement (ANJ) is numerical competence in which the concrete number is discriminated. ANJ hasn't been tested in pigeons (Columba livia) yet. Therefore six individuals were tested in discrimination of number "three" from ratio 2 vs. 3: two pigeons on "touch screen" and all six by opening small bowls that were closed by discriminated stimulus. Pigeons didn't reach required level of 70 % (they answered with success approx. 30 - 65 %) in any testing environment. Mixed presentation was created such as control of size, possition and shape of discrimination stimulus. It was also studied wheather pigeons used alternative strategies. Success in ANJ was compared with previous discrimination tasks (Kocourková, 2016) in both environment (discrimination of reduced black and white stimulus on the cap and discrimination of round-shaped black and white areas in the Skinner box). If was found out that pigeons weren't able to learn in the same condition discrimination 2 vs. 3 stimulus during the same number of trials which they needed in the previous discrimination task. During answering to the stimulus they didn't use any alternative strategies with one exception. The effect of social hierarchy in the group on the performance of pigeons wasn't found out. Keywords: Columba livia, numerical...