Is the T-maze an appropriate tool to measure parrot behaviour?

We implemented an inverted T-maze to analyse cognitive challenge preference of eleven captive kea (Nestor notabilis). Kea were previously trained to solve a visual discrimination task with varying difficulty levels. An easy and a hard version of the task were provided in each end of the maze. Exposure to the maze started with four training sessions of 20 trials in which one arm (i.e. the easy or hard task) was blocked for five consecutive trials followed by the other being blocked for the next five consecutive trials and so on, to force exploration of both sides. We then measured kea’s arm choice during eight additional sessions with both arms unblocked.
We calculated an exploration index (EI) with the number of times a kea chose a side of the maze different from their immediate previous choice (e.g. a kea choosing alternate sides for every trial in a session would get an index of 19 whereas a kea that always chose the same side would get an index of zero).
All kea correctly navigated (i.e. walked) the T-maze in both the restricted and unrestricted sessions. Six kea showed a bias for the right arm (EI≤1) in four consecutive sessions and were not tested further. Average data for the remaining birds’ EI show an increase in exploration in the eight sessions. The youngest kea had the lowest average EI. EI did not approach its maximum possible value, which could indicate that kea were actively showing maze arm preferences. However, the increase of EI across sessions could signify that kea’s preferences towards either arms were dissipating. To our knowledge, this is the first time a T-maze is implemented on a parrot species.