[3] For the rest of his career, he gave most of the zoology lectures based on a traditional curriculum that covered all major aspects of the subject as known at that time, but that was lacking in fieldwork.
He complained that he had been promised the full professorship if he succeeded in building up the zoology school, as he had, but without effect.
[1] McGregor has been described as "charismatic and forceful in the lecture theatre, but poorly qualified to preside over a scientific discipline that was on the threshold of rapid change.
Essentially insecure, he ran the department with a rod of iron, suppressing dissenters and, by and large, discouraging scientific debate".
[6] Starting in the 1940s, McGregor launched a campaign to protect the Waipoua kauri forest, giving the status of a sanctuary.
[9] He continued his campaign against forestry in the reserve after retiring in 1960, and founded the New Zealand Conservation Society.