Two men have pleaded guilty to killing more than 30 birds at a South Canterbury aviary.

Jonathan Fleming and Simiona John admitted they ripped the heads off parrots, galahs and other exotic birds at the Temuka Bird Zoo last month.

A third accused, Michael Kircaldie, has not yet entered a plea.

Timaru Bird Club secretary Lynette Carson was part of a group of bird lovers who gathered outside the Timaru District Court for the trio's appearance.

"We stood outside and let them know that they were scumbags and mongrels. And they took it better than their families took it, their families were a little bit irate this morning and asked us not to call them names. We were confrontational - but nothing happened."

Ms Carson says the bird club is asking for at least a three year sentence.

The two men will appear for sentencing in October.