Custom Django 'delete' action not firing from admin list view

I have a 'notes' model in my Django app where I've built some custom delete actions:

class Note(models.Model):
    [MODEL FIELDS HERE]

    def delete(self, *args, **kwargs):
        [STUFF HEPPENS HERE]
        super(Note, self).delete()

If I click into the individual note from the Django admin and hit the 'Delete' button, the custom delete actions work just fine, but if I check the box next to the note in the list view and choose 'Delete selected notes' from the dropdown, they do not.

What am I missing here?