This puzzle was built by my stepfather, James Valentine, and family friend, Tom Bostic. The orignial puzzle idea was obtained from:
Freeman, M. and Jenkinson, T. (2004). Kea (Nestor notabilis) Behavioural Enrichment Manual. Auckland Zoo Native Fauna Division. Auckland, New Zealand.
Here's a fun Speight's Summit Beer commercial that features a kea getting even with a litterbug!