Nice coin. The front changes to Queen Elizabeth in 1956, but the tui bird on the back remains the same. If your specimen were in fully uncirculated condition like the one in our picture, it would command a decent collector value, say $10 to $20 US dollars. In average circulated condition the value goes down to one or two dollars.
There is a *good date* coin in this series that is worth substantially more than the normal coins. It is a 1956 dated coin where the queen does not have a strap on her shoulder. These coins catalog at $45 when average circulated, and a whopping $700 when fully uncirculated. Just about all the coins have a shoulder strap - the ones without are extremely rare. A 1956 coin with a shoulder strap catalogs at a mere $8 when fully uncirculated.
Wikipedia reports of the tui bird on this coin: 'Tui are considered to be very intelligent, much like parrots. They also resemble parrots in their ability to clearly imitate human speech, and are known for their noisy, unusual call, different for each individual, that combine bellbird-like notes with clicks, cackles, timber-like creaks and groans, and wheezing sounds. The unusual possession of two voiceboxes enable Tui to perform such a myriad of vocalisations.