Auckland zoo has released its 300th kiwi chick today.

The four week-old male named Tihoihoi - Maori for raucous - is the first Coromandel North Island brown of the season and the 13th kiwi to be released onto the 83 hectare pest-free Rotoroa Island, which first began welcoming this rarest of brown kiwi a year ago.

Auckland Zoo field conservation manager, Ian Fraser says the kiwi will spend about a year on the island before being released to the wild.

"And is that time it'll put on enough weight to get big enough to have a decent chance of fighting off a stoat which is their main predator on the mainland so once they reach about 1200 grams in weight they are ready to be mustered up and taken back to the Coromandel where they came from."

He says it's still early days but overtime this sort of work is likely to make a difference to the population.

"The work we're doing out here on Rotoroa is as much about showing people conservation management and demonstrating the techniques that get used, you know it's really about advocacy as much as it's it about kiwi numbers."