"Normally Teina was active for around 10 to 12 hours but when he started to nest his activity levels dropped down to two or three hours – it showed he was a good and committed nester."
Hamilton was able to monitor the kiwi's activity via a chick timer – a "smart" radio transmitter strapped to Teina's leg. Chick timers were designed by engineers in Hawke's Bay to detect a kiwi's movement by using software to count how often a kiwi moves his leg.
Only male kiwi have chick timers because they incubate the eggs after the female has laid them.
Hamilton said as the days passed he had hoped to break the happy news of the addition to Teina's family.
"The truth was, he had sat on a rock."
The disappointing discovery was made by Hamilton when concern about the unusually long incubation period prompted him to check the nest while Teina was scavenging for snacks and using the loo.
"I put my hand in and felt a warm, smooth rock."
There could be many reasons why Teina fell victim to mistaken identity, Hamilton said.
"He could've been too busy cuddling up to his mate or he was just so keen on being a dad that his instincts took over."
The good news is Teina is going to make a great dad – when he finally gets a live egg.
"With the first nest the dads don't show enough commitment but Teina showed he just loves it."
To have a kiwi like Teina was incredible, Hamilton said, as he and his mate can breed for 50 years at a rate of three chicks a year.
"As long as a dog doesn't kill them they will be able to add 150 chicks to the kiwi population."