Hihi are so rare and endangered that even the London Zoological Society has stumped up money to survey their progress at Whanganui's Bushy Park.
Ecologist Kate Richardson, who works for Wildland Consultants, was in the midst of a four-day survey during Conservation Week.
She has a PhD on the elusive little birds, and her job was to find as many as possible within the 100ha forest reserve.
The birds need to be surveyed before their breeding season begins. Richardson will do her best to find out how many there are.
She'll catch and identify those that were raised in nest boxes and have been banded.