The country with the highest percentage of its bird species endangered is New Zealand with 30%

Looking at the endangered status of New Zealand birds is an insight into how tenuous their existence is. Nine birds are 'critically endangered'.

The Black Robin or Chatham Island Robin -Petroica traverse - is an endangered bird from the Chatham Islands off the east coast of New Zealand. The black robin was the world's rarest bird, and is New Zealand's comeback hero from the brink of extinction.  Extinction could not have been any closer in 1980 when there was one female named Old Blue and her breeding partner and three other males, but the black robin has been brought back to a population of about 254. 

The Black Stilt or Kakī - Himantopus novaezelandiae - is endemic to New Zealand.

Kaki is a wading bird, with all black plumage and long skinny red legs.  When Europeans settled, kaki were common throughout the country's rivers and wetlands.  As rivers were channelised and wetlands drained, and introduced predators spread, their total number dwindled to a low of 23 by 1981.  Kaki are now restricted to the rivers and wetlands of the Mackenzie Basin in South Canterbury.  They have been intensely managed since 1981, and captive breeding and release has increased the population.