Over 80 species of river birds are found along braided rivers from the mountains to the sea. Many of these birds and other braided river species such as the robust grasshopper are threatened or at risk for reasons explained here.
See a detailed explanation of the New Zealand threat classification system to learn how and why animals and plants are placed into these categories (you can also download the Threat Classification Manual).
To place it in context Nationally Endangered means two stops to extinction. Nationally critical means next stop – extinction.
Black-billed gulls, for example, are Nationally Critical – just one step from extinction. They don’t receive the same attention as iconic species like kiwis, and yet they are far more likely to vanish forever unless measures are taken, and taken very soon, to reverse this trend.
Declining is an early warning alarm, signalling something is wrong. Many birds and other species in this website that fall into this category, such as the white-fronted tern and black-billed gull are long-lived. While the total number of birds might appear to be reasonably high, if insufficient juveniles are being recruited into the breeding population, once adults reach the end of their lifespan the population can drop catastrophically.
3-7 page PDFs below include maps, types of river birds on each river in the South Island, and threats. These were extracted from Forest & Bird’s Important Areas For New Zealand Sea Birds: Sites on Land:Rivers and Estuaries, published 2016 (177 pages). NOTE: the last known sightings or surveys were at the time of publication. On some rivers, this may have been several years ago, as birds populations are dropping rapidly due to threats.
Marlborough & Nelson
Note: research papers on specific birds and rivers are listed under their respective pages
Hughey et al (2009) Birdlife: Application of the river significance assessment method to the Canterbury region (480Kb PDF). Regional councils are faced with the task of identifying water bodies of importance in their region – there is no objective method for undertaking this evaluation. As part of developing a ‘tool’ to achieve this task, this report applies the method for significance to:
The Expert Panel for the birdlife trial in the Canterbury region comprised Ken Hughey, Colin O’Donnell, Frances Schmechel and Andrew Grant. Peer reviewers were Murray Williams and Paul Sagar. Ken Hughey managed the case study.