Although rare globally, braided rivers link over 257 ha of New Zealand's mountains to our sea. This has created a unique environment with rich biodiversity.
Many of our native plants and animals have evolved to thrive in braided rivers, but some are now under threat because of introduced predators, habitat loss, weeds and climate change. So, with the help of local groups and individuals, we gather data on river birds to understand and address these threats to protect them.
You can help by monitoring the species below using our best practice methods and add to our database.
We gather data on:
- gulls - black-billed, red-bill and southern black-backed gulls
- terns - black-fronted, white-fronted and caspian terns
- dotterels - banded and black-fronted
- stilts - black and pied stilt
- spur-winged plovers
- south Island pied oystercatchers
- and wrybills
How to gather monitoring data
Step one: Choose a key question
Those who help to gather data use key question they want to answer that will guide their monitoring work. You might start with a question like:
- What is the population of a location?
- Are eggs surviving and chick fledging?
- Are birds succeeding to nest?
- Are adult birds surviving and juveniles recruited?
Once you choose a question to focus on, select the right methods for data gathering. DOC's best practice protocols (available below) can help you find the best-suited monitoring methods for your query, and how to use them.
The method you select will guide the timing of your data gathering, what data to record and how often and what to analyse.
Read DOC's best practice protocols for braided river bird monitoring (PDF, 9,826K)
Step two: Plan your monitoring
Time your data collection
Most data collection will occur between September to December. Some monitoring, such as for population trends, should match with breeding.
Choose a day when river flows are normal to gather data. Monitor the river flow for a week or two before you plan to gather data when there's dry weather. If there's been a significant flood, don't gather data any sooner than 7-10 days.
Use GPS
Plan to survey the same sections or locations of the river each time and mark them with a GPS unit. Take GPS coordinates of each river section or nest.
If monitoring populations, select a section and divide it into sections of 10-20 km lengths based on access points identifiable to the observers.
If you're gathering data on eggs, chicks and nests, you will need to locate nests by identifying and searching suitable habitat.
Have the right number of observers
Each data-gathering effort should use the same number of observers. The skills they will need will vary based on the monitoring that's underway.
Space observers around 50 - 150 m apart. This is far enough apart to avoid double counts but be able to communicate. How many observers your monitoring needs depends on either how big the river section you're targeting is, or the number of nests.
Ensure everyone has the right skills
Most braided river bird observers will need strong bird identification skills for sound and sight. This will minimise wrongful reporting.
Understanding behaviour will also help to know breeding behaviour and find nests. DOC's best practice document (PDF, 9,826K) contains more information on behaviours and how to respond to them.
Data gathering efforts that require bird banding, such as for adult survival and juvenile recruitment, are complex work. Contact DOC who can help you consider if the time and resources needed will be worthwhile. Bird-banding requires training and a certification.
If you come across banded birds while observing, let us know.
Step three: Collect and record your data
Use DOC's data collection template to gather data to answer any of the above key questions by selecting the correct sheet:
Data collection template (Excel, 31K)
Once observers have all collected their data, record it as soon as possible in the above template. Include GPS co-ordinates where required.
The best practice protocols document clarifies each data point for collection. If gathering nest success data, only note failures as one of the below:
- Predation
- Desertion (fertile)
- Flooding
- Died during incubation (infertile, addled)
- Died during hatching
- Damaged in nest
- Failed, cause unknown
You can find further guidance on the definition of these and on defining video recorded events in section 4.2 of the protocols document.
Step four: Analyse and report
Once you've recorded all observer's data, the method of analysis will depend on the key question.
For example, a section survey can be used to establish trends and help find what is influencing bird numbers in that section. Enter your data into the report summary and include any previous year’s data. You can find more on these assessments in section 2.2 and 2.3 of the best practice document.
Breeding success needs more layers of analysis to determine, and data on at least 30 nests to be statistically robust. The data collection table will help you establish hatching, fledgling and nest success values. These can be used to establish key conservation data, such as fledgling success per female. You can find the calculations in section 4.1.3 of the best practice document.
Mark-and-recapture data is much more complex to analyse. Get in touch with us for more information on this work.
Once you have completed your analysis, record your analysis and results in the same document.
Step five: Send your findings to DOC
Email a copy of your results to DOC. Copies can also be made available on the Braided River aid (BRaid) website. Let us know in the body of your email if you'd like your data made available outside DOC.
Email: agrant@doc.govt.nz