Please note: this article is an overview only and intended for readers who are not ornithologists (bird experts). If you want to dive into the nitty-gritty behind each method, or learn about other methods, more resources are provided below. We also have pages on monitoring native bats and monitoring reptiles and amphibians.
Which birds and where?
Which birds you monitor will depend on the area, the season, the weather, bird behaviour and habitat(s).
If you need some guidance on identifying birds, Birds NZ is an online encyclopaedia filled with photos, descriptions, locations, and audio recordings of native birds (see their ‘identify that bird’ guide on the homepage). Manaaki Whenua – Landcare Research also has a useful summary of local birds (both native and introduced) and some quick ways to identify them.
See further down the page for more resources and links.
Census vs. survey
There is some jargon associated with bird monitoring: for example, a census is an exact (or complete) count of a population within a small, specific area, usually involving birds that are easy to spot and not particularly mobile. A survey is an estimate (or incomplete count) based on observing a sample population over a particular period of time. All surveys involve certain biases (the time of day chosen, assumptions made by the person observing, etc.).
Surveys are able to be carried out by ‘citizen scientists’ (i.e. anyone who’s willing) and are vitally important indicators of local bird populations and also of the wider environment.
The 5 Minute Bird Count (5MBC)
This is the most commonly-utilised survey method for forest birds and doesn’t require any qualifications or experience. The 5MBC originated from the DSIR (Department of Industry and Research) in the 1970s, and since then there have been more than 200,000 recorded 5MBCs. (They’re effective, too; according to the NZ Journal of Ecology, the government was persuaded to halt logging of native trees on public land in 2002 because of data from 5MBCs.)
To perform a 5MBC, simply stand still for exactly five minutes and record every bird you see and/or hear during that time (native and introduced). If you’re not sure of the exact bird, note what you can, e.g. ‘gull species’ or ‘duck species’.
Your data should include:
- Which species and how many of each (try not to count the same bird twice)
- Your location (as specific as possible)
- Your name
- The date and time of your 5MBC (which season will affect population numbers)
- Any other variables (e.g. weather conditions).
The 5MBC is an easy, low-cost way to form a snapshot of the local birdlife, as well as compare with previous counts. However, it’s what is known as an ‘incomplete count’ and not 100% accurate because you’re using a small sample to make wider assumptions.
How to record and share your bird counts
- DOC has templates and spreadsheets for recording bird data (here’s a link to their printable PDF).
- Use iNaturalist or eBird (website and app) to record and share your bird sightings online.
- Bird counts can also be bird-specific, e.g. the annual Great Kererū Count.
- Manaaki Whenua – Landcare Research runs an annual New Zealand Garden Birds Survey each winter (here’s 2019’s tally sheet as an example, with bird photos included). This survey takes an hour to complete, can be submitted online or via post, and the results are turned into an annual report.
For more detailed information, read DOC’s advice on best practice for 5 Minute Bird Counts.
Aerial photo counts
This method is popular for difficult-to-reach locations when monitoring colonies of surface-nesting seabirds (e.g. penguins, albatrosses, gannets). Their nests are usually large and easy to spot. Useful for estimating population changes over time by taking photos of fixed locations, and often historical photos provide a ‘photopoint’ from which to continue.
Advantages include that it creates a permanent record and also provides long-term data from historical photos. However, there are certain limitations, e.g. bird numbers may vary throughout the day. Also relies on the clarity of photos. Photo counts should be carried out for at least three consecutive years, taken on the same date as earlier photos. If possible, best undertaken along with ground-based photo counts (see below).
See DOC’s information on performing aerial photo counts of seabirds.
Ground-based photo counts
Useful for monitoring colonies of surface-nesting seabirds (penguins, albatrosses, gannets, etc.) along with aerial photo counts. Involves similar pros and cons (see above).
See DOC’s information on performing ground-based photo counts of seabirds.
Kiwi territory mapping
Kiwi are extremely territorial birds that tend to stick with one area and one partner. Their calls allow them to form partner bonds and also maintain territory ownership. However, kiwi behaviour varies between, and sometimes even within, different species.
DOC has a kiwi call monitoring programme where trained staff sit in the bush and listen for two hours over four nights at a particular location. They also track kiwi movements from radio tags, the size of their footprints, and using trained conservation dogs. Kiwi monitoring requires good knowledge of the area and training/accreditation. If you have kiwi in your area, contact your local DOC officer for advice. (Here’s their information on kiwi territory mapping.)
Sources and further reading
- DOC’s birds inventory and monitoring page
- DOC’s 5 Minute Bird Count page
- New Zealand Birds Online website
- Birds New Zealand / Te Kāhui Mātai Manu o Aotearoa – Ornithological Society of NZ
- eBird Atlas NZ – NZ Bird Atlas
- How to monitor native bats and monitor reptiles and amphibians
- Researchers tackle challenge of monitoring rūrū.