Transect walks record the numbers and locations of native and introduced Lepidoptera, helping track population changes over time. Developed in 1973 by the UK Centre of Ecology and Hydrology, transects provide long-term data that reveal trends and early warnings of decline. Walkers record butterflies seen within an imaginary “box” around them, keeping the method and route consistent each year for reliable results.
Effective monitoring, of course, relies on people first being able to identify NZ’s butterflies and day-flying moths.
Chrissie Ward has been walking a transect regularly since 2009 starting each year in October and continuing until the end of March. Her walk is around the streets of Nelson, and when looking at the results of her transect the decline in (a) monarch butterflies and (b) overall Lepidoptera species over this period is alarming.
The long-term monitoring of our butterflies through recording transects will be very useful and we will train you to do this... whether it's a 1 km or 10 km walk, close to your home or somewhere else where you walk regularly. There is an app. set up to help you keep records. The important thing is being consistent over the years that you walk your transect.
Please email if you are interested in finding out more about creating your own transect.
Nelson Transect Results 2009-2026
Report on Nelson Transect, March 2026
