Monarch butterfly. Photo/George Novak
Last week we discussed how you can help out with the monarch butterfly tagging programme starting in March.
Here's another way you can become a citizen scientist and help collect information on the butterflies you see. Learn about walking a transect and how to observe butterflies.
What is a transect?
Scientists
use transects to monitor changes in our environment. A transect is a marked- out path, about 100 metres or several kilometres in length. A person follows the path at planned intervals to record observations of plants or animals.
In New Zealand, transects are used on land and in the water to monitor biodiversity (biological diversity), which means the variety and variability of species and ecosystems.
Transects also monitor species population size, record food sources and study pest radication.
Some transects have been regularly monitored for decades. For example, the Department of Conservation established a transect line in Takahe¯ Valley, Fiordland, in 1972. It is monitored annually to measure tussock seed food sources for the endangered takahe¯.
You may have seen a transect if you have been bushwalking. They are often marked by fluorescent pink or green ribbons and might be used for tasks like monitoring traps or counting species.
Why observe butterflies?
Butterflies react very quickly to changes in their environment which makes them excellent biodiversity indicators. By providing information on butterfly sightings and locations, we can help scientists study the impact of habitat loss and fragmentation, and climate change.
What to do?
You'll need to plan a route suitable for observing butterflies. It might be around your garden, or along your street. Butterflies prefer weeds and gardens to neat and tidy lawns so a transect along a fence line is likely to produce more sightings than a transect through your school playing field.
*Decide how often to monitor the transect. The Monarch Butterfly New Zealand Trust (MBNZT) recommends a weekly walk on warm, dry, sunny days from March to October.
* Make notes of any butterflies you see along your walk. Take note of the species, the time of day, weather conditions, location and what the butterfly is doing such as feeding on a flower or flying. You might even see a tagged butterfly (see last week's article for butterfly tagging), so make sure you note that down as well.
* If you're quick, you might be able to take photos of the butterflies. This will make it easier for you to identify the species later.
* You can log your sighting on the Report Butterfly Sighting page on the MBNZT website, where you will also find some helpful information to help identify butterflies, and find out about their host plants (for example, the monarch butterfly's host plant is the swan plant). www.monarch.org.nz/ monarch/introduction-toresearch/report-a-sighting/
*Transects follow certain rules, such as only reporting sightings within the defined transect area. For this activity, you can include butterflies you see in your neighbour's garden. Have fun with your observations!
Thanks to Science Learning Hub for this activity. www.sciencelearn.org.nz
* The House of Science Tauranga is a charitable trust which connects and resources the local science community to celebrate the power and potential of science. See www.houseofscience.org.nz or phone Chris Duggan on 027 337 9342 for more information.