Extreme Makeover: Wētā Motel Edition

Think of a motel. A bright neon sign flashing “VACANCY”. A building with lots of rooms. A large car park probably. These images jump into your mind. However, for many insects, birds and lizards the reality is a lot different. To them, a motel is a place to sleep for the night, one that is designed to recreate their regular habitat.

Above: Banks Peninsula Tree Weta (Hemideina ricta). Photo by Warren Chinn, iNaturalist NZ (CC BY-NC 4.0)

Wētā conservationists and researchers alike have used motels for decades to help monitor and conserve populations easily and without destroying habitats. You can even learn how to make them yourself. A common problem faced by both motel owners and conservationists is in filling up their rooms. How can they make their establishment more appealing?

For a human motel, the answer may come in the form of adding a free buffet breakfast or lowering room rates. For wētā motels, the answer might not be that simple. We looked at “Treeadvisor” (our imaginary insect review app similar to Tripadvisor) to investigate further.

Armed with this feedback, Mike Bowie, Warwick Allen, Jill McCaw and Rachel van Heugten from Lincoln and Canterbury Universities took to the forests to see how they could improve the occupancy rates of wētā motels, for the range-restricted Banks Peninsula tree wētā (Hemideina ricta).

The reviews from “Treeadvisor” are discussed in their study published in the New Zealand Journal of Ecology regarding the previous designs of wētā motels. One issue they discovered was that removing motels from trees to view the occupying wētā disrupted them. Condensation was created from some of the materials involved in the construction of the motels, making it hard to view inside. The entrance hole was also too large, leaving wētā vulnerable to visiting predators.

Wētā motels have been used since 1992. Mike Bowie has been involved in some of the original concepts and designs for the non-destructive monitoring of wētā, since 2006. Previous designs of wētā motels showed low usage by wētā and needed an extreme makeover. Mike and colleagues aimed to create a new wētā motel design, examine if forest type and lures could influence occupancy, and use the results to reassess the distribution of the Banks Peninsula tree wētā.

A Canterbury tree weta checking out the new motel. Photo by Mike Bowie, iNaturalist NZ (CC BY-NC)

The team were able to put together a new wētā motel design, eliminating many of the issues from previous models by changing construction materials and drilling smaller entrance holes. The chic natural wood design of the new motels reduced excess moisture and was considered to be closer to the natural habitat of tree wētā species. This design was used over the next several years to collect their data.

Motels were placed around eastern Banks Peninsula, including areas of remaining native forest, native reserve areas and small bush remnants known to contain Banks Peninsula tree wētā. They found that the new wētā motel design was useful for monitoring the Banks Peninsula tree wētā as well as its close relative, the Canterbury tree wētā (Hemideina femorata).

Forest type was shown to be an important factor with the Banks Peninsula tree wētā preferring motels in less heavily forested areas. It’s possible that heavily forested areas already had plenty of excellent natural motels for wētā to live in. For future monitoring of this species, a less dense and vegetated area, likely on the edge of a reserve, is more likely to increase occupancy rates.

The use of the female wētā excrement as a lure for customers was also a success (more so than with male excrement!), with a up to 80% occupation in motels when it was present. Peanut butter was the least successful, as possums and rodents interfered with the motels where this lure was used.

The new wētā motels showed high occupancy rates for the Banks Peninsula tree wētā. The new design allowed for easy and non-disruptive monitoring of tree wētā populations. The new model motel was found to be considerably better than previous models.

Cave wētā (Rhaphidophoridae) and other native invertebrates were also found to be booked into the new motel design. This indicates that the market for motels is far more diverse than originally thought and would be useful in monitoring wētā from other parts of the country or similar species worldwide.

With the new wētā motels considered a success for the researchers, we took to “Treeadvisor” one more time to see how the local population liked it.

Perhaps it’s just as well they don’t know that the owner is spying on them….

Findings from this research have been used in many studies as a reference for invertebrate monitoring and further research. The full study was published in 2013 in the New Zealand Journal of Ecology: Factors influencing occupancy of modified artificial refuges for monitoring in the range-restricted Banks Peninsula tree weta Hemideina ricta (Anostostomatidae).

This article was prepared by postgraduate student Marissa McDonald as part of the ECOL 608 Research Methods in Ecology course.

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