Contributed by Patrick Chee, Small-Mammal Control Planner, Pacific Cooperative Studies Unit – RCUH in collaboration with Division of Forestry and Wildlife Hawaii Department of Land and Nautral Resources
Every fall I find myself browsing Halloween decorations to see what rodents and cats are for sale. You might find that odd, but my job deals with invasive small-mammal issues here in Hawai‘i. Iʻm curious to see what people might find scary about small-mammals, and I find decorations to add to my Halloween decor. I actually keep several of them hanging around my office all year to remind me that these invasive predators are scary for Hawaiʻi’s native species every day.
Here in Hawai‘i, our native plants and animals made their way here across large
expanses of ocean and found a place free from mammalian predators on land, except for insect-eating bats. Unfortunately, the arrival of humans brought several non-native predators to our islands which would forever change the ecological landscape of Hawai‘i.
Mongooses, cats, dogs, and rodents decimated our native birds, snails, insects, and plants in the lowlands. Even now, in the refuges that still remain, mammalian predators have followed them into some of the most remote areas of Hawai‘i. For example, rats, cats, and mongoose have all been implicated in the extinction of ʻalalā (Hawaiian crow) from the wild. Cats in particular both directly prey on ʻalalā and spread toxoplasmosis which is known to infect them.
The ʻalalā was once found across most of the Hawaiian islands and played an important ecological role in the Hawaiian forest. The ʻalalā was a generalist that consumed insects and fruit and then distributed the seeds throughout the landscape. Predators have negatively impacted Hawaiʻi’s ecology and continue to do so at an alarming rate.
Because of these impacts on island ecosystems, the National Wildlife Federation,
with the support of CCH, passed a resolution which urges state and local governments to take humane steps to protect island wildlife from introduced predators including cats and rodents.
In addition to toxoplasmosis, outdoor cats are known to transmit a number
of diseases and parasites to wildlife and humans including hookworms, roundworms, and cat scratch fever.
The situation regarding cats is of added concern given their relationship with humans as companion animals. There has been significant pressure from cat advocates to promote Trap Neuter Return Manage (TNRM) programs as a way to address the growing number of cats established outdoors. Yet, significant scientific research shows that cat populations in these colonies often do not decrease over time, especially due to immigration or abandonment.
Outdoor cats are also more likely to live hard and shortened lives. An indoor cat may live 17 years whereas outdoor cats live an average of 2 to 5 years. In addition, Animal Control Contractors across the country have increasingly refused to intake stray cats and/or charge prohibitive fees in order to admit cats, a function which many had been contracted by their local governments to do.
Instead, they actively encourage TNRM or “return to the field” of cats to where they were found. This allows shelters to focus their limited space on socialized cats and cats that are injured or need additional care. However, this means healthy stray cats are returned to the area they came from where they can harm wildlife, leaving those who donʻt want the cats around with a serious dilemma. Either the individual must find a contractor to get rid of the cat or find a way to eliminate the cat themselves. Clearly, neither alternative is desirable, and local solutions are still not available.
There are a number of efforts by nonprofits, government agencies, industry, and private citizens to reduce the impacts of non-native predators on islands. Many of these stakeholders have been working to build relationships that benefit animal welfare, wildlife conservation, and human health. In a number of localities, efforts have effectively worked under the strategy of “One Health” which highlights how keeping pets indoors or effectively leashed/contained is good for the health of people, the health of wildlife, and the health of the pets themselves. Stakeholders are building on common efforts like promoting pet identification, addressing behavioral issues, requiring sterilization, and promoting pet rehoming or surrendering unwanted pets to a shelter. These efforts help promote a common goal of keeping pets in loving homes, rather than being released into the environment and becoming harmful.
Invasive predators in Hawai‘i have an ongoing and significant impact on Hawaiʻi’s native species. If we do not act soon, more of them will become endangered and extinct.
We will continue to share updates on our efforts to reduce invasive predator impacts with CCH, and we hope for your continued support. The scary truth is that we are all impacted by invasive predators in Hawaiʻi, and not just at Halloween.
Want to reduce invasive predators in Hawai‘i?
Contact your lawmakers and urge them to address invasive predators and their impacts on the health of people, pets, and our native species. CCH will keep you updated when policies addressing invasive predators are being considered by policymakers. Then, voice your support at the hearings (in person and in writing) to address the threat invasive predators pose.