You may have heard of ongoing mosquito birth control efforts on Maui to protect native forest birds from avian malaria, but what about rat birth control?
The Maui Nui Seabird Recovery Project is trying out family planning on rats to save its island seabirds. The original, native birds go back 70 million years, so they evolved without having to adapt to any mammalian predators.
"When people brought rats, mongoose, cats, pigs, goats, all these animals predate seabirds, and they were one of the, and continue to be one of the reasons that seabird populations decline," said ecologist and project manager Jay Penniman.
He said rodents are particularly a problem because their size allows them to get right into burrow nests.
"They eat eggs, they eat chicks, and they will even predate adults. On Midway, they tried to get rid of the mice recently because the mice started eating the albatross, just while they were sitting on their eggs," Penniman said.
The conservationist group has used rodenticides in the past, but the chemicals can unintentionally kill other animals who come along and eat the dead rodents.
Penniman said the group became interested in a new product to prevent rodents from reproducing: Evolve by the company SenesTech. According to SenesTech, the active ingredient is cottonseed oil, which hinders the reproduction systems of male and female rats.
The group has been running trials of the product to see how effective it is in the field. So far, the rodents have loved the bait.
"We've been doing it for several months now, and the bait disappears every time we put it in," Penniman told HPR. "We look at their age every time we catch them, and if we're being effective, we should see very, very few, if any juvenile rats, it'll just be adults."
He said they need to catch enough rats over a long period of time, a year or more, to start preliminary analyses and determine Evolve's efficacy in the field.
"After that, we would be looking at aerial broadcasts across areas so that you're feeding enough rats that you can suppress it," he added.
This interview aired on The Conversation on Sept. 11, 2024. The Conversation airs weekdays at 11 a.m. on HPR-1.
