Caitlin Wells, research scientist, in the koloa’s corner

Joey Wagner

A Colorado State University research scientist does one better than just braking for birds in the road. She has her sights set on saving an entire species: the endangered koloa. 

Caitlin Wells, research scientist, conservation biologist and lead author of a new scientific paper about the koloa, has a passion for helping wild animals, and the koloa is far from her first exposure to animal conservation, especially bird conservation. Her findings, published in “Persistence of an endangered native duck, feral mallards and multiple hybrid swarms across the main Hawaiian Islands” revealed that the koloa, the last endemic duck species on the main Hawaiian Islands, still stands a fighting chance.

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One of her first research projects involved following the endangered golden-cheeked warbler in central Texas.

“The first time I saw one of (the warblers) through binoculars, I was just amazed by how smart and charismatic it seemed, and I’d never really thought about other species having this whole internal world and way of navigating the world that was totally different from people,” Wells said. 

Wells has also traveled to Panama and interned with the Smithsonian Tropical Research Institute to work with birds and study their behavior and breeding.

The koloa project isn’t her first experience with studying Hawaiian birds either; she also worked on the Maui Forest Bird Recovery Project.

“There are lots of endangered Hawaiian birds,” Wells said. “Many of them are already extinct. Half of the ones that are left are endangered.”

Many Hawaiian birds have become endangered because of climate change, avian malaria and loss of habitat, Wells said

This is why, Wells said, working to eradicate the koloa’s threat of extinction seemed to have a higher chance of success than tackling other birds’ endangerment since the primary threat targeting the koloa can be narrowed down to a more specific culprit: the feral mallard.

While climate change, avian botulism, habitat loss, hunting, the introduction of non-native predators and the tourism industry have all contributed to the endangerment of the koloa, its hybridization with the domestic mallard is the biggest issue the species faces.

Chiara Zagnoli, a senior biology major, is currently working with Wells on interpreting data to understand the social structure of ducks and how this can help with understanding disease transmission like botulism, another killer of the koloa.

There are very few pure koloas left on the Hawaiian Islands except for on the island of Kauai, as found through a massive project where blood samples were collected and tested to determine the levels of koloa ancestry in the birds.

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a female mallard duck
A female mallard duck along Spring Creek Trail in Fort Collins on April 19. In Hawaii, the endemic Koloa looks similar to the female mallard but is genetically distinct and threatened due to inbreeding with mallards. (Ryan Schmidt | The Collegian)

Wells and her colleagues found that most of the birds on the island were 95% or higher koloa. Other islands had some birds who were about 50% koloa, many who were 10% koloa and some who were 100% feral mallard.

Saving the genetic purity of the koloa is important for a few reasons, Wells said.

“Hybrids might be less fit, less suited to their environment, so they’re less able to survive,” Wells said. “(Domesticated mallards) don’t survive as well on their own, … so when those genes move into the gene pool of the koloa, that makes them less able to survive, and it endangers them further as a wild species.”

The koloa is the only species left out of the main Hawaiian Islands’ endemic ducks and stands as a “unique piece of Hawaii’s history and the world’s biodiversity,” Wells said.

It is also a crucial part of the ecosystem, as it disperses wild plants and invertebrates from pond to pond and is prey to the pueo and ‘io, the koloa’s only native predators.

Saving the koloa is only one step in restoring habitats and ecosystems that have been destroyed in Hawaii.

Mark Paschke, the research associate dean of the Warner College of Natural Resources, said for every strand that is removed from the ecosystem, something else unravels somewhere else.

“When you lose a species, whether it’s a soil bacteria or a duck, there’s going to be ripple effects throughout the ecosystem because that critter is connected to all the other critters in the system,” Paschke said.

To save the koloa, however, steps have to be taken to remove the feral mallards from the islands in order to create more than one self-sustaining population, Wells said. 

While sterilization has been discussed, that process can be “torturous,” and many female ducks don’t survive. Wells said it is more humane to remove them or put them in captivity.

a female mallard duck
A female mallard duck along Spring Creek Trail in Fort Collins on April 19. In Hawaii, the endemic koloa looks similar to the female mallard but is genetically distinct and threatened due to inbreeding with mallards. (Ryan Schmidt | The Collegian)

“I’m a conservation biologist,” Wells said. “I don’t wanna kill any more animals than we have to, but if we’re weighing a couple dozen domesticated ducks with the existence of an entire species, that seems like a much easier choice to me.”

The authors of “Persistence of an endangered native duck, feral mallards and multiple hybrid swarms across the main Hawaiian Islands” include Wells, Philip Lavretsky, Michael D. Sorenson, Jeffrey L. Peters, Jeffrey M. DaCosta, Stephen Turnbull, Kimberly J. Uyehara, Christopher P. Malachowski, Bruce D. Dugger, John M. Eadie and Andrew Engilis Jr.

“We are important as humans, but no more important than all the other living beings on this earth,” Zagnoli said.

Joey Wagner can be reached at news@collegian.com or on Twitter @joeyleewagner.