An endangered Hawaiian duck or koloa, the only endemic duck remaining on the main Hawaiian islands, is threatened by genetic extinction due to crossing with wild mallards. This led to the creation of hybrid forms of koloa. But new research has shown that koloa's genetic diversity is high and conservation efforts on Kauai have been successful.
Caitlin Wells, a researcher at Colorado State University, conducted his research as a PhD student at the University of California at Davis. This study is the culmination of two decades of research conducted by scientists from the University of California, Davis; US Fish and Wildlife Service; University of Texas, El Paso; Wright State University; Oregon State University; and the state of the forest division and wildlife in Hawaii.
The results of the study give hope for existing efforts to protect koloa and other endangered birds around the world.
"The persistence of an endangered native duck, wild mallard and many hybrid swarms on the main Hawaiian islands" will be published on November 18 in Molecular Ecologyand Wells is the lead author.
Charismatic duck, located mainly on Kauai
Wells described the koloa as "a small, buffy brown and charismatic duck," like a female mallard.
"The fact that Kauai collages are pure and have many genetic variations are two really positive things that result from this study," said Wells.
Andy Engilis, co-author of the research and curator of the UC UC Davis Museum of Nature and Fish Biology, said that this study is crucial in the fight to save the wheel from extinction. Since the late 1980s, he has been involved in the protection and research of Hawaiian ducks.
"This study forms the basis for a new chapter in koloa reconstruction, a new trajectory towards recovery and withdrawal from endangered species," he said.
Kimberly Uyehara, a biologist at the Kauai National Wildlife Refuge Complex and research co-author, said the findings were significant.
"They are opening a new door to the kingdom of possible corrective actions for the koloa," she explained.
The largest koloa population is in Kauai, where the team found very few hybrid birds. On other islands, however, all the birds were hybrids or wild crusaders.
Historically, koloa existed on the main Hawaiian islands, but disappeared from all islands except Kauai and Niihau in the late 1960s due to habitat loss, predator introduction and unregulated hunting. Shortly thereafter, wildlife managers began captive breeding and release programs in Oahu, Hawaii and Maui to restore the collage. Unfortunately, the crosswords were never removed on these islands, which resulted in rapid hybridization.
This study was partially conducted to determine the genetic composition of Kauai's koloa. Earlier, wildlife managers and environmentalists reported that even Kauai's shelter contained hybrid ducks.
The research project involved a massive bird whirling project
The research team investigated 425 koloa, crosses and hybrids from the population of Hawaii, collecting over 3,300 genetic data points from birds. The project included a huge bird strapping project, led by collaborators from Oregon State and Hanalei National Wildlife Refuge. Team members took blood samples from hundreds of birds before being released.
Researchers also collected genetic data from cola carcasses recovered after botulism, especially in the Kauai population. All samples and samples are archived at the UC Davis Museum of Wildlife and Fish Biology.
"We used many tissue samples from rescued birds that unfortunately died as a result of the outbreak," said Wells.
Earlier, nature managers thought that if they leave koloa hybrids alone, the birds would eventually return to pure koloa on their own.
"We didn't find it," Wells explained. "If you don't have pure koloa parents who outnumber wild crosses, you won't reduce these hybrid proportions."
Why keep it?
The recovery of endangered koloa is important because the bird is endemic to Hawaii.
"His recovery can be considered a beacon of hope for many dozens of critically endangered birds found on the islands," said Engilis. Researchers also point out that its recovery is important because of its unique evolutionary history.
"If the environment changes due to climate change, Koloa has great potential for independent evolution, given the genetic diversity we've seen," said Wells.
Species hybridization is a difficult conservation issue. Sometimes it can threaten the animal's unique gene pool that is well adapted to the environment. In other cases where the species is inbred, it may be a good idea to increase the genetic diversity of the population.
"But here is the case where we have enough individuals with sufficient genetic diversity in koloa, and we have also genetically identified a hybridizing species," she said. "It seems very clear that we can separate those who move forward."
What's next with koloa conservation
Wells said the team's research provides insight into effective conservation management and the ability to recover this species.
"These efforts may one day lead to the deletion of koloa from the list of endangered species," she said.
Home trends pose a threat to Hawaiian jellies
A Little Duck That Could: Study shows that Hawaiian duck is under threat (2019, November 18)
was recovered on November 18, 2019
This document is subject to copyright. Apart from any fair transaction for private research or research purposes, no
some may be reproduced without written permission. This content is for informational purposes only.