Scientists from the Smithsonian using DNA data sets to outline the evolutionary family tree of the Hawaiian honeycreeper have determined that the 56 species of the native bird evolved from the Eurasian rosefinch.
In another important finding, the researchers linked the timing of the evolution of the honeycreeper to the formation of the four main Hawaiian Islands.
“It was fascinating to be able to tie a biological system to geological formation and allowed us to become the first to offer a full picture of these birds’ adaptive history,” said Helen James, a research zoologist at the Smithsonian’s National Museum of Natural History and an author of a paper on the study.
Fern Duvall, state Forestry and Wildlife Division wildlife biologist, who was not involved with this study but is working with two of the authors of the paper, James and Rob Fleischer, on a similar project with shorebirds, called the findings “dynamic” and “unique.”
Putting the research in context, Duvall noted that many bird experts believed the honeycreepers to be descendants of the house finch of North America. Instead, the researchers say the Eurasian rosefinch from Asia is the mother bird of the species.
As for the evolutionary discoveries, Duvall said it had been theorized that there was a link between the biologic and geologic development of the birds to the islands. The scientific connection made in the study is new, he said.
“For them to show that that is the case is dynamic,” he said Wednesday. “I think it’s an excellent example that birds’ forms are tied to diverse habitat types.”
What began as a handful of wetland ponds with dozens of birds overlooking Pearl Harbor has turned into a refuge teeming with hundreds.
The number of native birds, including endangered Hawaiian stilts called ae o, in the ponds at Waiawa and Honouliuli at the Pearl Harbor National Wildlife Refuge has been rising since the early 1990s, when a conservation recovery plan was developed, said David Ellis, refuge project leader.
Federal wildlife officials built fences to help keep out predators and began controlling invasive plants and managing water in the ponds.
“There’s been a very noticeable increase,” Ellis said. “There used to be only a few wetland birds that used these ponds ; now we commonly see hundreds, an important step for endangered species.”
The beautiful yet isolated Hawaiian islands hold a bounty of biodiversity, but many of those unique species are rapidly disappearing. The fast growth of invasive species is pushing native Hawaiian species, many of which are found nowhere else on the globe, into extinction. In fact, hundreds of Hawaiian plant species, along with dozens of mammals and insects and other species, already appear on the U.S. endangered species list.
Much of the landscape of Hawaii, especially lowlands near agriculture and cities, has already been transformed, with native species nowhere to be found.
“Invasive species are so prevalent. You’re hand weeding, trying to eliminate them and aren’t able to keep up with them. It feels like you’re fighting a losing battle,” Susan Cordell, research ecologist with the U.S. Forest Service, said recently in a prepared statement. “Restoring these lowland tropical forests to a historic native state is not financially or physically feasible.”
Invasive species are non-native species that disperse widely, rapidly, and at the expense of native species in an ecosystem. Not all non-native species become invasive, but those that do pose serious threats to all manner of plants, insects and animals.
So how can Hawaii preserve its biodiversity in the face of this ever-expanding enemy? A new idea is to try developing “hybrid ecosystems” – native and non-native species mixed in a way that benefits native biodiversity.
Marines at Kaneohe Bay are due to help endangered native birds this week by driving amphibious assault vehicles through the mud as part of three days of exercises that begin today.
The annual exercises at the Nuupia Ponds Wildlife Management Area at Marine Corps Base Hawai’i are called "Mud Ops."
The vehicles break up weeds on mudflats, improving foraging and ground-nesting opportunities for endangered Hawaiian Stilts that live there.
Without these efforts, the invasive pickle weed would crowd the birds out of their natural habitat.
The number of Hawaiian stilts using the ponds has grown to 160 from 60 since the Marines began Mud Ops 28 years ago.
Other native and migratory waterbirds have also started using the Windward O’ahu ponds more.
In the late 1920s, people intentionally introduced birds known as Japanese white-eyes into Hawaiian agricultural lands and gardens for purposes of bug control. Now, that decision has come back to bite us. A recent increase in the numbers of white-eyes that live in old-growth forests is leaving native bird species with too little to eat, according to a report published online on September 17th in Current Biology, a Cell Press publication. The findings show that introduced species can alter whole communities in significant ways and cause visible harm to the birds that manage to survive.
"Native Hawaiian songbirds cannot rear normal-size offspring in the presence of large numbers of introduced Japanese white-eyes," said Leonard Freed of the University of Hawaii at Manoa. "Their growth is stunted."