The deserted nature of the place was a perfect environment for these plants to go wild. In an attempt to discover the pristine land, finches migrated from the mainland to deserted Hawaii. Finding themselves in the middle of nowhere, these birds had to adapt and evolve. In fact, they evolved into a bunch of separate species. They were brought to the island in the 19th century.
Even Hawaiin people might not be able to distinguish native birds from the others. One of the few native Hawaiin birds is the Akiapolaau, a bird that evolved to fill in the place of woodpeckers in Hawaii. They sport vibrant yellow feathers with olive and grey-ish underparts in females and yellow-green backs with black-ish heads in males.
The male is known for its loud, complex singing. Today, we know of only three birds, one male and two females. Scientists are uncertain as to the best way to protect this species from extinction. Palila : Now found only in the subalpine zone of Mauna Kea, palila were also once found in the high forests of Mauna Loa and Hualalai on the Big Island.
Palila are dependent on mamane trees for survival, since they thrive on the seed pods, buds, and flowers of the mamane. They will also eat the insects that live in the seed pods. When non-native feral animals such as sheep, goats, and mouflon were introduced, they trampled or ate the mamane seedlings, and thus destroyed the habitat.
Without mamane trees, palila cannot survive. The palila population could benefit by removal or control of feral animals, and by reforestation of mamane trees. It pecks holes with the short straight lower mandible, then uses the long curved upper mandible to probe for insects and larvae. This means that an increased mortality rate due to disease and predation by rats and cats, will have a terrible impact on their population. And there are thankfully 'akepa species still on Hawaii Island and Kauai Island.
The next one was Maui nukupu'u, which was very unique with this long, decurved bill, and they were a yellow and green bird, kind of filled a little bit of a woodpecker niche in the forest, and they've also been gone for quite a long time now. And then the most interesting species on this list for me is a very recent extinction. So the po'ouli was last seen in , when the last known individual actually died in captivity.
What is happening there that is seeing so much pressure put on native species? What followed very quickly behind those landscape changes were invasive species. So we've had introduction of land mammals, which can depredate on all of our native - naive species that did not evolve with rats and mongooses and cats and all of these things that can eat them. And then the most current and most devastating introduction that we had was mosquitoes and avian malaria. So avian disease is still taking a huge toll on these birds and has pushed them into very small, high-elevation areas where they can survive, where they're not catching this disease being transmitted.
But those small, high-elevation areas are disappearing as climate change allows the disease and the mosquitoes to move higher and higher up the mountains. What can be done to help the remaining species survive? We are trying to reverse that declining trajectory, and we are trying to step in and implement recovery actions for these species.
Unfortunately, with the forces of climate change and something like avian disease, the tools in order to save these species are not readily available. There is a very large effort in Hawaii right now with 13 different agencies, lots of different people trying to implement an incompatible insect technique to control mosquitoes at a landscape scale. And we're hoping that this would allow those mosquito populations to be suppressed and stop the spread of avian malaria into these higher-elevation areas where these critically endangered species are still surviving.
It's - the forests are getting silent.
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