Thursday, November 5, 2015

Forest birds of Hawaii are the latest animals threatened by climate change


Some of the rarest creatures in the world could become extinct due to fossil fuel dependence.

Researchers used a variety of sources, such as a database of sightings and regional climate projections, which allowed them to predict future changes of distribution of species across the American islands.

An `I`iwi, also known as a scarlet Hawaiian honeycreeper Image credit: Harmonyonplanetearth/flickr
Previous conservation research regarding forest birds has focused on the links between climate change and avian malaria, whereas this study looks at the potential impacts of climate change on at-risk species. It's also easier for scientists to gauge the impact of climate change given the unique species residing on the island and their specific habitat requirements, compared with species in much larger territories. These habitat requirements are what limit any potential population expansion for forest birds.

All ten species investigated for this study are expected to lose over 50 per cent of the range of their habitat by 2100, and three of these species are set to lose over a staggering 90 per cent during the same period.

Hawaiian 'akepa Image credit: Casey Sanders/Wikimedia
One of the species concerned is the Hawaiian 'akepa, a very small bird found in ‘ōhi‘a and koa-‘ōhi‘a trees above 4,500 ft. It was once present in Oahu, one of the smaller islands of Hawaii, but the last possible sighting may have been in 1976. The population is estimated at 12,000 on the main island, but was as low as 230 in Maui in the early Eighties, where it was last heard in 1995.

An ʻōmaʻo (or Hawaiian thrush) Image credit: harmonyonplanetearth/flickr
The ʻōmaʻo, also known as the Hawaiian thrush, is one of the very few examples of a forest bird species high in number. However, because the bird is found only on the main island, it is considered vulnerable to future extinction. The bird feeds primarily on fruit and seeds, but occasionally eats small insects and vertebrates.
Previous research has shown the link between temperature, avian malaria and vectors for diseases, allowing researcher to investigate how climate change will cause malaria to move into higher altitudes, where these forest birds reside. The populations will decrease because of this, and also reduce overall distribution across the islands.

Although the authors recognise some of the successful conservation work such as controlling invasive species, and forest restoration, they conclude these strategies may not be enough, with even intact native forests unsuitable, due to the increasing temperatures spreading avian malaria. Will anyone care to mention these colourful birds at the upcoming UN climate conference in Paris?

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