Wednesday, April 30, 2014

Saving the Critically Endangered Palila Bird

Hawai’i is one of the most isolated lands in the world, sitting in the middle of the vast Pacific Ocean, almost 2,500 miles distant from San Francisco, its closest port-of-call. Up until the arrival of the first humans (some 1,700 to 1,200 years ago), the island chain was populated solely by flora and fauna that arrived in one of three ways: via bird, winds, or ocean currents. And many of those plants and animals that did manage to make the long voyage evolved over millions of years into completely new, distinct species.

downtown Hilo’s new Palila mural,
painted by Kathleen Kam
(you can order a signed print of the mural here)
It has been estimated that there were some 8,500 native species on the Hawaiian Islands before the arrival of the first Polynesian sailors, and that about 96% of these were endemic—i.e., they evolved on the islands and were found no where else in the world. Perhaps even more interesting is that these endemic species are thought to have evolved from only about 1,000 original colonizing species. In other words, some eight new species evolved from each one that made it to the islands. (Many of these facts, as well as ones that follow, are taken from this document.)

A good example of many differing species evolving from a single one is the honeycreeper. Scientists believe that a single ancestral species arrived in Hawaii about 20 million years ago, and that its descendants evolved into 47 new endemic species. The great diversity of the islands—from parched deserts to tropical forests to alpine mountains—explains the differences that evolved, with the new birds varying widely in color, plumage, and bill shape.

It is not thought that the arrival of the ancient Polynesians had a negative effect on these endemic honeycreepers (or on other endemic species), for although they would catch the birds on occasion for their feathers, the native Hawaiians were conscientious about allowing their plants and animals to flourish.

But with the arrival of Captain Cook and the subsequent flood of non-Hawaiian visitors, the endemic species—including the honeycreepers—began to suffer. Several factors have caused this. With the introduction of the some 9,000 new plants and animals between 1778 and 1994 came many that were harmful to the birds: mosquitos (which carry diseases that kill them); pigs, cows and sheep (which trample and eat the plants they depend on); house cats (which prey on them); and mongooses (which eat their eggs) are just a few of the introduced species which are causing the die-off and extinction of Hawai’i’s endemic birds.

In addition, the clearing of forest land, cattle ranching, and real estate development have resulted in the disappearance of virtually all the native vegetation at the lower and middle elevations of the islands. As a result, most of the honeycreepers’ habitat has been lost as well.

The Palila is an endemic honeycreeper which currently lives only on the upper slopes of Mauna Kea on the Big Island, and which is now listed as “critically endangered.” (You can watch a PSA about it here.)

A few weeks ago Robin and I volunteered for the day to plant seedlings for the Mauna Kea Forest Restoration Project—an agency our neighbor Jackson Bauer works for—which is restoring the Palila bird’s dwindling native habitat. An overview of what the MKFRP does (with some cool photos of snow on the mountain) can be found in this blog post by the American Bird Conservancy. As explained in the post just cited,

This project is working to restore high-elevation dry forest for the Palila, a Hawaiian honeycreeper listed as endangered in 1973. This Critically Endangered bird now occurs only on the southwestern slope of Mauna Kea, which is less than five percent of its historical distribution on Hawai’i Island.

Palila are dependent upon māmane trees, a legume (pea family), that provides these birds with about 90 percent of their diet in the form of seeds that are toxic to most other animals, yellow flowers, young leaves, and moth larvae found in the seed pods.

a healthy māmane tree

Unfortunately, even on the five percent of the Palila’s historical distribution that still exists, the māmane is suffering, largely as a result of sheep and cattle grazing. Although most of these animals have now been removed from the area, the damage has been done and there are far fewer trees than necessary for the Palila to survive. Our neighbor Jackson tells us that as of the last count, the estimate is that there are now less than 2,000 of the birds in existence.

Palila habitat, with lone dead māmane tree

After a walk through one of the more pristine areas of Palila habitat (during which we were lucky enough to sight two of the rare birds!), Jackson gave our volunteer group a demo on planting techniques. Here he is, a keiki (seedling) in one hand and digging tool in the other:

We split up into groups of diggers and planters. Here you can see the diggers:

Robin is nearest the camera

And here are more keiki being brought in for us to plant:

By the end of the day we had planted some 800 new seedings.

The MKFRP is doing a good job of getting the word out locally about the danger of extinction for the Palila. Here’s a photo of Robin and me at the recent Palila Parade, to celebrate the unveiling of the Palila mural downtown (see photo above).

Robin is a māmane branch and I’m a little rain cloud
(photo: Anya Tagawa)

But they could use more help! If you’d like to learn more about the Palila and their plight and efforts to save the species, and/or volunteer for the project or donate money, click here. They have a Facebook page you can like, too!

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