Wednesday, June 14, 2017

Japanese White-Eyes at Hawai'i Volcanoes National Park: Sometimes it's the Point of View

What's the most populous bird on the Hawaiian Islands? Visitors might suspect Mynas or Zebra Doves, given their ubiquitous presence in the tourist areas of the islands, but it's quite possibly this one, the Japanese White-eye (Zosterops japonicas). They are pretty little birds, but tend to be hard to see in the vegetation given their green color. There may be hundreds of thousands of them on the islands, and they can be found from sea level to 9,000 feet, and in both dry and wet forests.
It would be nice if they were one of the native species of the islands, but alas they are not. They were introduced in the late 1920s to help in agricultural pest control, but in a sense they themselves became pests. They may be a vector in spreading avian diseases, and they have been documented exploiting food sources in the higher altitude forests at the expense of native species.

Still, as with many of these invasive species, they are colorful and fun to watch. I saw this pair while walking through the "Bird Kipuka" (Kipuka Puaulu) in Hawai'i Volcanoes National Park on the Big Island. My previous post on the species had the better pictures (see it here), but this pair was doing something that was unusual looking. It appeared that one was grooming or picking lice off the other. I don't know for sure, but I'm sure there's someone out there who can tell me what they are doing.
I shot a short video to provide some more context. Enjoy!

Monday, June 12, 2017

Established and Spreading Fast, the Kalij Pheasant on the Big Island

Once again, in the category of "it seemed like a good idea at the time", someone decided to release a few dozen Himalayan pheasants at the Pu’u Wa’awa’a Ranch on the Big Island of Hawai'i. I'm guessing it was for hunting purposes. They didn't do much for a decade or so, but they reached some kind of population tipping point and began to spread. Their range has expanded across most of the forestlands of the Big Island, and a few have been seen on Maui and Oahu. These are the Kalij Pheasants (Lophura leucomelanos).
 I've seen them most often at the Bird Kipuka (Kipuka Puaulu) in Hawai'i Volcanoes National Park. They certainly add a splash of color to the forest floor, but their role in spreading disease or disrupting food sources for the native bird species is not clear. They sure are a shock when you are walking along a trail looking up and practically trip over them.

Friday, June 9, 2017

Saffron Finch at the Hawai'i Volcanoes Observatory

I'm continuing our discussion of the invasive birds of Hawai'i. Some have more or less replaced those species that have gone extinct, but others are helping prompt the extinction of the few that are left. It's a mixed bag with no easy answers. What one can say is that many of the invasives are beautiful birds. That makes sense, as many of them were caged pets that were released or escaped into the wild.
That's probably the story with the Saffron Finch (Sicalis flaveola), a member of the Tanager family. They are native to South America, and were popular cage birds. They first appeared on Diamond Head in 1965 and spread throughout Oahu. They appeared on the Big Island about the same time and spread across the lowlands. They've ranged into higher elevations and by 2000 they were noted in the village of Volcano next to Hawai'i Volcanoes National Park. That's where I saw them on one of my first trips to the islands in 2002. When I was there last month, they were still living in the same trees adjacent to the Hawai'i Volcanoes Observatory. I've previous posted on some I saw last year on the coast north of Kona.
At the end of the day we returned to the observatory in the midst of a rainstorm. It was still in the same set of trees, and was busy preening. They add a real splash of color to the scene, but their effect on the native birds is not well-known. It's probably not too serious, as they are generally a lowland bird, but I could be wrong.

Thursday, June 8, 2017

An Active Bewick's Wren on the Tuolumne River Parkway



I was walking the Tuolumne River the other day as I often do. Some days the birds are out and sometimes not. This outing I saw three bird species in one tree, some Starling nestlings, an Oak Titmouse, and a wren working out its wings.

With the lighter breast, I'm guessing it is a Bewick's Wren (Thryomanes bewickii), but I never got a good look above the eyes to see the white eyebrow to be absolutely sure (experts, I appreciate correction).
It got a good look at me apparently! It flitted around the branches for a bit, and then settled into a flapping display that I guess was either a food begging habit, or a territorial display. I got a short video, which you can see above. Again, those who know such things are welcome to comment!

Tuesday, June 6, 2017

A Northern Cardinal...in Hawai'i? The Very Definition of Non-native Species

So...you're walking down a tree-lined street in St. Louis, Missouri, and you see a flash of red in the branches. It's a Northern Cardinal (Cardinalis cardinalis)! You could have the same experience walking through the desert around Phoenix, Arizona. You see them on sports monograms. It's all normal stuff if you live in such places. That's where the bird occurs naturally.
But what if you are walking through an ancient kipuka (an island of unburnt vegetation within a lava flow) on the Big Island of Hawai'i? Well, that becomes strange. What is a bird of the eastern US hardwood forests and the desert southwest doing on an island more than 2,000 miles from the mainland? In the last few posts I've been exploring some of the non-native bird species of the islands, and how they have upended the original ecosystem. The alterations and changes began more than a thousand years ago, but the rate of change increased exponentially after European colonization of the islands. New bird species were purposely brought to the islands more than 150 years ago, and they brought new diseases that the natives had no resistance to. Bird species continued to be introduced throughout the 1900s, sometimes as cage releases of pets, but sometimes on purpose. The Northern Cardinals arrived about 1928, and they spread quickly to all of the main islands, and many of the minor islands as well.
It's always a shock to see a Northern Cardinal flitting through the rainforest. The bright red color really stands out against the vegetation. I saw this individual in a tree no more than 30 feet or so from the trail I was walking through the kipuka. Kipuka Puaulu is a unique place, an ancient forest of Ohia and Koa trees that managed to miss being overrun by a fairly recent basalt flow from Mauna Loa. I recently told the story of this kipuka and one other, and to me the story is absolutely fascinating; it even includes what may be the rarest plant in the world (at least for the couple of years when none existed).

It's unclear the effect the cardinals might be having on the native birds. They spread farther and higher than some of the other introduced species. In the meantime, they are beautiful birds in a spectacular setting, even if it is far removed from the original home of the species.

Monday, June 5, 2017

Red-crested Cardinals on Oahu

In 1928 or so, the coastal towns and farmlands of Hawai'i were bereft of native bird species. Non-native species brought to the islands for a number of reasons had carried in their blood the parasite that caused avian malaria. Mosquitos transferred the disease to the native birds, and they were largely extirpated from the coastal lowlands. Most of the natives only survive above 4,000 feet where it is too cold for the mosquitos to thrive.
It wasn't that there were no birds at all in the lowlands. The Common Myna, introduced in the 1850s to control pests in the sugar cane fields, was...uh...common. There were also Spotted Doves, House Finches, and European Sparrows. But these weren't enough for some of the residents. In the 1930s, a bird club called Hui Manu devoted itself to introducing colorful and interesting birds to the islands. The effort was well-meaning, but misguided as one could imagine. Some of their introductions spread well beyond the coastal forests and spread into the higher forests where the native birds struggled to hang on. The new competition didn't help matters.
In any case, a number of the introduced birds were naturalized, and have spread widely. These are the birds most likely to be seen by tourists who stay in the coastal cities. And some of them are very colorful, literally a delight to the eye. Among them most be counted the Red-crested Cardinals (Paroaria coronata). The red head and crest seem to throw off the color balance on my camera sometimes. I saw them all over Oahu, but got the closest when we visited Waimea Valley on the North Shore, and at Kualoa Regional Park west of Kailua. Kualoa is one of the most beautiful shorelines on Oahu.

The Red-crested Cardinals rarely venture above 1,200 feet, so they probably can't be regarded as one of the "bad" invasive species that threaten the livelihood of the native species of Hawai'i. They certainly add a splash of color to the urban and developed areas of the islands.

Sunday, June 4, 2017

And Here's the Grown-up Shama Thrush at Waimea Valley

The Shama Thrush (Copsychus malabaricus) is native to southeast Asia, but was introduced into the Hawaiian Islands in the 1930s-1940s. It has spread widely through the coastal forests of Oahu and Kauai, and would have competed against the native species, except that the natives had been extirpated by avian malaria and lost habitat. Some of them have in fact spread into the higher altitude forests where they may cause problems for the natives.

Thus it is that I have ambivalent feelings about the non-natives. I deplore the destruction of the original habitat and the loss of so many native species, but I also couldn't wish for the silent forests that led some well-meaning people to release their caged birds as a way of repopulating the coastal forests of Hawai'i. And certainly many of the new birds are colorful and interesting.
We saw this male Shama Thrush while we strolled through Waimea Valley on the North Shore of Oahu (we saw the juvenile and a female in yesterday's post). Like the bird, Waimea Valley is not exactly natural either. It's a botanical garden, filled with plants from all over the world. In an odd way, that makes the presence of the Shama Thrush a little less out of place. In any case, it is a beautiful sight.