For starters, the common myna was brought to Honolulu in 1866, in an effort to combat an agricultural pest, the cutworm moth, which was wrecking havoc on the sugarcane crops. The mynas were successful, as was their adaption to urban and suburban habitats; they quickly established themselves on neighboring islands. Mynas are striking looking birds, with their bold yellow legs and eye patch. Their confident, even cocky manner of walking instead of hopping can be amusing to watch. Far from shy and retiring, they are highly territorial, and make their presence known through a variety of squawks, clicks, whistles, growls and chirps. While many find them noisy and quarrelsome, they are talented mimics, and you have to admit that their range of vocalizations is pretty amazing. That is, unless you live near their communal roost. Every evening just before sundown, mynas (with the exception of incubating females) within a kilometer or so will meet up at the communal roost, which is typically in a tree with a dense canopy, such as a monkeypod or banyan. Here, they vocalize together in something called a communal noise, which, as you might imagine, can be overwhelming. Needless to say, their droppings at the roost site can pose a bit of a health hazard.
Acridotheres tristis tristis vs. Hawaii residents. Let's just say the common myna is not at the top of everyone's favorites list. This bird really gets people worked up, and there is little attempt to sugar-coat how they feel. So I felt compelled to do a little research to find out the good, the bad, and the ugly about this ever-present and vocal bird. For starters, the common myna was brought to Honolulu in 1866, in an effort to combat an agricultural pest, the cutworm moth, which was wrecking havoc on the sugarcane crops. The mynas were successful, as was their adaption to urban and suburban habitats; they quickly established themselves on neighboring islands. Mynas are striking looking birds, with their bold yellow legs and eye patch. Their confident, even cocky manner of walking instead of hopping can be amusing to watch. Far from shy and retiring, they are highly territorial, and make their presence known through a variety of squawks, clicks, whistles, growls and chirps. While many find them noisy and quarrelsome, they are talented mimics, and you have to admit that their range of vocalizations is pretty amazing. That is, unless you live near their communal roost. Every evening just before sundown, mynas (with the exception of incubating females) within a kilometer or so will meet up at the communal roost, which is typically in a tree with a dense canopy, such as a monkeypod or banyan. Here, they vocalize together in something called a communal noise, which, as you might imagine, can be overwhelming. Needless to say, their droppings at the roost site can pose a bit of a health hazard. Their nesting behavior is another issue: mynas like to nest in tree hollows, or anything resembling a tree hollow, like drainpipes and gutters, which doesn't endear them to many homeowners. Even more egregious, they compete for coveted tree hollows with other birds, and may even evict residents in unsavory ways. This behavior is documented in other countries, though I didn't locate specific information on this in Hawaii. Mynas have a varied diet; they'll scavenge roadside kill and garbage, as well as eat insects, fruits, lizards, eggs.... well, they're not very picky eaters. They have been observed eating the eggs of wedge-tailed shearwaters, ‘Ua‘u kani. That's a no-no. And the fruit industry isn't too fond of them either. Consumption of the berries of the lantana by mynas has resulted in the spreading the seeds of this invasive plant. And if things couldn't look worse for the myna's defense council, they also carry avian malaria, and a host of other mites, worms, and, well you get the picture. In 2008, they earned the notorius title of "The Most Important Pest/Problem" in Australia, and was one of only three birds to be included in the "Top 100 Worst Invasive Species" by the IUCN Invasive Species Specialist Group (ISSG) (by the way, we have another bird on that list here in Hawaii, the Red-Vented Bulbul). We'll Mr. Myna, you have the right to remain silent.....
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Even arachnophobes have to appreciate this endemic, non-venomous, eight-legged and tiny wonder: the Happy-face spider, Theridion grallator, or as it is known in Hawaii, nananana makakiʻi. It makes its home on four of the MHI: Oʻahu, Maui, Molokaʻi and the Big Island, and nowhere else in the world. The smiling face sits atop a translucent yellow body, though some lack markings altogether. Interestingly, the patterns on their backs vary from spider to spider, and from island to island. Hanging out on the undersides of leaves, they are protected when it rains and are camouflaged when it's sunny, as light streams through the leaves from above, casting a yellow-green hue. If you are interested in looking for them, you can inspect both native and non-native plants that have dome-shaped leaves that are not hairy, and unlikely to wave about in winds and rain. These spiders hunt at night, when their bird predators sleep. Using the vibrations of the leaf to locate insects, they sneak up upon them and ensnare them. Rare among spiders, they exhibit the social behavior of tending to their young, bringing tenderized catches to them for up to a month. They stay just one short year on this earth, reminding us: don't worry, be happy.
Today's post celebrates the wiliwili, Erythrina sandwicensis, or Hawaiian coral tree, an endemic tree so rich in history and with so many interesting twists (yes, wili means twist), I was inspired to share what I have learned about it. First, it's the only member of its genus to be native here. It is also one of the few native trees that is deciduous, losing its leaves when in bloom, often in the late spring and summer, though reports on this vary. Yet another unusual feature is it's spiky trunk, which become less pronounced as the tree matures. You'll find it on the leeward slopes, from sea level to about 2000 feet, as it prefers dry habitat. Leaflets are wider then they are long, and come in groups of three. The seed pods usually hold one to three stunning orange to red seeds (color variation is possible) which are used in lei making. Wiliwili means to twist and twist, referring to the way the pod winds opens to expose the seeds. Flowers are clustered, curved and come in a variety of colors including greenish-white, yellowish, salmon, and orange, and are pollinated by birds. The tree itself averages about thirty feet in height. Because the wood of the wiliwili has a low density, it was used to make everything from fishing net floats, to surfboards, to outrigger booms. And it's a tough old tree: drought tolerant, wind tolerant, and one of the few natives to survive on Kaho'olawe. Its nitrogen-fixing abilities also make it easier for other plants to get started on lava flows and eroded areas. Ah, but it has its challenges. Enter the beasts: the Erythrina gall wasps. They were first detected in July of 2005, and quickly spread throughout the islands, wrecking havoc on the wiliwili and other tropical coral bean trees. Curled up leaves and bulbous stems and petioles signaled the presence of the wasp, as the eggs of the wasp laid within the plant's tissues began to swell with their growing larvae. Some feared 100% mortality of the native wiliwili, as foliage loss and an inability to transpire meant the quick deterioration of the trees. Seeds were collected and banked, while specialists worked to control infestations. By 2008, the Hawaii Department of Agriculture employed the parasitic services of a second wasp brought all the way in from Africa, Eurytoma erythrinae. Let the battle begin. 5000 of these teeny tiny wasps (a few millimeters in length) were released, and quickly laid their eggs. Where? Right inside the gall created by the gall wasp. When their larvae hatched, they dined on the larvae of the gall wasp. I know... not a pretty visual, but war is hell. While the verdict is still out on the fate of these keystone trees of Hawaii's dryland forests, it seems that there is good progress being made. If there is a tree out there that can get up after a punch like that, it's the wiliwili.
A Honu world; shimmering, shining, splendid. This is the glorious green sea turtle of Hawaii, Chelonia mydas. No matter how many times I see one, I am always happy to be in their graceful presence. Perhaps it is their ties to both land and water that make them so special to islanders around the world (they are found in nearly every ocean). To the delight of bathers and snorkelers, honu inhabit the shallow waters around the islands, grazing primarily on limu and sea grasses. As marine reptiles, they must come up occasionally for air, and will haul out on beaches for rest and for warming their cold-blooded bodies - an unusual behavior for sea turtles. Honu are the most common of the five species that visit Hawaiian waters, and the largest of the hard-shelled turtles, getting to lengths of three feet and weighing as much as three hundred plus pounds. The "green" in green sea turtle comes from the color of the fat layer between the shell and body. Unlike their land-dwelling relatives, their feet have been modified into flippers, and their carapace streamlined into a teardrop shape. Good thing, because it's a long swim from their feeding grounds to the French Frigate Shoals, where they breed and nest on or near their natal beaches. Females make the trip every two to four years. After mating has occurred, she hauls up on the beach and flipper-digs a hole in the sand in which to lay her clutch of one hundred or more eggs. Once they have been tucked in all snug in their sandy bed, off she goes. She will repeat this process every couple of weeks, laying an average of five clutches during a season. About two months later, the hatchlings emerge and instinctively scramble to the water. It is a perilous journey, with any number of predators, and only a small percentage of the babies will survive to adulthood. They will forage in open waters for several years, during which time they are omnivores, unlike the adults which are primarily herbivores. Eventually, the juveniles will take up life in the shallows like their parents. With luck and our protection, these gentle friends may live as long as the humans they delight.
There are some birds that just have a bubbly optimism to them, and this is one of them. Inquisitive, active, and a versatile hunter of insects and spiders, the 'Elepaio is a wonderful bird to get acquainted with. Just the way it cocks its tail feathers makes it look as if it is posing a question. Don't be surprised if you see one flit down to the lower branches to check out what you are doing. The 'Elepaio belongs to the Old World Flycather Family, and is considered one of the most adaptable of Hawaii's native birds. They are generally recognized by small size and long tails; brown, black, white and rufus coloring; and white wingbars. It is said to mate for life and are loyal to the territory they choose. The female sings, and this is uncommon for songbirds. 'Elepaio are found on three of the MHI: Kauai, Oahu, and the Big Island, and were considered one species, but have since been split into three subspecies of Chasiempis sandwichensis: C.s.sclateri on Kauai, C.s. ibidis on Oahu, and C.s.sandwishensis on the Big island. It is not clear why they are absent from Maui Nui. The populations on the Big Island and Kauai seem to be faring well, adapting to a range of habitats, but the Oahu 'Elepaio was placed on the Endangered List in 2000, with limited ranges in the Wai'anae and Ko'olau mountains. In early July of this year (2013) the U.S. Fish and Wildlife Service announced that Hawaii has received a grant to purchase some 635 acres of critical habitat for the Ohau 'Elepaio. The 'Aiea Ridge Trail falls entirely within this area, and is a great place to go and see this endemic treasure, as well as several important plant species.
You've seen them, and pretty likely, you've felt them. The blue bottle, or Portuguese man-of-war makes it's presence known, with its beautiful blue-tinged gas float above and its stinging tentacles below. The can trail beneath the water as long as thirty feet, ensnaring and paralyzing unsuspecting prey. Blowing in with the trades, the man-of-war land en masse, usually on our windward shores. Not to be confused with their Atlantic cousins which go by the same name (but are larger, more tentacled, and pack more of a wallop), the critter we see here in Hawaii is a different species, Physalia utriculus. While often thought of as a jellyfish, it is actually a siphonophore: a predatory, marine colony made up of individual animals called zooids. The zooids have different forms and functions; some specialize in digestion, others in reproduction, prey-capturing, or flotation. One has to admire the design of the pneumatophore, the gas-filled float that keeps the blue bottle buoyant. A ridge along the top acts like a batten, creating a sail that transports the colony, along with the ocean currents. While the blue tinge makes it easy to spot on the beach, on the open ocean it is well camouflaged, much to the dismay of many swimmers and surfers. It is important to remember that the nematocysts - the stinging cells on the tentacle - can continue to inflict pain long after the organism has washed up on the beach. Leave it to the ghost crabs to do a little beach clean-up.
All critters needs a way to defend themselves, so why not put it all out there, with a splash of color to boot? That's what Heterocentrotus mammillatus, or the red slate pencil urchin does, star of today's creature feature. Thick, blunt spines cover its test (the rigid, calcium carbonate structure enclosing the internal organs) and are attached in a ball and socket manner, allowing them to move in any direction. Turns out that the red color rubs off easily, and so the spines were used like pencils or chalk, thus their name. A small red shrimp, Levicaris mammilata, may be found among the spines as well, blending in magnificently. The spines help the urchin to wedge itself into small crevices, which is typically where you'll spot them during the day. At night they're more mobile, using their spines and tube feet to traverse the reef. The tube feet radiate out in five rows, and the urchins use muscles to force water in and out of them, alternately extending and then relaxing the feet in order to move. The mouth is located at the bottom, with five "teeth" and a modified tongue used for scraping and eating algae, it's primary food. These urchins are sensitive to light, as well as touch, and have a sensory receptor that they use to keep themselves upright. Good thing, as some predators try to knock them over to get at the softer bits. I bet that sends a shiver down their spines.
Images from Hilton Pond Center. http://www.hiltonpond.org/ThisWeek060615.html "Sedges have edges; rushes are round; grasses are hollow right up from the ground." I learned a version of this little chant in a botany class, and have found it a useful tool when trying to identify graminoids. While there are always exceptions to the rule, you'll find that in most cases, a simple twirl of the specimen between your fingers will get you into the correct category.
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