Showing posts with label Islands. Show all posts
Showing posts with label Islands. Show all posts

Monday, December 24, 2012

I'm a Bleedin' Volcano

I did it to a lesser extent about two months ago, but we’re gonna try for another Endangered Ugly Ecosystem. This one is volcanic, reptilian, and arid. There’s only one problem: it’s immensely famous for being an ecological wonderland. Which it is. But it also looks much like this:


Sullivan Bay, Santiago Island--My photograph

Welcome to the real Galápagos. Yes, the cactus in the picture is listed as vulnerable (lava cactus, Brachycereus nesioticus). The islands were formed (are forming, really) by volcanic activity, so there’s been no contact with the South American continent, some 600 miles away. This means everything that arrives there must be able to manage at least a 600 mile drift, usually on mats of vegetation blown over from wherever they came. This leads to an over-representation in reptiles, because they’re really good at managing a long time without any food or water. Birds get blown off course in the process of migrating, but they’re not ugly enough for inclusion. Mammals tend to have much too fast a metabolism to let them manage months without food, so the only (non-sea-faring; there are sea lions) mammals on the islands are the ever-present mice, which can survive practically anything. There are also bats, which probably got blown off course like the birds.

What EUTs call the Galápagos home? Well, the marine iguanas (Amblyrhynchus cristatus), and land iguanas (Conolophus subcristatus and C. pallidus) certainly fit the bill. The giant tortoises (Geochelone nigra, with many, many subspecies) may not be ugly enough, but it’s certainly plenty endangered. In my attempt to be more welcoming to all kingdoms1, there are also the cacti: the lava cactus mentioned earlier, an endemic species of prickly pear (Opuntia galapageia, also with a few subspecies), and the candelabra cactus (Jasminocereus thouarsii). There are plenty of other endangered things, but most of them are too pretty for me to talk about.

Why are they endangered? Goats, mostly. They escape farms or get released by sailors2 and then they run rampant, eating tons of vegetation, leaving none for the tortoises or land iguanas, and stepping on all the reptiles’ nests. Remember the issues the blue iguanas had with cats and rats and dogs? Well, cats and dogs and (non-endemic) rats have been introduced in the Galápagos, so the iguanas here have the exact same problem. And, since none of them are found anywhere else in the world, the animals there are starting at a disadvantage.

And to top it off, hundreds of people are flocking to the Galápagos each day, walking around, taking pictures, et cetera, et cetera. And what does this do for the islands? Funds the conservation, as one pays for entrance into the Galápagos National Park and into the Charles Darwin Research Station. The rules about what the groups are able to do, always with a trained guide, are strict enough that tourists do not adversely affect the wildlife3. What are the conservation efforts doing? There are successful breeding programs for the tortoises4 and the land iguanas at the Research Station. There is lots of work going into the goat eradication program, which at times involves people in helicopters with rifles. If any of my readers have had to deal with invasive species closer to home5, this will not seem like overkill, and it is certainly getting the job done.

Edit: I've just put up a new t-shirt design. Enjoy.

1I’m still looking for an endangered bacterium. No luck so far.
2Alright, sailors releasing them were mostly in the 1700s, but it’s taken them until recently to get rid of those.
3Stay on the trail. No touching animals. Do not take sand, shells, bones or any other item from the island. Wash your shoes between islands to prevent mixing sand. Seriously.
4Baby tortoises are much too cute to be discussed here. Oh well.
5For example, have wanted to take a gallon of gasoline and a match to multiflora rose.

Sunday, September 23, 2012

Gonna Be a Blue Collar Lizard

I personally don’t think the Grand Cayman blue iguana (Cyclura lewisi) is ugly, but reptiles are usually given a bit of a short straw in terms of caring about their conservation. What they lack in ugliness (which is a bad thing?) they certainly make up for in being so endangered, with a long-term goal to get up to 1000 individuals, including those in captivity. They represent the last Endangered Ugly Thing that I’ve actually dealt with.

Endemic to a small Caribbean island that’s roughly 20 miles across, the blue iguana makes its living as the largest native land vertebrate on the incredibly sharp coral rocks that make up Grand Cayman. They somewhat fit the elephant’s niche as the large (they get up to maybe 5 feet long) herbivore, with no predators as adults, though the young are preyed upon by snakes native to the area.
They live up to their name well, though they are the bluest when they are either very angry or trying to impress a female. They differ from green iguanas, which are an invasive species in the Caymans, in a variety of ways, such as the shields on the green iguanas’ cheeks, or the thicker tail on the blue iguana.

The reason why blue iguanas are so endangered is, like the tuatara, after a few million years of isolation with minimal predators, human interactive has brought rats and cats, which go after the eggs and young, and dogs, which will attack the adults. This brought their population down far enough to earn them the distinction of the world’s most endangered iguana.

They are not without their champion, however, as the Blue Iguana Recovery Program has come into existence to help save the iguanas from the edge of extinction. Captive breeding programs at the Queen Elizabeth II Botanical Park have managed to hatch more than 80 baby iguanas the last few years. Female iguanas, when they are ready to lay their eggs, will dig a burrow. However, to the dismay of the conservationists who wish to incubate the eggs in a controlled environment, the female’s burrows are labyrinthine, with many dead ends, where only one will contain any eggs. After the eggs hatch, the young are kept at the botanical park until they are two years old, big enough to deter any rats and cats. These are released into a reserve on the sparsely populated eastern end of the island.

The news that I am very happy to impart upon you, the reader, is that these released iguanas spent the last weeks of this past June mating. This July, the females were busy laying eggs around the reserve. The past few weeks, the first of the hatchlings have begun to emerge from their burrows. These hatchlings represent the first generation of wild hatched iguanas in the reserve, untagged and free.

Sunday, September 9, 2012

Third Eye Blind(ish)

The Tuatara (Sphenodon punctatus) is a reptile that is also grouped into the "living fossil" category (see footnote on the lungfish). They belong to order Rhynchocephalia, which has existed worldwide about 220 million years ago, and the tuataras themselves look about the same as they did 140 million years ago. They aren't exactly worldwide anymore, as they are confined to New Zealand, and being an island species is never good news in terms of population.

While superficially resembling lizards, there are various characteristics separating the two groups, such as lack of external ears, another set of teeth, and a developed pineal eye1. This "third eye" may help in temperature regulation, circadian regulation, Vitamin D absorption, or something completely different.

Tuataras are nocturnal and able to function at much lower temperatures than most reptiles. They have long lifespans, taking 20 years to reach maturity and living up to 100 years. Like many predators, they subscribe to the idea, "Is it animal matter, smaller than my head, and easy to catch? Then it's food." Hunting by ambush, they will eat insects, lizards, eggs, and seabird chicks.

The endangerment of the tuatara starts out fairly textbook. After millions of years isolated on islands, humans interfere and begin habitat destruction, removing them from the New Zealand mainland. Europeans bring rats, which eat the eggs and the young. However, there is a newer problem facing the tuatara. Like many reptiles, incubation temperature determines the sex of the offspring. Too warm (above 71.6 degrees Fahrenheit for the tuatara) and the nest is all males, too cold (under 69.8 degrees) and the nest is all females. What happens when global warming comes into play? One female can only parent one litter at a time (and four years apart), so this hurts the population much more than if fewer males were being hatched.

There is hope for our spiny little friends. Breeding and release programs are working on bringing the tuatara back to the New Zealand mainland, with the help of rat-proof fencing. Various studies are being conducted to determine the extent of global warming's effect.

1Though not near as developed as this guy's, who I came across while searching for images.

Thursday, March 31, 2011

Nevermore

Crows have been long associated with death in Western culture. In Medieval times, they were known to follow armored soldiers into battle for the prospect of feasting on the casualties. In modern times, people see them eating roadkill, as Halloween decorations, or as the monsters from The Birds. While Crows certainly enjoy carrion there is another side to them less frequently seen in modern interpretations. For one thing, they are omnivorous so dead things are only part of their diet. For another thing, they might be just as smart as the prettier parrots.

Our main method of determining animal intelligence is looking at how well they solve problems. Crows are masters. They bend wires into fishhooks to pull food from thin tubes. They have learned to use cars to crack hard nuts—while waiting for the light to turn red to retrieve them. One person is trying to teach them to use a vending machine. They can mimic human speech, with more clarity than most parrots. So, when you see a Crow walking down the sidewalk, don’t think, “portent of death,” think “Whosa prettybird?”

Image from Michael Westerfield















The Hawaiian Crow (Corvus hawaiiansis), is locally known as the ‘Alala. It has a lot in common with your more familiar American Crow: they eat whatever they want (mostly fruit and eggs), they hang out in groups, are strong fliers, and like to play wrestle. They use tools to get to their food. However, the ‘Alala is larger, and has a larger, rounder beak.

Why the Hawaiian Crow is in trouble is up for debate: it could be disease, habitat loss, or introduced predators, such as rats or mongooses. Chances are good that it’s all of the above. There is no question that it is in big trouble. The last wild ‘Alala pair were seen in 2003. All the rest of them alive today—about 70 individuals—are in two captive breeding facilities. Release programs have been unsuccessful. Part of that is due to the aforementioned predators, but there’s a problem that the conservationists didn’t foresee. Crows are smart, but because of that, they need to be taught. Without a whole society to teach them, the new crows haven’t learned how to properly forage or escape predators.

Monday, October 18, 2010

Dirty Little Sea Kraits

(Alternative title: Krait Expectations)

It seems that media attention of non-charismatic species is growing. I recently had an interview with a French news site, which can be found here. Also, my wife (I’m still getting used to saying that) has taught me how to needle felt. Remember how I complained that there’s no such thing as a plush Lamprey? There is now. I would like to make more plush EUTs, but I need suggestions about which ones to create. Please leave suggestions, and I promise you’ll see them by the next post.

Image by Ryan Photographic














The Rennell Island Sea Krait (Laticauda crockeri) is like most other Sea Kraits in many ways: it uses its wide paddle tail and venomous bite to hunt fish. On the other hand, it is smaller, not striped, and, oh yeah, doesn’t live in the sea. Instead, they’re found in the brackish Lake Tegano in the Solomon Islands.

I suppose I should back up somewhat. Sea Snakes are exactly what they sound like—snakes that are well-adapted to marine life. They have large, oar-like tails for propulsion, smooth scales for less drag, big long lungs for hours of underwater hunting, and potent venom for easy hunting. Because of these traits, most of them hardly ever make it on to dry ground. Sea Kraits, however, are the least aquatically adapted of the Sea Snakes, with rougher scales and smaller tail fins that allow them to manage better on land.

Due to the small size of the range of the Rennell Island Sea Krait—that is, half of a small island in the South Pacific—it is automatically considered Vulnerable by the IUCN. However, the minimalistic human use of the island has helped keep the area pristine. While there is tourism, it seems to stay within the realm of nature observation with little impact on the ecosystem.

Tuesday, June 30, 2009

Perfect Past Tense - Earwig

If you are visiting through the Washington Post article: Welcome! I hope you stick around, look through my old posts, and leave some comments. If you’ve got any suggestions for animals to write about, I’d be glad to hear them. I’ve even got a forum here. As for my old readers (all six of you), I’ve got a nice, juicy insect for this month.

Image from Earwig Research Centre










Meet the Saint Helena Earwig (Labidura herculeana), the largest earwig in the world. It lives (lived?) on Saint Helena1, a small volcanic island in the South Atlantic. Much like Attenborough’s Echidna, this specimen in the picture is not cavorting around its tropical island home, and for much the same reason: this species might have gone extinct in the ‘60s.

While most earwigs will eat about anything they can get their mandibles on, the Saint Helena Earwig is probably mostly herbivorous. They seem to spend most of their time in burrows, coming out only during nights after it has rained. This withdrawn behavior probably has not helped the people who are trying to determine if, in fact, it has gone extinct.

Though, it is not as if people have stopped looking. There have been a number of expeditions over the years, mostly led and funded by the London Zoo. From what I’ve seen, The Independent has been incredulous, if supportive, of spending thousands of pounds for people to wander around a tropical island looking for earwigs.

Most of the island of Saint Helena seems to be in ecological peril, and long time readers of this blog will understand when I say: “It’s because it’s an island.” Remote islands have a very specific ecology that is easily thrown off balance. Then, humans show up bringing rats, pigs, cats, dogs, and deforestation, wrecking the whole place. In the case of the Earwig, people seem to be blaming an introduced centipede, as well as the clearing of an area of forest.

Conservationists are worried about the Saint Helena Earwig, as well as other endemic arthropods. An airport, proposed in 2005, has not been built for fear of destroying the only habitat in which these gentle, albeit freaky-looking, giants may still survive.

1Apparently named for the same saint as the volcano in Washington, though she doesn’t seem to have any direct connection to volcanoes.

Friday, January 30, 2009

Come Sail Away

I'll be the first to admit that this month's EUT isn't all that ugly, but they can't all be eldritch abominations from the dawn of time. It does, however, look very dragon-like, though the color makes it look like it's straight out of a cartoon.
Image from SailfinDragon.com













This is the Philippine Sailfin Lizard (Hydrosaurus pustulatus). It lives up to its name well, with a tail that would not look out of place on a Dimetrodon1. As one can guess from the scientific name, the Sailfin is not out of place in the water, using the sail to power its swimming through the rivers of the Philippine Islands. In this case, swimming is mostly a defense mechanism to avoid terrestrial predators, though they have been known to eat crustaceans. This supplements their mostly herbivorous diet of fruits and leaves.

The fact that the males have a larger tail fin, along with their crayon-blue color, suggests another reason for the fin; the same reason Blue Iguanas are blue--it looks sexy. If a male has enough energy to produce a fin that large, and can still escape predators despite being the color of an interstate sign, that means he's got some good genes to pass down to the kids.

The Sailfin Lizard is no longer listed as Vulnerable on the IUCN list. This is not necessarily a good thing. It has been moved to Data Deficient, which means we don't really know how bad it is. Life on a tropical island means habitat loss is almost a given threat, but overshadowing that is the pet trade.

Ah, the pet trade, such a mixed curse. It destroys the wild population, without killing that many of them. If they can be bred in captivity, it means they might be able to be bred to be released. It also means that there can be a higher demand for them, leading to more being taken from the wild. It about killed the Red-Kneed Tarantula and Macaws2, but it might save the Axolotl. It looks like it could go either way for the Sailfin Lizard. This guy (where I got the picture) is selling captive-bred Sailfins as pets, and these guys are breeding them the same way to be released into the wild.

1Dimetrodon are actually more closely related to us than they are to this lizard.
2You do not want a Macaw as a pet. They might be pretty, but imagine having a five-year old child for seventy years. Whose screams can be easily heard for miles. Who can bite through an eighth of an inch of steel.

Saturday, November 22, 2008

Put the Lime in the Coconut

Oversized arthropods will always be welcome on this blog. Alright, most arthropods are condidered icky enough, but there is a special type of revulsion saved for really big creepy-crawlies. Well, I've already written about the largest freshwater invertebrate, so the largest terrestrial invertebrate can't be far behind1. Also hailing from order Decapoda, this is the Coconut Crab (Birgus latro).

Image from Cook Islands Natural Heritage Trust







3





When I say "big," I'm sure that you're looking for some measurements to back that up. The Coconut Crab, also known as the Robber Crab or Palm Thief, has a body length of 1½ feet, with a legspan of 3 feet. It weighs up to 9 pounds but its strong claws can apparently lift up to about 60 pounds. Yes, this crab can lift a medium-sized dog.

Why is it so beefy? Well, anyone who has tried to open a coconut with simple tools can answer that. This is not an easy fruit to get into. The Crab will strip the outer husk near the germination pores (those things that make a coconut look like a bowling ball). It will then use one of its legs to punch a hole through the inner husk, and break the coconut apart. Once again, ARKive provides us with wonderful footage of this in action.

Mating occurs quickly and on land, and the female carries the eggs under her abdomen. She then drops those into the ocean, where they hatch into marine larvae that look something like shrimp. Coconut Crabs are closely related to the Terrestrial Hermit Crabs you'd see in pet stores, and the young will find snail shells to protect their soft rear-end. As they grow larger, their abdomen grows a thick carapace, so they lose the need to find snails. Good thing, too, considering their size. They also become fully terrestrial, though they can still drink seawater.

Coconut Crabs are found dispersed throughout islands in the South Pacific. Being a huge crab, no one would be surprised that they're hunted for food. Being an island species also means invasive species like rats, pigs, and ants are a problem for the juveniles. As the islands get more populated, habitat destruction is a problem as people encroach on the beaches. As population estimates vary from island to island depending on the number of people there, the IUCN lists the Coconut Crab as Data Deficient.

Conservation varies from island to island as well. Some places set hunting limits, while others have set up breeding programs. More research needs to be done to really find out how to help these huge creepy-crawlies out.


1The fact that weight is pretty much meaningless in the ocean leads to some pretty big invertebrates down there. The Japanese Spider Crab2(Macrocheira kaempferi) with a 13 foot legspan wins as the largest arthropod, while the Colossal Squid (Mesonychoteuthis hamiltoni) puts all other invertebrates to shame with a body length of 33 feet.
2You can't tell me that picture doesn't look like a video game boss.
3The image that many of you were expecting to see was probably
this one, which I would have used if I could have found an original source.

Sunday, September 28, 2008

When I Get Home

I know, I know. The monthly idea didn't work out so well and I ended up missing August (and almost September). Expect a post in October, or, better yet, suggest an EUT for me to write about. Phantom Midge suggested the Oregon Forestsnail (Allogona townsendiana), but the blog that she linked to was well written enough that I don't think I would have much to add. So, a random ARKive search turned up a big beetle that is one heck of a homebody.
Image from the Zoological Institute of St. Petersburg



















This is the Frigate (or Frégate, depending on your language) Island Tenebrionid Beetle (Polposipus herculeanus), and it is the largest known tenebrionid in the world. For all of you non-coleopterists out there, tenebironids are better known as Darkling Beetles1, and their larvae are far better known as mealworms. In day to day life, mealworms are seen in two situations: you either have a pet insectivore2, or you have flour that has been in your pantry far too long.

Now that we know a little about the family, on to the Frigate Island Beetle itself. Sources give it's length as 20 to 30 mm. That might not seem like much, but look at that picture again. That's not a small beetle. They are completely flightless--probably due to their size--and don't get around much. They spend the entirety of their lives on a few dead trees in a small area. The absolute farthest that they've recorded this beetle traveling is a whopping 19 meters3. The beetle is apparently able to find all its life needs on the few dead trees within those 19 meters. I haven't found what it eats, exactly; I wouldn't be surprised if scientists weren't sure. Looking at its kin, I would guess that the rotting trees are their main food source.

The Frigate Island Beetle has a fun defensive mechanism that I wish I had a visual for. It will, when threatened, exude a purple, stinking, staining chemical. I'm sure the t-shirts of the visiting entomologists look lovely after a day of research.

Frigate Island itself is a tiny island within a larger archipelago called Seychelles, just north of Madagascar. Of course, being from a small, pretty tropical island means that two things are threatening the beetle population: habitat loss and invasive species. A recent program to eradicate the rats (it's always rats) was succesful. Cooler still, the London Zoo has a breeding program, and you can even (figuratively) adopt a Frigate Island Beetle.

By the way, the Coconut Crab is also from Seychelles, and is listed as Data Deficient. It will likely get a post in the near future.



1Not Darkwing, Darkling!
2I, for example, have a tub of 50 in my refrigerator for my Leopard Gecko.
3Even for a beetle, this is small. The American Burying Beetle is not considered a distant traveling beetle, and is about the same size as this one, but can travel two miles on the scent of carrion.

Tuesday, August 14, 2007

Pretty Fly for a Cayman Guy

A while ago, a friend of mine suggested that I get in contact with the Blue Iguana Recovery Program to study those intriguing animals. A few days ago, he sent a request for me to write about another animal from his home island1. And since I’m always ready to take suggestions, here’s a disgusting, semi-parasitic fruit fly from the Cayman Islands.

Image from Carson (1974)
Please note the little white, seed-looking things around the crab's eye. Those are the eggs.

Drosophila endobranchia has no common name, though if it did, it would probably be something such as the “Cayman Islands Land Crab Fly.” It is, from birth, completely attached to the land crabs found there. The eggs are laid around the eye of the crab. Once hatched, the larvae make their way to the gills, where they have a veritable feast on the microorganisms living there. Afterwards, they wander to the mouth, where they will grab whatever bits of food they can from the crab. When they’ve had their fill, they fall to the ground and pupate. Don’t think they’ve left the crabs alone, though, because, after pupating, they hitch rides on the crab’s backs until they lay the eggs.

What makes them interesting (or, at least, what this article found interesting, I think it’s pretty neat too), is that there are three separate species of Drosophila in three different locations that have given up the usual fruit fly method of eating bacteria off rotten fruit, and have taken to stealing from land crabs. The strangest part about this is they evolved these methods completely separately from each other. One is from an island in the Indian Ocean, while the others (including D. endobranchia) live in the Caribbean, and each of their life histories are different enough to show that they evolved independently.

I can’t find them on any endangered species list, but with the small size of their habitat, which is frequently being taken over by resorts, I wouldn’t be surprised if their numbers were dwindling. Also, my friend is working with a man who likely knows more about Cayman Island ecology than anyone. If he thinks they’re endangered, I’d take his word for it.

1The entire message was:
Re: Your endangered species blog.
Drosophila endobranchia
Whaddya say?

Saturday, April 14, 2007

Maxwell's Silver Sword

My parents just came back from a cruise in Hawai’i1, and I felt compelled to ask if they found any exciting wildlife. They had, in fact, found a plant with this blog in mind. Instead of saddling Florabot with this one, I figured I’d write my first plant post.

Image from Dad

The Hawaiian Silversword (Argyroxiphium sandwicense) is a spiky, once-flowering relative of asters and sunflowers. There are two subspecies, the Halekala Silversword (ssp. macrocephalum), shown above, and found on Maui, and the Mauna Kea Silversword (ssp. sandwicense), which is found on that mountain on the Big Island. There are some differences between the subspecies. This means, that to tell which one you’re looking at, it helps to have a botanist and a dichotomous key.

The Silversword gets its name from the sharp, sword-like leaves that are covered with silvery hairs. These hairs reflect the hot Hawaiian sun, cooling down the plant, and the bristly leaves protect the center from predation. They grow on the sides of volcanoes with very shallow roots. They spend fifteen to fifty years growing as a short, sharp rosette, and then send a single stalk up to nine feet high with fifty to six hundred flowers2, set seed, and die.

Since the roots are so shallow, goats, sheep, and cattle easily uproot this plant when trying to eat it. Other invasive species, like Argentine ants, are also causing problems. Hikers can accidentally do same, or intentionally. Apparently, hikers used to pick them as proof they climbed the mountains where they grow. There’s no information on when “used to” was.

Lots of people are working on saving this prickle-ball. For example, people at the University of Arizona are currently working on making sure the Mauna Kea Silverswords don’t become terribly inbred after only a few were saved in the late ‘70s. Also, better signage and visitor education has helped remove some threats.

1I suppose I really can’t complain.
2They’re fairly small flowers.