the praying mantis

This is a California Mantis, Stagmomantis californica. Being a Maine boy, I didn't know they lived out here, or much about them, until I did a little research.

This is actually just one member of the clade Mantodea, which contains around 2,000 species, about 20 of which live in the US. Mantids are probably best known for their
body morphology, from which their name is derived ("Praying" refers to the position of the front legs, and "mantis" is the Greek word for "prophet"), but also the fact that they are sexually cannibalistic.

Mantids have a long, slender body with large forelegs, modified into giant pincers that are good at catching and holding prey, which can include insects and arachnids, but also small reptiles, birds, and mammals [cautionary heads up to those who like mice more than insects]. These, along with the ability to swivel their heads 180˚ (exceptional in the insect world) make them excellent predators.

Insects in general are fascinating creatures, mostly because of their prevalence (there are over a million cataloged species, more than double the total number of other species on the planet, with likely 5-9 million more that we don't know about), their resilience (terrestrial insects have been around since the Devonian period, about 407 million years ago), and their adaptability (they come in all sorts of shapes and sizes, and have some amazing environmental adaptations (like this moth on cement). Mantids can have the same camouflaging coloration, which helps them hide from predators, but also from prey, for the element of surprise, like this one, on a gum tree:

or these Ghost mantids:

Like all arthropods, mantids' growth is marked by a molting cycle, and they grow into and shed an exoskeleton several times during their lifetime, which is about 10-12 months. Some can have large wings, but are usually only used by the males in searching for female mates during the mating season. The one on my shoulder appears to be a female, because her wings extend only part-way down her abdomen, (males' wings extend beyond the end), and her larger cerci.

Speaking of sex, the praying mantis is also notorious for its kinky sexual practices. In an interesting evolutionary twist, during or immediately post-copulation, the female mantis will turn around and start eating the male, as a high-energy snack for the developing "buns in the oven." Check this out:

In most species, the males like to survive a sexual encounter so that they can go on to knock up more females and get as much of their genetic information into the pool as possible. However, in this case the male is offed after his first time, and his body contributes to the health of his young. His offspring still benefit, so it's not all bad.

The praying mantis is a fascinating example of a product of evolution, and these capable predators can be found all over the world, often in your back yard, or in my case, neighborhood park.


(images from Wikipedia, video from YouTube)


the great pacific garbage patch

The other day, I was at the Green Festival in San Francisco, and I overheard someone talking about a giant island of plastic in the Pacific ocean, "Twice the size of Texas."

I'd heard a few things about it, but didn't know much, so I thought I'd look into it. Turns out that it may or may not be the size of two Texases, as no one's got an official measure, but it sounds huge. And deadly.

The Earth, as some of you may know, is round, and spinning. Because of factors such as solar heating, the shape of land masses and the inertia of water, several large, perpetual currents exist in our oceans, and their existence has a strong influence on things such as weather, water temperature, migratory routes, and human trade and military activity.


As you can see, what's created are essentially giant eddies, circular water flows with relatively stationary centers. One in particular is the North Pacific Subtropical Gyre (we'll call it the NPSG), with an area of approximately 10 million square miles.

The currents of the ocean can have a profound effect on the atmosphere above, as the temperature and flow of water can affect ambient air temperature, humidity, wind, and precipitation. The NPSG is no exception. The center of this gyre is also known as the "horse latitudes," because shipping vessels hundreds of years ago would run into dead air and wouldn't be able to fill their sails. After weeks sitting in the same place, they would end up dumping their livestock, including horses, into the water, in an attempt to lighten the load and move along. Must've been good eats for the sharks.

(Edit: Another, more verifiable etymology for the name "horse latitudes" is from an old tradition of throwing a straw-stuffed effigy of a horse off the side of the ship in celebration of a sailor's having worked off a debt to the ship's paymaster. Since these debts were frequently worked off halfway across the ocean, this became the place for the practice. How interesting that the practice of dumping things in the middle of the ocean continues to this day...)

Turns out, the same current and weather patterns that trapped ships long ago is now having the same effect on human wastes. Over the last few decades, a giant mass has been accumulating at the center of this vortex, composed of trash generated by oceangoing ships, runoff from terrestrial storms, broken fishing nets, and lost cargo from big storms. One of the most dangerous components of this flotilla of flotsam is the large amount of plastic.

Plastics, including polyethylene and polypropylene, are synthetic polymers that have remarkable strength, flexibility, and durability. They're used extensively in every aspect of modern civilization, from cars to medical devices to naughty toys. It is their durability, however, that causes the problem.

Instead of being biodegradable, plastics are photodegradable. This means that instead of being broken down by biotic processes such as bacteria, they are broken down by exposure to light, particularly from the sun. The other critical difference is that, where biodegradable substances are returned to the life cycle in the form of natural chemicals, photodegradable plastics are just broken down into smaller and smaller pieces, creating a large volume of molecular-sized synthetic polymers.

One of the chemical properties of these polymers is that they absorb and give off different chemicals, some of which are nonylphenols, PCBs, and the infamous DDT. When plastic in the ocean is eaten by living organisms, the toxic chemicals within are released into that organism. In phytoplankton, toxic chemicals are consumed and then passed long the food chain up to higher trophic levels, and the concentration of these chemicals increases exponentially at each level, in a process called biomagnification.


Following the diagram above, replace the porpoise with a person, and consider how people are truly integrated in the global ecosystem.

The amplification of these toxins can have profound effects on higher organisms. In the case of DDT, the accumulation in birds makes their shells weaker, and so, when attempting to incubate their prospective young, the parent birds inadvertently crush the eggs, destroying any hope of a subsequent generation.

Also perilous for those birds, such as this late albatross, small plastic objects look like food, but lack the same nutrients:


Due to the nature of its currents, the NPSG has been collecting and consolidating in its center vast quantities of these non-biodegradable plastics, which in turn have been able to amass and release large amounts of toxic substances into the oceans and the food web. Scientists have named this area "The Great Pacific Garbage Patch," and have been researching it with greater interest. With time, we'll be able to figure out exactly how big it is, and hopefully figure out a way to clean it up.

But is it an island? As it turns out, no. It's actually worse than that. Instead of being a giant floating island of plastic trash, the center of the NPSG is actually more like a dilute soup of plastic pieces big and small, intermixed with all of the living phytoplankton and zooplankton. This makes it that much more difficult for plankton-grazers to get nutritious food without picking up little pieces of plastic. It also means that it's that much more difficult for us to figure out how to get the plastic out of the ocean without taking out tons of marine life as well.

One of the best resources on all of this is the Algalita Marine Research Foundation. Here is a series of Plastics in the Enviroment (PDF) handouts that details this stuff in an easy-to-read format. There, you can also check out the Action sheet on plastics (PDF) and What you can do about plastic pollution (PDF).

Let me know if you have any more questions or insight, I love feedback.


[This post has been revisited and re-edited in light of new understanding and research, so as to be as factually accurate as possible. PH 11/7/11]


This is the official beginning of my blog.

For those of you who don't know me, my name is Patrick Hilton. I live in California, where I've spent the last year enjoying the natural beauty and improbably good weather of the central coast, reveling in the joy of academic discourse, and marveling from afar at the profound stupidity of political administration.

I came out here last summer to escape the stressful and rarely-rewarding life of emergency services and the homogeneous culture and mentality of greater New England (To all you back home: yes, California is everything legend would have you believe).

In the time since, I've been able to recapture the love for the outdoors that I had as a youth in rural Maine, but in addition, I've gained greater appreciation for the beauty of the natural world. Being reintroduced to nature as an adult, both in personal experience and through a formal education in biology, chemistry, physics, and astronomy, I'm better equipped to recognize and understand the beauty of the highly organized natural world. I've learned that, as one delves deeper into the abyss of scientific knowledge and discovery, the world becomes exponentially complex, but equally fascinating.

As I explore further the scientific universe, I learn exciting new things--sometimes broad concepts, sometimes small tidbits of information that are just the tips of icebergs of research potential. With my increasing momentum of discovery, I find myself to be more and more passionate about the things I'm studying, and feel a strong urge to share the secrets of science with those around me.

My hope is that, perhaps with a proper guide, I can recruit more interest in nature, and inspire others to become as passionate as I am about preserving the amazing world in which we live. (I am by no means an expert in anything at all, so if you have more insight into things I talk about, or if you disagree with the things I say, please don't hesitate to share your knowledge or opinions here. Part of what makes scientific research so excellent is that it is subject to review by everyone else... this isn't the Catholic church.)

Let's get started, we have a lot to cover.