Tarantulas

Beginning in late June, the prevailing winds in the American Southwest change directions. Warm, moist tropical air from the Gulf of California suddenly finds itself being pulled into the dry Arizona landscape. With this influx of warm, moist air, the North American Monsoon begins. Storms pop up all over Arizona and the rest of the Southwest, but this rain doesn't come in the form of widespread and gentle storm fronts as it often does in Ohio. Instead, isolated, but intense, thunderstorms with torrential rainfall form around the region, dotting the landscape. On one typical July day during the summer field season, the dorms at the Appleton-Whittell Research Ranch in Southeast Arizona were surrounded by these monsoon thunderstorms.

The monsoon storms are a welcomed event for those living in the hot Sonoran Desert and semi-desert grasslands. Rain means a short respite from the soaring temperatures. But for a male tarantula, the rain means love is in the air. The monsoons signal the start of the mating season for the tarantulas in Arizona, and males begin an epic quest to find females. Males throw all caution to the wind and spend all the waking hours of the day wandering in search for a female tarantula's burrow. Since the females tend to stay in their burrow unless driven out by starvation or by a predator, it comes down to the males to seek them out. And that brings us to this male that we found hanging out on the dormitory at the Appleton-Whittell Research Ranch.

Meet the...uh... I'll be honest, I'm not sure what this species is.  Dr. Chris Hamilton, the author of the paper I discuss below, reached out to me and identified this as Aphonopelma chalcodes, the Desert Blonde Tarantula. The location (SE Arizona), habitat (semi-desert grassland), and golden carapace all help key this individual out to A. chalcodes. The Desert Blonde Tarantula is a tarantula in the genus Aphonopelma. Aphonopelma is one of the 100+ genera of spiders in the tarantula family (Theraphosida), and all of the native tarantulas in the United States belong to this genus. Although it is easy to get a tarantula in the western US down to genus, getting an individual down to the species level can be very difficult. In fact, no one is really sure how many species of Aphonopelma tarantulas are in the US, mainly because the Aphonopelma genus is (well, used to be) a complete taxonomic mess. But why though?

Okay, it’s time to delve into some science. What is a species? Although it seems like a simple question, it turns out it’s quite difficult to define what a “species” is, and it’s even more difficult to have the majority of biologists agree with a single definition. Most people have been taught that a species is a group of animals which can freely reproduce with each other. This is not really correct however, as many different species can hybridize with each other. The concept of a species is more complex than that. So then, what is a species? Well, there’s a lot of different concepts. In fact, there’s more than two dozen species concepts, and a list of the 26 most common ones throughout recent history can be seen here. Nowadays, most biologists define a species using the Unified Species Concept. This concept defines a species as a separately evolving metapopulation lineage. This definition isn’t as confusing as it may sound, and if you want to read all about it, please see Kevin de Queiroz’s 2007 paper at this link. I won't get into the details of the Unified Species Concept, but just know that our changing definition of a species has resulted in some problems when it comes to classifying animals.

Historically, animals were classified into species according to differences in morphological (or physical) characteristics. Aphonopelma tarantulas were one such group of animals. They proved quite a challenge though. As it turns out, many Aphonopelma tarantulas look very, very similar. Classification based on morphological characteristics became difficult, and the genus descended into a taxonomic chaos. Then everything changed when it became possible to look at the genetics of an organism. Being able to see how closely related or diverged one organism’s DNA is to another revolutionized the field of systematics (the field of classifying animals). With this new approach, scientists began classifying species based on their DNA. This approach uncovered an interesting secret. Scientists were finding that some animals which looked exactly the same (and therefore were thought to be the same species) actually had very different DNA. Thus the concept of a “cryptic species” arose. A cryptic species is one which looks exactly like another species, but in reality is a completely different one. A non-tarantula example of this would be the Northern and Southern Ravine Salamanders, which were previously thought to be a single species as they look exactly the same, but DNA analysis in 1999 revealed two separate species.

Of course, scientists decided to re-evaluate the Aphonopelma genus using a genetic approach. Maybe this would reveal some truth in the current taxonomic mess that was Aphonopelma. I want to stress that doing something such as revising an entire wide-ranging genus is a tremendous undertaking. First, genetic work is expensive. Second, you would need DNA samples from hundreds and hundreds of individuals in order to get a representative view of the evolutionary relationships, as tarantulas are so wide-ranging (they span throughout the south from the Mississippi River west to the Pacific Ocean). Getting enough samples is not only expensive due to the traveling necessary, but is also incredibly time intensive.

And this is exactly the undertaking that Chris Hamilton, Brent Hendrixson, and Jason Bond took on. This team of scientists from Auburn University and Millsaps College just published (Feb. 2016) a massive revision of the Aphonopelma genus. In this study, they combined the relatively new genetic methods of classification with the classical morphological and ecological methods in order to “delimit” the species within the genus. This integrative approach is much more effective and thorough than simply using any one technique alone. Before this study, there were 55 Aphonopelma tarantula species described in the US. This study found that there were actually only 29 true species. Only 15 of the 55 originally described species were supported by their findings. In addition, they described 14 new cryptic species. The rest of the originally described species were found to be either unsupported or a case of a single species getting named twice or more by separate scientists.

However, the authors pointed out that this is only the start. Although they sampled 1000+ tarantula individuals from a wide range of localities, there are probably many more species out there that they simply didn’t come across. Between incredibly remote and rough terrain, and the difficulty of finding individuals in the wild, it is probably nearly impossible to completely sample every species in the US. There are surely more species out there, but many of those are likely to be highly localized or in hard to access localities. If you want to learn more, I highly recommend reading the first several pages of this giant study (which comes in at a staggering 340 pages). The paper can be found at this link. 

 

I think it's safe to say that a lot of people probably fear tarantulas. They're big, they're fuzzy, and, gasp, they're spiders. Now, I love spiders, but I can understand the fear. Though, as with many animals, much of that fear is rooted in misunderstanding. Tarantulas in the United States aren't dangerous. None of the American species have dangerous venom. A bite from one is equivalent to a bee sting. It's not going to feel pleasant, but it's nothing to freak out about either. American tarantulas rarely bite though. A more common line of defense in the Aphonopelma tarantulas is their use of urticating hairs. These tarantulas have species bristles on their abdomen that, when the tarantula feels threatened, can be "thrown" off with their legs. The tarantula will throw these bristles toward the threat, where they will embed themselves in the skin. These bristles then cause irritation to a varying degree, depending on the species. This irritation is essentially just an uncomfortable burning sensation. It's similar to the kind of reaction you would get from touching Stinging Nettle. Even so, American tarantulas are pretty docile. It really takes some harassing for them to defend themselves, and that level of harassment should never even happen. If you leave a tarantula alone, they pose literally no threat to you at all.  

This is one of my favorite photos from the summer. I had set up a simple white backdrop in the lab for photoshoots with the lizards, and we decided to put the tarantula in it. He was a good sport for me and allowed a few shots before wandering off the backdrop and onto the table. I know not everyone will agree with me, but I think they're magnificent creatures. Finally seeing a tarantula in the wild has fulfilled a wish I've had since I was a very small child.

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This post ended up being a lot longer than what I had planned, but my intent on identifying this tarantula to species took me down the systematic rabbit hole. This post is a bit more science-heavy than usual, but hopefully I explained the concepts well! If you have any questions, or want a more in-depth explanation of something discussed, feel free to drop me a comment below! Thanks for reading! I would also like to thank Dr. Chris Hamilton for identifying this individual to species.

Western Diamondback Rattlesnake

Night falls over the semi-desert grassland outside of Elgin, Arizona. The Mustang Mountains rise above the acres of dry grass like a silent shadow. Common Poorwills, Common Nighthawks, and Elf Owls call out from the dark among the chirping of crickets. Nestled in the grasses, another creature slowly explores the land looking for a meal. His journey brings him to a gravel driveway...

This gravel driveway sits right outside of the Appleton-Whittell Research Ranch dormitories. As he slowly slithers across the driveway, an unsuspecting field tech out on a night walk stumbles across the beautiful 4.5 foot long Western Diamonback Rattlesnake. The field tech runs back to the dorm, yells "SNAKE," and suddenly the horde of herp-loving techs and researchers scramble out of the dorm and toward the (probably confused) rattlesnake. This individual wasn't the first Diamondback of the field season; in fact, it was actually the 3rd individual that visited the dormitory!

The Western Diamondback Rattlesnake, Crotalus atrox, is a species of venomous rattlesnake which ranges throughout the American Southwest from southern California to western Arkansas. A rather generalist when it comes to habitat preference, it can be found in a wide variety of places. They utilize habitats such as coastal plains, deserts, prairies, pine-oak forests, rocky hillsides, and more. They're a large species of snake, both in length and girth. Adults average between 3 and 5 feet long, with the occasional individual reaching upwards of 7 feet. You will often see images floating around the internet with people holding dead (yet giant looking) rattlesnakes. Oftentimes the captions will say it was a 10 foot, or 15 foot, or some other ridiculously-long rattlesnake. Those are all hoaxes which utilize the forced perspective camera trick. The record Western Diamondback Rattlesnake length is 92.5 inches, or 7.7 feet. For more info on these fictional giant rattlesnakes you see on Facebook and the like, check out David Steen's blog post on the "giant killed rattlesnakes."

Of course, the name “rattlesnake” stems from the characteristic rattle at the end of the tail. This rattle is made of keratin, the same material that makes up our fingernails and toenails. The rattle consists of several overlapping hollow parts that when pulled against each other produce a dry rattling noise. To watch the individual pictured rattle, check out this video I took. As a general rule, snakes only want to bite as a last resort when they feel as if their life is directly threatened. When a rattlesnake feels threatened by a human, it will typically go through a series of actions. First, if it feels the threat level is low, a rattlesnake will simply sit still or try to escape the immediate area unnoticed. If a person continues to stay in the area, or moves closer to the snake, the rattlesnake will often begin to rattle (but not always). This rattling serves as a warning to potential predators and threats. By announcing that it is there to the threat, the rattlesnake is essentially saying "I see you, you see me, I'm letting you know that I am dangerous. Leave me alone and I will leave you alone." If the threat continues, however, the rattlesnake might resort to biting.

Bites by venomous snakes are extremely rare, however, and most bites that do occur happen when someone is either harassing the snake (e.g. trying to kill it) or if they accidentally step on it. Although bites by venomous snakes are serious, they're rarely deadly. In fact, of the 7,000-8,000 Americans who get bit by venomous snakes a year, less than 1% of those victims die. To put this in perspective, 9 times more Americans die each year from lightning strikes than snake bites. All in all, the fear of venomous snakes most Americans have is incredibly overplayed, and I think that is very important to point out. Snakes are not nearly as scary as what people think. Given respect and appropriate distance, rattlesnakes pose no threat.

Unless you're a rodent, that is. If you were, then this is definitely not the face you would want to be staring down. Western Diamondbacks have been recorded preying on a wide variety of animals, from birds to reptiles to insects and more. However, mammals make up the vast majority of their diet. And when it comes to mammal prey, Western Diamondbacks love rodents. Oftentimes a Diamondback will position itself along a rodent path and wait for an unsuspecting mouse or packrat to scamper by. One lightning-fast strike later and the Western Diamondback has a nice meal.

It is always a pleasure seeing a snake of any species in the wild, but it's a wonderful day when you see any sort of rattlesnake. I've wanted to see a diamondback rattlesnake (either Eastern or Western, I'm not picky) for years now, and I was ecstatic to see as many as I did over the summer. There's just something magnificent about these beautiful, but sadly misunderstood, creatures. 

National Park Service Centennial

I am alive! Between being incredibly busy and having a total lack of motivation to write, I haven't posted anything in nearly 2 months. But here I am, and for a special day. Today, August 25, 2016, is the 100th birthday for the National Park Service! I just wanted to throw together a few photos highlighting the national parks I've been to, along with some suggestions of things to do at those parks and what have you. So, here we go!

Grand Canyon National Park, one of the quintessential national parks in the United States.

The National Park Service was established on August 25, 1916, by the National Park Service Organic Act as passed by Congress and then-president Woodrow Wilson. Actual national parks are older than 1916, however, with Yellowstone National Park (established in 1872) being the first national park in the United States. Several other national parks were then created, but each of the parks were individually managed. As the parks grew in number, Congress decided to establish an agency that would collectively oversee the parks, instead of leaving them to be individually managed.

The National Park Service doesn't only manage and oversee national parks; the agency also manages most national monuments, such as White Sands National Monument in New Mexico, which I've covered previously. In addition to National Monuments and National Parks, the agency manages several other types of locations such as National Historic Sites, National Battlefield Parks, National Parkways, National Recreation Areas, National Seashores, and other such properties.

As of now, I've personally visited 11 (of the 59) national parks and many other locations managed by the NPS. They all have their incredible beauties and differences, but I've never been to a single national park that left me underwhelmed. My personal favorite, so far at least, has been Petrified Forest National Park (which I've covered at this link) in Arizona. It was the first park I was able to visit west of the Mississippi River, and it was the first place that I really got a taste of "The American West."

Another personal favorite is Arches National Park. The juxtaposition between the beautifully sculpted red sandstone with the soaring La Sal Mountains in the background just makes for a mesmerizing place.

Zion Canyon in Zion National Park, Utah, as seen from atop Angels Landing.

This summer, while coming home from a field technician job in Southeast Arizona, I decided to take a 10 day road trip back to Ohio. I meandered up through Arizona, through southern Utah, through Colorado, and then back to Ohio via I-70. My plan was to hit as many national parks and other awesome natural areas as best I could for as cheaply as I could. In total I visited 5 national parks, and an assortment of national forests and other parks.

The Narrows Hike (Left), Angels Landing Hike (Right)

The two most memorable hikes from my roadtrip both came from Zion National Park in southwestern Utah. I did both the two most famous hikes at Zion: The Narrows and Angels Landing. The Narrows is a deep and narrow canyon which one can hike through. There is no "trail," and you just hike through the Virgin River. I opted to do 4 miles upstream and then 4 miles back downstream. The Angels Landing hike is a grueling climb up to the top of Angels Landing, a rock formation which rises 1,488 feet above the floor of Zion Canyon. The Angels Landing hike is infamous for the last 500 vertical feet in which you have to scramble up a steep sandstone face with over 1,000 foot drops on either side of the trail (which is sometimes only 2 or 3 feet wide). I'll hopefully be writing a post or two more on Zion in the near future!

Many National Parks, especially ones like Yellowstone, the Grand Canyon, and Yosemite, are known for being really busy, especially during the summer months. People visit these parks in droves because they are something special, but not every place the NPS manages is crowded and overflowing with people. In fact, if you're willing to sacrifice some comforts, you can easily escape the crowds. For example, try visiting busier parks in the winter, when attendance is drastically down. Another thing you can do is simply go off the beaten path. Take the photo above. This double arch is called Grosvenor Arch. It's in Grand Staircase-Escalante National Monument in Utah. Grand Staircase-Escalante NM is a gigantic plot of land that lies between Grand Canyon, Zion, Bryce, Capitol Reef, and Canyonlands National Parks. It's an easy drive from any of those, yet has only a fraction of the visitors. This is mainly because it's wild. In this park you oftentimes have to take crazy dirt roads for miles to get to places without bathrooms or water or what have you. If you're comfortable with that and plan for the seclusion, you can often find yourself totally alone. I visited Grosvenor Arch over the summer, and there were about 5 people at the trailhead. To get there, you had to drive 20 miles one way down a dirt-rock-sand road, and even cross a creek. Not many people are willing to do that, and the touristy crowds disappear for those who are willing to.

Alpine tundra and spruce forest as seen from the Trail Ridge Road, Rocky Mountain National Park.

But it's still nice to be a tourist at a busy park. When I traveled to Rocky Mountain National Park in Colorado, I visited the park on a Sunday afternoon. The crowds were insane, and the traffic was bumper to bumper, but the amazing views like the one above made it all worth it.

Cuyahoga Valley National Park in the Autumn.

Ohio even has its own national park! Although the vast majority of national parks are out west, Ohio is home to Cuyahoga Valley National Park, near Cleveland. Sadly, I've never properly explored the park, but many of those who live in the Cleveland area are very familiar with it! I've only visited for research, but hopefully sometime soon I can visit it for hiking!

The Great Smoky Mountains as seen from the Blue Ridge Parkway, North Carolina.

The national parks belong to you and I. They were created to protect amazing natural features for future generations to enjoy and visit. Sadly, there are many threats to the future of these treasures. Climate change is affecting all the aspects of all the national parks, from the wildlife to the plants to even the namesake features (For example, Glacier National Park is expected to lose all the namesake glaciers by 2050). On top of that, some politicians are currently trying to open up the national parks to activities such as mining and other horribly detrimental activities. And then there's the threat of invasive species, tourists damaging natural features while visiting, and a whole slew of other threats. These national parks should be protected for our children, their children, their children's children, and on and on and on. We have to take steps to ensure these lands are conserved and protected, because once they're gone, they're gone. It is our duty to do so.

Have you been to a national park? If so, which one is your favorite? Leave a comment below!