Friday, May 29, 2015

Cecropia Moth

A few days ago I visited Carlisle Reservation, a park in the Lorain County Metroparks district. Just a few minutes down the trail, a flash of red in some low herbaceous plants caught my eye. As I moved in closer, I was astounded to see an incredible Cecropia Moth taking refuge from the strong winds of the day.

Cecropia Moth hyalophora cecropia
The Cecropia Moth (pronounced "say-crow-peeah"), Hyalophora cecropia, is a member of the moth family Saturniidae, also known as the giant silk moths. I was absolutely ecstatic that I had found this species, a lifer for me, only two weeks after finding yet another giant silk moth lifer, the Luna Moth. Interestingly, both the Cecropia Moth and the Luna Moths were found hanging on small herbaceous plants on very windy days. This could possibly be explained as a simple coincidence, but I hypothesize that these large moths were simply taking refuge in low-lying parts of the forest, as they would be most protected from the wind in those locations.

Cecropia Moth Size
The Cecropia Moth is an incredibly massive moth. In fact, this is the largest regularly-occurring moth species in Ohio! They can reach wingspans of 6 to 8 inches, but are typically between 4 and 6 inches. This individual was pushing the upper limits, and probably had around a 6 inch wingspan. The Cecropia can be found all throughout Ohio, typically in places where a forest meets a large open space such as an old field or meadow. Like the Luna Moth (as well as all other giant silk moths), the adult Cecropia Moth lacks any sort of mouth, rendering it incapable of eating. As a result, the adult moth only lives for about a week; its sole goal during that extremely short period is to find a mate and reproduce. This species has only one generation in Ohio, and you can find them from May to July.

Cecropia Moth Body
Very fuzzy, isn't he? And yes, this individual is a male. Cecropia Moths can be easily sexed by paying attention to their antennae. Males, such as this one, have very feathery antennae, while the antennae of a female are much less feathery and bushy. The male's feathery antennae are incredibly sensitive and are used for sensing out a prospective female's pheromones. During mating time, which is between 3 and 4 AM, the females will release pheromones into the air. Males can pick up these pheromones with their antennae from up to a mile away, but many males will travel up 7 miles in order to find a female.

In a few weeks I'll be moving back down to Athens County. I hope to get a mothing setup and begin mothing somewhat regularly. If you like moths, stay tuned for more!

Tuesday, May 19, 2015

Melanistic Garter Snake

For half of this summer, I'll be living up in Northern Ohio helping with some salamander research as a field assistant. It's only been 2 weeks so far, but we've found so many interesting and wonderful things. The best find of last week came from one of the field sites on South Bass Island in Lake Erie.

Melanistic Eastern Garter Snake
Olivia Brooks, who is the one behind the nature-oriented Twitter account Wild Earth, is the other field assistant. We're always on the lookout for snakes, and while in the middle of trying to find salamanders, Olivia yelled "snake!" We ran toward Olivia and were met by a very young Eastern Garter Snake. I've covered Eastern Garter Snakes before, and you might notice that this one doesn't really look like a garter at all. The coloration is all wrong, right? Garter snakes aren't black?!

Melanistic Eastern Garter Snake Ohio
This is indeed an Eastern Garter Snake, Thamnophis sirtalis sirtalis, but it is an individual with melanism. Melanism is essentially the opposite of albinism. While albinism is the absence of melanin (a dark colored pigment found in skin), melanism is the overabundance of melanin, leading to an individual with an abnormal amount of black coloration. Melanistic Eastern Garter Snakes can be found along the Western Basin of Lake Erie and on some of the Lake Erie Islands. Some populations can be up to 50% melanistic in this area, meaning there will be a mixture of normal-looking and melanistic individuals within one area.

Eastern Garter Snake Ohio
The photo above shows what a normal Eastern Garter Snake looks like. This normal-colored individual was found at the same exact location on South Bass Island as the melanistic individual we found. I have no clue as to what the exact ratio between the two types is, but it would be very interesting to do a survey and get an estimate!

Melanistic Eastern Garter Snake
So why is there such a high concentration of melanistic garters in Northwest Ohio? Mutations that lead to melanism can arise randomly in any animal that has melanin; however, mutations that cause melanism and albinism are very rare. This leads to sporadic occurrences of the color abnormality that randomly occur across multiple populations. For a trait like melanism to "build up" in a population, there must be something else going on. More specifically, being melanistic must benefit the individual in some way. If the trait was bad for the individual, it would quickly be selected out of the population. If it had a neutral effect, individuals with the trait would only exist in very small numbers. Adaptive melanism can be adaptive for many different reasons. For example, in Black Panthers, which are actually just melanistic Jaguars, melanism leads to better camouflage as these predators hunt in the dark of night. In the Eastern Garter Snake, being melanistic makes it easier for an individual to warm up when basking in the Sun. The color black absorbs all the wavelengths of the white light of the Sun, resulting in the black individual gaining relatively more heat energy than the predominantly brown individuals. Snakes are ectotherms ("cold-blooded"). This means that they do not hold a constant internal temperature like we do, but instead rely on the ambient heat of the environment to regulate their internal temperature. For a snake to be able to hunt successfully, their body temperature must reach a certain threshold. By being able to reach that threshold quicker and easier, melanistic garter snakes have an advantage in being able to find and eat more food than the normal individuals, who have to wait longer for their temperature to reach that threshold.

Sunday, May 17, 2015

Luna Moth

Last week I was walking along a path at Old Woman Creek National Estuarine Research Reserve in Erie County, Ohio. Suddenly, something on a Mayapple caught my eye...

Luna Moth camouflage
Can you find both Luna Moths?
I quickly stopped and took a closer look. Much to my surprise, the object that caught my eye was a Luna Moth, a lifer for me! I then noticed that not only was there one Luna Moth, but a few inches away there was also a second one. I have been wanting to see this beautiful species for years, and I was ecstatic that I finally had the chance!

Luna Moth Actias luna
The Luna Moth, Actias luna, is a very large moth. In fact, this species is one of the largest moths in North America. Its wingspan is 4.5 inches on average, making this species an incredibly impressive sight. The Luna Moth is found in the deciduous forests east of the Great Plains, and in Ohio they can generally be found from May through October. The Luna Moth can have 1, 2, or 3 generations a year depending on where you are within their range. Ohio falls in the 2 generation range, which means these individuals are part of the first generation for the year. While the Luna Moth can be found in every county in Ohio, they are hard to find and sadly on the decline. If a Luna Moth is hanging from a leaf, their camouflage makes them very hard to spot. Most people see Luna Moths when they are perched on a wall or other surface that makes their bright green coloration stand out. It's been even harder to find them recently due to a decline over the past several years. This decline is especially pronounced near cities and large towns, but the exact cause, or causes, remain unknown.

Luna Moth on Plant
The adult Luna Moth has a very short life. The only goal for an adult is to find a mate and reproduce. While this is the same goal across all species, the Luna Moth life cycle is missing essentially anything it doesn't need to achieve that goal. Upon metamorphosing, the adult moths lack a way to feed. As a result, they only live for about seven days before starving to death. That single week is spent looking for a mate, and then waiting for death. Since they cannot eat, the moths need a large storage of fat to live off of. If you look at the photo above, you can see how large the abdomen (about the size of a big thumb). This is due to all the fat the individual accumulated in the caterpillar stage in order to last through the adult stage.

Luna Moth Face
Who can't love a cute face like this?
Luna Moths are hard to find since they are so short-lived, but even if you've never seen one in person, you probably recognize them. They're a commonly represented moth in our lives. Commercials, cartoons, magazines, and more all utilize Luna Moths for advertisement or plot devices. Moths, in general, are an overlooked group of animals, but it is impossibly hard to overlook a Luna Moth, and so they pop up a lot in pop-culture. There's nothing quite like seeing one in person though, so keep an eye out the next time you take a hike through a forest. You never know what you might find.