So far in my newfound photography hobby, I have found it nearly impossible to get a good picture of a butterfly (without it being dead). Moths, on the other hand, are pretty easy, since they will sit still and let me get in close. Butterflies are just too spooky, and I don’t have a good enough zoom lens to get good pictures from farther away. One day, when I have a little bit more time, I’ll find a nice flower patch and just play the sit-still-and-wait game.
I did, however, get lucky the other day while I was out at lunch looking for kudzu bugs. A big, beautiful, orange butterfly was fluttering around, so I stopped and waited. It still wouldn’t let me get in close enough to get macro level shots, but it did allow me to creep up close enough to get a few decent pictures.
Beautiful Butterfly
Danaus plexippus? Was This A Monarch?
At first glance, I thought it looked an awful lot like a monarch, and we do have some milkweed growing around campus. Milkweed is the primary food source for monarch caterpillars. Regarded by many as the king of butterflies, monarchs are one of the most famous members of the insect class. But, their population is in decline, and their life cycle makes them especially vulnerable to environmental changes.
Monarchs Spoil Their Babies
For starters, monarch larvae are very picky eaters. Female monarch butterflies will only lay their eggs on milkweed. She will even go so far as to taste test the individual plant to make sure it will be palatable for her spoiled little brats before she lays her eggs on it. Milkweed is the collective name for plants belonging to the Asclepiadacea family. Most species are native to more tropical climates, but the US is home to the common milkweed; a suitable food source for monarch caterpillars. It is commonly found in open fields and roadside medians, but the occurence of milkweed in the US declined 21% between 1995 and 2013, most likely due to increased use of chemical herbicides. And, by destroying the milkweed, we are cutting out a vital intermediate part of the life cycle of the majestic monarch butterfly.
A Great Journey
No doubt, you’ve heard stories about the great monarch migration. Winters in the continental US are too cold for them to survive, so they must migrate south some 2500 miles to the warmer tropical climates in Mexico. But, the life span of a migrating monarch is only 2 - 6 weeks. How do they travel such vast distances in so little time? It turns out that they don’t. The journey to their overwintering grounds takes multiple generations. That is why the milkweed is so important! Without it, these butterflies are not able to hand the baton off for the next leg of their journey.
A Symbiotic Relationship
Monarchs enjoy a symbiotic relationship with milkweed, gaining benefits beyond a simple food source. While the butterflies help to pollinate its flowers, the milkweed provides the butterflies with a protective toxin. The plant contains chemicals called cardenolides that are toxic to most animals, but monarch caterpillars are equipped with enzymes that render them immune to the poison. In fact, this biological mechanism enables them to collect and store the chemicals in their body, making the butterfly and its larvae poisonous to predators. If an inexperienced bird or other animal makes the mistake of eating a monarch, it probably won’t be fatal; however, it probably will result in a bad day. Take this bluejay, for example. It only took about 12 minutes before it began vomiting. This bird will live to eat again, but you can rest assured monarchs will be off the menu. In fact, most scientists agree that the monarch’s bright orange coloration serves as a warning that it is poisonous
There have been some recent studies that indicate perhaps the toxin held in the monarch are really not much of a deterrent. After all, some birds do eat monarchs on the regular, and they handle it just fine. However, I think it has more to do with the fact that some animals are not sensitive to the poison, while others have learned which parts of the butterfly contain palatable amounts of toxin.
At Long Last, The Journey Is Complete
The monarch butterflies that make it back to the overwintering grounds in Mexico will be four generations removed from the group that left the previous winter. Upon arrival, they will find their way back to the exact same trees that their ancestors used high up in the mountains. They flock by the tens of thousands there in the oyamel fir trees. Their clustering behavior allows them to keep warm and conserve energy, which allows them a much longer lifespan than their migratory ancestors. They will survive the entire winter; and, since there is not any milkweed around their they will have to migrate back north to lay their eggs and thus begin a new migration that will take another 4 generations to complete.
What’s That, You Ask? Was My Butterfly A Monarch?
Unfortunately, it was not. The butterfly in my photos is a species known as a viceroy ((Limenitis archippus). You can tell by the thin black line that bisects the main lines in the lower wing. Monarchs don’t have that. Their extremely similar coloration is an example of a phenomenon known as Batesian mimicry, where the non-toxic, perfectly palatable viceroy looks so similar to the monarch that predators avoid it completely! This is probably something that we’ve all learned at some point.
But Our Entire Lives Have Been A Lie!
I actually learned while doing research for this article that my knowledge of monarchs and their opportunistic lookalikes is out of date. Like, WAY out of date. In a study published back in 1991 in the journal Nature, it was proven that the viceroy butterfly is also toxic. Its caterpillars feed on the leaves of willows and poplars, which imbues them toxins, as well. So, monarchs and viceroys are actually partners in mimicry; a phenomenon known as Mullerian mimicry where both species benefit. If a bird eats a viceroy, it will also avoid monarchs.
Nature is amazing! Every time I start out trying to write a short simple post, I end up learning all kinds of awesome new things that I have to share. I hope you’ve enjoyed learning about both of these beautiful butterflies.
* All photos taken by me using Canon Rebel T3; Lens Model: EF-S18-55mm f/3.5-5.6 IS II. Macro shots were taken using a cheap screw on macro adapter; post processing performed using Darktable unless otherwise labeled.Thanks for reading today’s article! If you enjoyed it, maybe you would like to check out some of my other recent content:
**Find out a little bit about the majestic luna moth.
Take a look at the small stagshorn fungus.
Learn about the silver spotted skipper and its creep looking caterpillar.
Read my rant about the confusion between venomous and poisonous organisms that I entered into @suesa’s Science Challenge #2
Take a walking tour of Hardy, AR
Or, read my newfound use for Steemit in my classroom.