New Conservation Intern: Abrianna

Hi everyone! My name is Abrianna Sadler and I am the newest research intern here at Audubon’s Corkscrew Swamp Sanctuary. I grew up in Pennsylvania, spending my winter weekends camping in northcentral PA and vacationing to the east coast. These years fostered my passion for wildlife and the environment. I went off to gain an Environmental Science degree at Allegheny College, just two hours north of my hometown. Thinking I wanted to pursue a carrier in the field of environmental conservation led me to a study away semester that ended up including that summer at the Duke University Marine Lab in Beaufort, North Carolina. Here I had my first introduction to the intensity of ecological research while volunteering in a saltmarsh ecology lab. I gained a love and appreciation for the field aspect of research and I was hooked! Through multiple courses and projects, my interests really began to take shape, tending to revolve around how organisms and their ecosystems were coexisting with humans. I was eventually able to design my own study through an undergraduate thesis examining the impact that habitat fragmentation, such as paved roads or hiking trails, had on terrestrial salamander movement. All of these experiences culminated with my first job post-graduation as a research assistant at the Rocky Mountain Biological Lab in Gothic, Colorado. In the alpine ponds of the Colorado mountains another path was carved in my research interests as I was introduced to these freshwater ecosystems. I was an assistant in a study looking at aquatic macro-invertebrate species shifting ranges due to climate change, specifically caddis-fly larvae!

Common Mudpuppy (Necturus maculosus)

This seasonal position came to an end and I returned to Pennsylvania to serve a one-year term as an AmeriCorps Service Member with the Western Pennsylvania Conservancy performing the duties of a watershed technician. From conducting backpack electrofishing surveys for native trout to searching for Mudpuppies and Hellbenders (two species of aquatic salamanders) I gained many skills and had exciting experiences while working in those very same streams I spent my early years splashing around in! While wrapping up my one year term, I searched for opportunities that would allow me to continue growing my aquatic research skills and that brought me here to Corkscrew Swamp Sanctuary! In the short month I’ve been working as a conservation intern I’ve been introduced to many new experiences and the unique environment of the western everglades. Fish sampling, wading bird point counts, and herpetological surveys are just a few of the exciting field opportunities I have been able to take part in. I have already learned so many new and local species and can’t wait to continue growing my knowledge in aquatic research and conservation here at Corkscrew and in southern Florida!

Things that go bump in the night

It was a cloudy, windless night. The only sources of light came from the nearly full moon filtering dimly through the cypress trees, and our headlamps bouncing along the boardwalk. The shrieks of caterwauling Barred Owls echoed eerily through the swamp, and the light pattering of falling cypress needles sounded like soft rain all around us.

As we scanned the swamp with our headlamps, we saw that we were surrounded by hundreds of tiny pinpricks of light. Some of these reflections, we discovered, were frog eyes, which frequently disappeared with a loud "SQUEAK" and a plop into the water.

One of the many Cuban Treefrogs we encountered

However in an unexpected turn of events, many more of these iridescent pinpricks turned out to be spiders! And big ones, at that.

Fishing spider with an egg sac

The strangeness continued as we passed through one of the rain shelters and found a round, fluffy object with a feathered tail nestled in a corner of the ceiling. We stared in shock and bewilderment for several seconds before realizing that it was a bird (a Carolina Wren, to be exact). But what was it doing? Is that how birds sleep? We were making quite a lot of noise -- why didn't it wake up and flee?

It turns out that dozing beneath the cover of these rain shelters is fairly common practice for the Carolina Wrens that inhabit Corkscrew. As we continued on our nighttime escapade, nearly every shelter that we came across contained at least one fluffed up wren snoozing the night away, seemingly oblivious to the curious humans blundering about beneath them.

Among the frogs and the spiders and the birds, we also bumped into a few other critters in the night, including some elusive geckos, a surprised raccoon, and even an opossum staring inquisitively down at us from its perch up in a tree.

With Halloween fast approaching, it's easy to get into the spirit of wandering the swamp after dark. Who knows what unexpected things we may find next time?

~Lara

An Unexpected Friend

         This last week working with the Corkscrew Swamp Research team I went into a portion of the swamp deemed the Central Marsh Transect (CMT), a location frequently sampled for wetland fishes. The crew had gone out the previous day and set minnow traps. Minnow trapping is an especially interesting type of fish sampling as it requires placing several traps that have a variety of large and small sized mesh around the area being sampled. The traps have two sides that act as funnels, allowing fish and other wetland invertebrates inside, but preventing their escape. The traps are placed either completely or mostly underwater and are left there for 24 hours before their removal.
         As we began our task of finding and collecting the previously set minnow traps, it seemed like an average day. Several traps were empty, while some contained Crayfish and/or Mosquito fish. Little did we know, our last few traps had quite the surprise in store for us. As we reached the wet prairie we pulled up a minnow trap that had been set by some Alligator Flag, and in it was a small brown and black snake! I had never seen a snake get caught in one of these traps, or even seen many wild snakes. I was elated that we had such a good trap!

         At first my partner and I were nervous to touch it and were unclear what to do with it now that we had caught it. Luckily another crew member quickly identified the snake as a Banded Water Snake (Nerodia fasciata). She then opened the trap and began to investigate whether the snake would be too upset with us to be handled. The little snake seemed unbothered, and without another question I leaped at the opportunity to hold my first wild snake! The little snake was so calm as he crawled up onto my arm. We proceeded to measure his body length before setting him free back into the wet prairie. We then continued about our tasks of collecting the remaining minnow traps. Overall though, I must say, it was a very successful day in the swamp!I can't wait until I get to run into one of these little friends again!

- Evan, Conservation Intern

Mimicry in the Swamp

In the spirit of October and the impending dress-like-your-favorite character/star/dog/fruit day, let’s talk about mimics at Corkscrew, of the non-human animal variety. I typically don’t think about Halloween until the day after (when all the candy is on sale, duh), but this gives me a good excuse to talk about evolutionary strategies, and no one in their right mind would pass up an opportunity like that … right??



Cemophora coccinea coccinea (Photo Credit: Lee Martin)

So let’s get to it. Most people can think of an example of mimicry, like the palatable Scarlet Kingsnake (Lampropeltis elapsoides) or Florida Scarlet Snake (Cemophora coccinea coccinea) mimicking the coloration of the unpalatable Eastern Coral Snake (Micrurus fulvius) to avoid predation. Mimicry is an evolutionary tool employed by some animals, both prey and predator species alike, to either avoid predation or, in the case of predators, lure prey into a false sense of security to make predation more successful. But what makes a mimic a good mimic? Is there such thing as a bad mimic, or are there situations where a bad mimic is still effective? A good mimic, in theory, would closely resemble the harmful species, or model, with mimetic advantage decreasing as similarity to the model decreases. 


Model Danaus plexippus (PC: Lee Martin)

There are two common types of mimicry, Batesian and Müllerian. In Batesian mimicry, the palatable or harmless species mimics the harmful model to trick predators into thinking it is also harmful. In Müllerian mimicry, both mimic and model are unpalatable and develop similar physical traits to benefit from shared protection. Monarch (Danaus plexippus) and Viceroy (Limenitis archippus) butterflies are 

Müllerian mimic Limenitis archippus (PC: Lee Martin)

an example of this, because both are toxic and therefore unpalatable to potential predators. Regardless of the type of mimicry, mimics must be sympatric to models (occur in the same areas) to benefit from their protection. There must also be a sufficiently high frequency of models to mimics, so that predators have enough experience with the dangerous model to reinforce aversion to the warning signal. Otherwise, predators learn that the warning signal is a ploy, and there is no longer any mimetic advantage. However, there are always situations that bend the rule.

Many mimics have ranges that extend beyond that of their model, and individuals that exist in these areas are called allopatric mimics. Müllerian mimics are still harmful without a model, so aposematic (warning) signals would remain an effective strategy in allopatry. Batesian mimics do not have this protection, but may still benefit from mimicry when predators have an innate aversion to the mimicked trait, or if the trait has some other selective advantage such as enhancing crypsis or increasing resource acquisition. Finally, some predators that have large home ranges may come into contact with the harmful model where mimics are sympatric, and thus still avoid mimics in areas where the model is not present.

Many animals at Corkscrew display mimicry, from Scarlet Kingsnakes to Viceroys. Discovering the mechanisms that cause such phenomenon to occur is fascinating and remains somewhat speculative in nature. There is much we have yet to learn about these evolutionary processes, and the best thing? It’s happening right in our backyard!  

- Randi Bowman, Research Intern