Fish and Friends

This week the research team and I went to the Panther Island Mitigation Bank to conduct bimonthly fish sampling. The process of fish sampling is rather simple given our use of throw trapping methodology accompanied by the use of minnow traps. Throw trapping specifically is the method of throwing a large square trap into an undisturbed area with at least a few inches of water. Next, seines and nets are used to remove all of the fish and other aquatic organisms from the area within the trap. This methodology allows for  brief insight into the ecology of sampled wetlands as the traps help demonstrate the biodiversity, population sizes, and variability of species between wetland habitats.

A division of the research team throw traps a
shallow marsh in the Panther Island Mitigation Bank

Throw trapping can be a rather exciting field activity as you get to interact directly with the fish and be in the back-country, embracing and studying the environments that we, as researchers, have all come to love so much. Sometimes rare fish, reptiles, and amphibians are even caught in these traps fostering our need to learn more about our environment and the crazy critters that inhabit it. However, despite these great attributes, my favorite part about throw trapping are the conversations and bonds that are formed over the nets.

With each trap taking an hour or so to process, throw trapping creates the time and space for researchers to connect not only through their work, but through their conversations as well. During throw trap sampling I have gotten to know more about my coworkers music tastes, movie preferences, and past experiences than I ever thought I would. As we spend time hunched over the seine pulling fish after fish out of the trap, we joke about the shows we watch on Netflix. Or while sifting through mud and vegetation for organisms we discuss our past college courses and our future goals, making the time spent in the field fly by. This has taught me that, while research practices and work may seem mundane at times, these days spent out in the field not only embrace our love of the environment that we study, but the love for the people that we study it with.  

Two members of the research team and I finish up a
throw trap at the Panther Island Mitigation bank

I look forward to our next sampling event where we will continue to improve our knowledge of wetland ecology and fishes, as well as continue to grow our friendships!

- Evan, Conservation Intern

Road Mortality: What we can do about it

Dead Glass Lizard (Ophisaurus sp.) hit by a car

Driving around the Naples area, it’s hard to go 5 minutes without seeing a dead animal on the highway. Reptiles, amphibians, birds, rabbits, and even the rare Florida Panther (Puma concolor coryi) are the unlucky victims of a fragmented habitat that in the best case inhibits natural movement and gene flow and at worst kills an animal trying to travel between suitable habitats. Numerous studies have looked at the effects of road mortality on various species in Florida, with a variety of concerning findings.

One study conducted over a 2-year period (1987-1989) reported encountering 1,018 snakes on an 11.3km road segment, 70% of which were found dead or injured by cars (Bernardino & Dalrymple, 1992). Another study, by Steen et al. 2006, reported that female turtles are more likely to cross roadways than males and therefore experience higher road mortality, potentially skewing sex ratios near roadways and leading to population declines. From 1979-1991, 32 Florida Panther deaths were recorded, with the most common cause (15, 46.9%) being road mortality (Maehr, Land & Roelke, 1991). This is just a small sample of the literature regarding road mortality, but it is apparent that regardless of the species or location, the intersection of wildlife and vehicles never bodes well for the wildlife.

Eastern Corn Snake (Pantherophis guttatus) basking in the road

So what can be done to reduce the threat of road mortality on wildlife populations? Various mitigation approaches are used, including motorist behavioral modification (speed limits, signs, lights) and animal behavioral modification (wildlife crossing structures, habitat alterations). Wildlife crossing structures include underpasses, overpasses, drift fences, exclusion fences, and culverts, to name a few. Each mitigation approach has its pros and cons, and determining the most effective strategy requires extensive research and monitoring of wildlife populations and causes of unnatural mortality. Location, structure dimensions, habitat cover, noise levels, the use of fencing, and many other factors can determine the success or failure of a crossing structure. To learn more, check out the papers referenced below (Foster & Humphrey, 1995; Dodd, Barichivich & Smith, 2004; Glista, DeVault & DeWoody, 2009).   

References

Bernardino Jr F, Dalrymple G. 1992.Seasonal activity and road mortality of the snakes of the Pa-hay-okee wetlands of Everglades National Park, USA - ScienceDirect. Available at https://www.sciencedirect.com/science/article/abs/pii/000632079290928G (accessed December 9, 2018).

Foster M, Humphrey S. 1995. Use of Highway Underpasses by Florida Panthers and Other Wildlife on JSTOR. Wildlife Society Bulletin 23:95–100.

Glista DJ, DeVault TL, DeWoody JA. 2009. A review of mitigation measures for reducing wildlife mortality on roadways. Landscape and Urban Planning 91:1–7. DOI: 10.1016/j.landurbplan.2008.11.001.

Dodd C, Barichivich WJ, Smith LL. 2004. Effectiveness of a barrier wall and culverts in reducing wildlife mortality on a heavily traveled highway in Florida. Biological Conservation 118:619–631. DOI: 10.1016/j.biocon.2003.10.011.

Maehr D, Land E, Roelke M. 1991. Mortality patterns of panthers in southwest Florida. Proceedings of Annual Conference of Southeastern Fish and Wildlife Agencies 45:201–207.

Steen DA, Aresco MJ, Beilke SG, Compton BW, Condon EP, Dodd CK, Forrester H, Gibbons JW, Greene JL, Johnson G, Langen TA, Oldham MJ, Oxier DN, Saumure RA, Schueler FW, Sleeman JM, Smith LL, Tucker JK, Gibbs JP. 2006. Relative vulnerability of female turtles to road mortality. Animal Conservation 9:269–273. DOI: 10.1111/j.1469-1795.2006.00032.x.

- Randi Bowman, Research Intern

Getting Outside the Gator Hole

A few weekends ago the other interns and I decided to take a weekend away from the gator hole (what our dorm is affectionately called) and explore a bit of south Florida different than the swamp. On a Friday afternoon we took off from Corkscrew for a camping trip at John Pennekamp Coral Reef State Park in Key Largo. As we set up our tents by the light of our car headlights we were anxious to wake up in the morning and explore the sound just over the trees from our campsite. The following day met us with a few surprises! We were not prepared for the hoards of sand fleas that like to hang around in early November which meant we were walking around in pants, long sleeve shirts, and socks and sandals. This put a bit of a damper on hanging out in the sun on one of the State Parks two beaches so while Amy and Lara went kayaking, Randy and I decided to hop on one of the snorkeling boats out to explore the offshore reefs! The ride out to the reef was worth the trip, with sparkling blue water that was almost turquoise at spots and so clear you could see the bottom even at 25 ft.

As we swam along the surface of the Altantic ocean I snapped photos so that I could later identify all that we saw along our 4.5 hour excursion. Occasionally taking deep breaths and diving down to get a closure look of the world going on below us is how I got these two snapshots of what we saw! One of the most common corals we saw were Gorgonians, commonly called sea fans, which is a soft coral. Even in the photo above you can see the Gorgonians swaying with the current. Hidden behind the sea fans may be another type of soft coral called Plexaura, also known as sea rods, although it's hard too see. The orange coral with the white tips is Milleporina or fire coral. Used for defense and capturing food fire corals have a neurotoxin in their polyps that if touched will leave a stinging sessions and/or rash at the point of contact so be careful to avoid accidentally grazing this coral! Circling this patch of coral is a Parrot Fish (Scarus spp.). They are a reef fish and like to feed on the algae on the corals and reef bottom. Seen weaving between the sea fans is a French Anglefish (Pomacanthus paru). This species will act as cleaning stations in the reef removing and eating parasites from other reef fish! These are just a few of the colorful corals and fish we saw out in the water. Too soon the captain called us in for the last time and we began our trip back into shore. The following morning we packed up, rather quickly in the rain, and head back home to Corkscrew. Our weekend of exploration was over but we were already planning for our next exciting trip!

CREW Bird Banding

Thrilled about this freshly banded Grasshopper Sparrow

As someone with a keen interest in birds and thirst to learn as much as I can about the different ways to study them, one of my main interests over the past few months has been to get experience mist-netting and helping to band birds. So imagine my excitement when I learned that I would get the opportunity to do these very things just a few minutes down the road at CREW!

A little background on bird banding: one of the best ways to understand avian movement and population demographics is by capturing individuals, attaching a small, metal band with a unique number to their legs, and then taking various body measurements such as mass and wing length before releasing them. One of the most common methods of trapping small birds is called mist-netting, which essentially consists of strong nets strung up between poles that, under the right conditions, can appear almost invisible. 

Grasshopper Sparrow

The banding at CREW is led by Bob Altman, an experience bird bander who has conducted extensive research on various avian species in Oregon and has been banding at this site for 3 years now. This banding project is focused on sparrows, in large part due to the extremely threatened Grasshopper Sparrow that winters here in south Florida. While Grasshopper Sparrows are the sparrows we most commonly get in the nets, he also bands Savannah and Swamp Sparrows when they do get caught.

Savannah Sparrow

Swamp Sparrow

One of the most surprising things to me so far is that about 40% of the sparrows that we catch are recaptures, meaning that they were already banded. Some of these recaptures were caught and banded by Bob at the exact same net 2 years ago, indicating that they migrated back to the same section of the same field each fall! Recaptures are super useful, because Bob can then go back to the data he took when he first banded that bird and see when and where he'd caught it and compare its body measurements. 

Flushing birds into the mist nets

You may be wondering how we get these birds to fly into the nets when they're set up in a big, open field? The method is pretty simply: we chase them. Between 4-7 volunteers will stand in a line parallel to the nets with a long rope stretched between them and walk quickly towards the nets, dragging the rope along and flushing birds towards their temporary prison. In the process, we get a lot of birds other than sparrows, mainly tons of Palm Warblers and the occasional Common Yellowthroat and House Wren. These species we just extract from the nets and immediately release (lucky ducks). When we encounter sparrows, we carefully put them into small cloth bags to be banded and processed. 

Banded Grasshopper Sparrow

This has been an awesome experience for me so far because Bob has been showing me all the different steps of mist-netting birds, including setting up and taking down the nets and extracting and handling birds in a safe manner. Banding is also an important way to inform the public about how researchers collect data on birds, and is a useful form of citizen science because of how visible and hands-on the process is. There are almost always between 3 and 6 volunteers who come out to help Bob every morning before sunrise, which really demonstrates how much people care about birds and are passionate enough to dedicate their time to helping in their conservation and research. While waking up before the sun can be tough sometimes, something about seeing the sun rise over the prairie and getting to hold birds is so humbling to me, and every morning I leave with a renewed sense of satisfaction that what we're doing is really contributing to our understanding and the conservation of these threatened species in the face of climate change and human development.

~ Lara

New Education Intern: Amy

Hello everyone! 

My name is Amy Craker, and I am the new Education Intern here at Corkscrew Swamp Sanctuary.  I am originally from Fort Wayne, Indiana and I just graduated from Purdue University in May of 2018 with a Bachelor’s of Science degree in Wildlife. My first job out of college I worked as a biological field technician for an environmental consulting company collecting data for research involving wind turbine effects on bird and bat species.

I have always had a passion for nature and learning and I am excited to bring those together as I assist with youth and public education programs here at Corkscrew. When I’m not working, I enjoy reading, crafting, photography, and anything outdoors. I also am kept busy with planning for my wedding next summer! 

I look forward to getting to know you during my time here! 

A Walk on the Wild Side

This last week the research crew and I made our way to a section of Corkscrew called the Central Marsh Transect (CMT). This area is commonly used for routine fish sampling and even the occasional swamp walk with Corkscrew volunteers. On this particular outing we sought to sample three ecosystems along the transect including the wet prairie, pond cypress, and bald cypress locations. Dividing into two groups to tackle the project, we thought we had an easy day in the field ahead of us. Little did we know what was awaiting us in the swamp.

As we trudged through the ankle deep water with reeds and alligator flag towering over us, my group made our way to the bald cypress location to begin sampling. This required us to move through both the wet prairie and pond cypress locations first, as the bald cypress is the deepest and furthest out sampling location along the CMT. Making our way into the pond cypress the lowering of water levels could already be noted, despite it only being the end of October. This left many logs, cypress knees, and lower vegetation exposed. Having sampled these locations several times, we all had gained a certain level of ease walking through the mucky swamp waters. Stepping over logs and brush had just become apart of the job. However, as a took my next step, following closely behind another team member, I looked down and much to my dismay the log that I thought I was stepping on was actually an alligator’s tail!

Alligator after moving from the path and
 perching itself on a pile of fallen branches.

I leaped forward as the alligator that I had just disturbed began to squirm beneath me. The crew member I was following hadn’t even realized that he had also stepped on that same alligator while leading our group through the pond cypress. Now standing less than five feet from the large creature in knee deep water, we realized just how big and close to it we were. The alligator seemed to reach around six feet in length, and was much more mature than any other alligator I had run into while walking through the swamp. Awestruck we realized what had just happened. One of the oldest, seemingly most deadly creatures on Earth had just been beneath our very feet, and besides moving a foot or two off the path, it didn’t seem to care.

It was that day in the swamp that I realized just how wild and unpredictable this place can be. I also realized just how foggy the general public’s idea of alligators and and their supposed aggressive behavior is. These wild alligators, having not been in regular contact with humans, did not respond aggressively to our presence. Instead the large reptile opted for coexistence with our group. This is not to say that wild animals should be approached or disturbed within their natural habitat, but a friendly reminder that when in nature, we are putting ourselves in new, and unpredictable conditions and must proceed with caution and respect. I will always remember the day that I accidentally stepped on an alligator’s tail as a day that I was humbled by the beauty and coexistence that exists within our natural environment here in the swamp.

Until next time,

Evan

Aerial Adventures at Corkscrew

Flying might be one of the most unnatural things a human could do, besides scuba diving. I love scuba diving, so it is only natural that I find joy in flying. On commercial flights I’m the one smiling and laughing when the plane hits some turbulence that makes your stomach turn. So when I learned I’d be going on a wading bird flight in a small plane – a Cessna P210 – I was excited. When I was told we should expect turbulence, I was even more excited. But I’d be lying if I said I wasn’t a bit apprehensive about motion sickness. I’d never had a problem with it before, but here I would be in a small plane taking tight turns and hitting the airborne equivalent of speed bumps, all while scanning the ground for wading birds, jotting notes, taking pictures, and staring through binoculars. People, including the pilot herself, advised taking Dramamine as a precaution before the flight. I decided to forgo any precautionary measures in favor of finding out for myself whether I would get sick or not.

The plane was a 6-seater, with two backseats, one middle, and a seat each for the pilot and copilot. Being the least essential non-navigating part of our 3-person team, I sat in the back, accompanied by two stuffed teddy bears I figured might provide a modicum of cushion in the event of a crash (or at least something to hold whilst screaming during the rapid descent). Kidding! With our research technician Lee in the copilot seat and a lively woman with 40 years of experience in the pilot’s seat, we were ready for takeoff.

We were wheels-up at 0932, quickly climbing to our cruising altitude of 1,000 feet. Next to touching down, taking off and climbing is my favorite part of a flight. The moment the wheels leave the ground is almost magical, and then there’s nothing below your seat but air and increasingly tiny objects tethered to the ground by gravity. All it takes is fuel, engine-driven propellers, and a craft of the right morphology to best gravity, and oh what a feeling it is to be free of it (figuratively of course, you’re not exactly floating up there).

 Anyway, our survey was really quite simple in method and objective – we were to fly around agricultural areas until we located a group of wading birds, circle and take notes, pictures, and a GPS point, and wash, rinse, repeat until our general survey area (Naples vicinity) was covered. We saw about a dozen groups, with the majority clustered around active farm implements such as excavators digging out canals or small ponds and tractors tilling fields.

Wading birds clustered around an excavator

It was strange at first, seeing Great Egrets (Ardea alba) and Woodstorks (Mycteria americana) crowding the ever-moving mechanical arm of an excavator, each trying to get first crack at whatever the claw-fringed bucket managed to scrape up. This unexpectedly beneficial interaction diminished the hard work of locating food through either tacto-location or patiently waiting for a fish to swim within striking distance. We saw group after group of wading birds occupied in this way, while the natural swamps and wetlands remained largely unfrequented. I have no doubt the wading birds will return to these areas once they start to dry down, for the lowering water levels will concentrate prey populations and increase foraging efficiency. But for now, it seems as though these farmlands, the middle ground between Florida’s natural areas and concrete-encrusted developments, may play a more important role in the conservation of these birds than we thought.

Photo taken between groups of wading birds to separate sets

With that in mind, we completed our aerial circuit and set our course to return to the Immokalee Regional Airport. Entertained as I was by the pilot’s tales of adventures across the country on the wings of this Cessna, I was sobered by the reality that aerial surveys like the one we had just completed were the cause for many accidental deaths in our field. Between 1937 and 2000, 66% of the 91 documented fatalities that occurred in wildlife research and management activities were the result of aviation accidents. As we neared the landing strip, our pilot warned of a bumpy landing. The slight wobble in the wings along with the slight queasiness I had acquired during our last loop of our 12^th and final group of wading birds returned my attention briefly to the protection the teddy bears probably would not offer in the event of a crash, but that didn’t stop a wide smile from settling on my face as the ground rushed closer. The moments leading up to the wheels finally leaving the sky and once again touching the Earth were tense with excitement and anticipation. We touched down much smoother than the pilot had warned, rapidly decelerating once all wheels were solidly in contact with the ground. We taxied to the small airport terminal, and with that, the flight was over. Those few airborne hours left me with a heightened respect for biologists that regularly conduct aerial surveys, and a somewhat better knowledge of how wading bird foraging habits have adapted in the face of habitat loss. I hope that these flights will continue so that we can provide information that may prove valuable to the conservation of wading birds. With any luck, I’ll get the chance to tag along again!

- Randi Bowman, Research Intern