Follow Solberg on a Survey

Two weeks ago I described some of the work being conducted by Cliff Maehr and Jenna May at the Florida Panther NWR. This week I am excited to take you with me on my Anuran Survey. With our wildlife conservation heroes Batman and Swallowtail…I felt obligated to give myself a catchy conservation-orientated nickname. And thus, Anurman was born! His attention for detail and affiliation for frogs has given Anurman an edge with anurans. Anura is the Order that encompasses all families of frogs and toads. So if you’re not sure whether it’s a frog or a toad, you can call it an Anuran and never be wrong!

Project Background

Here at the Florida Panther National Wildlife Refuge I’m seeing how many different species of Anurans I can find across different habitats on the refuge. Because frogs and toads have permeable skin and a biphasic life cycle, they are very sensitive to disturbances. Alterations to habitat, pollution, and too much exposure to UV rays are more likely to affect Anurans before they begin affecting other animals like mammals. And because of this sensitivity, Anurans are a great indicator species of ecosystem health. If an area is being affected by a disturbance, Anurans are one of the first to go!

Using Anurans as an indicator species allows one to assess habitat quality and managment applications. In addition, you can prioritize restoration work. This is important when you have little funding and a large area of habitat to manage. This is something I hope to contribute to the Florida Panther National Wildlife Refuge.

So as a very general rule,
Anurans within an Ecosystem = Healthy Ecosystem

However, there are some exceptions to this. Bull frogs and cane toads can be found in high densities in disturbed areas! Sometimes our actions make conditions good for one species. Think about crows, mice, and other generalist species. So by looking at the number of species present or species richness, I am able to get a more accurate representation of ecosystem health. After all, you can’t put all your eggs in one frog…or basket, whichever you prefer!

My neighbor Fred
Southern Toad, Bufo terrestris

So what is the best way to survey Anurans? Some species like this Southern toad vist my house on a daily basis. Fred is easily captured, identified, and extremely predictable. But what about other species? There are a lot of variables to consider:

• Time
• Funding
• Manpower
• Transportation
• Tools
• Accessibility
• Season
• Time of Day
• Weather
• Region
• Habitat
• Site
• Terrestrial Species
• Aquatic Species
• Are Species Active?
• Do Species Call?
• Are Species Easily Captured?
• Can Species be Identified Easily?

Just to name a few…

Although I did some undergraduate work with amphibians, I didn’t realize the extent of surveying Anuran species until I designed my own study! So I did the sensible thing and started Googling.

Once I had the basics, I began conducting some more in-depth research. I found that Florida has 33 species of Anurans! Of these only 17 species occur in the South Florida Region (14 native species and 3 introduced species). Out of these 17 species in South Florida, 5 species are tree frogs (Family Hylidae). That encompasses nearly a third of all the species in my area! So I decided to set my sights on them.

Green Tree Frog, Hyla cinerea

Tree frogs are easily identified by their large toe discs, long limbs, and slender waists. Arboreal creatures, tree frogs spend much of their time inhabiting trees. They often seek refuge in moist tree nooks or within the boots and fronds of palms. Thats not to say they can't be found on the ground! You can often find tree frogs hiding around your garden hose in warmer months. A popular method for catching such frogs is the use of pvc pipe. Small diameter pvc pipes provide a safe refuge that can easily retain moisture and provide a humid home for tree frogs. Few animals can climb up pvc pipe, so this method helps avoid indiscriminate capture. After all, you wouldn’t want to find a venomous snake in your pipe!

Methods

Pvc pipes were cut, drilled, and placed at chosen sites on the Florida Panther National Wildlife Refuge. I chose sites based on habitat type, proximity to water, and accessibility.

Three days a week, I wake up early and hop on the ATV to visit my survey sites. Every morning brings new wildlife encounters and lessons. I have the opportunity to see first-hand how these different habitats change over time. And what’s more exciting than checking the unknown? You never know what you’re going to find at the bottom of a pvc pipe. One morning I found a half-frozen Green Anole lizard. He must have fallen in the pipe scampering up a tree. But a few hours in my pocket had the lil fella good as new, before he was released back into the wild.

During every capture event I record the species, size, weight, pipe, site, and date captured. Weather data is also an integral part of my data collection.

Results

Thus far the only species of tree frog I have captured in my pvc pipe refugia is the Cuban tree frog. They are an invasive species of tree frog introduced from Cuba. These frogs not only out-compete native species but will eat native species as well! So despite my inability to assess habitat quality from one species, my results have opened my eyes to perhaps, a larger issue.

A massive Cuban Tree Frog, Osteopilus septentrionalis

When things don’t go according to plan… take what you can from it and learn. Because you never know where it will take you!

Wishing you all the best,
Matt Solberg

Biology Team Update

Time has flown here at the Florida Panther National Wildlife Refuge! On March 16th we had a successful Open House event at the refuge. Gates were opened to the public and about 200 hundred people came pouring in for Bird walks, Buggy rides, and Orchid tours! Hunger Game fans joined in, as kids learned archery skills and facts about the Florida panther. I watched as imaginary warriors on armored steeds lit the battlefield with arrows. I couldn’t help but join them, quickly realizing my right-handed, left-eye dominant technique put me at a disadvantage. My first arrow missed the target entirely! I quickly switched hands as the children laughed. Aiming with determination, my next arrow hit the target! I smiled at the little boy next to me and we fought off our imaginary enemies. I was thankful such activities could get children interested and involved in wildlife conservation. I was also thankful that practice left me shooting just as well as the children.

With little staff the event couldn’t have been what is was without help from Friends of the Florida Panther group and volunteers. Our gratitude and thanks goes out to the volunteers, sponsors, and everyone that contributed to the event.  Attendees got a chance to see part of the refuge normally closed to the public. With land set aside for Florida panther habitat, it was a rare opportunity for the public to see first-hand the results of our work. A diversity of habitats, managed by the fire crew and biology team to preserve a natural system. But much of our work is disguised. Management regimes like prescribed burns attempt to mimic natural fires. They maintain a balance by limiting dominating shrubs and exotics and allowing grasses and forbs to grow. With the cycling of nutrients and new growth, prescribed burns offer beneficial foraging opportunities for wildlife. During my anuran (frogs and toads) surveys I find these areas full of activity! Turkey and deer reveal themselves as the sound of the ATV spooks movement. Swallow-tailed kites and red-shouldered hawks fly overhead, foraging. And tracks on the sandy substrate reveal high traffic. Elusive as they are, Florida panthers and bobcat leave traces as they patrol these charred areas. There is much to be seen after a fire.

In addition these series of small fires also reduce the chance of a large wildfire sweeping across southwest Florida. So while benefitting nature, prescribed burns also benefit us. We also practice other management activities such as exotic removal and herbicide treatments. We work to suppress and eliminate invasive exotic plant species that would otherwise take over. And believe me…you should see some of these plants! They quite literally “Take Over”.  Most of our work concerns Brazilian Pepper, Cogon grass, Old world climbing fern (Lygodium microphyllum), and Ceasar weed…to name a few. It’s an endless battle, but if we let these plants sweep across the land then we’re simplifying our world. These invasive exotic plants choke out native plants needed by many of the animals that make use of the refuge. I will make an effort to get some pictures of exotic plants to better illustrate this!

Batman and Swallowtail

The adventures of Batman and Swallowtail begin with two Biological Interns chosen to pick a project to build our understanding of wildlife on the refuge. Cliff Maehr elected to study the Florida Bonneted bat and Jenna May chose to concentrate on Swallow-tailed kites. And thus, Batman and Swallowtail came to be!

Thanks to Cliff Maehr, the support of the Biology team, and advice from local biologists, we were able to confirm the presence of the Florida Bonneted bat on the Florida Panther National Wildlife Refuge! This was exciting news for a species we still have much to learn from. Using Anabat detectors to pick up the frequencies given off by bat vocalizations, we are able to distinguish bat species without physically seeing them. This proves especially handy when you have furry brown blurs whizzing above your head at dusk! The Florida bonneted bat is Florida’s largest bat and was proposed for protection under the Endangered Species Act (ESA) on October 3, 2012. Very little is known about this bat’s behavior, range, and roost sites. It has been an amazing opportunity to assist Cliff Maehr placing Anabat detectors in a variety of habitats on the refuge and driving transects at night. We have just touched the surface and I am confident we will walk away knowing more about this bat than much of the scientific community.

 

Florida Bonneted Bat

taken by Kathleen Smith of the Florida Fish and Wildlife Conservation Commission

 

 Swallowtail

 

photo taken by Larry Richardson

February welcomed another species to the refuge! Swallow-tailed kites have migrated hundreds of kilometers to nest here in southwest Florida. A risky journey over the Gulf of Mexico from Central and South America. This beautiful predatory bird sports a 4 foot wingspan. A monogamous bird, kite pairs mate for life. Watching them soar in the air with their forked tail is something else entirely. Like vultures they use the air currents to fly, rarely flapping their blade-like wings. Would you believe they eat and drink on the wing? Have you ever witnessed a barn swallow drinking?  Much like swallows, swallow-tailed kites fly low and skim the surface of the water, dipping their beak. Jenna May has been searching for Swallow-tailed kite nests at Florida Panther National Wildlife Refuge. Her focus is nest distribution and vegetation surrounding nest sites. I was lucky enough to find our first nest alongside our new expert Jenna May. But marking the nest with the GPS proved even more challenging! Imagine delving into thick hammock trying to keep your eye on a particular tree in the distance. Jenna and I learned the hard way. Locating a nest is far more difficult than it sounds. But hard work reaped rewards! Dr. Kenneth Meyers paid us a visit to inspect the nest. Well known for his work studying Swallow-tailed kites, he was proud to have Jenna May leading further investigation. His passion instilled much of my own for these beautiful birds.

 

photo taken by Larry Richardson

Follow this link to see the southbound Swallow-tailed kite migration: http://arcinst.org/arci-news-blog/NewsBlog/an-ocean-behind-the-andes-ahead


Whats Next?

Well Batman and Swallowtail aren’t the only heroes in this story. There ally has been hard at work studying the diversity of frogs and toads on the refuge. And that is a story that will have to wait until next time! In the mean time, we'll be watching those kites!

 

The Swallow-tailed kite nest Jenna May and I discovered!

 

 Fare thee well friends, More Soon!