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Clarkii by County: Northern Monroe

Continuing on our tour of Nerodia clarkii variation in Florida – let’s go a little south to northern Monroe County. I’m dividing the county into two because the Keys are a long string of island, and there’s some differences in clarkii variation between the upper and lower Keys.

 

The Keys have what is potentially the most robust populations of Mangrove Snakes in Florida – This is probably due to a mixture of an abundance of habitat that is relatively competitor free – the Keys are free of the iron fist of the Florida Watersnake, which is a superior competitor and keeps clarkii from penetrating very far inland. Being Florida Watersnake free also prevents the hybridization issue I talked about in my last post. So just how abundant can clarkii be? Here are the results of about an hour of searching with a couple of research assistants:

Bucket o' clarkii

And the story gets even more amazing – a friend of mine boasts of finding more than 100 clarkii in a single evening of searching.

As you can see, a lot of the Keys clarkii are drab in color:

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but you’ might also notice some muted copper colors in there – these colors will typically show up very well on the venter.

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And some individuals also show copper blotches vibrantly on the dorsum:

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A good many of the individuals in the upper Keys are brown in base color, but it’s not uncommon to see other colors as well, including a lovely gray hue -

 

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And as always, the red coloration turns up now and again – I find one once every ten snakes or so in the Keys:

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This coloration is not always a solid blood red, but sometimes will include muted yellows and such. I was previously under the assumption that the coloration/pattern ‘fades’ to solid red as they mature, but I’ve seen some blatantly-adult individuals that defy this assumption. Below you can see the same adult, but the pattern/color variation is a little easier to see. IMG_1027

 

And with so many snakes, they can be potentially found anywhere in the Keys – this is one of the few localities that I’ve herped personally where seeing them in the trees at night is a possible good searching method…. These following two shots are in situ (though I’ve spent hours trying to pose clarkii similarly on other occasions. I personally prefer it when they do it on their own.)

 

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Close-up:

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And a few other odds and ends to round off the northern reaches of the county, including some feeding shots. Unlike in nearby ENP where hiking seems to be useless, I’ve found the vast majority of my Keys clarkii hiking in shallow-watered mangrove swamps.

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Feeding on a minnow:

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That’s all for North Monroe – more to come! I just added a “Like” button on the right, so be sure to “Like” Field Ventures on Facebook.

 
 

Clarkii By County: Miami-Dade

In anticipation of an upcoming article on the Salt Marsh Snake (Nerodia clarkii) in Herp Nation Magazine, and the (hopefully) near completion of the data-gathering phase of my research on clarkii in southern Florida, I’m going to review some of my experiences with the species. Instead of a smattering of stream-of-conscious ideas and such, I’ve decided it would be interesting to systematically review what I know of the species in every Florida County I’ve come across them in. For my readership, I think the interest will be in the fact that a.) the foraging and movement ecology of clarkii seems to be different on a local level, in other words they simply act different in nearly every county; and also the pattern and coloration is extremely variable across their range (more elaboration in future postings, and of course the upcoming Herp Nation Magazine article.) So sit back, relax, enjoy.

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Let us begin from the familiar: Dade County – Everglades National Park. Yes, there are other sites in Dade from which to view clarkii, but ENP is rife with them and many herpers have seen the species there. For this reason, I’m sorry to inform you that if you’ve seen clarkii in ENP, you may not have seen clarkii. From our work so far, we’ve encountered 19 Nerodia clarkii-like animals there, of which sixteen have been hybrids between N. clarkii and the Florida Watersnake, N. fasciata, and only three have been pure clarkii. This is one of the interesting things about the species: they readily hybridize with Florida Watersnakes, especially in large-scale mixing zones such as the Everglades. Our work initially began in ENP where we were testing the use of traps for detecting clarkii. Without giving away the data, the interesting tidbit about clarkii at this population is that road cruising seems to be the best way to come across them, and it also seems to be one of the only productive ways to turn them up. Of course I’m not saying it’s impossible to hike them up in ENP, they certainly forage, eat and live outside of the roadways. However, perhaps because of the dense mangroves with extremely deep mud that makes the habitat difficult to search, or perhaps because they forage at different times or in different manners from other populations, we found only a single clarkii by hiking, despite much time spent looking. (And full disclosure: the clarkii we hiked was on a right-of-way, meaning it would’ve been road cruised in seconds had we not already been out of the car.)

Dr. Chesnes checking a trap for clarkii

Dr. Chesnes checking a trap for clarkii

 

Now on to the variation. Holding with their hybrid nature, most of the clarkii encountered in ENP are banded in some way:

Pure clarkii:

15263277375_149118d244_z clarkii x fasciata:

8737089472_6c2c5caeb1_zPure clarkii:

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clarkii x fasciata:  8737101614_ea45180a5e_z

However, occasionally one will look a little more classic clarkii (not that I know what that is, and I can’t seem to find a great picture of one.) And it seems that the red trait is not a recessive one even when fasciata is in the mix, and hybrids will still often turn up with a clarkii bloodred coloration: this individual was a clarkii x fasciata:

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That’s all for this segment, in the weeks ahead we’ll take a gander at Indian River, St. Lucie, northern and southern Monroe, Collier and Lee Counties – and maybe, just maybe a new county record or two.

 

 

NOTE: This research on Nerodia clarkii was partially funded by a Palm Beach Atlantic University Quality Initiative Grant, so many thanks to them. To help us continue our last few months of research, please consider making a small donation to Field Ventures

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New Section: Field Ventures Photography

Hello all;

 

Field Ventures now has a new section with some of the photography seen here for sale – the proceeds from the sales go towards reptile and amphibian research (currently, Mangrove Salt Marsh Snake research) – check the page out here: http://fieldventures.wordpress.com/field-ventures-photography/ or on the tab at the top of the page.

 

-JDH

 
2 Comments

Posted by on 22/08/2014 in Uncategorized

 

Welcome To Florida

It had been a long, exciting night in Everglades National Park. Road cruising had been good to us that evening – nearly every afternoon for the past two months had been mired in rain, which is oftentimes a kiss-of-death for roadcruising in southern Florida. This night, however, was dry, warm and of overcast skies to obscure a big moon. I surmised that it should be a great night, and it was: so far we were at 22 snakes, including one hatchling Python – fresh out of the egg caught down near Flamingo. Tom, Dermot, Eric and I were crammed into my car and neither Dermot nor Eric had the pleasure of cruising up and laying hands on a wild python, so it was a fun and exciting night already.

 

So we were continuing on, noticing a set of taillights up ahead. Typical etiquette in ENP in the depths of a summer night is to stop and talk to any other herpers you see (and trust me, if someone’s there braving the mosquitoes between July and September it’s probably a herper.) Well, consequently the taillights turned into break lights, so we drove up to say hello and see if they’d turned up something interesting. As we rolled up, I noticed there were two vehicles off to the side, and a small gaggle of people in the road. One of them appeared to have a snake in his hand, but I couldn’t yet see what species it was as the scene was bathed in headlights from vehicles and my eyes hadn’t adjusted. Naturally though I assumed it was a python since that is the only snake species that a lot of people have Letters of Authorization to search for in the Everglades. True, one can obtain a permit to study any other species occurring in the park if they have a legitimate study need and do the proper paperwork, but I know most of the other folks who have permits for that kind of stuff, and these folks were certainly not any of them. So, the gentleman with the snake walked closer to the window, and as my eyes finally adjusted I saw that he did not have a python in his hands. Not even close: his fingers were wrapped around the neck and head of a two foot Florida Cottonmouth.

 

In my mind, I was running through a mental checklist of everything that was wrong with this situation:

 

Handling wildlife in the park: Illegal without a permit…

 

Possessing a venomous snake in Florida: Illegal without a permit…

 

Handling a venomous snake by pinning the head: Irresponsible, both in terms of the likelihood that he’ll get bitten and the fact that the cottonmouth looks like its head might pop off at any minute.

 

But, fortunately, I’ve been blessed with the ability to carry on a conversation while completely distracted.

 

“How’s it going?” I asked.

 

“Oh doing ok, are you guys out looking for snakes?”

 

“Yeah…”

 

“Nice, any luck?”

 

“A little bit, 22 snakes so far.”

 

A dismayed look came over his face, “Really? Man, we’ve only found three Cottonmouths tonight, no non-venomous at all.”

 

A wave of incredulous bewilderment came over me. If this was their third Moccasin of the night and this fellow was squeezing its head like the last bit of toothpaste in the tube; what horrors had the first two been subject to?

 

Oh well, the matter at hand: “Well, if you didn’t pick up every Cottonmouth you saw, you might get a chance to see some of those non-venomous snakes on the road.”

 

Snickers from girls with him. I try my best not to be a jerk to people, but in the current situation my comment was really the least of the options running through my head.

 

“No, no,” he pleaded, “I’ve been doing this all my life, I have a lot of experience working with venomous snakes.” He looked about 25 or 30.

 

“You don’t say.”

 

“Yeah… Have you guys seen any pythons tonight?”

 

“Yeah, one hatchling.”

 

I know the frustration of being out in the Everglades and not turning up the target python, so I offered to show it to the group, despite my misgivings about the ringleader.

 

We threw on our caution flashers, got out of the car and walked to the back, where I grabbed the bagged up python and got it out.

 

“Yeah,” said the one with the Cottonmouth, “my friend and I are out here showing ‘the Adventure Girls’ some of the Everglades’ snakes, we’re hoping to see some nonvenomous.”

 

It was only then that I noticed the assortment of folk that were standing in the road. Initially there were only 3 or 4 of them, but now they emerged from the two vehicles that had evidently been crammed full as clown cars: ten, twelve people now stood around us in a clumped gaggle. The group, I noticed, looked like they’d just emerged from an 80s rock music video: the Cottonmouth wrangler had acid wash jeans, a beater shirt with armholes going down to his waist and forearm tattoos that the fog of war has since scoured from my memory. The “Adventure Girls” had a diverse wardrobe – many wore tights: some pink, some giraffe print; and at least one wore a rag of an open-sided Whitesnake t-shirt (appropriate, I guess?), and a bikini underneath. The clouds of mosquitoes around us had me thinking that either they were all doused in enough DEET to kill a man, or the huge quantities of exposed skin among the group was going to be red and welted ere long.

 

Master Moccasin told his group how Pythons were an invasive species, etc., and all while the Cottonmouth was in his clutches, and we were about ready to depart. But before we did, he had some more questions for us:

 

“Hey, do you know Cobra Carl?”

Inaudible groan from me.

 

“No, ‘fraid not: I know Boomslang Bobby and Rattlesnake Rachel though.” Ok, maybe I shouldn’t have said that…

 

“No, he’s a legitimate herpetologist.”

 

Ok, joking aside, “ahh, no sorry, I usually don’t hang out with people with snake names in front of their names.”

 

By this time, the poor Adventure Girls even saw the danger both the snake and the guy were in because of his irresponsible handling, so we decided that was a good opportunity to mosey.

 

“Anyways, good luck, have a good evening.”

 

The group thanked us for the close-ups of the python and we hopped in the car. We slid away, and were silent for 3 or 4 seconds of deep contemplation… and then an eruption of laughter.

 

“Did that really just happen?” someone said. I wasn’t quite certain myself, it was a surreal moment. I considered calling the Park Service, but I was pretty sure they weren’t collecting anything, so there’d be no evidence of his lawbreaking. We slid down the lonely road, finally exiting the park where a lone, big Cottonmouth was crossing. I looked back and saw familiar headlights coming fast. I jumped out of the car, snake hook in hand, and flung the snake as far as I could off the road: somewhat crude methodology, and I’d have chastised myself in any other situation for such flippancy with a snake. But those headlights were coming on quick. If the snake knew, he would have thanked me.

 

 

This hatchling Burmese python was the least strange sight of the night.

This hatchling Burmese python was the least strange sight of the night.

 
6 Comments

Posted by on 12/08/2014 in Tales From the Field

 

Exotic South Florida: Farming For Chameleons?

 

Hello all, I’ve finished up my Master’s Degree and finally have some free time on my hands that isn’t spent working on theses and whatnot – so a little thought I’ve been musing on for some time… But first, an anecdote:

 

 


I walked through the lonely rows of twisted avocado trees, intently scanning for something off… Something that would betray my saurian quarry, something – there it was! A flash of light green, almost lime in color, a telltale sign that I had not only found my target species the Oustalet’s Chameleon (Furcifer oustaleti), but that I’d turned up a female at that. I got a little closer, waiting for the color to make itself manifest as a curly-tailed shape. But it didn’t: I got close and examined the light patch in the illumination of my headlamp, and sure enough: t’was a caterpillar.

 

Such has been a typical scene from searching for Oustalet’s Chameleons in Dade County from the past year-or-so. Chameleons are becoming ever-harder to find because of constant nightly pressure from collectors of every sort, and their roommates in the agricultural lands they call home – caterpillars, other insects and Anoles of various species – seem to be abundant. Of particular note are the caterpillars, which the grove workers have complained of late have a tendency to eat the leaves on the avocado trees, which in turn affects the overall fitness of the plant, and in turn fruit production. What’s interesting is, when I first started looking for Oustalet’s in years past, these chameleons were plentiful: a dozen or more in a night was little problem oftentimes. During this time one of the only living things found in the grove were the chameleons themselves: seldom if ever was a caterpillar or insect of any kind detected.

So, given the concerns in southern Florida about overuse of pesticides, might we not turn to herpetofaunal biocontrol? These chameleons have the potential to limit prey species, which coincidentally are often agricultural pests species – in fact, a study done by UF found that most of their diet consisted of insects (http://www.conference.ifas.ufl.edu/intecol/presentations/Posters/Vinci_Chameleon_Final.pdf). Obviously, the big question here is whether Oustalets (or Veileds, or any other species for that matter) have the potential to become invasive. This is a question that has received little research (and understandably so: there are bigger exotic fish to fry!) but as of now it does seem that they are largely dependent on agricultural areas as a source population, though they have been found in far lesser densities outside such areas. Let’s hear from some of the Field Ventures readers: what do you think about Oustalet’s Chameleons (or other species) as pest control in Florida?

 

 

 
 

Freshwater Ecology lab field work, 2014

Well, I just finished what (might) be the last draft of my thesis before my defense and also just finished my last teaching assistantship of my Master’s career. In between searching for jobs (anyone need a good ecologist?) I’ve had some time to look through some of the pictures my students took in the Florida Atlantic University Freshwater Ecology class I was TA’ing this summer semester. It was a great class, and we got to do and see some very interesting stuff – although as I was helping teach the class I didn’t photograph quite as much as I would’ve liked. But, fortunately I had a couple, and also one of the students in the class, Jen, graciously let me use her photos – so most of them in this post belong to her.

 

So, after finishing up my thesis field work and delving into the deep dark corners of my house to write for months on end, I got to get back into the field and some of my former haunts with this class and Dr. Dorn (the prof. for the class, and my graduate advisor) got to show them some of the wonders of a world present right among them (though seldom considered).

 

To initially introduce the class of some quantitative ecology field methods, we brought them to a retention pond behind the Davie campus.

Seineing:

Passive aquatic traps:

Plankton netting:

Fyke nets (I’d love to give these a shot for Rainbow Snakes!)

 

 

Some of the bounty:

Jaguar Cichlid (I think):

Tilapia:

 

Next we got to take a look in two of my former study wetlands in Jonathan Dickinson State Park. This was a lot of fun, we picked two of my sites that were right next to each other – sandhill lakes of similar size – and looked at the invertebrates in the two in terms of species assemblage (generally) and size structure.

 

The Florida Park service (via park biologist Rob Rossmanith) was gracious enough to help us with site access deep in the scrub:

 

 

 

Site 20: lot’s of fish.

 

Largemouth bass:

Lake Chubsucker:

Physid snails:

 

Long story short, some low activity invertebrates, but mostly fish.

 

Site 19: fishless. Mmmm.

As seen from the ridge above it.

Some of the catch; Buenoa sp., Damselfly larvae, Procambarus fallax and Anax junius larvae (and I think another species of dragonfly too):

Tadpoles:

Barkin’ Treefrog (Hyla gratiosa)

This one I’m not 100% on, as I didn’t catch this size class during my field work. I think a barking treefrog young of the year, but I’m not too sure.

Damselfly:

A leopard frog, showing the telltale “soul patch”

The particularly impressive Pinewoods Treefrog, Hyla femoralis:

Cricket frog larva and adult:

We found only 4 tadpole species total in the pond; though I know of at least 6 species that breed there. From left to right: Barking Treefrog, Pinewoods Treefrog, Cricket Frog, Leopard Frog.

 

We also visited some other wetlands of interest in the area;

 

A seepage bog filled with sphagnum: a rare site in Florida.

And a cypress strand which hadn’t filled up for the wet season yet. in the high, dry strand itself we found this Lethocerus sp. under a board:

 

And nearby in a ditch was the last water in the immediate area:

But even in this primordial soup was life – seminole killifish, mosquitofish, black acara and one watersnake (not captured for obvious reasons). Dr. Dorn was brave enough to sample the puddle with a bar seine – you can see the contents in the background and one of the seminole killifish in the foreground.

and a Black Acara:

And in the sand nearby were plenty of Oak Toads living it up in their post-metamorphic life.

And one last site to briefly dip-net for the day; the fish-filled site 5. Not much going on here besides fish, unfortunately.

 

Finally, the last week of field work involved going to the Loxahatchee River via the Riverbend Park put-in. It was some people’s first time in Kayaks; so an interesting time for sure.

Turtles were aplenty:

I even outfoxed a couple with the dipnet.

Hazards were many:

 

 

We did some dipnetting, including a couple in the group trying to net some big fish at one of the dams.

…and crabs among the snail beds:

I wanted to dip this Vallisneria (Tapegrass), but the flow was a little too quick:

And on our lunch break I took to looking for snakes:

And was rewarded soon thereafter with a Brown Watersnake, Nerodia taxispilota:

We also turned up some water lettuce at one of the dams, which provides excellent habitat for a wide range of herps and invertebrates:

more dragonfly naiads:

And the ever-abundant P. fallax

And also the invasive Insular Apple Snail

Then something amazing happened. I took a dip into the water lettuce and thought I’d gotten an amphiuma. On closer inspection it proved to be an American Eel (Anguilla rostrata) elver! I’d spent hours (and days) looking for these (and their predators) in Fisheating Creek; now to have one turn up haphazardly in a dip – wow.

We got two in one dip, this one and an even smaller elver – and then one of our group saw a larger (~2ft) one down by the second dam – it singlehandedly made an already-excellent class that much more worth it – need any more be said?

 

Thanks for viewing all, hope you enjoyed.

 

-Josh

 

 

 

 

 

 

 

A couple publications

Ones I neglected to post last year – dietary notes from the Florida Green Watersnake.

 

Holbrook, J. D., C. A. Young, D. P. Young and N. Greenwald. 2013. Nerodia floridana (Florida Green Watersnake). Diet. Herpetological Review 44(3):525.

 

Vogrinc, P., J. D. Willson, A. M. Durso, L. A. Bryan, Z. Ross, J. Holbrook and D. Filipiak. 2013. Nerodia floridana (Florida Green Watersnake). Diet. Herpetological Review 44(4):695.

 
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Posted by on 30/04/2014 in Uncategorized

 
 
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