Common snapping turtle (Chelydra serpentina)

If ever a Midwestern aquatic species deserved the appelation "Grendel", it would be the common snapping turtle. Trotlines have been lines terrorized, anglers aggravated, mothers menaced and whole canoe paddles bitten clean through. Its' reptilian reign of terror has endangered many a dangling digit...

...or at least that is the perception.



Common snapping turtles do indeed possess a powerful, formidable bite.

Frankly though...they are just too lazy to generate any legitimate concern. Whenever a human fares poorly in an encounter with a snapping turtle, you can be sure some form of stupidity has been committed...by the human.

For instance:

Our lab often dealt with snapping turtles during a time I was doing experiments in drainable ponds in graduate school. The turtles would lay across the open pond drains while ponds were being emptied. I suspect they were attempting to catch and eat the animals being sucked out by the flow. Often when this happened, the flat bottoms of the turtle shells would block the drain and slow the draining process. The turtles had to be moved to keep us on schedule. Normally, we used a bent piece of reinforcing bar to drag them away from the pipe. We'd haul them out of the pond and carry them down to creek for release (so they could crawl back up the hill later to get into our ponds all over again).

One day, I was draining a pond when the flow in the drain pipe slowed to a trickle. Turtle time. Unfortunately, the rebar was nowhere to be found.

"I know what I'll do", says I to myself. "I'll just kick the turtle until he moves away from the pipe!" (You must understand it had been a long and mentally fatiguing day).

I waded into the pond in an old-fashioned pair of green rubber hip boots. The water was murky so I couldn't see my feet. I could, however, feel with them. There he was. Large, solid and sitting over the drain. One kick. He didn't move. Second kick. Nothing. Third kick...and the turtle had had enough. He swung around and bit my foot solidly as it hit him. After much jerking and pulling and screaming like a frightened school girl I managed to wrench free. A distinct whitened point in the exact shape of a snapping turtle mouth showed where his beak had grabbed the heavy rubber boot.

Fortunately, the kicking did the trick. The turtle moved and the flow resumed. At some point during the draining, the turtle apparently buried itself in the mud (as is their habit) and I never saw it. The next day, however, there was a drag mark about a foot wide leading out of the pond. Given the breadth of my adversary, I felt lucky to still have all my toes.

The lessons I learned from this incident are as follows:

1. If you kick a snapping turtle 3 times, you will get bitten.

2. Find all your equpiment BEFORE you begin a job.

3. If you're have a reputation as a semi-macho biologist and you're going to scream like a schoolgirl, be sure no one hears.

Snapping turtles are not looking for trouble. They're looking for a place to hide or sleep or bask or eat or have sex or lay eggs.

One of my favorite places to see snapping turtles is the Nanney Biological Reserve owned by the University of Illinois. The Nanney reserve is a backwater floodplain of the Embarras River south of Champaign. The floods that periodically fill it foster a rich, productive community of organisms adapted to and dependent on periodic innudation.

To be clear, the Nanney reserve is not the kind of place one would choose for a genteel stroll in the country. The silt and slop are often knee deep and the vegetation is insanely dense. Standing water is a mosquitoe's friend and they are there in astonishing numbers. During my visits I normally wore long sleeves and waders just to keep the insects, spiders and brush from shredding me to bits as I slogged through the mucky undergrowth.

Despite the rigors, the place did have its' charms.


This photo is of a large wet meadow in the north end of the Nanney refuge. The bit of water visible in the bottom of the photo extends across the entire field. Quite a few interesting creatures can be found living in and around these flooded fields. Walking through the head-high vegetation, one might encounter deer, beaver, muskrats...and especially snapping turtles.



I found this magnificently slothful beast sunning on the edge of the same wet meadow pictured above. Approximately three feet long including the tail and head, he was the very image of bloated, languid, leisure. Apart from his size, three unique things intrigue me about this mini-Grendle.

1. His back is covered with mud. Apparently he has recently emerged from having buried itself. Snapping turtles apparently do this on a regular basis, possibly as a means to avoid predators.

Pause for another story about pond draining:

Walking the basin of a pond that had been drained, I once found an odd dark stob in the mud. Curious what this object could be, I bent over to inspect the stob and gave it a gentle tap with my finger. Two nostils immediately flared open in it's center. It was a ten pound snapping turtle buried in the silt to hide from us during the draining...

...and yet another narrow escape for my foolish phalanges.

2. This snapping turtle is missing the claws on his left rear foot. Frostbite? Animal attack? Disease? Whatever took the foot apparently wasn't hurting the turtle, since...

3. It's emmensely fat. Clearly this animal is having no trouble finding food.

What does a snapping turtle eat?

Whatever it wants, obviously. In the Nanney reserve the choices are virtually endless.


The picture above is one of the old oxbow lakes can be found in the southern end of the property. During the spring, after the river has flooded the flood plain and the lakes are full, an amazing melange of living things can be found here.

Immediately after floods, fish swim in the lakes until predators and declining water quality thin them out. Smallmouth salamanders crawl down from low mounds along the water's edge and lay their eggs here. Hyallela azteca, an aquatic isopod, grazes among the rotting cottonwood leaves on the bottom. During the flood, burrowing crayfish emerge from deep undergroud to hatch and release their young into the lakes. I found three species of crayfish there; Cambarus diogenes, the devil crayfish (that species is currently being separated into several sub-groups; I found the orange form which doesn't have a name yet), Procambarus acutus, the White River crayfish and Falicambarus foidens, the digger crayfish. This is the only documented population of F. foides in Champaign County (and I might add, with a modicum of pride, that I was the one who found them).



Crayfish chimneys such as the one above are as dense as one per square meter along the edges of the backwater lakes. It was no coincidence that most of the snapping turtles I found were cruising in those lakes. I'm sure the turtles were a major reason I never found fish carcasses when those lakes dried up. The crayfish and salamanders must have been tasty morsels as well.

So dense were the snapping turtles in those lakes that Steve Buck, the caretaker of the University of Illinois natural properties, considers them a pest. Smallmouth salamander numbers there are dwindling and according to Steve, it's because of the turtles. He may be right.

Yet the turtles and salamanders have been living there together in that backwater almost indefinately. Why would the turtles suddenly be a threat?

Certainly it is an eire feeling to wade through darkened shin-deep water and suddenly see those tell-tale ripples inching among the flooded tree trunks. It is enough to quail the strongest stomach to realize you are standing among a group of invisible 40 pound animals packing enough firepower to bite through a canoe paddle. Maybe Steve is experiencing some emotional transference after having had that experience a few times too many...

...or maybe, the system has been altered to the point that these populations are no longer in balance.

Flood mechanics have changed over time. Due to urbanization, drainage tiles and channelization, more water empties more rapidly off the land and the old natural patters of flooding and subsidence have been shortened and intensified. Some animals do well in these circumstances. Snapping turtles, when they aren't being boiled in a stew or kicked in the hiney by mentally defective bioloigsts, are apparently one of those.

Only study and experiments will determine with certainty what the role of common snapping turtles is in the flood plain lakes of the Nanney Biological Reserve.

In the meantime, it is nice to at least have a few portly water monsters around...

...to keep our imaginations alive.

The UMS Waterworks Class in Boneyard Creek

My friend Gary teaches a course called "Waterworks" at Urbana Middle School. In Gary's course the kids follow a curriculum of water-related science issues and field experiences. This includes an exploration of Boneyard Creek, an urban stream here in Urbana. When Gary called and asked for an assist I was delighted to help.

Check out what we found!

First of all, let's be clear that Boneyard Creek is a miserable dog of a stream. You can see one of the many "bank improvements" here on the right of this picture. Those blocks of boulders in steel mesh are actually one of the more aesthetically appealing things you'll find in Boneyard Creek. Much of the bank upstream has been encased in iron coffer dams. That's a plastic grocery bag there in the water beside my foot. Earlier this year a murdered body was recovered from the Boneyard. Many's the time I've driven over Boneyard Creek to see booms deployed in an attempt to control some chemical spill. It seems there were some pretty serious liquid waste disposal issues on the University's engineering campus. The Boneyard bore the brunt of those.

Recently the University has tried to make amends. A restoration was attempted on campus that for some reason also included a weir just upstream. Unfortunately, when the floods came (as they inevitably do), the water backed up at the weir and blew out the banks. That sediment washed downstream and filled a large pool where the University had constructed a nice veranda and expensive terraced landscaping. The ambiance there now includes litter strewn mud flats and an anaerobic stench.

Thanks for trying, University of Illinois.

So there it is. The Boneyard. A typical urban stream with a heap of problems plus riffles and pools and a grim, determined remnant of aquatic animals.

Let's meet them.




This is a longear sunfish (Lepomis megalotis). Nice. This sunfish species prefers streams over lakes and it prefers higher quality habitat. Apparently, this one is lost, but maybe not terribly so. We picked him up in a stretch of stream with reasonable habitat and overhanging trees that provided some canopy cover. I also saw smallmouth bass in the stretch where we collected this guy.

Hmmm. It seems even a miserable dog of a stream can show some encouraging signs of life.



Etheostoma blennioides. The greenside darter is named for its' blunt face that resembles a marine fish known as a "blenny". The common name comes from its' color. Those wicked leaf-green fins on this breeding male are some of my favorite colors on any fish anywhere. Boneyard Creek is full of greenside darters. Look for them among the rapids among the broken chunks of concrete and car batteries.



Creek chub, Semotilus atromaculatus, may be the single most common fish species in Illinois. With a wide mouth that can slurp up prey of many sizes, the creek chub is a tolerant foraging generalist that occurs just about everywhere. I think there are creek chub renting the apartment next door. This is a breeding male that was taken from the Boneyard on a jig hand-tied by Jim Zoreb.

Thanks, Jim!



Another very common fish species in Boneyard Creek and throughout Illinois is the central stoneroller (Campostoma anomalum). The upper lip of this species has a distinctive horseshoe shape due to a cartilaginous ridge it uses to scrape algae off rocks. That feeding behavior is the origin of their common name. Once upon a time, central stonerollers were thought to be the only obligate herbivorous fish species in North America. It turns out fish have rather loose allegiance to their feeding behaviors. Quite a few other North American fish species eat algae, and central stonerollers eat algae plus a few other things.



Catastomus commersonii, the white sucker, is the most common sucker in the state of Illinois. You can see the sucker-shaped mouth on the bottom of it's face. They use that to slurp and taste their way along the bottom, looking for delectable aquatic invertebrates.

This white sucker is rather small and immature and has an odd arrangement of scales on its' dorsal side. Maybe it has seen one chemical spill too many.



Here's a photograph of the catch from one of our seine hauls. This should give you an idea about the kinds of fish that dominate small streams in Illinois. This is a state where the minnow is king.


This is the striped shiner.

The dark raised edges of the scales on this breeding male make it easy to identify its' genus (Luxilus). To seperate the species (chrysochephalus vs cornutus) you have to see if the stripes running down the body connect behind the dorsal fin. On a striped shiner (chrysocephalus), the stripes connect.

You can see the stripes can't you? No, not the raised edges of the scales, the STRIPES...running down the length of the body. What?? You can't see them?? Are you kidding me??

Ok, yeah, I can't see them either.

Welcome to the world of minnow identification.



This picture is included to show that the rosy faced shiner (Notropis rubellus) does indeed have a slightly rosy face. That is sometimes if it's a male it has a rosy face. If it's not a breeding male, its' face won't be rosy and it will look exactly the same as an emerald shiner...which isn't green.

Are you writing this all down?

ADDENDUM: STOP THE PRESSES!! Apparently some genetic work has split rosy-faced shiner into 4 distinct species now and much of what had been called the rosy-faced shiner is now considered to be a different pre-existing Notropis precombrus. Checking the Illinois Natural History Survey data base, it does indeed appears that the "carmine shiner" is what is found in Boneyard Creek.

http://dsp-psd.pwgsc.gc.ca/Collection/CW69-14-466-2006E.pdf

Who knew minnows were so exciting.

Behold the green sunfish, Lepomis cyanellus. Destroyer of fisheries, harasser of congeners, pesky brat and denizen of nasty degraded streams across the Midwest...

...yep. The Boneyard's got 'em.



This is a female northern crayfish, Orconectes virilis.

One of the claws (chelae) has been broken. Crayfish fight with each other and with predators using their claws. It's not uncommon to see them with broken or even missing claws. This female has been carrying eggs (the dark mass of tiny spheres on its' abdomen) since winter.

Once the eggs on her abdomen have hatched she can molt, repair the damage and begin again...

We did indeed have a fun time catching aquatic animals that day. We found some pretty cool animals and saw for ourselves that this body of water is still alive and kicking. Maybe things are looking up for Boneyard Creek. More than one person has expressed amazement at the numbers and diversity of fish that already live there. The City of Urbana has additional restorations planned. Prairie Rivers Network now has a clean-up every year that coincides with the Boneyard Arts Festival. People seem to care about its' fate.

Maybe the Boneyard too can molt, repair the damage and begin again. So long, and check back with us next year when Gary's class checks up on the Boneyard again.

West Indian Manatee (Trichechus manatus)

Meet the manatee capture crew for Wildlife Trust, lead by Buddy Powell (captain Ahab there in the tower).

Buddy and crew recently came to Placencia Lagoon for their second year of affixing radio transmitters to West Indian Manatee. They are hoping to learn the about the distribution and ecology of West Indian Manatees in coastal Belize by tracking their movements over time and analyzing the environmental variables affecting their use of various habitats. As field work goes, this is exciting stuff.

In the first phase of the capture, the boat captain finds a manatee in water of suitable depth and then deploys a net around the animal. "Anchors" (people) then jump into the water to keep the net in place in case the manatee tries to break free or if currents shift its' position.

A secondary net is then deployed inside the first net and the manatee is drug toward the stern of the capture boat. Note that the capture boat has both a tower for spotting manatees and transom in the midships to keep the propeller away from netted manatee. When the manatee is hauled to the rear of the boat, the crew all stand in the back to submerge the stern, the manatee is pulled aboard...

...and then the fun begins.

In this picture a female manatee is laying in the capture vessel and one of the technicians is monitoring CO2 levels in it's breaths. That along with frequency of breaths, heart rate and a variety of other data are collected to ensure the manatee is safe and not overly stressed while on the boat. At that point, the alien abuduction sequence begins.

Tissue samples are taken for DNA analysis. Sonograms are recorded. Body length, fecal samples, tear samples, photographs. In the name of most holy and exact science, everything up to but not including the dreaded anal probe is visited on the manatee...

...which generally seems non-plussed by the whole event.

Finally, a strap and a buoyant radio transmitter are affixed to the tail and the manatee is slid off the stern and back into the lagoon. Last year the Wildlife Trust collared two manatees. This year they refitted the same male for another year of observation. Other manatees were marked in the Southern Lagoon near Gales Point. Biologists will use Yaggi receivers to track the manatees over the course of the next year, monitoring their movements and habitat preferences.

Belize is one of the last bastions of the West Indian Manatee. As a developing nation, the coastline and habitats of the manatee are being gradually altered. Knowing where and how and why the manatee selects habitats will help guide conservation efforts for this most unique animal.

Spiny soft-shelled turtle (Trionyx spiniferus spiniferus)

This is a post about a turtle, but the photo here at the top is of a freshwater mussel survey. These are biologists (Shari, Mike and Diana) from the Illinois Natural History Survey literally crawling in the river shoving their hands into the muck and sand substrate of Kickapoo Creek to find freshwater mussels. Using this technique over the course of a three year study in this stream, we found quite a few freshwater mussels of about fifteen different species.



As you can imagine, this is difficult work. The water is cold. The substrates are hard. Pushing fingers into a river bottom over and over again tends to have a battering effect on the hands, and the hazards are probably too many and unpalatable to mention here. If you need any insights into the mind of a biologist, you should be aware that most of the people in our lab loved doing this job. Certainly I did.

One day in particular, that love was put to the test.

We had covered a large transect with a sand and gravel bottom. We were just about to quit and leave for the next site when I remembered that this stretch of stream also included a substantial side channel. In this channel was a spot where an massive burr oak had toppled into the stream. When it fell, it pulled up its' root ball and left a deep divot that had become permanently filled with water and created a pool.

Standing there at the edge of the side-channel, I immediately saw a small depression in the sand just inside the pool. Hmm. That could be a buried mussel, says I to myself. I strode confidently to the spot, thrust my hand into the depression and drove it down into the muck.

Normally, the feel of a buried mussel is so slick and substantial that even cold-numbed or bruised fingers can distinguish them immediately. In that side-channel pool, I did indeed feel an object buried in that small depression. My fingers closed around it reflexively. "Gotcha!" I was pleased to have found something in this unique habitat and I was curious what it might be. I noticed this specimen seemed unusually large and the texture wasn't quite what I was expecting. Never the less, with a firm steady pull, I was able to begin extracting the mystery mollusk.

Our project was especially concerned with mussel diversity. We wanted to know if the new sewage treatment plant being built on this creek was going to affect its' biodiversity. To that end, we had been tracking nutrients and fish populations and algae growth and all manner of data before and after the plant was open.

It had always been a pleasure to find animals along the creek. One day it might be a massive whitetailed deer bounding out of tall grass, antlers broad enough to form a chair with extra room on either side. The next it might be one of the beavers we found literally everywhere building dams and gnawing trees. Over time was saw innumerable songbirds, raptors, coyotes, reptiles...

...one day I had even stood amazed as a spiny soft-shelled turtled glided to a spot just beside me in a sandy riffle...and shimmied into the sand until it was completely buried and invisible. In the blink of an eye it disappeared leaving just the tip of its' snout visible above the sand. Who would have thought a simple turtle capable of such a thing?!

Those things weren't really on my mind that day in the side-channel pool. I was, however, a bit confused as to why a mussel would be so difficult to pull out of the muck. How odd so much force would be required. I remember imagining briefly how unique and interesting this mussel must be! After one final pull my hand emerged from the goo...

....with my fingers curled around a bony reptilian face complete with razor sharp lips, two eyes and a snout.

A few admissions are in order.

First, there was shouting. I must admit that for the next few seconds the air was filled with loud yelping verbage as profane as ever a terrfied biologist might ever muster. I pulled my hand away from that mouth and leapt backward with a speed and alacrity I have seldom mustered before or since.

Second, to be entirely truthful, the wildlife of Central Illinois are farily benign. It's pretty hard to play the fearless naturalist when the most ferocious thing for miles and miles around is a white-tailed deer. However. If one were determined to be injured by wildlife in a stream in Illinois, grabbing a turtle by the face might be one of the more effective ways to accomplish that. "Man mauled by turtle" would have been an attention-getting headline in the News-Gazette to be sure.

One additional admission that is necessary here is that I am not entirely sure it was a softshell turtle I had grabbed. The snout was foreshortened and covered with mud and from the angle I held it and was thus of indeterminate length. The lip seemed heavy and there were fine lines running along it toward the mouth. I did go back to the spot were the turtle was buried and found the broad back of his shell by thrusting my foot down through the muck. It was smooth and quite large but somehow I wasn't really in the mood to dig it all up. I confess I've told this story before with the species in question having been a common snapping turtle.




I can't honestly say which it was.

I am quite sure, however, it wasn't a mussel.

Oh. And when the study ended two years into the plant's operation, we did find some evidence that it was causing some mussels to lose weight. Fortunately, the numbers and diversity of mussels (and fish) were unaffected. Hopefully someone will be keeping an eye on that over time. I'd be willing to help...

...but I might not sample the side-channel pool.

Summer tananger (Piranga rubra)

Only recently have I taken to carrying a camera with me around Belize. They're expensive and in some cases off-putting since they make you look like a tourist. It's also one of those dreaded "possessions that posses you". Over time it finally occurred to me how many astonishing things I was missing by trying to look cool and I decided the camera was coming with me regardless of how foolish I looked. Fortunately, a compact, shock resistant water proof camera has reduced the anxiety of bringing one along.

So now shots like this spring up all the time. On a simple walk to the store, I rounded a corner in the road and there this fellow sat, impossibly red and splashing around this filthy, but apparently functional, mud puddle. For a moment a yellow-headed warbler was also sitting there beside him but he flew away before I could frame the shot.

That's how Belize is. The diversity of animals there is just astonishing and you never know what is around the bend. I normally see twenty species of birds on a simple walk to the road. If you pay attention (and people who know me will attest that I do, much to the misfortune of my driving and conversational skills), you'll eventually see things you never imagined before. That does of course require a modicum of luck...

...and a few other things as well.

The summer tananger (or beebird) is a neotropical migrant. That means every year, for the few years it lives, it migrates from tropical places as far south as Boliva to open oak and hardwood forests of the United States. They're even found in the Midwestern US and Illinois where I currently live. Unfortunately, I've never seen one there (despite my wildlife viewing compulsions). The upshot of this bird's annual migration is that it requires suitable habitat in two different ecoregions, sometimes in two entirely different continents. What happens to them in the US affects their abundance in Belize and vice versa.

Presently, populations of the summer tananger appear to be stable. However, as their name implies, this species feeds on bees (and is actually a pest around apiaries). Honey bee populations in the US have crashed in the last year. Will the summer tananger find alterative prey while in the US and remain stable and unaffected?

Keep your eyes open and let's find out.

Goliath Grouper (Epinephelus itajara)

Biologist Eric Fernandez and I encountered this fish during a day of sampling in Placencia Lagoon. The man who had caught it was a Garifuna fisher from that village of Seine Bight. We found him happily paddling back home from drop fishing and checking set lines tied to the mangrove the night before. The hook from the set line was still in the grouper's mouth.

We paid the fisher to take a tissue sample from this fish. From the stable carbon isotopes in that sample, we found this fish was feeding from a foodweb based primarily on mangrove. In some senses, this fish was unique. Most of the fish we tested in the lagoon had used a much higher proportion of carbon from sea grass and single celled algae. Almost all the tissue in this fish came from animals that had been feeding on mangroves. I suspect crabs were its' primary prey.

The link between mangroves and goliath grouper is well established. Recently scientists have discovered that as juveniles, they live among the prop roots of red mangrove. Later, they migrate out to the Mesoamerican Reef where they can attain sizes well over 100kg. Fishers in Seine Bight have targeted Placencia Lagoon goliath groupers (formerly known as "jewfish") for generations. That fishery is still active and Seine Bight fishers still actively harvest goliath grouper in gill nets and with handlines.

Considered alone, the long standing goliath grouper fishery is probably not a threat to the sustainability of this species. Certainly some economic benefits arise from their harvest. The fish in the picture above represents a modest economic boon for the man who caught it (US 2$ per kg at approximately 10kg). However, coupled with the large scale changes that are occurring in coastal Belize, there are concerns about the conservation status of this species. After all, the fish in the picture above is still very much a baby. How many of those "smaller" fish are maturing to become adults and reproduce? When coupled with the wide spread removal of mangrove by developers, and the reduced water quality from effluent sources is there reason to be concerned about goliath groupers in Placencia Lagoon?

An additional concern is raised by a recent study by the Biodiversity Institute found that tissues in just over half goliath grouper they sampled in Southern Belize contained methyl-mercury levels above the USEPA threshold for health advisories. Children and pregnant women feeding on goliath grouper more frequently than twice a week are at risk are at risk for neurological damage.

http://www.briloon.org/pub/doc/posters/07Grouper.pdf

Some data from this study seems to indicate that the higher a goliath grouper feeds in the food chain, the more mercury it is likely to contain. Mercury increased with delta-15N levels in the tissues of this species. This pattern fits well with the observation that mercury bioaccumulates, or concentrates in the tissues of animals that feed on other animals. Delta-15N also tends to rise as fish feed higher in the food chain.

Because larger fish tend to consume larger prey that are often higher in the food chain than smaller prey, it is possible that consuming larger goliath groupers poses a greater health risk than smaller ones. These researchers will examine this and other questions over time.

Kickapoo Creek Fish

Our Illinois Natural History Survey electrofishing crew collected this and the fish species below out of Kickapoo Creek in McLean County in central Illinois. If you think you know these species, weigh in with a guess. Some of these are well known. Others will be a bit harder. If this generates some interest, I'll have more ID questions later.