More Box Turtle Stories? Not Quite!

I had mentioned at the end of my recent Turtle Dog post, that there would be more box turtle stories to share.  Figured it was about time!

Earlier in the summer my students and I had another opportunity to work with our state regulatory agency to conduct some rare reptile surveys.

This time, however, we would not be fortunate enough to have Turtle Dogs along to help.  Instead we had a lot of humans, which we got together in a coordinated fashion to "pound the ground" looking for turtles. 

Thus, we all met at a completely different site than the ones we had worked previously.

After a brief organizational meeting and a run-through of our objectives (find as many turtles as possible), we set to our task.  The habitats we would be working in were very cool...including some beautifully well-managed oak savanna....

 

 

High-quality oak savanna habitat is something of a rarity these days.  The primary reason for the loss of such habitat is its conversion to agriculture and urban/suburban development.  But, there's still more that threatens oak savanna and prairie habitat: uncontrolled vegetative succession. 

 

What is succession, you ask?

 

I'll have to keep this somewhat simple, to avoid making this post too long.  So, I'll briefly define succession as the directional change of a plant community from an early community of species that establish immediately after disturbance to a final community of species that are superior competitors. 

 

The community that establishes immediately after a disturbance (such as a fire, or heavy grazing) is called a Pioneer Community.  Pioneer communities usually consist of colonizing species that have specific characteristics. 

• They are often small annual species, and ones we might consider "weedy"
• They can generally handle harsh conditions (high light intensity, high heat, low moisture)
• Their seeds are often dispersed by wind
• They are easily out-competed by later successional species.
• They reach sexual maturity quickly.  In this way they can quickly reproduce and disseminate their seeds to adjacent disturbed habitats before the later successional species (which are theoretically superior competitors) move in and push them out.

Eventually, other species, that perhaps grow taller (e.g., shrubs) enter the area....shade out the pioneers and change the species structure within the community.  An example would be a mowed field that is left untouched for years eventually growing in with shrubby vegetation.

 

In theory, successional change will continue to occur (i.e., the plant communities will progress from pioneer to climax) if no further disturbance happens.  Thus, over time this community will eventually change from a pioneer to a Climax Community.  The climax community is the final community an area can achieve post-disturbance....in other words, these species are the best competitors and will not allow new species to come in, out-compete them and replace them. The plant species in Climax Communities have the following characteristics:

• They are usually larger as adults and shade-out competitors (e.g., trees)
• They are often slow to mature
• They have shade-tolerant seedlings
• Their seeds are dispersed by gravity or seed-dispersers, such as birds 

Image Source: http://faculty.ycp.edu

 

One last important point: Although successional change is directional (i.e., moving from Pioneer to Climax Community) if a new disturbance happens, the community undergoing succession can be knocked back to its pioneer community (or some earlier successional state).

 

So, how does the concept of succession relate to the previously mentioned oak savanna?  Well, although too much disturbance is obviously a bad thing, not enough natural disturbance can be bad as well.  Habitats like prairies and savannas typically have a vegetation community that is in an earlier successional state when compared to woodland.  Thus, these habitats are dependent upon natural disturbance to persist.  Usually this disturbance comes in the form of natural fire or moderate levels of grazing/browsing by herbivores.  What this means is that even if a prairie or savanna parcel is protected from development, it must be properly managed or succession will occur until the parcel is no longer comprised of savanna.  So, legally protecting land is only half of the battle.  It is necessary to have the means and resources to effectively manage the prairie and savanna to keep it in an earlier successional state.  The typical management practices used on savanna and prairie include mowing, hand removal of vegetation (chainsaws, etc.), herbicide applications, and purposely starting (controlled) fires.

 

WHEW!  Sorry about the wordiness of this post!

 

Anyhoo...back to the story.....

 

The site we were surveying in had received appropriate management to maintain savannas.  For example, you can see the limited understory vegetation, yet mature trees, in the picture below.  This occurs because a controlled fire was used to kill back much of the small vegetation.  The large trees, however, are resilient to low-intensity fire and so they persist.  Management of this habitat is designed to keep the community in an earlier successional state in a way that specifically promotes oak savanna.

 



 

Interestingly.......this post about "Box Turtle Stories" doesn't have much ado about Box Turtles!

Not for lack of trying, however.

There were at least 18 individuals surveying at one point during the day.  We went over and back over locations on-site that exhibited evidence of box turtles.  The oak savanna habitats were surveyed intensively, as were the more open grassland/prairie type habitats (note the prairie below is starting to grow in with more woody vegetation, i.e., succession is occurring!).

Some of the strongest evidence to suggest box turtles are around is the presence of fresh "forms" in the ground.  These are shallow burrows that the turtles dig in the ground for short-term respite from unfavorable conditions, or to sleep in at night. These forms usually don't go back very far, and they are shaped sort of like the profile of a box turtle shell.  We found plenty of fresh forms on-site during our surveys (see below), so we knew box turtles were active in the area.

One would think that 18 competent surveyors vs. a slow-moving innocuous reptile would be a contest stacked heavily in favor of the humans.

You'd be wrong!

Despite the fact that we knew there were box turtles in the area, and found fresh evidence of them when we arrived, not a single box turtle did we see!!

We DID find other reptiles (one of which was possibly even better than finding a box turtle.....more to come).  For example, we found several beautiful Smooth Greensnakes (Opheodrys vernalis).

This species is mostly insectivorous (eats insects) and prefers the shrubby edges adjacent to grassland/prairie, as in the picture below.

Let me tell you, there are few species that are harder to find than a green-colored snake that hangs out in the grass!

We also found a nice little juvenile Eastern Hognose Snake (Heterodon platirhinos).  Note the upturned scale on the tip of the rostrum (or "nose").  This gives them the appearance of having a "nose" similar to a hog....or that's how it appeared to the person that named them!

 

But those weren't even the best finds that day!

Looks like a snake, doesn't it?

It's not a snake, although it is a reptile....and it is in a closely related group: the lizards.  Snakes and lizards are both in the taxonomic Order Squamata, while snakes are in the Sub-Order Serpentes.....the lizards are in the Sub-Order Lacertilia.

What we have here is a leg-less lizard....the Western Slender Glass Lizard (Ophisaurus attenuatus attenuatus).  An incredibly rare find in our neck o' the woods!

So, how can we tell this is a lizard?  Superficially, it looks just like a snake.  Yet, there are certain clues that belie this critter's ancestry....

First, all lizards have a hole on each side of the head, which is essentially an ear opening.  Snakes have no external ear-opening.

See the hole circled in red below?  You have to look carefully!

Lizards also have movable eyelids, something that snakes don't possess.  In other words: lizards can blink.  Obviously, I can't show you moving eyelids in still photos, so you'll have to trust me that these lizards can blink!

There are other differences too, but this is good enough for the current blog post.

These interesting little critters are not only hard to find, they are hard to catch.  At certain times of year (such as late spring) they have a tendency to sit concealed in the thatch of short grasses.  This provides them with cover and allows them to still soak up the sun.  It also makes them incredibly difficult to find.  Usually one only sees these lizards if they are almost stepped on, which prompts them to make a quick break for it.  The motion gives them away and they can be located.

In addition to their cryptic nature, there are two other difficulties a glass lizard surveyor must deal with: (1) they are incredibly fast, (2) they have the ability to perform caudal autotomy (i.e., break off their own tails when captured).  Why?  The tail, after separated from the body, continues to thrash and twitch....presumably to distract the predator and allow the lizard to escape.  The ability to break off pieces of their body is also apparently the origin of the name "glass" lizard.

We don't want them to loose their tails if they don't have to.  The tail takes a while to regenerate.  Better if they use that strategy when it really counts (i.e., avoiding a real predator).  Yet, if one is incredibly gentle when capturing and handling the lizard, they are much less-likely to drop their tails.

So, capturing glass lizards requires a quick, but careful, response.

We actually found a fair number of glass lizards, which was even better!

I tried to explain to my students that I had seen less than five of these lizards in my entire life up to that point.  On that day, we found 10!!!

On at least one occasion, there were two right next to each other......

...and so ended our second effort at finding box turtles.  Although not a box turtle was found, we still got some great wildlife captures!

There's still one more small box turtle story to tell, but I'll save that for a later date.

Advanced Ecology Lab: 2013 (Weeks 1 & 2)

Another year is upon us!

We have several specific purposes with our lab exercises in this class.  They were, firstly, designed to give students practical experience that mimics what professional ecologists, natural resource regulators or environmental consultants would do.  The students conduct a variety of environmental assessments throughout the semester....use their results to make recommendations and write a professional-style report of their findings.

They apply skills that they've learned in past classes (such as in our 200-level Field Methods in Ecology class), and new techniques they are taught in this class throughout the semester.

Week one is primarily devoted to a site visit and reconnaisance.  The entire property is walked....different community types are identified...and a guess is made as to how the site fits into a landscape context.

Based on this assessment, they break into groups and find locations for their first long-term monitoring initiative on-site: camera traps!

During week two....it was time to head back....service the cameras and delineate the boundaries of the habitats/communities on-site.

BUT, the weather found a way to make things more interesting.  Twenty-four hours before lab this week....the temperature was in the mid-50s.  Normally, I would say this is unheard of for January 'round here, but looking back at a blog post from last January reminded me that this is becoming the norm. 

And they say climate change is a myth!

Anyhoo, the warm temperature was not all that was in store for us.  When I left the house on the morning before we had lab, it was still warm and misting.  All of the snow that we had gotten previously was completely gone.

But things changed suddenly.  The temperature dropped drastically over the course of a few hours and the mist turned to snow.  By mid-afternoon, it looked incredible outside!!

Perfect weather for field work!

This required students dividing into groups and selecting one of their habitats/communities....following the periphery and recording GPS points.

They also had to flag the common boundaries between different habitats so that they could easily coordinate their data later....

We also checked the cameras....and the usual suspects showed up....

The White-Tailed Deer (Odocoileus virginianus)...note the raw-looking pedicel where the antler recently came off....

The Raccoon (Procyon lotor)

The Todd (Vulpes vulpes)

But that snow....I can't pretend I don't love it!



Field Ecology Methods Week 2 (2012): Reptiles

After a week of invertebrates and Limnological techniques, the students spent some time learning how to conduct some standard surveys for reptiles.

First, we checked the existing artificial cover objects on-site for snakes....

This resulted in only TWO juvenile Gartersnakes (likely born this year).  But it was unseasonably warm on the day we checked the boards (upper 80's)....probably too warm for snakes.

The students then worked to measure out additions to our existing coverboard grid. 

Few things make me happier than to see all 18 of these students working hard in the field and no one standing idle.

Let's face it....field work can be grueling (especially in the warm conditions we had while deploying the boards).  But, this gives the students a small taste of less than ideal field conditions that one might face as a field ecologist.  It's not all catching Cougars and Narwhals every second (or as a colleague here says...there's not a "gorilla behind every tree").

After the artificial cover objects were laid, we moved over to the creek and deployed some hoop traps for turtles.

........................................

The traps sat for a night, and a small group of volunteers came out with me the next morning to check and re-bait the traps.

Thankfully, we had more luck with turtles than with snakes.

Two large adult Snapping Turtles (Chelydra serpentina).....

Five cute little Painted Turtles (Chrysemys picta).......

We took our morphological measurments, such as carapace (or upper shell) length....

Then we released the turtles back into the stream.
.........................................

The next day it was back to check the traps again, and this time the entire class was present.

...and once again, we had good fortune!

Day 2 yielded 14 painted turtles and one little snapper....a good haul!

Once again, appropriate morphological measurments were made....the turtles were given a permanent mark....and released back into the creek. 

Hopefully, we'll see some of them again in the spring!

For more information on standard survey techniques for reptiles, see this excellent new book:

McDiarmid, R.W., et al. 2012 Reptile Biodiversity: standard methods for inventory and monitoring. University of California Press. Berkeley.

The following book is also a good introduction to standard reptile survey methods.  Unfortunately, it's out-of-print, but you can still get it from libraries or through interlibrary loan.

Karns, D.R. 1986. Field Herpetology: methods for the study of amphibians and reptiles in Minnesota. Occassional Paper 18 of the James Ford Bell Museum of Natural History, University of Minnesota.

Field Ecology Methods Week 1 (2012): invertebrates and limnology

We have a 200-level field methods in ecology class that is required of biology majors in our field ecology concentration.  It's meant to expose students to a variety of different field techniques, to give them a general flavor for what's out there (and...frankly...allow them the opportunity to learn if they don't like field ecology before they are a senior and can't switch their concentration!).

I helped out with our summer version of this course a few months ago (see here).

It's team-taught and each faculty member brings something different to the table, which is great.

I'm coordinating the course this semester.


We started off the course last week with some field survey techniques for insects, taught by our resident entomologist.

First, the students were given a bit of instruction on the tools they'd be trying....

Then it was off to do a bit of collecting....

Some students started by knocking insects from dead tree branches into the apparatus below.....

Others tried their hands at catching flying insects with the hand-held nets.....

After insects were captured with the methods involved, students took some time to experience grabbing them with a special tool called an "aspirator" (see below).  Basically, this device allows one to suck up an insect into a sample bottle, without fear of accidentally swallowing it.  The aspirator also allows students to catch insects without having to grab things that might sting or bite their fingers!

I joked with the students that I wanted as many pictures of them using these "aspirators" as possible, as there is no way NOT to look dopey while using them :)

But hey...they work!  And by the end of the lab, they had caught some stuff.  I missed pics of some of the cool spiders they found unfortunately.  Too caught up in the moment, I guess).

Soldier Beetles (Family Cantharidae), juvenile Boxelder Bugs (Boisea trivittata), and a Katydid (Family Tettigoniidae) below....

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Lab 2 last week was focused on a simple introduction to standard Limnological techniques.

Again...we always start off with a bit of instruction...this time from our resident Limnologist/Aquatic Toxicologist....shown here holding a plankton tow net.

Then, it's down to the dock to take the equipment for a test-spin and collected samples to be sifted through back in the lab at a later date.

This included (in addition to the zooplankton net), some hands-on time with the Secchi Disk, which is a standard tool for measuring water clarity.

Students also experienced using an electronic water quality meter refered to as a Quanta Multimeter (made by Hydrolab).  It measures dissolved oxygen, pH, water conductivity, temperature, depth and turbidity (or clarity).

Students used Kemmerer sampler (below) to sample phytoplankton which may be too small for the mesh size on the zooplankton tow net (since zooplankton are larger than phytoplankton).

...and then the rain began.....

...and then it REALLY started coming down.....

But I heard not one word of complaint.

And, as an instructor, that always pleases me when things don't go as planned...