'Ole Yellow Legs

One of the great things about going to school in northern Michigan is the amount of pristine riverine habitat in the area. These habitats are home to the Wood Turtle, a Species of Special Concern in Michigan and a protected species throughout its range. In Michigan, this species prefers small to medium sized rivers where a sandy or gravel bottom occurs. In addition, sandy banks and woodland habitats are also needed for nesting and foraging respectively. As the herp atlas project continues in Michigan, a few friends and I have taken the opportunity to identify strongholds of this species in some of Michigan's rivers.

This section of river is a perfect example of perspective Wood Turte habitat. The river is surrounded by a large tract of mostly undeveloped woodlands, which is ideal. We found a place to drop in at and kayaked the river one quiet morning. The sun was out and the temperature was in the low 70s, we couldn't have asked for a better morning.

 

This particular river has a very sandy bottom and averages 2-3 feet in depth, with some pockets of  8-10 feet of water. There are plenty of sandy "beaches" along the switchbacks in the river which are great for nesting purposes. After about ten minutes, we spotted this.

An adult male Wood Turtle found basking on a log jam on a cutback in the river. We were able to get a good look at him and snap a few shots. This individual was our first of five on the day. It appears that this river system is home to a rather healthy population of Wood Turtles as several juveniles were seen. Later on in the morning, we noticed a healthy adult female out on a mucky bank moving about, so we decided to get a better look at her.

Wood Turtle - Glyptemys insculpta

While taking a look at this girl. We noticed that some of her outer marginal scutes had been notched, indicating that this individual had been marked for a study. I'm not aware of anyone who's doing research on this particular river system, but I'll have to follow up with Jim Harding to be absolutely sure.

We saw a few more Woods throughout the afternoon and enjoyed our trip. The next morning, my good friend Alex and I headed out to a different river system. This river runs through some highly developed areas, but the upper branch is much more remote and holds some excellent Wood Turtle habitat. We concentrated on an 5 mile stretch of the river which is basically undeveloped. We'd seen Woods farther down stream, but we wanted to see how far upstream they occur. Here's an aerial of the section we decided to kayak.

This river was a little different from the river we checked the day before. Instead of a purely sandy bottom, this river transition between sand, gravel, and a combination of both. The river is also a great fishery for several trout species and Smallmouth Bass. We dropped in around 11:30AM and within five minutes I spotted a large turtle near the bank of the river, sure enough it was our first of three Wood Turtles on the day.

 Wood Turtle - Glyptemys insculpta

This large male was in absolutely perfect shape. We stopped him just for a few minutes to get a health check on him and to get a measurement or two.

We let him on his way and jumped back into our kayaks and headed downstream. We were pretty excited that we had found a Wood Turtle so quickly and it wasn't more than ten minutes later when we struck gold again. Along this stretch of the river we made quite the spot.

Th

This Wood Turtle was basking next to a Northern Map Turtle & Blanding's Turtle. Unfortunately, the other two individuals escaped before I could snap a photo of the three species side by side. I was able to take a swim and sneak up on this small male though and secure him for a few photos.

Wood Turtle - Glyptemys insculpta

We ended up seeing a total of three Woods on the day and allowed us to gain more data points for this particular river system. The Herp Atlas project is still in need of ANY herp observations made in Michigan, so get out there and record what you find, when you find it. As with anything, our data collection on Wood Turtles will aid in understanding the distribution of this species in Michigan and help management of it in the future.

Eastern Box Turtle Conservation

Of all Michigan turtles, the Eastern Box Turtle is by far the most charismatic. A Species of Special Concern in Michigan, this species has declined drastically from its former distribution in the state. Nest predation, habitat fragmentation, road mortality, and illegal collection are the catalysts for the decline of the Eastern Box Turtle. Today, populations persist in pockets where grassland and mature woodlands still exist without fragmentation. Michigan individuals are often brightly colored with yellow or orange and have much broader carapaces than individuals of the same species which exist farther south in the range. This summer, my internship has allowed me to get direct involvement with the study and management of this species through captive head starting programs and aiding in telemetry studies.

Even today, nest predation and road mortality are the most significant threats to the longterm survival of this species in Michigan. Raccoons are estimated to occupy 700-800% of their original population numbers at the turn of the century. This explosion in population is due to the species ability to adapt the modern urban landscape and capitlize on being an opportunist when it comes to feeding. One behavior that the raccoon has learned is rading turtle nests which have been freshly laid. This has gotten to the point that usually the only turtle nests one can find is a predated nest by racoons. Roads are also an issue. Box Turtle habitat is often fragmented due to development and roads and in areas where populations exist, this species is extremely vulnerable to being killed moving from one patch of habitat to another.

Farther south in their range, Box Turtles are traditionally known as a woodland species. But in Michigan, they prefer a mosaic of community types. Michigan Turtles often are found along woodland edges in grasslands but they occasionally wander into wetlands such as fens. They are often found in some sort of cover and are rarely out in the open except after summer rainstorms. Here's an example of a Box Turtle as found, see if you can spot her.

See her?

Box Turtles have a wide diet which includes worms, insects, plants, berries, and fungi. In the late summer when wildberries fruit out and drop to the ground, Box Turtles can often be found concentrated under or around large berry patches. Sometimes the evidence of Box Turtles is hard to miss.

These mushrooms bare the unmistakable beak marks from a foraging Eastern Box Turtle. 

The culprit as found a few feet away. Earlier this summer we were lucky enough to aid in a few telemetry studies on EBTs in southeast & southwest Michigan. Studies such as these which evaluate habitat use, home range size, diet, and other factors are critical for the continued understanding of the life history of the species which in turn helps land managers properly manage habitat where these turtles exist of have the potential to exist.

Eastern Massasauga Observations

I've been away from here for awhile, mostly because a full time internship has taken up the majority of my time. However, I've managed to get some field time with the limited free time I've got. I've been focusing on a few different species in the field this spring and summer and I'm attempting to compile data for the Michigan Herp Atlas and future research projects. I'll get to the turtles later on, but for now I'll talk about rattlesnakes. I'll spare the grief of giving the usual fluff about Eastern Massasauga Rattlesnakes; how they're shy, secretive, etc. As I further my studies at CMU and continue to collect casual observations on these snakes, I've become more and more interested in their ecology, behavior, and so on. Everytime I encounter a rattlesnake in Michigan, I take GPS coordinates and other data. Since 2006, I've kept a detail photo record of individual rattlesnakes I've encountered and its allowed me to recognize certain snakes at a few different sites by looking at blotch count and unique head patterning. If I recognize a snake, I'm able to add the point into GIS software under that specific snake's data set. Three observations or more of the same individual allows me to create a polygon overlay which is a loose idea of what that snake's home range is. Now, this is a rough estimate and not quantifiable by statistical analyses, however it does give me and idea of what areas a specific rattlesnake is utilizing at any given field site.

Thus far, I've made 34 observations on 30 different rattlesnakes in the 2010 field season. Two of these individuals were snakes I'd seen in the past few years and helped aid in my analysis of a few separate sites. In the early part of May, my girlfriend and I took a walk on a trail in the early morning and managed to encounter two adult rattlesnakes, both of which appeared to be gravid females. One was in shed while the other was a very dark coloration, almost borderline melanistic (more on that later).

To give a rough idea of what I'm talking about, here's a aerial photo with a few polygons on it. Each time I've encountered a snake I've seen before, I enter the GPS coordinates of the spot it was found at. This automatically adjusts the shape of the polygon to the minimum area this snake has covered. It's cool to see overlaps in the home ranges of these snakes. Here's three individuals that I've seen over the past few seasons.

GIS analysis and mapping has aided in identifying clusters of data points which in turn provide an idea of activity centers by looking at these points overlayed on an aerial photograph. With the help of this, I've been able to identify significant sites where rattlesnakes seem to concentrate and different times of year. One area of particular interest is a small meadow which is bordered by a fen on one side and stream on the other. This site appears to be a significant site for gravid females & neonates.

Since June, I've observed three gravid females mulitple times in this small meadow as well as a handful of yearlings. Here's some shots of gravid females & yearlings from the past few months in the small meadow.

I've also been monitoring a large grassland complex at another site where I've observed at least four different snakes. Most have been found basking in open grassy patches in the morning while others have been found tight to shrub cover in the late afternoon. I've even had instances where I've found snakes basking right along the grassland edges on trails or two-tracks that bisect the grassland.

Most of the time these snakes avoid mowed grass or roads. But occasionally they do wander onto these areas. Most people will never encounter an Eastern Massasauga on a roadway. But in parks, preserves, or state game areas where they occur, it is mindful to keep a watchful eye in the unlikely event that one crosses a road.

Until next time...