Yesterday with the help of district forester, Oliver Markewicz, my "Trees and the Maine Forest" students began the initial setup of a F.I.G. plot in the T.A. Forest. F.I.G. stands for Forest Inventory Growth and is a statewide program headed up by Project Learning Tree and the Maine Tree Foundation. This program encourages schools to establish long term plots in forests near their campus with the purpose of monitoring tree growth and patterns of change over time in the Maine woods. The ongoing data from schools all over the state is posted HERE. Our data should show up on the website in the near future. The students working to do the initial setup of this plot have the honor of starting something that will continue long after they have left Thornton Academy. It is neat to think about the possibility of their children someday taking my class and performing the same measurements on the same trees in what should be a much different looking forest.
Students have spent the first half of the semester working hard to practice identification of 25 common southern Maine tree species as well as master the measurement techniques used daily by foresters and loggers. Our F.I.G. plot is circular with a radius of 37.24 feet which amounts to one tenth of an acre. Beginning at magnetic north, students worked clockwise around the plot first identifying, then performing quantitative and qualitative measurements on all trees with a DBH greater than five inches. DBH stands for "diameter breast height" and is measured at 4.5 feed above the ground on the high side of the tree.
Students perform measurements on a young northern red oak under the guidance of district forester, Oliver Markewicz.
Part of our previously mentioned squirrel research in Maine Fish and Wildlife class involves RFID (Radio Frequency Identification) readers that will be fitted to feeders all over campus and in nearby neighborhoods to monitor the travels of our collared squirrels. Each collar houses a microchip that the readers will be able to sense and record when the squirrels pay a visit. This data will help to unlock the mysteries of our squirrels' home ranges and the distances they are willing to travel to a known food source. While my lab aide, Sam, is hard at work programming our readers, I figured it would be a good idea to set up a few feeders around campus to get our squirrels acclimated to using this new style of food delivery. Last year's feeder can be seen in previous posts and requires a squirrel to lift a lid to get at a mixture of corn and sunflower seeds. This year's data collection hinges on the squirrel's collar getting within an inch or two of the RFID reader which presented a unique challenge. How do we force the squirrel to put its face near our electronics AND how do we keep those electronics safe from the nasty weather conditions so often experienced during a Maine winter?
Enter the new jar-style feeders. Their simple design forces a squirrel to stick its head inside the waterproof housing then reach into the jar to get at the food reward. Ideally, during one of their multiple entries into the feeder their chip will get close enough to the reader to be picked up. The housing itself is made of a composite deck post and the removable lid will provide a convenient way for students to get at the reader and swap out the batteries and SD cards where our data will be stored. The jar is a simple wide mouth canning jar capable of housing a few days worth of food.
A close up of our new feeder. There are several now deployed around campus.
While the design of these feeders seems perfect for what we are trying to accomplish, there was one major question left to be answered. Will the squirrels be able to use them? After deploying a few feeders with my wildlife classes last week, we set up a game camera on one of them near where we had collared several squirrels this fall. Over the weekend, we got our answer. Within 24 hours there were squirrels investigating the feeder and shortly there after, jackpot, squirrels successfully getting at the food. There are now several "pros" out there who are quite adept at utilizing this style feeder. This includes at least one collared individual. It wont be long for the rest of our population to solve the corn riddle either.
A collared squirrel visits a new jar feeder in the T.A. Forest.
We are hopeful that the bugs will soon be ironed our of our electronics and we can begin to equip our feeders with RFID readers. Stay tuned for further developments!
We have now wrapped up our trapping efforts for the fall of 2016 and are working to begin monitoring the movements of our newly collared squirrels through the upcoming winter. In all, we placed collars on eight squirrels, two on campus and six in the woodlot adjacent to the Eastern Trail. The two campus squirrels have been highly visible and can often be seen utilizing our new jar style feeder in front of the latin building. The six collared along the Eastern Trail have not been as conspicuous to the casual observer but have been showing up on the game camera on a regular basis.
A collared squirrel utilizes the Eastern Trail feeder earlier this week.
In the coming weeks, we will be working to equip up to ten feeders with RFID readers. This sensing equipment will be designed to pick up on the presence of a microchip in each squirrel's collar. When a squirrel reaches in to the feeder to grab some corn, the date, time, and chip number will be recorded. Hopefully, this will help to shed some light on the movements of our squirrels between campus and nearby neighborhoods over the winter. As with any new technology implementation, there will undoubtedly be some unforeseen hurdles to overcome. This process of brainstorming solutions to problems is great for kids and a lifelong skill that will serve them well beyond their high school squirrel researching days.
On a related note, we have had other visitors at the Eastern Trail feeder since it has been loaded with corn and sunflower seeds. Songbirds, mice, flying squirrels, and a raccoon have all been observed on the feeder over the past week.
A raccoon helps itself to a squirrel food "treat" on Halloween.
Recent wind and rain has knocked down much of the brightest foliage around southern Maine. If you look closely while in the woods, you may still be able to find one of the last splashes of fall color. Witch hazel (Hamamelis virginiana) is common tree throughout our region's mixed deciduous forest. It is generally small and comfortable growing in the shade of the understory. Its large slightly lobed leaves turn yellow and drop early in autumn revealing stringy yellow flowers.
Tiny yellow flowers are visible on this witch hazel tree in the T.A. Forest.
This is the last tree in Maine to bloom and relies on a group of moths active in the fall and winter for pollination. Once the flowers are pollinated, they develop into a seed capsule that takes a year to mature. After ripening, the capsule bursts open shooting tiny seeds up to thirty feet from the tree. I have always wondered what it would be like to witness this subtle event happening in the forest. Talk about right place, right time!
As of this writing, we have trapped a total of twelve squirrels since October 11th. Of those twelve individuals, three were young of the year and thus too small to be fitted with collars, another was a recapture from this year. This means that in the past two weeks, we have collared eight squirrels. Most notably, the first squirrel captured was sporting a green collar from last year's research! This squirrel was fitted with another green collar, this time including a fancy RFID microchip. The remaining squirrels have all been fitted with an orange collar. Keeping the green collars on our "year one" squirrels will help us to keep track of year class in our future observations and begin to build some idea of possible life span.
A squirrel waits in a live trap on campus.
Subscribers may remember last week's post regarding our struggle to capture squirrels on this bumper acorn year. All of this changed when we added walnuts to the equation. After searching around online, I found a story where a Minnesota biologist with the same trouble capturing squirrels began having success after switching to walnuts for bait. The next day I sweetened my offering by sticking with the usual chunky peanut butter but adding a few walnut halves. Immediately, we began catching squirrels. It seems that while acorns are plentiful, a fresh walnut is too much to resist. Lab aide, Sam is preparing to equip a squirrel feeder with a RFID sensor in the next week or so. We are hoping to begin monitoring multiple feeder sites within the next few weeks. Stay tuned!
This photo was taken moments after release of a campus squirrel. Look closely for the orange collar.
Our fall trapping season got underway yesterday morning for the T.A. Squirrel Project. This year's trapping has started off a bit slower than last year. In the fall of 2015, we captured 5 squirrels in the first two days. I half expected the same success rate this year and was surprised that only one squirrel was captured all day yesterday. This was a juvenile squirrel and was too small to receive a collar, thus it was measured and released. As of second block today, there were no new captures.
I set a game camera up on one of my forest traps hoping to get video of a squirrel entering the trap. Instead, I was rewarded with some evidence as to why our trapping season may be a little more challenging this year. It is a banner year for acorns from the northern red oak (Quercus rubra) trees in the T.A. forest. Acorns as well as beech and hickory nuts are commonly referred to as "mast" by wildlife scientists. Mast producing trees are important as food sources for squirrels, deer, wild turkey, bear, as well as a host of other Maine creatures. It seems the squirrels are currently flooded with a bounty of acorns offering a high energy food source that doesn't risk entering a trap. Last year was a much lighter year for our T.A. mast producing trees and it makes sense that the squirrels would have been more eager to enter the trap after our peanut butter in mid October. My gut tells me that as the season rolls on, the acorns will become more scarce and our catch rate will increase.
Watch as this gray squirrel carefully hides an acorn in the leaf litter on the forest floor.
I close the traps each afternoon and open them the next morning in an effort to avoid catching skunks and other nocturnal critters. When I arrived at this trap this morning, I found it flipped upside down with the leaves disturbed all around it. It seems squirrels are not the only creatures that like peanut butter. Check out the videos below to see some of our night time visitors.
A dog out for a walk along the Eastern Trail must have followed its nose right to our trap.
This raccoon flipped our trap over and carefully stole all the peanut butter from inside.
In Maine Fish and Wildlife class, we are preparing to begin our fall gray squirrel trapping next week. Last year's research helped to begin piecing together a rough population estimate for our campus but ended up creating more questions than answers. How far will squirrels travel to visit a feeder? What is the typical home range of a gray squirrel? Do squirrels seek different habitats at different times of the year? This year's research is geared toward answering our new questions. The collars our squirrels will be wearing this year are almost identical in to last year's model except for one key modification. This year's squirrel collars will be carrying a RFID (Radio Frequency Identification) chip as well.
We plan to have 10 feeders spread throughout campus and nearby neighborhoods equipped with electronic RFID readers. When a squirrel and its microchip get within an inch of the reader, its presence will be recorded. This will offer important data on home range as well as documentation of suspected seasonal movements from our campus to nearby neighborhoods. Any data collection we are able to do this fall will be scientifically valuable as there is almost no published research on gray squirrels.
Note the RFID chip protruding from the custom housing on the squirrel collar.
Yesterday we employed Thornton Academy's 3D printer to build custom housings for the microchips. These plastic housings will keep the RFID chips safe from the weather and securely attached to the collar. Having this piece of technology in my classroom is a great way to connect science and engineering with my students. A huge thank you has to go out to junior, Sam Archibald, for his computer programming talents in making this program happen this year.
