While out working on tree identification with my Trees and the Maine Forest students yesterday, an observant class member exclaimed, "Look, a squirrel!". As we peered upward into the old white oak (Quercus alba) just behind the varsity baseball diamond, squirrels began to seemingly appear out of nowhere. Before long there were four juvenile eastern gray squirrels (Sciurus carolinensis) resting on branches around a small cavity. These youngsters are spending some of their first time outside of the tree cavity that has been their home for approximately 10 weeks. Gray squirrels are capable of having two litters of 1-6 offspring per year. It is likely that the squirrels near you are preparing to send their second batch of youngsters out into the world right now as well. Keep your eye out for smallish squirrels with fresh looking coats and slightly less bushy tails. These are sure signs of juvenile squirrels. The mortality rate for young gray squirrels is extremely high as they acclimate to the dangers around them. Predators, car collisions, and other sources of mortality claim a high percentage (~75%) within their first few months.
Can you pick out the two young squirrels resting in the tree?
As we prepare to resume our gray squirrel research in Maine Fish and Wildlife class, it is important to be able to distinguish between juveniles and adults in the trap. We do not collar juveniles due to their high rate of mortality and their necessity to continue growing before donning some fancy neckwear. Once a squirrel is in the handling bag, it must weigh more than one pound in order to be collared. Speaking of collared squirrels, I spotted one along the Eastern Trail yesterday near the back end of the soccer field. In addition to visual observations, Ian was able to get a collared squirrel on trail camera last week! Thats right, there are still collared squirrels running around the T.A. forest. We will most likely begin trapping in year two of our research next week. There will be plenty of updates on our more high tech approach to come. Stay tuned.....
Look closely for the green collar on the squirrel's neck in this video.
I have two lab aides this semester who will help with the day to day tasks involved in our T.A. Squirrel Project research. Brandon and Ian both completed Maine Fish and Wildlife last year. They are each reliable and possess a high level of interest in wildlife biology and the Maine outdoors, making them perfect candidates to invite back. Part of their work throughout the semester will be to operate the class trail cameras around the T.A. forest. They have each been assigned a camera with the goal of capturing interesting photos and video of our campus wildlife. This task is easier said than done. Regularly catching wildlife on a remote camera requires a thorough understanding of the creatures you are trying to document, the ability to read wildlife signs, and a little bit of luck. Both Ian and Brandon have had success already with their cameras.
Brandon set his camera over a dried up vernal pool in the vicinity of the one highlighted in my previous post. Over the weekend, the camera captured some interesting play behavior from some gray foxes cruising through the dry pool. These foxes appear to be mature adults and are most likely a mated pair. When thinking of wildlife engaging in play behaviors, we often assume that only young creatures play. In reality, play can be an important social interaction for creatures of all ages. The form of play shown in the video is certainly helping the foxes practice movements used while hunting but is also undoubtedly serving to strengthen the social bond between these two individuals.
This summer's drought conditions were certainly hard on a variety of species and our vernal pool amphibians are no exception. These creatures rely on temporary bodies of water in the forest for reproduction. Wood frogs, spring peepers, and spotted salamanders are in a race against time as larvae. They must complete their metamorphosis and emerge before the pool completely dries up. A dry vernal pool (like the one shown below) can spell doom for many larval frogs and salamanders but serves as a smorgasbord for a variety of predatory creatures.
A dry vernal pool in the woods behind T.A. Note the wood duck nesting box on the far end.
At first glance there is little sign of drama at this once bustling woodland pond. A closer look reveals tracks that tell a tale of predators taking advantage of an ecosystem in flux. One of the most obvious signs of life in the mud were fresh fox tracks and the neatly excavated tunnels of small mammals created as the foxes hunt. The fox's hearing is keen enough to pick up the sounds of tiny creatures moving in their network of tunnels beneath the mud. A quick pounce from the fox is all it takes to capture its prey.
A fresh fox track in the mud.
A dug out small mammal tunnel indicates the foxes in the T.A. forest are well fed.
While the fox tracks indicate recent activity, a myriad of old raccoon tracks show that several weeks ago dropping water levels provided an easy meal. As the pool shrunk and began to disappear the raccoons took advantage of amphibian larvae and aquatic invertebrates cornered by their shrinking home. The tracks they left in the mud have dried and been preserved. Recent winds have blown just enough sand in the tracks to highlight them against the dark mud.
Raccoon tracks (Front Feet) preserved in the now dry mud.
