Day Eight, (Sunday) Back to the Field at Cook's Lake

Our day began with Chris’ presentation of the preliminary data collected from the first week of field work. This was the work that was completed only in the grassland area. He showed us how to take the numbers and plug them into a formula (called the Jolly-Seber) which would provide an estimate for each small mammal accounted for (meadow voles, bog lemmings, short-tailed shrews and mice, or should I say mouse.) This number is called the MNA, which stands for the Minimum Number Alive. The resulting numbers for each species is as follows: Meadow Voles 34, Bog Lemmings 3, Shrews 3, and Mice 1. What we actually measured is the population and the distribution of the mammals, using the common method of Capture, Mark, and Recapture.

In addition, we went over the deer population surveys that we had conducted throughout the first week. Chris showed us a method of calculating the droppings (called deer pellet groupings) in order to estimate how many deer per hectare are using (or living in) the Cook’s Lake area. We figured out that using our data, there are .375 per hectare, which ultimately comes out to about 30 deer per kilometer. According to Chris, this number was fairly consistent to what Teams 1-4 came up with this year. The number of deer living on this land affects the project because the deer eat the vegetation that serves as shelter for the rodents being monitored. When the covering is lost, the voles become vulnerable.

After the data crunching, it was back out to the field. Back at Cook’s Lake, we reset the traps at a new site, one that seemed much more challenging to maneuver. Our new site is deep in the woods and in order to set the traps we had to do some fancy footwork. Jen, Bob and I (Team E-the teacher team) hypothesized that we would not trap as many voles as we did in the grassland area. We found out that a different subspecies of vole inhabits the forest. It is called the red-backed vole, as you might guess, due to its coloration.

I will share a few more tidbits about Day Eight on Thursday, when we hopefully be able to return to the "Chataway" Cafe for the final time. Right about now, Chris and the others should be coming to pick us up in the Earthwatch bus. I hope you enjoy perusing the blog until then.