Mammals of Nova Scotia with Mr. Rimlinger: Day 8: Saturday, March 30, 2013

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View an article below about my expedition to Nova Scotia in the Daily Pilot, Sunday, April 7, 2013. Thank you Jeremiah Dobruck of the Daily Pilot.

http://www.dailypilot.com/tn-dpt-0407-harbor-day-global-teachers-20130405,0,3465353.story

Good Bye Nova Scotia!! I will miss you!!

Weather report: High: 6C, Low: 3C, Skies: partly cloudy.

Capture, Mark, and Recapture!!

As you already know, you can’t catch them all, but only 2!! Overall, Team 1a only had 4 official door closings on our Longworth traps. One red-backed vole was caught once; the other was caught 3 times. So for the whole week, only 2 voles per 100 traps. Is this good or bad? For me, it was still a great experience! The important thing is that we collected data; therefore, this was good information for the study. Does this data make sense? Yes, it does. It’s the weather that determines the population of mice or voles. Spring hasn’t really sprung in Nova Scotia as of March 30^th, so it was expected that the numbers would be low.

During my stay in Nova Scotia, Dr. Chris presented two excellent discussions about climate and ecology.

During our discussion on climate, Dr. Chris shared data and evidence for the different climatic changes that have occurred on earth. We learned that the climate changes because of the variation in position of the continents (Plate Tectonics), Earth’s orbits (Milankovitch Cycles), volcanism, photosynthesis uptake, and human uses (Anthropogenic Potential).

Nova Scotia has a lot of biodiversity; therefore, it is a good place to study climate change effects on small mammals because we can get a large sample size. We also know that small rodents are susceptible to change. In the long-term, the climate is changing, has changed in the past, and will continue to do so. It is inevitable. The problem with climate change is how humans have restricted mammal’s freedom to change. We have fragmented, destroyed, or exploited their habitats. This prevents them from responding to the change. Therefore, it’s the mammals that are “generalist”, rather than “specialist”, who have the best shot at survival.

In our discussion on ecology, Dr. Chris told us how it is a study of abundance and distribution. We want to know how many there are, and where they are! The scientists are doing an excellent study of ecology. They are looking at the interactions of the climate, mammals, and their habitat.

We talked about the data we collected. We used the Lincoln-Petersen Index to determine the population of mice or voles at the research site.

The Lincoln–Petersen method^[3] (also known as the Lincoln index) can be used to estimate population size if only two visits are made to the study area. This method assumes that the study population is "closed." In other words, the two visits to the study area are close enough in time so that no individuals die, are born, move into the study area (immigrate) or move out of the study area (emigrate) between visits. The model also assumes that no marks fall off animals between visits to the field site by the researcher, and that the researcher correctly records all marks.

Given those conditions, estimated population size is:

where

N = Estimate of total population size

M = Total number of animals captured and marked on the first visit

C = Total number of animals captured on the second visit

R = Number of animals captured on the first visit that were then recaptured on the second visit

Sample calculation

A biologist wants to estimate the size of a population of turtles in a lake. She captures 10 turtles on her first visit to the lake, and marks their backs with paint. A week later she returns to the lake and captures 15 turtles. Five of these 15 turtles have paint on their backs, indicating that they are recaptured animals.

In this example, the Lincoln–Petersen method estimates that there are 30 turtles in the lake.

I’m sure there calculations are a little more complicated than this, but I think I get the picture. Using our capture, mark, and recapture numbers from the research site, we have a population of 2 voles per 0.5 hectare.

The following video is of Dr. Chris Newman sharing his thoughts on science, his interest in animals, especially mammals, and Lycos! Thank you Brian for sharing this video.

I want to send a special thanks to Dr. Christina Buesching and Dr. Chris Newman for sharing their research and knowledge of mammals. This week has given me greater insight for teaching science and also a greater appreciation of mammals.