Hello my name is Mrs. Deacon. Please join me as I travel to Nova Scotia to study the ecology of mammal populations.

Wednesday, October 6, 2010

Working Together to Build a Field Station

     Part of our responsibilities when arriving in Nova Scotia was to assist the Primary Investigators in continuing to contruct a field station. Our daily schedule begins when we arrive at the site, Cook's Lake. The first things that we need to do is to check our traps from the night before. We then will do a variety of tasks - surveying for field signs, constructing GPS maps, or construction on the field station. I chose to assist in the building.

     The other teams this past year have constructed a lot of the station... our job was to put the finishing touches on the construction, as you can see in the video.

Tuesday, October 5, 2010

In Search of Deer using Scat

     Field signs are a useful tool to assist in counting populations and the presence of animals.  As stated in last night's post. field signs can include Scat / Poo (which scientists now can use DNA to determine the type of animal), tracks, burrows, feeding remains, damage to trees, calls / vocalizations, hair / other shed “bits” (ex: antlers from deer), dead animals – most you find as road traffic accident, and smell.
     In Nova Scotia, we learned a technique to examine an area for deep droppings.  This is called PGI or pellet group inventory.  We counted droppings in a 10x10 area which is 1/100th of a hectare.  On average, a white tailed deer will produce 20 piles / hectare / day (1 hectare – 100 meters by 100 meters).
     We found 51 droppings in our ten random sample areas.  To calculate an approximate number of white tailed deer in the area, 51 / 10 = 5.1 / 8 = 0.6375 white tailed deer / hectare.  So if we take the area of the whole place of interest, say 54,000 and multiply it by 0.6375, it gives us a rough population of approximately 34,000 deer in the area.

Monday, October 4, 2010

Analysis of Data Collected

      In order to collect usable data, we can use many different techniques in the field.  We can begin with observation of the organisms in the study.  Depending on the organism, it may be difficult to observe much of the population.  If observation is letting you down, you can look also look at field signs.  Field signs include Scat / Poo (which scientists now can use DNA to determine the type of animal), tracks, burrows, feeding remains, damage to trees, calls / vocalizations, hair / other shed “bits” (ex: antlers from deer), dead animals – most you find as road traffic accident, and smell.

Deer prints

Beaver Dam

Beaver damage

Porcupine Scat

     Finally, we can set up traps.  We here in Cook's Lake, have set up two types of traps: live traps and camera traps.  The first type, live traps can allow us to measure the animal, assess its health, take samples from the animal, find the sex of the animal, and mark as an individual. A camera trap does not inconvenience the animal at all and does not stress the animal.  We may be able to see the animals behaviorand numbers, and camera traps are not  as much labor as live traps, but they are very difficult to recognize individual animals.
     The purpose of these methods is to estimate an organisms population within an area.  With the live traps, we have been using the "Mark - recapture method" to estimate the size of the wildlife population.  The formula we use to extrpolate the population is called the "Lincoln - Peterson Model", which is as follows:

[(N+R)/R] x M=Population estimate

where: N = new captures, R = recaptures, and M = marked.
So therefore, using this formula, we are able to figure...

Capture site #1: Hardwood Brush

Chipmunk [(0+1)/1] x 4=4
Deer Mice [(1+2)/2] x 4 = 6

Total [(1+3)/3] x 8 = 10.6 / half hectare or 25 / hectare

Capture Site #2 : Forest

Chipmunk [(1+1)/1] x 1 = 2
Deer Mouse [3+1)/1] x 4 = 16
Red Backed Vole [(2+3)/3] x 5 = 8.3
Bog Lemming [(1+0)/0] x 1 = 2

Total [(7+5)/5] x 11 = 26.4 / half hectare or 53 / hectare

What does this data tell us?  Define the term density. What is the density of each of the populations sampled? What are four factors that may impact the density of a population? 

Sunday, October 3, 2010

Kejimkujik National Park

     Today, we travelled to Kejimkujik National Park ("Keji") to examine the forest.  Keji "is representative of the Atlantic Uplands forest region, including mixed coniferous and deciduous vegetation. While much of the forest has been disturbed by past logging, superb stands of large old growth hemlock and sugar maple-yellow birch can still be found." (http://www.pc.gc.ca/) Much of Nova Scotia's forests have been damaged due to many years of logging.  Within Keji, we went to an area called the "old growth forest" containing Hemlock that gave us insite into what the inland area of Nova Scotia would have looked like if the trees had remained.
     Eastern hemlock is one of the most shade tolerant tree species in the Park. Where it can escape severe fires, it can become the oldest species as well. These factors allow it to gain dominance in size and composition on the absence of major disturbance. Several groves of hemlocks, from 200 to 300 years of age, are found in the Park. 

    Forest fires do not often occur in this area, therefore the Hemlock forest has been able to reach status as a climax community. What is a climax communty?  What happens in a forest after a forest fire?

Thursday, September 30, 2010

Collaboration in Nova Scotia

When looking at the work we are doing here in Nova Scotia, the Pentucket Habits of Learning come to mind.  Last Sunday, eleven strangers came together to work towards a similar goal - assist in the Mammals of Nova Scotia research project.  We are from all walks of life- there is a newlywed couple from Australia, a Japanese woman, a doctor from Minnesota, an English teacher from San Diego, a retiree that has completed 63 EarthWatch expeditions, a great aunt that is taking her niece on a two month tour of the east coast of North America, a 22 year old college student, and myself.
     In order to be successful, we need to be able to collaborate and work together as a team to accomplish the tasks. An effective team member must participate, be supportive, be open minded, share, listen, and be flexible.  It is challenging to consistently have a positive attitude when faced with many tasks, but think about how you will feel when you have completed the tasks and accomplished your goal. Being at the end of my first week here in Nova Scotia, I feel that I am a part of a team.  That we have completed our tasks as a  team... thanks to our being able to successfully collaborate.

We now come to the end of week one. Tomorrow, we finish our three days of trapping in our first quadrants.  Tomorrow evening, we begin to "crunch our data" and look at the population densitites of the small mammals that we have been investigating.  See you tomorrow...literally! :-)

Wednesday, September 29, 2010

Checking the Traps

  Today we spent the day checking the traps that we had laid out yesterday.  We needed to check the traps twice, once in the morning when we first arrived at Cook's Lake and then again, right before we left in the evening.  Here, in the video, Dr. Christina explains how to inspect the traps without loosing the animal that we had obtained. 
    Typically, the small mammals that we catch are red-backed and meadow voles, deer mice, and white footed mice.  Sometimes other small mammals, such as chipmunks, flying squirrels, or jumping mice may be captured in the traps.  Today, we mainly caught deer mice, red-backed voles, and chipmunks. 
     Once the animals were removed from the traps, they were inspected for weight, sex, and reproductive status and the information recorded.  We then marked the animals and returned them to the areas that they were caught.

Here I am holding a deer mouse that we have caught in our trap
  Your assignment tonight is to post some questions that you may have thus far so that I can respond to them when I skype into the class on Friday morning!

Tuesday, September 28, 2010

Prepping and Laying Out the Traps

     To catch the small mammals, you need to prepare the traps and set them down in an organized manner, or so I learned today.  The trap we are using is a long silver trap with two sections.  The first is the entrance and the second is the housing.  

 Dr. Christina showing us the trap

     To prep the traps, the team need to clean out anything that may have been left from the previous team that used them.  When this was finished, we took a "tennis ball" amount of grass and put it into the trap for bedding.  We didn't want to put too much grass or the mammal would over heat and we didn't want to put too little for fear that the mammal may suffer hypothermia.  To the grass, we added a tablespoon of food.

Collecting grass for bedding
     We assembled the two piece traps, readying them for deployment.  The team was divided into five groups (A - E) and each group was responsible for laying out their twenty traps.  Sure, you may think that sounds easy... just lay them wherever and your finished.  But no, this is scientific work we are doing here so we must be organized!
     Team "C" acted as the center point and measured 10 meters from each deployment.  All groups walked in a straight horizontal line (as best they could), setting their traps every 10 meters as we walked through trees and brush.  Also, while setting the traps, each group was responsible for marking their trail so that when we get back tomorrow, we can FIND the traps!

Adding the bedding to the trap

     Many of the trees in this area of the forest were coniferous trees, specifically pine trees.  Pine trees usually grow one main growth shoot.  If the tree looses that main shoot, then the next longest shoot will take over, and so on.  Pine weevils coevolved with its host, the pine tree.  The weevils will lay egg on the highest growing main shoot.  The larvae will hatch, eat the bark, and eventually kill the shoot.  Weevils also only lay their eggs on shoots that are in the full sun for most of the day. (These pines are warmer and help with incubation).  Would stopping the act of clear cutting forests (cutting down all the trees at one time), aide or hinder this commensalistic relationship? Why? Explain.

Monday, September 27, 2010

Why Monitor Mammals?

  This is the question of the day.  Why would we want to study small mammals?  What could this tell us about the ecology and about the world we are living in?  How do we define Ecology?  First let's start off with the definition of Ecology.  Ecology is defined as the study of factors which determine distribution and abundance.
     In order to answer these questions, we need to understand what makes mammals different than other organisms.  Mammals are endothermic, they feed milk to young, and they have bodies covered in hair.  But, the fact that mammals have a larger olfactory part of their brain, their ears have evolved the three small bones called the malleus, stapes, and hammer, they have a soft pallet which allows for sucking and breathing at the same time and a diaphragm, which not only aides in breathing but separates the gut from the rest of the body which allows for running and swinging from trees.  We are mammals.
     So, by studying small mammals, we see the how their abundance and distribution may be affected by different factors .  Things like how the area is being managed / maintained, eco-toxicology, environmental / climate change, the impact of human growth and loss of habitat, the impact of other mammal species moving into area (such as deer, coyote), the impact of introduced species, and inter-species interactions. 
     Methods of "how" we go about studying the mammals will be discussed throughout the week.  I leave you with tonight's assignment... how does the Parelaphostrongylus tenuis (or Meningeal Brain Worm, a nematode) affect the abundance and distribution (or ecology) of the moose and white-tailed deer populations in Nova Scotia? (Post your thoughts on schoolloop, not here.)