Hello my name is Ms. Heard. Please join me as I travel to Nova Scotia to study small mammal populations!

Wednesday, April 4, 2012

This morning we started by checking our traps.  Out of all 100 traps, we had only 3 red-backed voles.  We also checked again at the end of the day and found only one.   Our consistently low numbers really show how this time of year is when few animals are left from a long winter.  Many died during the winter months, so those few who survived will start mating soon.  In past years, the trap counts in the fall have been many, many times bigger than the trap counts in early spring.  I got to empty the trap of one animal each time today.  Here are some pictures of me emptying a trap and then holding a red-backed vole.

Do I look like I am having fun?  I like handling these little rodents.

The voles are really soft and kind of sweet, though they are not at all happy about being caught and held.  However, they have adapted to stress.  In their lives they are stressed often, like every time a bird of prey flies overhead, so their bodies are well suited to handle the physical response to stress.  They calm down and carry on immediately after the scary thing has passed.  So as soon as we release this little guy, he'll be happy again.

It is hard to catch the vole in the plastic bag.  It wants to run away.  This little guy was hard to trap in the corner because he kept squirming.  If you grab them by the fur/skin on the back of the neck, between the head and shoulders, you can pinch there to hold them up without hurting them.  They have no nerves there, so they can be carried without any pain.  It is just like how a cat can pick up her kittens by biting them on the back of the neck to carry them.

When we took a close look at this guy, we discovered he was the one we caught this morning!  He must have been really hungry.  When I opened the trap this afternoon, he had pooped a lot from his two big trap meals!

Today we did a lot in the field.  We did three transects for deer droppings.  This meant we used four poles to stake out a measured area of 10 meters by 10 meters.  Then we stood at arm's length from each other along one side of the square and all walked or crawled through the square counting how many piles of deer droppings we found.  On Friday morning we will learn how to use those numbers to extrapolate how many deer live in the area. 

Then we made habitat piles again in part of the forest.  This is sort of a complicated thing to me:  this area of the forest is relatively new growth, but with some non-native species, and is cluttered because of human intervention about 20 years ago (before the research started here).  So the scientists decided to thin it by taking out certain trees.  Normally, whatever trees die in a forest would fall to the ground and become nice habitats for animals as they slowly decay and become part of the floor.  However, since the thinning of the forest meant a lot of trees were cut down all at once, the normal pace of forest decay and regrowth was sped up. That means that the forest floor had way more debris on it than would normally occur.  This means that the general habitat was more cluttered, and more difficult for the larger animals to get around.  So we cleaned up the debris, to get the area back to the way it was before the thinning and cutting.  However, by piling all the debris into big mounds, we created things larger animals can use to hide in, sleep in, or have babies in.  So we turned too much clutter into nice new homes for animals.  Here are pictures of team members at work and piles we built. 
It will take some time for the animals to make use of these piles.  They need to figure out that suddenly these piles exist, and it will take some time for our scents to wear off.

 Tomorrow morning the team heads back to the field to collect the traps and cameras for the last time.  I look forward to Ms. Khan's upper school class, the 6th grade and 1st grade tomorrow.  See you guys via Skype tomorrow!


  1. Dear Ms. Heard,
    It was nice to read your blog and skype with you today. We want to respond to your blog. Here are some questions we have: How big is a vole? How does the trap work to catch the vole? And what kind of big animals will use the tree piles that you built? Lastly, what big animals do live in Nova Scotia?

    Talk to you soon!


  2. Hi 1D,

    A red-backed vole is about 20 grams and about 3 1/2 inches long. The trap has a door on it at the entrance to the tunnel. When we set the trap out, the door is propped open. If the animal goes into the tunnel, to get the food at the opening of the larger boxy part of the trap, the animal will have to walk across a wire. When it steps on the wire, the door drops closed. Then it can not be opened from the inside. Then the animal has no choice but to go further in and enjoy the food and bedding we put in there.

    The biggest mammals in Nova Scotia are deer, coyotes, and bobcats. There are moose further north from here, but none left in this area anymore.

    Good questions, boys!
    Ms. Heard