Thursday, April 5, 2012

Vole-O-Rama

Yes, folks it's been a week of voles.

RECAP
Last week, Nova Scotia experienced unusually cold temperatures for this time of year.  Our total count of live-trapped small mammals was: 3 red-backed voles and 1 bog lemming.

THIS WEEK
Nova Scotia is still not quite at normal temperature, but it is still significantly warmer than last week.  Our total count of live-trapped small mammals is: 9 red-backed voles and 1 field mouse.

A red-backed vole, Dr. Buesching, and me (don't make me say I)
My hypothesis, that red-backed vole counts would be smaller this year, as compared to previous years when warmer temperatures were recorded, seems to be correct.

I'll be able to confirm my findings tomorrow - our last day of the project - when I speak with all senior blocks via Skype.  Expect to have a conversation with me in Magnussen's Biology class.  Be prepared with questions!

FIFTH CHALLENGE QUESTION
all answers get credit; first right answer gets a candy bar...the winning post must clearly include the why

Even in the best of times, live-traps usually yield less catches earlier in the week than later in the week.  This is true no matter the type of area (forest, clearing, field or bog) where the trap is set.  WHY is this true?

Hint: think about who is setting the trap AND how the trap looks...


SIXTH CHALLENGE QUESTION
all answers get credit; first right answer gets a candy bar...

Scientists in the field record ALL kinds of data, live-traps are only one way to note animal presence.  Other indicators of animal presence are known as field signs.  Field signs can also be used as data for research. Besides live traps, what are other ways you can record the presence of animals in the field?  List at least THREE field signs to win.

Hint: use your five senses and think about what animals might leave behind if they pass through a natural habitat

Tuesday, April 3, 2012

More live-traps AND more snow!!

The lobster boat dock close to our home in Nova Scotia
Hey kids!!!
Hope you had a great vacation and it was fantastic to see SO many comments.  A reminder: there's a four-hour time difference between here and Nova Scotia, so when you are just getting out of school, I'm getting ready for dinner.

Sometimes this means you may post a comment and not see a response from me for over a day.  Please be patient!  I'm out in the field the majority of the time, but promise to answer all questions pertaining to Nova Scotia, animals in the field, and the project in general.
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Now, onto the Challenge Question winners:
Sierra earns a Canadian candy bar for her correct answer to Challenge Question #1: 
Where in the forest would a researcher be most likely to set a live-trap and successfully catch a mouse?  Why?


Her answer - taken from her posted comment - is right on the money:
"You would want to place the traps near tunnels at the base of vegetation, paths across leaf litter, moss or soil. Also the edges of boulders and logs because they like to hide from their predators and they like to rub their bodies on the rocks and logs. They are able to move along paths when there is leaf litter better without being spotted."
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CONGRATS SIERRA!!!
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You may be able to see the square-glint of metal in the lower left hand corner of the photo below.  You'll notice that we positioned the trap right along the line of the tree roots and stump.  Mice feel safer running along the edges of things because, if they run out in the open, they risk being spotted and eaten by a predator.  We camouflage the trap, not so much to make it blend into the habitat but to keep it warm overnight.  Many mice and voles have an overnight stay in the live-trap and we want to make it as comfortable as possible.


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Mimi earns a Canadian candy bar for her correct answer (via email) to Challenge Question #2:
What climate factor might create a low vole count?  Why?


Mimi's answer: "Hibernation time! when it's too cold the voles hide and hibernate until its safe again (weather wise)."


The low vole count we are currently experiencing has a lot to do with how cold it is here. Normally, temperatures are heating up at this time, but - while it continues to snow - the voles and other small critters would rather stay bundled up inside, conserving their energy for the warmer months ahead.  In addition: mice and voles have dark coats that are easy for their predators (such as owls, bobcats and raccoons) to spot in the snow.


Caloy gets a Runner's Up - for being the first to post the correct answer to Challenge Question #2 in a blog comment (but not before Mimi beat him to it).  =)


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Now, onto our new discoveries!!!!


Last week, in total, we caught three red backed voles and one unexpected critter - a bog lemming.
Lemmings are incredibly soft, but not as cute as mice or voles
Bog lemmings are Maple-leaf Mammalians, no doubt, they just aren't seen as often in the area where we are collecting our data.  They tend to live in wetlands, like bogs, and we hadn't set any live-traps near water during our first week.  A lemming is a kind of rodent - just like mice and voles - but are usually gray in color with a tiny tail.  Anytime we live-trap ANY of these small mammals we drop them into a plastic bag and catch it by the scruff of the neck.  


Then we put the critters back in a plastic bag and Dr. Buesching collects the data she needs on a clipboard, including the weight of the small mammals.
This lemming weighed about 18 kilograms, a healthy weight
THIRD CHALLENGE QUESTION
all answers get credit; first right answer gets a candy bar...the winning post must also include both the why questions and some physiological explanation for the correct answer


Why don't the critters suffocate when we put them in a plastic bag?  It is tightly closed to prevent an escape.  Why do humans suffocate, then, if enclosed in plastic?


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Yesterday, we were out setting live-traps again, but we moved them to another place on the large piece of land that's being used for the study.  It was snowing while we prepared the traps.


Last week we placed traps in a forest and a clearing.  A clearing is the worst to walk through!  It's basically a forest-in-the-making so it's full of small trees and bushes that are at shoulder height and above.  We had to fight to get through the underbrush and I would often come out onto the other side with my hat missing and my glasses on side ways.


This week, we are placing the live-traps in a field and a bog.  Fields are straight-forward, fairly wide open places.
Look at the bottom right hand corner; you'll see the bright pink trap markers we set to remind us where the traps are
Bogs are a little more difficult.  The ground is wet and muddy and tends to hang onto your shoe when you are trying to step away.
My trusty box of live-traps, bedding to keep the animals warm once they're trapped, and pink marking tape

FOURTH CHALLENGE QUESTION
all answers get credit; first right answer gets a candy bar...the winning post must also include the why and BOTH what questions


Why do we choose different areas on the project land (forest, clearing, field and bog) to study?  What are the benefits of this?  What would be the scientific language to describe this approach?