Saturday, 15 March 2014

Aha! The Rodent mystery is solved (I think)

There have been a lot of tracks about in the powdery snow.

I've been deeply suspicious about some tracks. I know what mice tracks look like. Little toes, teeny feet. The deer mice tracks from step-to-step are about 2" apart.
I consulted my sources, various guides. Reviewed previous posts/photos: Tracks in the snow. These were different.

There was a dragging tail, which is typical of a mouse in snow, but the feet were larger than mice. I haven't see these tracks too often. Not until recently, with the terrible cold we've had: The Polar Vortex. It's been around under the bird feeder.


tracks with a tail
–much larger than
a mouse
The tracks are 8" apart.
We have a lot of rodents about. Rodents are characterized by constantly growing incisors. The single largest group of mammals >is Rodentia. Most non-flying mammals are rodents: there are about 1,500 living rodent species (out of about 4,000 living mammals overall).

This is a large and varied species: according to uBerkeley,
  • the larger family includes common pets: guinea, muskrats, chinchillas, porcupines, lemmings, deermice, field mice, voles and packrats,  
  • but excludes shrews, moles, hegehogs, rabbits (double incisors).
Most are herbivores.
Lots carry disease, like Hantavirus.
A lot of these are diurnal, we see deermice in the daytime all the time, but see evidence of their tracks from the night, and safety, of the dark.

Capybara - largest rodent
Vole (larger than deer mouse).

Love the little toes!
The largest rodent, Capybara, I happen to have a photo of one, from the Lynwood Fun Fair. They can be 66 kilos!


Back to my critter, which is nocturnal.

Packrats or Woodrats

Woodrat - from Wiki
I've heard of packrats, vaguely. My mother always accused me of being one! And she was right. You never know when you need stuff for crafts!

After doing some research, there seems to be quite a few varieties of woodrats; Eastern Woodrat  ( Neotoma floridana >) a Key Largo WoodratAllegheny woodrat, Bushy-tailed woodrat, or PackratBushy-tailed Woodrat - Neotoma cinerea, The Allegheny woodrat ( Neotoma magister ), is a species of " pack rat >" in the genus Neotoma . Once believed to be a subspecies of the eastern woodrat , extensive DNA analysis has proven it to be a distinct species. [2]

The rats that infest cities are called Norway rats. (Our soon-to-be D-I-L's cat caught and ate one a few years ago in Vancouver.)

woodrat Wiki

Woodrat house - used with permission
Kim Cabrera
Woodrats build really cool homes (see: Kim A. Cabrera's web page: out of sticks and shiny things. This is why they are called packrats!

I shall have to have a look out for this type of shelter in our forest/wetland, it's great habitat for them. The previous homeowners stacked brush in the forest to clear paths. They might be a house! They build bulky nests of stick, towers that can be 5' tall.

They are anywhere from 28cm - 45cm (11 - 18"), including the tail, near as I can figure.

The mystery of this critter is that something has been in the shed, gnawing and removing the garbage can lid. Several times now, I'd thought I'd forgotten to replace the lid.
I've checked for holes in the shed, but the snow is up around it and I needed snowshoes. I grabbed snowshoes, and couldn't see any entrance in.

Identifying tracks

There are lots of things to determine: the length of the track, size of the tracks, my hand span is 8", which would fit with a woodrat.
Lots of track aids. This one includes Eastern woodrats!
Beside my thumb: 4" - 6" from the top set of prints to the last paw. Yep.

Time to link up with Saturday's Critter party....  

Evidence in the shed

I've seen chew marks on the handles, and I'm now sure I put it on after I filled the bird feeder the other day.
I cannot imagine how a woodrat pried the lid off, but it must have!
There are tons of black sunflower seed hulls on the floor, and something has eaten a lot more than would fit into a mouse tummy!

Their scat is quite different, too.
just for comparison
This is not how I left this garbage can,
filled with yummy black sunflower seed!
sharp teeth!

Determined little twerps!

The key to the mystery is the scat.
The black, rice-like ones are mice.
The larger, beige ones have
to be a larger woodrat.


eileeninmd said...

Great critter post! So many cool critters..The Capybara is new to me! Thank you for linking up with this weeks critter party. Have a happy weekend!

TexWisGirl said...

we have wood rats here but they mainly nest under our deck, wooden dog house and wood pile. but they are cute little pests. :)

sandyland said...

so in love with birds down rt hand side

carol l mckenna said...

Very informative post and great shots for CC ~

artmusedog and carol

Grandma K said...

Great research.

Pack rat - yep. Being a science teacher AND a crafter, you never know what will come in handy!!

Red said...

Yes, pack rats are a big nuisance. While back packing in the Rockies we used to run into them from time to time. they'd make a mess of your pack.

Hilary said...

You're a good sleuth!

Anonymous said...

Destructive little critter!

Andrea said...

I am not familier with wood rats ... I do know though, that if the garbage can lid is flipped, it is usually a racoon. I would hate to think of a rat big enough to flip the garbage can lid. Interesting investigation ... glad it is your wood rat and not mine :)

Andrea @ From the Sol

bettyl-NZ said...

You didn't give up--that certainly is a plus to solving the mystery! Great post with lots of great info!

Karen said...

A woodrat! Cool! A great post, and I am glad you have solved the mystery!