December 16, 2012

It looks like Lake Wicwas is just about frozen over at this point, and with snow in the forecast, it may last even if we do get some warmer weather this week.  Snow cover would slow the formation of thicker ice though, so we'll have to be very careful before venturing out onto the lake in the coming weeks.

The otters don't have that concern - they don't have a problem if they find a thin spot;  on the contrary, they look for the open spots so they can come up and play on the ice.  Here's a set of tracks where they were hopping along and sliding on their bellies on the ice last week.

River Otter Tracks and Slides

I took a walk up to Arbutus Hill Pond yesterday, and found it well frozen, with about 4 to 6 inches of ice.  There was also still some snow up on the slightly higher elevations.

Along the way I found ice crystals growing up out of the wet ground,

as well as some fresh crystals on leaves from the prior day's moisture.

Back along the shore line, Linda saw a leech attached to a rock under the ice!  It was attached by its front sucker - leeches have two suckers, one at each end (they also have two brains!) and waving its body slowly in the water.  Normally, in the summer, they appear a solid dark black, but this one was light colored with spots, which is how they are described in the literature.

Fresh Water Leech under the Ice

In reading about leeches I learned they aren't a risk to humans, as the parasites they carry cannot survive in humans.  They are adapted enough that they inject the enzyme hirudin into their host that prevents blood from coagulating, and also release an anesthetic so the host is unaware of their attachment.  If you do get a leech on you, it is recommended that you remove it with your finger nail, as they do not leave mouth parts behind like a tic.  You should not use heat or salt;  that will release the leech, but it will first disgorge its stomach contents into its host - so forget that African Queen movie scene with Humphrey Bogart and Katharine Hepburn!




Think snow!