Brrr!

Temperatures were in the 30's-40's during the day this week, and in the 20's at night! Brrr! On Tuesday we got a little rain and some hail. On Thursday we woke up to an inch of new snow on the ground! It kept snowing intermittently for the rest of the day. We ended up with a total of about 3" of dry powdery snow. The kind of snow that squeaks when you walk on it! It was so beautiful! I wandered for hours in our neighborhood, taking pictures, following tracks, watching birds, and reveling in the wintry landscape! More snow is predicted for this coming week. Hopefully, the storms will keep coming for a while. Right now the snowpack in the mountains is at a minimal level. We'll be grateful for anything we get!  

Empty Oriole nest in winter

Winter Brrrds!

Birds use a variety of techniques to survive cold winter temperatures.  They eat as much food as possible when it's available.  When food isn't available, they puff up their feathers and rest.  They have thicker plummage in the winter, which keeps the cold out and the warmth in!  They stay out of the wind by perching next to the trunk of a tree and near the ground, or by roosting in a cavity.  Sometimes a group of birds will even huddle together to conserve heat!  Some birds can drop their body temperature and go into a state of torpor, to conserve energy!  Some birds just leave the area, and fly to warmer climates!  That's probably what that Red-winged Blackbird has done.  I haven't seen him this week at all.  I hope he somewhere warm, with lots of food available!

Common Raven - Corvus corax            American Robin - Turdus migratorius

A pair of Common Ravens has been around all winter, and mid-February to early March is the time that Ravens start nesting!  Ravens mate for life, so I am assuming that the ones in our neighborhood are a mated pair.  Ravens usually build their large (5' wide x 2' tall) nest on a rock ledge that is protected by an overhanging ledge.  They have also been know to make their nest in the top of a large tree that has dense foliage.  They lay 3-7 eggs, and incubate them for 20-25 days.  The young are usually able to leave the nest 5-7 weeks after they hatch.  I saw a Raven in Grass Valley carrying a twig in its beak this week!  I'll let you know if our two local ravens start exhibiting the same behavior!

This week an American Robin showed up on the Hawthorne bush in our backyard!  I watched it eat the berries for several days.  Apparently it's not uncommon for Robins to show up in their breeding grounds as early as February!  I was a bit concerned that it might not find enough to eat so I checked out the Cornell website at www.feederwatch.org/learn/common-feeder-birds/, to see what food I could provide for the Robin!  It's a great website, and listed several types of food for Robins.  The only thing I had available was fruit, so I cut up some apples and put them outside.  The Robin didn't seem interested in them initially but it might, once all the Hawthorne berries are gone!  I'll just have to wait and see what happens!

Mountain Quail - Oreortyx pictus

The unidentified feathers pictured last week are Mountain Quail feathers.  One of my neighbors found a dead quail outside his home.  It had a broken neck, so it probably flew into a window.  Male and female Mountain Quail are hard to differentiate in the field.  The only visible difference is that the female has slightly shorter feather plumes on its head.  Both male and female have beautiful, striking plummage.  A small group of Mountain Quail showed up at my bird feeder this week!  I've been seeing small groups of them throughout this winter, scurring into the bushes as I approach.  It turns out that the groups are composed solely of related family members!  They will migrate up to higher elevations to breed in the Spring.  

Pussy willows in snow - Salix sp.

Cold-blooded Critters

The cold temperatures have put a stop to insect movement for now.  They cannot regulate their body temperature, like birds and mammals.  Once temperatures drop into the 30's, most insects become immobile.  

Bumblebees can keep moving at 32°, but can't move their flight muscles at 30°!  I'm assuming that bumblebees retreat to their underground homes when temperatures start to drop.  Mated queen bumblebees overwinter, usually underground, as adults.  When temperatures warm up these females start looking for a nest site to start a new colony.  They may use an old rodent burrow, a clump of dead grasses, or the base of a hedge as a nest site.  Once a queen establishes a nest site, she builds a "honey pot" out of wax, and fills it with regurgitated nectar.  She also makes a ball of pollen.  Then she lays 4-16 eggs on this pollen ball, and covers the whole thing with wax!  She then broods her eggs, by sitting on them, for approximately 4 days, and sips nectar from the honey pot.  The eggs hatch into caterpillars that eat the pollen ball!  After they eat all the pollen, the caterpillars pupate in silken cocoons.  In a few weeks, the adults emerge from the cocoons.  At this point the new adult bumblebees are all female!  These new females become workers for the queen bumblebee and help build the colony.  The queen keeps laying eggs through the summer.  In the fall, the last batch of eggs the queen lays will be unfertilized.  Male bumblebees will develop from these eggs!  At the same time female larva will develop into queens. The male bumblebees and the new queens mate.  The males are then kicked out of the hive!  These are the bumblebees I've seen spending the night on the flowers in our garden!  Eventually the old queen, the workers, and the male bumblebees all die.  Only the newly mated queens will overwinter.

    rear end of a Bumblebee - Bombus sp. California Tortoiseshell - Nymphalis californica

Some butterflies, such as the California Tortoiseshell pictured above, overwinter as adults.  Other butterflies overwinter as eggs, caterpillars, or chrysalides.  To keep from freezing, adult butterflies reduce the amount of water in their body fluids by 30%, and replace it with glycerol, sorbitol, or other types of anti-freeze.  They also store fat in their bodies in the fall!  As temperatures begin to drop, these adult butterflies hide in small crevices to spend the winter.  They then enter into a state of diapause, in which their metabollic and respiratory rates slow down.  When these adult butterflies emerge in the spring they often look quite tattered, due to their long lives of 8-10 months.  Most adult butterflies only live for a few weeks!  Wow!!!

Frost "curtain"

Window Frost!

It's been so cold that frost has been developing on some of our windows!  It forms when the outside of the glass is exposed to very cold air, and the inside of the glass is exposed to warmer, slightly moister air.  The patterns are incredibly intricate and beautiful!  Window frost is also called "fern frost" or "ice flowers".  These finely detailed patterns that repeat themselves are called "fractals".  The size of the frost crystals vary, depending on the amount of water vapor in the air and the amount of time the crystals have had to build up.  Aren't they amazing?

American Black Bear - Ursus americanus

Early this week I came upon a Black Bear cub on the highway!!!  It was pretty little and even shorter than the guard rail!  I was so surprised to see it!  I drove a little further and parked where there was room, and then ran back to take a photo!  The little cub was just walking down the highway in the oncoming lane!  I was worried that the bear might get hit by a car!  I ran back to my car, drove a little further where I could make a u-turn, and then headed back to where I had seen the bear.  Luckily the little bear was nowhere in sight.  I was glad that it hadn't been run over!  I looked around for a while, but didn't see it again.  Hopefully, it had ambled back to its mother!

Black Bear mating season is from June through early July.  The cubs are born sometime in January to early February.  The litters range from 1-5 cubs, but 2-3 cubs is the usual size.  The cubs weigh 7 ounces when they are born, and will nurse their mother while she is still hibernating!  When the cubs emerge in spring they weigh 4.5 -11 lbs!  They are totally weaned at 6-8 months, but stay with their mother through the next winter, until they are around 17 months old.  Female Black Bears do not tolerate adult males except during their brief mating season.  They raise their young on their own.  

When Black Bears are in hibernation they do not eat, drink, or produce bodily wastes.  They also do not experience any bone loss, or reduction in muscle mass!  They can sleep for 5 months, wake up, and climb a mountain!  This is not something a human could do!  Scientists are currently studying the biochemical processes of Black Bears to see how they deal with hibernation.  So far they've found out that since they are metabolizing mostly fat, they do not accumulate large amounts of urea in their blood.  The urea that does accumulate is converted to "creatine", which is non-toxic.  They have also figured out that Black Bear nitrogen wastes are biochemically recycled back into protein, hence they don't experience loss in muscle mass!  It all amazes me!

What's happening down on the river?

Is the hummer still around?

How is the fox?  

Where are the deer?

Check back next week for the answers to these questions and more!

Your questions and comments are greatly appreciated!

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