Meteorological Spring

Red-flowering Currant (Ribes sanguineum)
Native Red-flowering Currant blooming in the Kukutali Preserve
The seasons of the year, spring, summer, fall and winter are each about three months in duration.  There are two reckonings for determining the seasons, astronomical and meteorological.  The astronomical reckoning is established by the tilt positions of the earth relative to the sun.  These positions are referred to as equinoxes and solstices.  An equinox occurs on a date when the durations of daylight and darkness are equal.  These happen on roughly March 20 and September 22.  The March equinox determines the start of astronomical spring.  For 2015, this will occur on Friday, March 20 at 22:45 Greenwich Mean Time.  In the Pacific Northwest, that will happen at 3:45 PM daylight time.

Solstices occur when the sun reaches its highest and lowest points in the sky.  In other words, the earth is tilted furthest toward or away from the sun for the observer.  These occur around June 21 and December 22 and mark the beginnings of astronomical summer and winter respectively for the northern hemisphere.

Indian Plum (Oemleria cerasiformis)
Native Indian Plum blooming in my yard
Meteorological spring is determined by the average temperature during three-month periods.  The warmest period is summer and the coldest is winter.  The seasons between them are spring and fall.  In the northern hemisphere the breakdown becomes spring (March, April and May), summer (June, July and August), fall (September, October and November) and winter (December, January and February).

Of course, if we travel to Australia, this all changes.  Spring begins in September, summer in December, fall starts in March and winter begins in June.  When the northern hemisphere is tilted toward the sun, the southern hemisphere is experiencing winter.


Meteorological Spring Begins Today March 1

Northern Flicker Males (Colaptes auratus)
Northern Flicker Males in Deception Pass State Park
Around here, it seems spring has been underway for the last couple of weeks.  All of the photos here were taken during this period.  Above, I caught two male Northern Flickers in Deception Pass State Park.  They were in an apparent territorial dispute.  It involved dancing, posturing, tail flaring and do-si-do-ing around the tree trunk.

American Wigeons (Anas americana)
American Wigeons on Skagit Bay
I always know spring has arrived when rafts of American Wigeons start passing by on Skagit Bay.

Banana Slug (Ariolimax columbianus)
Banana Slug (Ariolimax columbianus)

After disappearing for the winter, our Banana Slugs are now in their "Coming-Out."  I found these on Kiket Island in the Kukutali Preserve across the bay.  I have observed that Whidbey Island slugs have spots while Fidalgo Island slugs are plain.  Kiket seems to have both.

Song Sparrow (Melospiza melodia)
Song Sparrow (Melospiza melodia)

Also on Kiket Island, I came upon another apparent territorial dispute.  This time it was a pair of Song Sparrows near the beach.  All puffed up, this bird first waved his right wing at his opponent, then his left wing.  This alternating gesture went on for a few minutes.

Song Sparrow (Melospiza melodia)
The challenger, Song Sparrow in the Kukutali Preserve
This bird was the object of his ire.  Except for a spiky hair style, he perched impassively.  This is apparently an example of Song Sparrow machismo.  When this bird took off, the first one went right after him.

Oregon Grape (Mahonia aquifolium)
Oregon Grape on Kiket Island
Oregon Grape is another early bloomer in the Pacific Northwest.  Our winter was warm and rainy interspersed with more sunny days than usual.  This might be a recipe for a great season of wild flowers.  It will be interesting to see what affect this will have on the wild Pacific Rhododendrons at Deception Pass this year.

Red-flowering Currant (Ribes sanguineum)
Wild Red-flowering Currant and friend
When in April with his sweet showers
Have pierced the drought of March to the root,
And bathed each sprout through every vein with liquid
By which power the flower is created.

When the West Wind blows with his sweet breath
Through every field and forest enlivened
The tender new leaves, and the young sun
Has run through half his course in Aries.

And little birds are making melody,
those that sleep all night with open eyes
(so nature incites them in their hearts),
then people long to go on pilgrimages.

-Geoffrey Chaucer, The Canterbury Tales c. 1387-1400