Photo by Corey Husic

Wednesday, March 16, 2011

March 16th Phenology Notes

Well I had the good fortune to travel to Costa Rica last week.  It is always a wonderful place to visit because of the natural beauty, the wonderful people, the good food (especially the tropical fruit), and, of course, the amazing birds.  Besides seeing many wonderful tropical residents, we also saw a number of neotropical migrants that will make their way through Pennsylvania later this spring.  This included several warbler species like American Redstarts, and Chestnut-sided, Black-and-white, Blackburnian, Tennessee, and Golden-winged Warblers that were all still enjoying the hot temperatures.

I returned to PA to learn that there had been flooding rains and I was just in time to lose an hour of sleep as we turned our clocks ahead.  Both of these are signs of spring.  But there are many other signs as well.  I have received many reports of wood frogs and spring peepers, and heard that there had been sightings of salamanders during the heavy rains last week. 

Woodcocks are heard every evening in our field.  A pair of mallard ducks have returned to our small pond which lost its ice cover sometime while I was away.  The snowdrops and aconites seem to have multiplied in my gardens, but I am also seeing leaves of daffodils, tulips, day lilies, honeysuckle, tansy, and Artemsia.  Even my miniature rose (near the house) has leaves emerging.

There is a yellow color in the stems of the weeping willow and in the forsythia branches.  Our aspen (Populus sp.) are full of buds that look like pussy willows at first.  These will soon turn to flowers borne in long catkins. 

Aspen "fuzzy" buds that will soon be catkins
(I will try to get a better picture tomorrow when the light is better)

The same aspen terminal branch (different exposure) showing leaf buds
Aspens are in the family Salicaceae which also includes the genus Salix (willows) and I had never before realized how similar the early flower buds were to what I called "pussy willows" as a child.  Spring comes much later in the Upper Peninsula of Michigan, but picking a "bouquet" of pussy willow branches to bring inside was a sure sign that the long winter was coming to an end.

Aspen - the flower buds are new quite obvious in the profile against the late day sky
Members of the Salicaceae plant family produce salicylic acid which can be extracted from the bark (e.g. of willows).  It is a hormone involved in plant growth and development, physiology, and resistance to pathogens.  Extracts of willow bark were long ago identified as a pain reliever and fever reducer; we now know the active ingredient is salicylic acid.  This led to the commercial product of a related compound (acetylsalicylic acid) in what we know as aspirin--first produced by the Bayer Company in the late 1800's.  But Hippocrates wrote about this plant-based treatment back in the 5th century B.C.!

Salicaceae trees are an important food source for the caterpillars of Viceroy butterflies (the ones that look somewhat like Monarchs).  These caterpillars sequester the salicylic acid in their bodies making them bitter and not a particular good food source for predators which can end up with upset stomachs! 

With predictions of temperatures in the 60’s for the next few days, be prepared for many more signs of spring.

If you are interested in seeing where some of our species of interest are showing up, I recommend the website for the Journey North project  You can see the current location (and northward movement) of things like Ruby-throated Hummingbirds, Robins (first sightings, singing and waves), earthworms, over-wintering Monarch butterflies, Red-winged Blackbirds,and Barn Swallows.  Clearly from the maps (and the reports you have been sending me) the robins and blackbirds have already come to our state!

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