The Observer’s Eye: Phenology and Our Changing Seasons

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Daniel Burden
Program Specialist, Value Added Agriculture
Iowa State University Extension & Outreach

Grinnell NotebookLiving on an acreage and having immediate access to nature in your backyard, or simply being a person who loves nature and the outdoors means that instead of the couch-bound throng, you are probably getting outside at all times of the year.  All of us note the seasonal events that to some extent chronicle each passing year.  It can actually be a fun family and personally fulfilling exercise to chronicle our passage by composing a formal naturalist’s journal and outdoor calendar.  You may even want to scrapbook it with photos, notes and collected items.

Naturalists have a keen eye for seasonal change.  The technical term for the science of how the events relate to one another is “phenology.”  The word is derived from a Greek word that means "to show, make appear, or bring to light.”   For the last hundred and fifty years or so, phenologists have keep records of natural events and their relation to calendar date, day-length, temperature, moon phase, extreme weather events and to one another.  The result has produced much of our meaningful knowledge about the natural world.  This includes things like the migration and breeding patterns of birds and other wildlife, insect emergence patterns as they relate to crop production, how species continually adapt to land-form or climate change, when to plant the garden, or the best time and place to begin the hunt for wild greens or mushrooms.

Your choice of note book or system is up to you.  Me, a former scientist, I keep a modified version of the “Grinnell Notebook,” a formal wildlife-biologist’s record-keeping system.  A scrapbook project with the grandchildren is equally appropriate.  But for phenology we need to change it up a bit from the usual “chronological-diary system” in one important way; we need it in the form of a calendar.  This is pretty easy to set up.

My notebook began life as a hard-cover spiral-bound artist’s sketchbook.  It is sturdy and has archival paper that will not yellow or fall apart with time.  After leaving a few blank pages in the front for a simple table-of contents and introductory notes, I did a quick page count and then subdivided that number by 12 for the months of the year.  In my book this gives me 13-pages for each month of the year.  I then numbered the pages and placed a labelled colored tab at the start of each new month.  I mostly record written bird-feeder sightings, entries for upland bird hunting with my beloved pointing dog, and some wild food collection notes; 13 pages per month should give me about eight to ten years or so of recording in this notebook.

Some folks may want a lot more space to write if they do a lot of journaling or scrapbooking.  It is your book and your choice; simply plan accordingly.   If you are inspired to write a lot, well, you may want to purchase twelve volumes, one for each month of the year.

Since I use a modification of the Grinnell system, my project was ready for use with the inclusion of a plastic straight edge and an indelible-ink pen.  A good pen is important, an archival record isn’t much good if your dog slobbers on it or your best friend dumps a cup of coffee and you lose ten year’s-worth of data.

To begin an entry, one goes to the proper month and on the first page rules a vertical line down the left side of the page for a margin line; on the left side of which is recorded the day-of-the-week and calendar date are recorded; on the right side, one records the observation, pastes a photo, etc.   When the entry for the event is completed, the straight edge is used to rule a horizontal termination line below it.  The start of each subsequent entry will again be the day and date in the left margin with text or images to the right and so on.

The value of the journal lies in noting important observational data that will help you later when you have accrued enough entries for a given month to begin to see patterns and relationships of events.  This could be time of day, weather, and unique events like the first hard frost or rain after a prolonged dry spell.  Trees can be important indicators; when a particular trees or shrub buds, flowers, or drops seeds or leaves.  For example, some tree in your backyard is in the midst of flowering; you observe the rare occurrence of a few McGillivray’s warblers in the mix of Mourning warblers and Common Yellowthroats feeding on tiny insects attracted to the flowers.  If you have the observation of the bud-break, you can now roughly predict that in so many days, give or take a few; coupled with the  first of that tree’s flowers, you might just have a few McGillivray’s warblers  in the canopy.

If I consider my entries December, 2015, I see how the small forest hawks are starting to hunt songbirds by my birdfeeders.  Usually my songbirds don’t have many run-ins with the Sharpshin and Cooper’s hawks of the nearby river valley, but as usual, after we get hit with some freezing rain or a pretty good snow fall, the fast little Accipiters begin making rounds of our backyards to nab the complacent song birds.  From prior years observations, I can almost predict to the hour when I’ll see the songbirds vanish to cover as the first demon-eyed hunter shows up in the trees.  By the way, if you use field guides or other references to identify plants or animals, note the title, author, edition and page in your record; this usually is not that important, but if you have a something that is tricky to identify, it could be valuable as you work to unravel your little mystery.

Here, midwinter, I’m going to mist-net, collect data and band songbirds in my backyard with my ornithologist friend as part of one of research studies.  Years from now, that entry should bring back a lot of great memories.  Then there is the coming of spring.  I’m already looking forward to March and April.  This will be my first year logging my mushroom and wild asparagus finds, and sometime well before that, the flights of shorebirds and waterfowl will be heading north and crossing through our state.  By mid-April, I’ll be out with my spotting scope and binoculars gawking at one or the other of the many little closely related warblers or flycatchers.  I plan to all of this in relation to the size of oak leaves or other easy to observe benchmark indicator.   I want to note when trees pop their buds his spring; as well as when different trees drop their leaves this fall. 

During the growing season, there is a lot going on in the plant world. If I was a dedicated horticulturalist or really into wildflowers, I think that I would probably need a much larger notebook.  The way it is going, I hope I have saved enough space for entries in the one that I have.  Oh well, fill one notebook; start another.  I now that as my journal evolves, I’ll be able to pick it up, leaf through the entries for the month, and anticipate a pattern of interconnected events that will enrich my life by deepening my mindful appreciation of our wonderfully interconnected world.

In phenology, one thing leads to another.  Once you make an observation and start looking back at related ones in your notebook, as I’ve already noted, you will be able to predict when upcoming events will take place.  One begins to relate specific natural indicators to other events that are related only by their timing.  This is logical since many natural events are timed by combinations of temperature and day length.  There’s an old adage that the morel mushrooms are out when an oak tree’s leaf is the size of a mouse’s ear.  This is true.  I later learned that this is also my cue to get the canoe and start hunting for large-mouth bass.  The bass are aggressive and there is a lot of fun to be had.  Don’t forget to log those fishing hot spots and time of day they “turned on” to aggressively feed.  Now that’s important data for next year.

If you have children or grandchildren get them involved in a common journal.  It is a great way to personally connect and foster positive values, from developing a deep appreciation for the incalculable wealth of our natural world, the ability to find peace as a quiet observe, to understanding the importance of being able to clearly communicate by composing words on paper.  Keeping a nature journal is always fun, but it means far more years down the road when we can look back at how we have shared our love of the wonders around us with the truly special people in our lives.

Further research…

Handbook of Nature Study; Home of the Outdoor hour Challenge (for children)
Wikipedia article on Joseph Grinnell:
Wikipedia article on phenology:
Sierra Club Nature Journal

Date of Publication: 
January, 2016