Blue Neotropical Navigators of the Night Sky

Image From Birds & Nature Magazine, 1896

Today I was walking down one of the trail gardens of the historic Fairlane Estate — a beautiful and historic property once owned by Henry Ford but taken care of today by the University of Michigan – Dearborn — just kind of wandering around, enjoying the afternoon. The garden trails are nice — shaded completely by big, old trees on both sides — and are usually teeming with all kinds of life, some easier to notice than others. You’ll usually notice the squirrels and chipmunks first; they scratch tree bark, scoff at one another or at you, and rustle crunchy leaves as they bound across the forest floor. Next you’ll see the chunky American Robins pipe-pipe-piping in the forest understory, lazily flapping their way from branch to branch, or you’ll hear the Grackles browsing for insects on the ground…

… and then there are all the little things in between, usually noticeable after you stay still in one spot for a long period of time. If you are like me and you zone out along the trail every few minutes, it becomes easier to accidentally notice those little things that you might not otherwise notice. (So… Zoning out is not always a bad thing to do.)

Today, one of those “little things” was the sound of little chirps coming from a spot just off the trail — a little nest!) — as well as the little blue bird that kept fluttering down to tend to it. Using the 300mm lens as a magnifying tool, I counted 2 chicks total; although I guess that it is possible that there could have been one more.

Both the Latin and Common names of this little neotropical migrant bird are inspired by its brilliant color. It spends the breeding season in most of the Eastern United States and winters in Central America. What is unique about this bird is that it migrates at night, navigating by the stars, according to this 1965 research study from the University of Michigan, conducted at Sloan Planetarium in Flint, Michigan:

IN  Part I  of this publication (Emlen, 1967), I  discussed  the Zugunruhe
orientation exhibited by  caged migratory Indigo Buntings, Passerina 
cyanea. The majority of the experimental birds consistently demonstrated
an ability to select the appropriate migration direction when tested under 
natural or artificial (planetarium) night skies.  These  results, in  con-
junction with predictable behavioral changes under manipulated plane-
tarium skies led me to hypothesize that  celestial cues provided at  least
one means of enabling this species to determine its migratory direction.
Since the outdoor experiments were performed on moonless nights, and
all  planetarium tests were conducted without projecting the planets, the
stars themselves are implicated as the informational cues. .

Can you imagine what that setup would look like? An enclosure of these magical blue birds housed in a planetarium at midnight… kind of a romantic scene. Apparently they would put the birds in cone-shaped cages with an inkpad at the bottom, and note the direction and quantity of the little inked footprints that were left upon the slopes.

A figure from the study — “Zugenruhe orientation under the natural night sky analyzed as a function of time of night”:


As an extra treat, here’s a handy color chart of some brilliantly-colored birds of North America. I want to include this NOT only because it’s gorgeous artwork, bt our blue-colored bird of interest is featured alongside some of his blue friends:


If you are saying, “Boy, these birds look a lot like those in Roger Tory Peterson‘s field guides”, you must really be good: Roger Tory Peterson — naturalist, educator, author and artist — indeed paint this color chart of birds for this isssue of LIFE Magazine which came out in 1947. I think it’s very lovely. (Thanks Google Books!)

You can access some of the other pages from the issue here.

Want to go even FURTHER back in time? Check out THIS spread of bird paintings from a “Wood Warblers” feature in a 1938 issue — also by Roger Tory Peterson. Gorgeous. (Our bird of interest is in there, too.)

Back to OUR birds! Here is the Indigo Bunting male spotted earlier today, perched on a branch with  a watchful eye on the intruder:

Another shot — the feathers on his crown are erect, clearly agitated by my presence:

Blurry pic of the Indigo Bunting female, in the branch of a fruiting Pokeberry:

The nest — about a foot above the ground:

I wish them much success in raising a new generation of beautiful, blue, neotropical, night-sky navigators who have chosen to make their home here on the University of Michigan – Dearborn campus in metropolitan Detroit!

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