EGGStravaganza

Sturgeon Bay, Wis. (March 22, 2024) – EGGStravaganza will again take place at Crossroads at Big Creek on Saturday, March 21 at 2:00. Understand that this is NOT an Easter Egg Hunt, but rather a special session of our weekly Family Science Saturday program. Generations of families have discovered that learning about the science of eggs is enjoyable, educational and memorable.

The program begins in the auditorium with several  remarkable videos showing how, over a period of 21 days, a single cell chicken embryo develops into a fluffy yellow chick inside a thin shell.  

Following the videos,  families will  move into the science lab to dissect unfertilized eggs.

Then the real fun begins. To demonstrate the phenomenal structural strength of an egg shell, participants will roll, squeeze, and toss  eggs…. and even drop raw eggs out of the second story window of the Collins Learning Center. Finally, the whole group goes outside unless the weather is extraordinarily unpleasant, and each young person gets one egg with which to experiment. (This has the potential to be messy.)

We have learned over the years  that participants get the idea that all eggs are similar….that they are all “ovoid”, which comes from the Latin word for egg and means “egg-shaped.” But eggs, even those of our native Door County birds, come in a variety of shapes.

Many eggs are tapered—almost pointy at one end, but our owls lay round eggs and cavity nesters like woodpeckers and chickadees and birds with cup nests lay eggs that are roundish or oval.

I had been taught that egg  shape was determined by “the roll factor.” Spherical eggs could easily roll off a cliff. But eggs with a pointy ends would roll in  tight circles, making them perfect for cliff-nesting birds; or in our case, ground-nesting killdeer. In contrast, the eggs of cavity nesters or birds with cup-shaped nests are not going to roll anywhere so they can be round or oval.

Clearly, egg shape adaptations have survival advantages so I never questioned this explanation. But Mary Caswell Stoddard, Assistant Professor of Ecology and Evolutionary Biology at Princeton University did question it.

She  pulled together a team of researchers from both sides of the Atlantic who, using  photographs stored in an online database at the Museum of Vertebrate Zoology at UC Berkeley, measured 49,175 bird eggs collected all over the world for the past one hundred years.  The researchers looked at two features: asymmetry, or how pointy the eggs are, and ellipticity, or how much the eggs deviate from a perfect sphere.”

They then, using a special computer program, ran their data through a whole raft of variables (many of which I would not have thought of) searching for correlations and they found one! One they didn’t anticipate.

“We discovered that flight may influence egg shape,” according to Stoddard.

She explained, “To maintain sleek and streamlined bodies for flight, birds appear to lay eggs that are more asymmetric or elliptical. With these egg shapes, birds can maximize egg volume without increasing the egg’s width – this is an advantage in narrow oviducts.”

In other words, slender birds which fly well produce long, tapered eggs.

The eggs we examine during  EGGStravaganza will be ovoid, and if conditions allow,  visitors might be able to visit the chunky- bodied hens that lay egg-shaped eggs. 

Speaking of eggs, a student from Sawyer School already has found salamander eggs in Big Creek and this is the time of year northern pike and suckers usually swim up the creek to spawn.

Due to our extremely dry winter, Big Creek is very shallow and we do not know when or even if fishes will come into the preserve.  BUT…follow Crossroads on Facebook or watch our website. We will post progress and offer pop-up programs when conditions are promising.