EGG-Stravaganza

By Coggin Heeringa, Interpretive Naturalist, Crossroads at Big Creek, Inc.

After extensive review of scientific research, we at Crossroads have determined that it is highly unlikely that rabbits deliver eggs to Crossroads at Big Creek. But other creatures, large and small, do. Consequently, our programs this week will all focus on eggs in one way or another.

Saturday Science, our free weekly family program, will be our traditional EGG-Stravaganza. Understand that this is not a religious event, nor is it an Egg Hunt. But because people of many different faiths traditionally use eggs in their observances, this seems the perfect time of year to learn about the eggs of birds.

We start by meeting Justin the Journeyman who will be in the rock garden with his hens. Then viewing several remarkable videos about chick development. Next, we do our Eggs-periments. Families will have hands-on (or actually hands-in) opportunities in oology – the science of eggs.  Learners of all ages will crack, break, and throw eggs, and even (yes, this is part of the tradition) drop them out the window from the upper level of the Collins Learning Center. Each family will dissect an unfertilized egg in the lab before going outside to toss raw eggs. 

By now, Northern Pike should be spawning, which means the mature pike move out of the bay. Females will deliver and release millions of eggs, males will fertilize them, and eggs will begin to develop in the warm shallow wetlands of the Big Creek watershed. 

In an article in the Minnesota Conservation Volunteer, Scott Moeller explained that young pike “develop inside a tiny egg [about the size of a candy sprinkle] for about two weeks, all the time in danger of being discovered by a fish, turtle, or other predator.

“After hatching from their soft eggshell, they remain stuck to an aquatic plant by a sticky patch on their foreheads for the next 10 days. At this stage, they are known as sac fry. The name comes from the large yolk sac that is still part of their [fish-shaped “small fry”] bodies. The energy-rich yolk sac is similar to what is in a chicken egg, but with one big difference: While chicks consume their yolks before hatching, the fish do not consume the yolk until after they hatch.”

While the pike fry and fingerlings are developing upstream, White and Longnose Suckers, taking their own cues from the temperature and flow velocity of water in The Cove Estuary, splash their way up into the Crossroads Preserve to lay their own eggs, that when they hatch, become food for growing pike fry.

Thousands of adult suckers and their eggs create an infusion of nitrogen and phosphorus – what researcher Dr. Karen Murchie of the Shedd Aquarium calls a “much needed buffet of nutrients” for the plants and aquatic insects (plus ravenous baby pike) in Big Creek.

Crossroads is involved in community science research pertaining to pike and suckers.

The connection between tributaries and Lake Michigan for spawning is very important for the health of many native fish species. Sea lamprey, an invasive fish species that causes harm to Lake Michigan fish, also enter tributaries in spring to deliver their eggs and spawn. 

Providing access to Lake Michigan tributaries for species like Northern Pike and suckers must be balanced with trying to prevent sea lampreys from accessing areas in which they like to spawn.

Our next Fish Tales Lecture on Wednesday, April 12, will feature Dr. Daniel Zielinski from the Great Lakes Fisheries Commission in Traverse City, Michigan. He will describe the on-going efforts to achieve “The Development of Selective Connectivity for Fish Passage and Invasive Species Control at the FishPass.” He will inform us how science and engineering are being applied to increase connectivity to critical tributary habitats for native spawning fish while at the same time preventing invasive lampreys from gaining additional areas in which to spawn. His research is being conducted on the Boardman River in Michigan and its application will directly affect fish passage efforts on the Wisconsin side of the lake.

Finally, our soil is alive and teeming with creatures. Most soil creatures are single cell organisms, but an unimaginable number of nematodes, springtails and worms, to name a few – lay eggs.

Soil scientist, Dr. Jamie Patton, Outreach Specialist for northeast Wisconsin with the Nutrient and Pest Management Program (NPM), UW-Madison, will certainly discuss soil organisms when she and Becky Wiepz, Superintendent of the Peninsular Agricultural Research Station present the next Master Gardener Lecture, “Answering Local Questions with Research and Demonstration – 2023 Projects at Peninsular Agricultural Research Station.” This Master Gardener program on Thursday, April 13, 6:30 p.m. will offered in-person at Crossroads and recorded.

Also, this week, the Door Peninsula Astronomical Society will hold its monthly meeting at the Stonecipher Astronomy Center on Tuesday, April 11, at 7:00 p.m. DPAS President Dave Lenius will share the amazing story of how the twin Voyager 1 and 2 spacecraft are exploring where nothing from Earth has flown before. Continuing on their more-than-40-year journey since their 1977 launches, they each are much farther away from Earth and the sun than Pluto. If the sky is clear, the meeting will become a Viewing Night.