August 23

My early morning hike takes place where the sun rises along a secluded Lake Michigan beach on the southeast end of Beaver Island. Seeing and hearing the waves lap the shore ahead of me, I pause to examine the wrack that includes small stones and zebra mussel shells. Further up the beach, the wrack includes a carcass of a Northern Water Snake being decomposed by blackfly maggots. Continuing north, I explore the perimeter of a vernal pool beside the foredune where a variety of wildlife catch my attention. Florae include: yellow blossoms of Silverweed, pink blossoms of False Foxglove and white blossoms of Arrowhead. Faunae include: a ¼ inch, well-camouflaged American Toad, a ¾ inch Leopard Frog and a Sandpiper scampering along the shore. Suddenly, I notice commotion, nearly hidden among the beach grasses where a Blue Mud Wasp catches a much larger Beach Wolf Spider, stings and paralyses it. These spiders are experts in camouflage usually hiding in the sand or under driftwood during the day. Although its bite is poisonous and can be painful, it is not lethal to humans. As I continue to observe, the wasp drags the spider toward a previously constructed tube of mud. Once in the tube, the wasp lays a single egg on the paralyzed spider and caps the tube with more mud. The egg then hatches and the grub eats the spider as it grows. Next spring when pupation is complete, the adult wasp pops out of the tube and flies off. Working my way back along the back dune, I come upon yellow blossoms of Shrubby Cinquefoil and Hoary Puccoon. Approaching our lake rental, I observe one of a few Monarch butterflies feeding on blossoms of Spotted Knapweed, but only one Monarch caterpillar feeding on a milkweed leaf. Over the past several summers on the island, we’ve noticed significantly fewer Monarch adults and larvae. This trend is consistent with the latest research results showing a major population decline all along their migration route (stock photo). Scientists conclude the main reason is climate change. Like most butterflies, Monarchs are highly sensitive to weather and climate. They depend on environmental cues such as temperature to trigger reproduction, migration, and hibernation. In addition, climate change has reduced the milkweed population, a host plant they depend on. These fragile creatures also face a decline in their overwinter habitat as well as the effects of an increasing frequency of extreme weather events such as droughts, severe storms and temperature extremes.

 

Sandy path along a beach

Monarchs within my reach

Lake water’s cool and clear

Breaking waves are all I hear

Horizon meets a rising sun

Up ahead, sandpipers run

Back dune, sedges & ferns

Overhead, gulls & terns

Just another quarter mile

Barefoot on Beaver Isle

 

D. DeGraaf