Hello Fall!

Welcome back to school everyone and hello fall!

Though Friday was the fall equinox of 2018, and temperatures have just started to cool down, Eberwhite Woods still looks like a green jungle. But that green will soon change to many red, yellow, orange, and brown, and animals will begin to prepare for winter.

Right now, birds and frogs are not very obvious in the woods - their mating season is over, so frogs have stopped calling and birds are duller in color and vocalizing less. The woods are still filled with noise - chattering chipmunks and squirrels, and their sounds are easily mistaken for birds or frogs. These small mammals are all over the woods and are loudly protecting their territory and warning off interlopers. A fun way to spend a walk with kids is to have them look for the many caches of nuts these rodents have made around the woods.

In addition to the small rodents, the other noisy creatures of the forest and surrounding meadow are insects. If you stop to listen to the background noise of the woods, you will hear the cicadas, katydids, and crickets calling (and night is even louder). These insects will continue to call for the next few weeks before temperatures plunge and they grow quiet. Most of the calling that we hear from these insects are from males calling to attract mates. But there are some variations in this function and more information see - http://songsofinsects.com/. In addition to the insects in the woods, which are primarily high up in the tree foliage, there are many insects that are easy to observe in the Zion meadow (retention pond area and grassy field adjacent to the woods) that will continue to be active until it gets too cold.

Common butterflies recently spotted in Zion meadow

(Species from left to right, top to bottom: Eastern tailed-blue wings open, ETB wings closed, Pearl Crescent, Cabbage White, Clouded Sulphur, Common Checkered-Skipper).

We are very fortunate to have the retention pond, grassy field and vegetable gardens adjacent to Eberwhite Woods. This open habitat, with lots of vegetation and flowering plants, especially native plants, attracts many insects! And all of these insects provide food for birds and other animals. Professor Emeritus of Linguistics, at the University of Michigan, John Swales, has been studying local butterflies of Washtenaw County (~100 species) and those around the Zion Meadow.  Over the years, John has recorded approximately 47 species around the Zion meadow. Butterflies often depend on particular plant species for survival, at both the caterpillar stage (munching on leaves) and the adult butterfly stage (flower nectar). The monarch is an example of a butterfly species that is dependent on one type of plant, milkweed.

Here is a link to an interview with John Swales about butterflies in Washtenaw County: http://www.wemu.org/post/issues-environment-butterfly-species-washtenaw-county

Monarch butterflies and Migration

(Monarch chrysalis, monarch caterpillar, male Monarch on swamp milkweed, Viceroy butterfly: a non-toxic mimic of the Monarch butterfly that is usually found in wetland areas but does not use milkweed as a host plant)

Many butterflies can only survive on one type of plant (eg. monarch and milkweed) and cannot survive if these "host" plant species are not present. Thus, native vegetation is very important to maintain healthy butterfly populations. The Zion meadow has milkweed and supports a population of monarch butterflies with the milkweed host plant, and by providing nectar from many of the late summer blooming plants that the monarchs depend on for nectar. Monarch butterflies are probably the most well-known butterfly species in the US and have a fascinating natural history because of the incredible migrations they undergo. Monarch butterflies in Michigan are part of the population (east of the Rocky Mountains) that migrates to one location in Mexico to pass the northern hemisphere's winter. The monarch butterflies that we observe flying around in the late summer are likely headed to Mexico so wish them luck on their long, treacherous journey. Can you imagine flying to Mexico? For more information on monarch migration: https://en.wikipedia.org/wiki/Monarch_butterfly_migration).

(Monarch butterfly migration 1) March; 2) April; 3) End of April; 4) April – June; 5) June – August; 6) September – November: Wikipedia)

Cicadas (and their enemy)

Cicadas are one of the loudest insects of Eberwhite Woods, especially on the hot and humid days of August and early September. They are the creatures that make the forest hum. Cicadas live underground as nymphs, with some species living for many years underground (periodical cicadas). The common dog-day cicadas of our region (Tibicen sp.) lay eggs on tree limbs or bark, feed on plant juices as young nymphs, then drop to the ground and bury themselves. They may pass 2-5 years underground feeding on plant root juices. In late summer, they will emerge from the ground and climb up a tree or shrub. There, often hanging upside down on a branch, they undergo metamorphosis and turn into an adult cicada. They then spend the rest of their short adult lives (a few weeks) on vegetation, sucking on plant juice and reproducing. Cicadas also serve as important food sources for many other animals, including another insect, the cicada killer wasp. 

(Cicada nymph molt, cicada adult, Eastern cicada killer dragging away an adult cicada)

Though the name is a bit scary sounding, and the wasp is probably the BIGGEST wasp you have ever seen, the wasps are pretty harmless to humans. They are not aggressive and have no interest in us. The adult wasps fly around tree branches looking for cicadas. When they find one, they sting it and drag it back to their burrow, which is made of a few cells where new wasps will develop. The wasp will collect between 1 - 3 cicadas and put those in one cell of their burrow. They will then lay an egg in each cell and seal it off. The egg will hatch and the larvae will feed on the cicadas before emerging as adult wasps. The cicada killer wasps like to make their burrows in sandy, sunny areas and that is why they can even be spotted in sandboxes of local parks!

Fungi in the Woods

(From left to right: Chicken of the Woods, Common Puffball, Oyster Mushroom)

Chicken of the Woods is a beautiful (and tasty - but please don't harvest - leave them for everyone to see and enjoy) fungus often found on oak trees. The fungus is parasitic and causes a brown rot on the host tree.

There are puffball mushrooms of all sizes around Eberwhite Woods. Compare the photo of the puffball mushrooms to the oyster mushrooms. The unique feature of all puffballs is they do not have a cap with spore-bearing gills underneath like you see on the oyster mushroom. Instead, the spores are produced internally and disperse in dust-like clouds of spores when the puffball bursts open - either by raindrops, gusts of air, or as I've witnessed with groups of kids in the woods - sticks:)
The oyster mushroom, on the other hand, has a cap with gills underneath. The sole purpose of these gills is to produce spores which are dropped by the millions and scattered by the wind.

All photo credits: Wikimedia or author