Early Spring 2019!

Spring is finally here! The forest floor is covered with a new carpet of green and birds are singing all around us. Amphibians are calling from the ponds and insects are flying through the air. If you haven't been to Eberwhite Woods recently, come explore and observe the new flora and fauna that have suddenly appeared with the change of seasons. And please stay tuned, because new animals and plants are appearing in the Woods each week!

Amphibians & Reptiles

The early amphibians in our Woods are spotted salamanders, wood frogs, and spring peepers. The spotted salamanders are very elusive and spend most of their lives in hiding - under leaves, in burrows, under trunks, etc. However, when the conditions are wet and warm enough in early spring, often by March, the adults leave their hidden homes and head for vernal ponds where they will breed. (These salamanders are dependent on vernal pools and cannot breed in larger bodies of water with fish as potential predators). Often, many individuals will migrate to ponds en masse and if you are lucky enough to see this migration, it is an amazing feat! Females lay eggs in clutches and males fertilize the eggs, and both male and female adults leave the ponds after a few days and head back to their shelters, where they pass the rest of the year. The larvae develop over a couple of months, lose their gills, and eventually migrate out of the pools in search of an upland home. The small larvae start out eating zooplankton and then eat larger aquatic invertebrates as they grow. The adults feed on all sorts of soil invertebrates. This species is not federally listed as endangered, but it is very sensitive to habitat disturbance or destruction and can locally go extinct.

Spotted Salamander

While many amphibians and reptiles burrow deep down in the mud under ponds or on land below the frost line, a group of small forest frogs have a different way of surviving the winter – they freeze! This group includes some common species one might find in Eberwhite Woods, like spring peepers, and wood frogs, and possibly chorus and gray treefrogs.

Wood frogs might just be the superheroes of this group, and the entire amphibian world, because they can freeze up to 2/3 of their body water and survive in a “frozen” state for approximately seven months in temperatures down to zero Fahrenheit! As temperatures start to drop with the onset of winter, wood frogs produce natural antifreeze, in the forms of glucose, that they pump into their cells. They also begin to store urea (pee) that helps prevent too much ice from forming in their body. As the watery parts of their body begin to freeze, creating a hard, icy block, their individual cells remain unfrozen. And as the winter temperatures plunge, a wood frog’s heart eventually stops beating, the lungs stop working, and individual cells, though frozen, stop communicating with each other.

As soon as the temperature warms sufficiently, the frogs begin to thaw. Depending on where they live, a wood frog may thaw and leave hibernation from early March – mid May. Their hearts start beating even before their entire body has thawed. It takes about one day for a wood frog to thaw and one more day for them to migrate to a pond to breed. In parts of the wood frog’s range where winter temperatures fluctuate, like Eberwhite Woods, the frogs may go through various freezing and thawing cycles. However, they don’t completely leave the hibernating state until early spring. Wood frogs are considered “explosive breeders” because they migrate in masse to bodies of water to breed. Here, the males call females with a duck-like quacking sound. After breeding occurs, females lay egg masses in the water and tadpoles develop over a couple of months. New adult frogs eventually migrate away from pools and start their terrestrial lives under leaves or trunks, or in burrows.

Woods frogs and peepers are calling now in the Woods, along with American Toads that just started trilling. For a great link to help you identify calls, here.

Wood Frog

Spring Peeper

American Toad

Garter snakes are common throughout many different habitats in North America but are often found in moist areas or near water. They are very common in Eberwhite Woods and can definitely be observed swimming in the ponds where they will gladly consume any amphibian they can get ahold of. Their diet all consists of any other terrestrial animals they can overpower. During mating season in spring, males mate with many females. Females give off a pheromone that can attract many males and may lead to a mating ball where up to 25 males surrounded the female and compete over her. Some students observed this happening a couple of weeks ago in the Woods! Garter snakes are ovoviviparous, which means they give birth to live young, and the young are incubated in the lower half of the female's abdomen. Though these snakes are NOT DANGEROUS to humans, they do have a small amount of mild venom. They are beautiful and fun to watch as they slide through the wildflowers and ponds of the Woods.

Garter Snake

Wildflowers

Wildflowers are beginning to explode in the Woods and different species will begin to bloom as the weeks pass. If you visit the Woods throughout the spring you will become familiar with many different types of flowers and watch a beautiful show of color light up the forest!

Bloodroot, one of the earliest flowers to appear, is an interesting plant. The juice that comes from the stems and rhizomes is red and toxic - please don't sample this plant! Extracts of this plant are sometimes used for commercial purposes in dental hygiene products and were used by Native Americans for various purposes. Also, the flowers produce pollen, but no nectar. Mining bees (Andrena) like the one shown below, do collect pollen from the flowers. The seeds of Bloodroot are spread by ants, and the seeds have a fleshy part of their seed, called an elaiosome, to attract ants. The ants take the seeds back to their nest, feed on the fleshy part of the seed, and then leave the rest of the seed in the debris area of the nest. The seeds are happily protected and then germinate in the rich soil found within the ant nest.

Bloodroot

Yellow Trout Lily

Pink Trout Lily

Cutleaf Toothwort

Spring Beauty

A Few Insects (because there are so many)

Over the last couple of weeks, and especially on warm, sunny days, insects can be seen flying through the Woods. Butterflies are flitting about and many different bees can be observed. Most of the bees we are currently observing are small, solitary bees that are attracted to the early spring wildflowers and trees. While honey bees are very important crop pollinators, solitary bees (do not have hives) are very important pollinators for crops and wildflowers! Michigan is home to over 450 species of bees. For more information about bees please click here and here!

Mining Bee (Adrena sp.) nest and bee leaving nest (early pollinator)

Though a number of butterflies are found in the Woods, a greater diversity of butterflies is found in the grassy area and meadow near Zion Church and parking lot entrance to Eberwhite Woods. John Swales has been observing and recording butterfly species for many years in this region and he has observed nearly 50 species in the Eberwhite Woods/Zion meadow area! Like wildflowers, new butterfly species will appear week by week throughout the spring and summer.

Eastern Comma

Mourning Cloak

Red Admiral

Birds

These early migrants are fun and exciting to find. All the birds below have been spotted recently in Eberwhite Woods. It's a great time to head out an look for them before the waves of later migrants come - right now there are only and handful of migrants to learn and identify. The first blue-grey gnatcatcher in Ann Arbor this spring was found in Eberwhite Woods. The Woods are wonderful habitat for migrating birds and this FOY (first-of-the-year) is a great reminder of how important this little pocket of urban forest is for a lot of migrating species.

A lot of people think "nuthatch!" when they first spot the brown creeper - they both like to run up and down tree trunks, but the brown creeper travels upright and has a curved bill, whereas the nuthatches tend walk face-first down the tree trunks.

If you see a bird with a distinctive "tail flick", that is the eastern phoebe.

The kinglets are constantly darting around in the trees, they are hard to get a long, close, look at - but watch for the brilliant flash of red or gold on their crowns, that makes them easy to identify.

There have been 3 pair of wood ducks spotted in the woods this spring - it would be great if one pair decided to stay and nest! Unlike many waterfowl that nest on the ground, wood ducks are cavity nesters. They look for large holes in dead trees to raise their young, who then take a leap out of the nests when they fledge!

Yellow-bellied sapsuckers (YBSA) are a woodpecker that migrate through the woods in the spring. Watch closely and you may see one pecking away at a tree - making a row of exploratory holes looking for sap to eat. They make holes in bands looking for a tree that is photosynthesizing. Once they find a photosynthesizing tree, then they start making holes in columns above their exploratory band. There are 3-4 trees with great examples of these YBSA holes in Eberwhite Woods.

Lastly, our great horned owlets are ready to fledge. Both owlets are flapping their wings a lot and "flying" from one side of the nest to the other. Pretty soon they will fly/hop to nearby branches - this is the branching phase. Hopefully they will be able to stay high-up in the trees while this happens, but a lot of times, they end up falling to the ground and are unable to fly. This is a critical time to keep your dogs on their leash for the safety of the owlets, and other EWW users.