The marvelous month of May has arrived in Eliza Howell Park and it is bringing out nature lovers. The forest floor is alive with small ephemeral flowers and some of the elusive colorful warblers are pausing briefly on their 3000-mile annual spring migration from Central America to the North Woods.
One of the marvels of May in the park is observed by very few people — the emergence of the year’s Praying Mantises. It happens quickly and the timing is weather-dependant, so not fully predictable. Someone in the right spot at the right time (probably late in May) can observe the fascinating phenomenon of a hundred or more young mantises crawling out of and away from an egg case in which they spent the last 8 months.
Scattered in the park, mostly near the meadow wildflower field, are a number of egg cases (oothecae) of the Chinese Praying Mantis, attached to shrubs, limbs of small trees, flower stems, and vines, usually 1 to 4 feet from the ground. This photo is from this week.
Later this month, tiny new mantises will emerge en masse from the cases that survived the winter intact and healthy. Last year, a colleague and I witnessed such events most clearly May 21 to May 23.
Praying Mantis young are very small. The egg case is usully only about an inch high and contains dozens to hundreds. Though tiny, they emerge fully developed, except that they lack wings. They head away immediately and begin to search for other insects to eat.
Praying Mantises do not survive the winter as adults. The new ones that energe in the spring die in the fall, after mating and egg laying. I usually don’t see them until some time in August, by which time they are fully grown and are preying upon the insects attracted to the summer flowers. The Chinese Praying Mantis is often over three inches long at maturity
After mating, females lay eggs (making the cases at the same time). In Eliza Howell, this usually occurs in September. This egg case was new when this picture was taken in mid September.
From September until May, through the long cold winter, the Praying Mantis population is contained in these insulated oothecae
By far the largest number of Praying Mantises in Eliza Howell Park are the Chinese species — and my observations above all apply to it. This year, though, we found a few cases that are distinct enough (and placed differently enough) to be a different species. It is probably European Praying Mantis, a little smaller species also found in Michigan.
As it gets warmer, we will try to keep an eye on these few cases as well. I have no experience with what they look like as the young emerge. With watching — and with sone luck — perhaps it will happen this year.
The weather has been cool this spring, so I do not expect mantis emergence within the next few days, but I hope I am there whenever it happens. It is a “Wow!” experience.
It is always a challenge picking the dates, weeks in advance, for early spring wildflower walks. The challenge is in selecting a time when the short-lived blooms are visible. They are called “ephemerals” for a reason.
This year Spring has been colder than average here in Detroit and first flowering is later than normal. But, thanks to a couple of recent warm sunny days, a variety of small flowers can now be seen on walks in Eliza Howell Park.
Bloodroot grows on a little higher ground than most of the other early spring flowers, so it is now usually my first stop before I head down to the floodplain. There is only a limited number of days to observe this one-leaf, one-bloom flower, named after the orange-red rhizomes.
I tend to post something about Spring Beauties ever year. They are the most common early flower in the park, small, and ranging in color from mostly white to pink. As the second photo here shows, when the flowers appear, the insects come.
This is the first year that I have noticed that a number of participants on these wild flower nature walks are as excited as I am to see the insects. Pollinators have been receiving a lot of publicity and it is having an effect!
Yellow Trout Lily
Named Trout Lily because the mottled leaves reminded someone of a Brown or Brook Trout, this is also is quite common. At least the leaves are common; not every plant has a flower. It is a true lily.
White Trout Lily
Less common is another species of Trout Lily. The leaves of White Trout Lily are a little narrower. An alternative (and misleading) name for Trout Lilies, “Dogtooth Violet,” is more often used for the white species.
Another flower that varies a little from white to pink is named for the ridges on the leaves and a tooth-like growth on the roots. It’s size is evident in the second photo, with the presence of a large bumblebee. It is popular with pollinators.
Dutchman’s Breeches is, at least in Eliza Howell Park, a quite uncommon flower, one that I always enjoy seeing. Its name comes from the appearance of the flower, suggesting pantaloons, hanging upside down and somewhat inflated. (The flower names that we inherit from previous generations sometimes add to the fun of wildflower walks.)
There are a variety of other wildflowers that will soon be blooming near the river, including varieties of Violets, Wild Ginger, Wild Geranium, Trillium, and Mayapple.
Back up from the river, in the park fields, there are a few scattered locations where Pussytoes (named by the resemblance to a cat’s paw) grow. They are short and not easy to spot. The photos show the difference between the male and the female flowers.
The flower season has begun. For the next 6 months or so, there will be flowers blooming in Eliza Howell, the species and locations differing as the seasons progress. The pollinators and humans visiting the park welcome them.
One of the advantages of walking in the same park regularly — and of taking pictures in different seasons — is that I have the opportunity to see and to review later the ways in which different species develop over the months.
As I approached a patch of Hemp Dogbane in Eliza Howell Park this week, I was struck by how colorful the plants look now in the Speing sunshine. They had shiwn no color in the Winter.
I also noticed seeds floating away in the breeze, attached to tufts of silk. I find wind seed dispersal fascinating, so I stopped for a closer look.
Remembering that I had seen Hemp Dogbane seeds dispersal last Fall, I was curious about the extended released. So I took a look at some photo records.
A picture taken in the Winter doesn’t show any seeds being released at that time, but it does appear that some of seedpods still contain seeds, though most are open and empty.
According to the Fall photos, the Dogbane was full size (nearly 4 feet) by the middle of September
And, by that time, the numerous seedpods were well developed.
Each plant has many seedpods, reportedly 10 to 60 (I have never counted), and each of the seedpods contains dozens of seeds. So a large patch of Hemp Dogbane, such as the one I have been visiting, produces an enormous number of seeds.
The first evidence that I have of seed dispersal from last year’s plants is from September. Most seeds reach maturity by October.
Hemp Dogbane is also called Common Dogbane and Indian Hemp. The “dogbane” name comes from the fact that the plant is poisonous to dogs (and other mammals). The “hemp” name refers to the fact that native Americans used fibers from the stems as twine.
Hemp Dogbane is native and widespread in the United States. It looks to me similar to some types of milkweed, especially the stems and leaves. Flowering occurs in June – July. Milkweed seeds are also attached to light-weight tufts that lets them float away.
Even though I return to the same locations time after time, I am always learning. Better said: Because I return to the same locations time after time, I am always learning. Before now, I did not know that Hemp Dogbane seed is “blowing in the wind” in the Fall and again in the Spring.
As I indicated in the last post, April is a month for checking the forest floor, looking for and admiring the emerging spring wildflowers. April is also a month for checking dead trees or limbs as well as holes/cavities in live trees.
There are approximately 14 bird species that (always or usually) nest in tree cavities in Eliza Howell Park. The beginning of cavity nesting season might be a good time to comment briefly on a few of them.
It is not too difficult to spot Red-bellied Woodpeckers excavating holes at this time of the year. They often stop their work to call out loudly, especially the male who does most of the excavation. In EHP they often choose a large dead tree or a dead limb on a live tree. They might have used the same tree or limb before, but they make a new nest each time.
European Starlings often use old Red-bellied Woodpecker nests for their own use — and sometimes use brand new ones. I have several times over the years seen Starlings watching as the woodpeckers near completion of a new nesting hole and then move in to take it over when the woodpeckers are away. Once inside, the Starling is able hold off the larger and more powerful Red-bellied Woodpecker, which will then start over, making another hole from the beginning.
Wood Ducks breed in the park and they, too, nest in tree cavities. Contrary to Red-bellied Woodpeckers, their nests are not at all easy to find. At this time of the year, I sometimes see a pair or two moving quite high among the acres of large trees near the river, early in the morning. They are apparently “house hunting,” checking out natural cavities that they might use.
Wood Ducks do not excavate and they do not add any nesting material, so there are not many times to see them around the nest. Once the eggs hatch, the young leave the nest the next day or so (drop/jump to the ground) so there is no back and forth to the nest after hatching. So the opportunities to spot the nesting tree are few. Finding a Wood Duck nest in this park means being in the exactly right spot, at the right time, looking in the right direction.
People are sometimes surprised to learn that the little Black-capped Chickadee is a cavity nester. Perhaps the bigger surprise is that it often (though not always) excavates its own nesting hole. It frequently selects a stump, long dead and rotting. It is not able to dig into wood as well as a woodpecker, but it gets the job done.
One pair is currently working on the hole indicated below, the picture taken earlier this week from across the river.
The White-breasted Nuthatch is another small bird that nests in a tree cavity, but it does not make its own; it uses a natural cavity or an old woodpecker hole.
This is one species that will sometimes use the same nest more than one year. I am currently keeping an eye on a nesting location (a natural cavity about 15 geet up a tree trunk) used each of the last two years. If they return to it again, it will likely happen this month.
Bluebirds are well known as a bird that will nest in a box (and a pair will sometimes use a box in Eliza Howell), but it seems that they prefer other cavities here. The photo above is from 2021, when they used a hole that had been made or enlarged by chickadees a couple years earlier.
April is the usual time for Bluebirds to prepare a nest. I have been watching a pair recently. They are in the same general section of the park quite often and I am hoping that I will soon see them carrying nesting material (the behavior that usually leads me to a nest).
There are four species of woodpeckers that nest in Eliza Howell: Hairy, Red-bellied, Downy, and Northern Flicker. Downy, the smallest, is foraging in pairs now, but it is probably just a little early for them to begin a nest.
As is the case with the other three woodpecters, they excavate a new hole each time. In the case of Downies, their hole is usually on the underside of a dead tree limb that slants, that is not vertically straight, as can be seen in the photo above.
Great Crested Flycatcher
Very few members of the flycatcher family nest in tree cavities; the Great Crested is the only one in eastern North America. Its nests are in either natural or woodpecker-made holes.
Great Crested Flycatcher does not return from its winter grounds until May and begins nesting later than most other cavity nesters, after tree leaves have emerged.
Most birds make a nest outside, placing it on tree or shrub branches or on the ground, and constructing it with varying types and amounts of plant and other naterials. There is a sizable minority of species, however, that nests in cavities. They include a number of year-round residents and the cavity users tend to start earlier.
The cavity nesting season has begun.
One of the annual field trips offered by Detroit Audubon is a spring woodland wild flower walk in Eliza Howell Park. In winter, I select a date for that event, long before I have a sense of how quickly spring will progress.
Based on past records, this year’s date is April 23. It’s a cold spring this year and I am hoping the selected date will coincide with peak blooming time this year.
The spring flowers are small and low to the ground. Though it may take a close look to appreciate them fully, many are fascinated by these first wildflowers of the year. Three of several species here every year are:
These perennial wildflowers have little foliage, grow in the woods before the trees have leaves to shade the ground, and are short-lived, dying back before summer. They are often referred to as “spring ephemerals.”
The plants are just starting to emerge. Spring Beauty is one of the earliest; I saw these leaves just yesterday.
Spring Beauty is also one of the most abundant of the spring ephemerals in the park, showing several different color variations.
The leaves of Violets are also becoming visible.
Violet is a common yard flower, often growing where it may not be wanted and not always greatly valued. But I annually find myself seeking out — and admiring — the varieties found in Eliza Howell.
I have also seen the first indication that Mayapple is emerging, the stem just starting to poke up.
Mayapple differs from many of the other woodland spring wildflowers in that it is larger, with a lot of foliage and few flowers (which bloom in May). Mayapple is sometimes referred as the umbrella plant, and part of my enjoyment of it in April is watching the way the leaves unfurl as the plant grows.
A Mayapple plant has a single flower that hangs under the leaves.
April is a time to watch for certain migrating bird species and a time to try to locate / watch early nest making.
But much of the time during the next 2 – 3 weeks I will be looking down at the forest floor as I walk: watching how the flowers are developing, how abundant common species are this year, and looking for species that are not very common here, such as Dutchman’s Breeches
An annual April highlight is watching spring woodland wildflowers — and sharing the opportunity and enjoyment with others.
The last week in March was warmer in Detroit in 2021 than it is this year. On March 27 a year ago, I saw the first butterfly of the year in Eliza Howell Park, a Mourning Cloak, definitely one of my favorites.
Because it is one of the few butterfly species that spend the winter here as hibernating adults, it emerges as soon as it “thaws.” We do not need to wait for them to arrive (some butterflies migrate) or to complete development (some butterflies spend the winter as caterpillars or pupas). We just need some warmer weather.
Mourning g Cloaks are not rare, but they are not among the well-known butterflies. This may be becaise of their unusual life.
They emerge from hibernation (a winter spent under loose bark of trees, in log piles, etc.) in the Spring and begin to feed on tree sap, rotten fruit, and dung. Before long, they will mate, lays eggs on trees, and die. At this stage of their life, I usually see them in the woodland.
The new generation completes deveopment in June or perhaps early July. Last year, I spotted this one on June 24. It is on aspen leaves, one of the host species for their caterpillars, and may have just emerged from the chrysalis.
The new adults feed for a few weeks, but not often on flowers. They are usually seen on leaves or on the ground. This photo was taken on July 2 last year.
Mourning Cloaks are very long-lived for butterflies. The generation that emerged last June is the same generation that will be coming out of hibernation soon. They feed actively for a month or more as new adults before taking a “rest break.” They estivate (become dormant during dry weather) later in the Summer.
While Mourning Cloaks do not often visit flowers, I did watch one last July 17 as it acted very much like a nectarer, on a Purple Coneflower and then on a Wild Bergamot.
Following the period of estivation, Mourning Cloaks again feed in the Fall until time to hibernate.
The calendar of active time (marked in red) under the next photo helps to clarify the life pattern of the Mourning Cloak (Taken from Larry Weber, Butterflies of the North Woods, 2nd. edition.). I do not know of another Eliza Howell butterfly species with a similar life.
Mourning Cloak is a large butterfly, about 4 inches in wingspan, vary attractive, and not easily confused with any other species. And it is often the first butterfly seen in the spring. What is not to like!
My wish is that more people get to know this fascinating insect.
Three weeks into March, the Eastern Redbuds in Eliza Howell Park in Detroit still look like they did when the leaves fell last Fall.
But three weeks into April, the Redbuds will represent the brightness and beauty of Spring. What a difference one month makes! (The April photos are from April 20, 2021.)
The flowers usually appear in April before there are any leaves on these small trees and the seeds hang on into Winter (sometimes through the entire Winter), long after the leaves have fallen.
As might be guessed from the shape and look of the seeds, Redbud is part of the legume family of plants (which include beans and peas). Contrary to other legumes, however, Redbud cannot fix nitrogen from the atmosphere (the legume trait that is perhaps best known to organic gardeners).
In Eliza Howell Park, the Redbud is quite common along the edge where the trees and the fields meet. It is is not noticed much until the flowers appear in April, calling attention to itself for two or more weeks.
Southern Michigan is at the northern end of the native range of Eastern Redbud.
My experience has been that, while Redbud in bloom is quite well known to individuals who come on nature walks, Redbud in seed is not. This is not surprising, of course; there is no comparison in terms of visibility and attractiveness.
The Redbud in April is only a few short weeks away .
Watching Praying Mantises is an annual nature walk activity in Detroit’s Eliza Howell Park in late Summer and very early Fall. When Winter comes, long after the Mantis adults have died and the leaves have fallen, the egg cases (“oothecae”) are much easier to spot. Based on the many oothecae visible this year, the Praying Mantis population in the park will be substantial in 2022.
Most of the egg cases were clearly made by Chinese Praying Mantises, the most common Mantis here. Their egg cases are usually of a similar size and shape and location.
Recently, I found an egg case that was significantly different, different enough to indicate that it has been made by a different Praying Mantis species.
The case is smaller, more flat, placed on the nearly horizontal underside of — and flush with — a small fallen branch.
All the published information that I have seen indicates that there are only two Praying Mantises in Michigan: Chinese and European. As the names indicate, both are introduced species. They were brought to North America and released for pest control purposes over a century ago. They can perhaps be considered naturalized at this point.
The most common native Praying Mantis in the eastern part of the country is called “Carolina Mantis,” It is particularly common in southeastern U.S., the range reaching not quite as far north as Michigan.
Or maybe it is in Michigan.
In each of the last two years, a local observer has found a Mantis in the same location in Dearborn, Michigan, that definitely appears to be a Carolina Mantis. (The location is near the Rouge River, less than 10 miles downstream from Eliza Howell Park.)
It is much smaller than the Chinese and European Mantises, is mottled, and the wings do not extend as far as the abdomen does.
Compared with the typical Mantis seen in Eliza Howell, the differences are clear.
So the question that I am seeking an answer to is whether the ootheca I recently found on the underside of a branch in a brush pile is an indication that the Carolina Praying Mantis is present here in the park. That would be a great find, but,…
While I am convinced that this egg case is not Chinese Mantis, I do not know European Mantis as well. The published descriptions / photos of the European egg cases do not provide a definitive match to the recent find, but also not a definitive mismatch.
This collage (below) gives an indication of the variety of Mantis oothecae currently present in the park. At this point, I am able to identify positively only the one on the bottom right (Chinese). I am hoping/attempting to get opinions from professional entomologists on the others.
There is very little more exciting than learning something new. This latest egg case find has provided me with more information as I seek an answer to the question of the number of species of Praying Mantises present in Eliza Howell Park.
Now that March is here, there are new signs of emerging Spring almost daily in Eliza Howell Park. One is the cooing sound of the Mourning Dove, a sound not heard for several months.
The small-headed, long-tailed Mourning Dove is one of the most common birds in the United States.
Mourning Doves have been present all Winter, but things have changed. Usually when I see them in Winer, they are in small flocks. Not now. Now they are in pairs.
In the northern part of their breeding territory, Mourning Doves migrate south for the Winter. It is very likely that those that we see in Detroit in the Winter breed further north (and winter here) while those that breed here winter further south.
If that is the case, the doves now cooing probably returned recently.
“Mourning” Doves are named that because their cooing sound was considered sad. Cooing can, however, also be considered warm and soothing and contented (think of a baby cooing).
Since it seems to be a form of communication from one dove to its mate, “cooing” might be thought of more like “wooing” rather than to mourning.
Whether considered mourful or amorous or something else, the cooing is not singing; doves do not open their beaks when they coo. Rather, they puff up their breast and the sound is caused by the air vibrating their muscles/skin.
Cooing is just one of several fascinating aspects of Mourning Dove behavior.
They start nesting very early in the spring. I saw a pair making a nest on March 12 one year. The early nests are in sheltered locations. In this one (next photo) in a spruce tree, the bird on the nest can hardly be seen.
Later in the season, they often nest on a horizontal branch of a medium to large deciduous tree in the park. Whenever I come across a pair making a nest, I spend time watching, fascinated by their method.
They put together a nest very quickly, a nest made of material such as twigs and grasses and evergreen needles that are placed on the tree limb, with, it seems, nothing but gravity and a somewhat flat surface holding them in place. The male brings this material, piece by piece in rapid order, while the female stays at the chosen spot. He steps on her back and she turns her head to him. He hands off (“beaks off”) the piece he has brought and she takes it and places it around herself while he flies off to get another, often returning within less than a minute with the next piece. They take breaks away from nest making, but still often complete the nest within 2 days (compared with the several days to two weeks of many other species). The finished nest looks fragile and barely able to keep the eggs from rolling off.
Both female and male doves incubate the (almost always) 2 eggs and both feed the young after hatching.
Two eggs are apparently all that their eating and feeding practices permit. Mourning Doves eat seeds and grains almost exclusively. They store these in their crop before they are digested.
Most birds, including many seed eaters, feed insects to their young. Mourning Doves do not. They are able to make a limited amount of a milk-like food from the glands of their crop, which they regurgitate and feed to the young. This is called “crop milk” or “pigeon milk. ” Later, they feed seeds to the young.
Mourning Dove pairs share responsibility for nest building, for incubation, and for feeding young. Somehow, referring to their cooing communication as “mourning” doesn’t seem to fit.
I have recognized Mourning Doves all my remembered life, but, until I began paying careful attention to this common bird, I did not realize how unusual it is.
In Winter, when almost all the trees in Eliza Howell Park are leafless, American Sycamore trees stand out, with their attractive multi-colored bark.
While some of the Sycamores appear to have been planted for parkland purposes, more have grown naturally, especially along the river. American Sycamore is native to eastern North America and is often found in bottomland near rivers.
When I stop on the footbridge over the Rouge River during my walks, I always check on the one on the right as I face upstream.
This range map is from the USDA. Other species of sycamores can be found in the west.
American Sycamore seeds are also distinctive. The seedhead is a roundish ball, about 1 inch in diameter, hanging from a peduncle (stem) that can be 6 inches long. They mature in the Fall, hang on the tree through the Winter, fall to the ground in Spring and open to disperse seeds.
A seedhead contains perhaps 100 seeds.
Older trees often have cavities that are used by both birds and mammals. The trunks are sometimes hollow and were used as nesting and roosting sites by Chimney Swaifts before structures with chimneys provided plenty of other hollow vertical locations.
Sycamores are a little less noticeable during other seasons when the trees are leafed out, but I have found it important to check them carefully in May and June, when birds are nesting.
I occasionally find Blue-gray Gnatcatchers and Mourning Doves and Orchard Orioles nesting there. But it is Eastern Kingbird that particularly favors American Sycamore for its nesting tree. I typically find 3 or 4 Kingbird nests in the park each year, and the big majority of them over the years have been in Sycamore trees.
When Sycamore is planted along streets or in yards, it is sometimes considered a “dirty tree” that clutters lawns with pieces of shed bark. In a natural setting, however, it is a fascinating tree — in looks and in the fauna it attracts.
American Sycamore is very high on my list of trees for nature walkers to know.