Carolina Wren: Loud, Often Hidden, No Longer Rare in Michigan

Bird watchers sometimes refer to a time and location with few noticeable birds as “quiet.” In Eliza Howell Park, January and February are the quiet times of the year. Many species have migrated south and the food supply is limited (and no one has placed bird feeders here). In the first two weeks of January, I have seen only 15 species.

Few species does not mean, however, that they are of little interest. One that I am encountering quite often this month is the Carolina Wren.

Photo courtesy of Kevin Murphy.

Carolina Wren is more easily heard than seen. Its loud song can be heard throughout the year, even in January. I see it most often in the forest understory or at forest edges, as it forages among logs and in brushy thickets. Usually it does not come out in the open even to sing.

It does not “pose” for photos very often. I am not aware of any photos of it taken in the park; the two in this report were taken elsewhere.

I caught a glimpse of one in this thicket today, saw just enough to identify it:

This is the only wren found in Michigan that does not migrate. It has historically been a bird of the southeast and has been gradually expanding north in the last century. (This current range map is from the Cornell Lab of Ornithology.)

Carolina Wrens eat insects and spiders primarily. Their spread north has been related to more mild winters, as well, perhaps, to more backyard feeders. They seem attracted to residential neighborhoods where there are trees and brushy shrubs.

They are now a fairly common breeding bird of southeast Michigan, something that was not the reality a few decades ago.

The Michigan Breeding Bird Atlas I was completed in the 1980s and MBBA II was completed two decades later. A comparison demonstrates a significant change. (Yellow means possibly breeding in the specified location; orange means probably breeding there; red means definitely breeding there.)

Those of is who have not grown up aware of this bird are finding that it is definitely worth getting to know. It is richly colored, with a bold white stripe. Females and males look very much alike and they are normally found in pairs all year round, long-time mates. They nest near the ground, usually in some sort of cavity. The common form of their loud song is distinctive and memorable.

Photo courtesy of Kevin Murphy.

It will be weeks yet before the first migratong birds return in March. Meanwhile, the birds of winter include some fascinating species that invite return visits.

Bladdernut Seeds: Ready to Float Downstream

Not often, but sonetimes, winter is the best time of the year to find a particular tree species. This week I found a clump of Bladdernut trees (or shrubs) in Eliza Howell Park. The seed capsules still clinging to the stems, noticeable now that the leaves have fallen, were what caught my attention from a distance — and drew me close for a better look.

This clump, made up of trees about 12 to 15 feet tall, is very close to the Rouge River. The trees can easily be passed by without being noticed (I have done it many tines) as they are similar to other small trees that make up the understory of the forest.

The seed capsules are distinctive, one to two inches long, lightweight, and feeling like dried paper. They have been described as “bladder shaped,” the source of the name given to the tree. Each segment of the capsules contains one or more small seeds that, at this time of the year, are dried and loose. The capsule is a rattle when shaken. The seeds are almost the same color as the capsule that holds them.

Bladdernut is native to eastern North America, often found along rivers and streams. (The range map is from the USDA.)

As I examined the seed capsules on the trees, pulling the branches down for a better look, a few capsules fell. On the ground, unopened and lightweight, they are ready to be carried into the river the next time the water rises after a heavy rain (or after melting snow). At least some of these seeds will likely end up a long way from the parent teee.

One capsule fell into the river and immediately began to float downstream.

Plant seed dispersal occurs in a variety of ways in addition to simply falling (dispersal by gravity). Wind dispersal is common; cottonwood and milkweed are two examples. Dispersal by animals is probably even more common; nuts are carried away and buried and the seeds of fruit that is eaten by birds often pass through their intestines and dropped quite far from the fruit source.

Bladdernut is a good example of seed dispersal by water. It would be fascinating to know how far the bladdernut seeds I was observing this week will travel before spring.

Birds of Eliza Howell 2020: The Special Month of May

Having just completed my records of 2020 bird observations in Eliza Howell Park, this might be a good time to outline a report.

May is typically the month with the greatest number of species. And it was again in 2020. In fact, I recorded more species in May, 2020, than in any other month in the 16 years I have been keeping records — 96 species.

So, it is appropriate, I think, for this year’s report to feature May birds.

Among the many birds present on May was the Cape May Warbler.

Photo by Margaret Weber.

Note: All the bird pictures in this essay were taken by Margaret Weber — and all were taken in Eliza Howell Park in May, 2020.

Almost all of the warblers that are seen in Eliza Howell are migrants that pass through southeast Michigan quickly in the spring and again in the fall. This year I noted 21 different warbler species in the spring, many quite striking in their breeding pluumage.

Two more examples are Bay-breasted Warbler and

Nashville Warbler.

The total number of bird species observed in EHP last year was 118. The numbers varied a lot over the months, as they do every year, reflecting the migratory behavior of so many species: January – 24 species; February – 24; March – 39; April – 57; May – 96; June – 44; July – 42; August – 50; September – 68; October – 62; November – 34; December – 29.

While the Scarlet Tanager nests in some lacations in southern Michigan, so far my observations of it in the park have been mostly in May, when it arrives back north.

Some of the birds that spend the summer and do nest in Eliza Howell are best seen in May, when the trees are not yet covered with leaves and the males are displaying in an effort to attract females.

Baltimore Orioles are common.

Rose-breasted Grosbeaks also nest here.

Another species that breeds in the park and is easier to see in May is the Great Crested Flycatcher.

In 2020 I was able to locate over 40 active bird nests, representing 22 different species.

Only a few have nests accessible enough for me to sneak a quick look at the eggs – and a quick picture – when the adult is off the nest.

Starting from top left and going clockwise: Gray Catbird, Blue Jay, American Robin, Northern Cardinal.

As I write this, I realize how difficult it is to reflect in a short posting the excitement and the learning of 12 months of bird watching and bird study. This may be one of the situations in which pictures convey so much more than words. Thanks to Margaret’s photos, some of the reality and beauty of Eliza Howell birds 2020 may show through.

Some 2020 Discoveries

As the calendar year nears the end, I am remembering some new discoveries made during over 230 nature walks in Eliza Howell Park this year.

A “discovery” is something that I have just become aware of, regardless of how long it has been here or how common it is. Among the countless natural phenamena present, there are some every year that I notice and/or focus on for the first time.

Hickory Hairstreak is included in my annual butterfly list for the first time in 2020. It is very small and I was excited to get this picture on July 3.

Some of the 2020 discoveries have already been featured in this blog: for example, Wild Ginger on May 13…

… and Partridge Pea on August 8.

One of this year’s discoveries, the mushroom Wood Ear, was pictured without special attention in an October 22 report on mushrooms on logs. Perhaps It does resemble an ear?

I have often observed Fall Webworm caterpillars in the park and have sometimes seen Tent Caterpillars, but 2020 was the first time I became aware of another caterpillar that lives in silken webs on trees: Euonymus Caterpillar.

I have often watched the large Milkweed Bugs, which sometimes congregate in large numbers on Common Milkweed plants, especially when they are going to seed. This year I became aware that the Small Milkweed Bug, which also feeds on milkweed seeds, is found here as well.

The two milkweed bugs are distinct species, though they look similar. Large is on the left, Small on the right.

Among other 2020 discoveries is one that I have noted in the park before, but only in isolated plants that have been hard to relocate. This is Scouring Rush (Horsetail). The new find this year is a patch of Scouring Rush, in a location that can easily be included in walks, providing me with the opportunity for more detailed study.

During this pandemic year I have been very fortunate to be able to continue my Eliza Howell Park walks uninterrupted. In fact, I visited the park more frequently than in other years. These are only some of many discoveries this year

In January 2021 begin my 17th year of nature study in Eliza Howell Park.

Grape Vines in the Treetops: Impressive and Baffling

A favorite walking route in late Fall and in the Winter is in the woods, heading southeast from the footbridge along the river. (The path is roughly indicated by the orange dots on this map.)

From a number of the trees along the path, especially beyond the convergence of the two branches of the Rouge River, hang long woody vines. The vines are unattached to tree trunks, hanging from branches in the canopies. Here are two examples, one photographed on a sunny day and one on a cloudy one.

The vines are often rooted several feet from the trunks of the trees whose canopies they now occupy, 30, 40, or 50 feet from the ground. The long vines are bare of leaves and fruit and have few side branches. To find the leaves and fruit (in season), one would need to go to the canopies. The woody vines that carry nutrients up are often 2 – 3 inches in diameter, with shedding bark.

There are different wild grape species native to Michigan. I think that these might be Riverbank Grapes, though I am not able to make a definite identification.

This picture of fruit was taken in another location in the park earlier this year. I do not see grapes in this section of the park, though the vines tell me that there are probably grapes in the treetops.

I am fascinated by the size and the age of these splendid vines. I wonder how many decades they have been growing here before I started walking in these woods.

I am also intrigued by the question of how they got to the canopies. Vines do not have trunks that support themselves upright. They are more like ropes than trees; they need to be attached to something in order to climb.

As I have noted in other postings, different vines hsve different methods of climbing. Poison Ivy, for example, attaches itself to tree trunks by hairy rootlets. So its ability to climb tall trees is understandable.

Grape vines climb by using tendrils, small leafless stems that can grab and hang onto limbs or other stems for support, as can be seen in this picture.

I haven’t been there to check, of course, but I have no doubt that these vines are attached by many tendrils in the tree canopies and that the entangled smaller vines up there keep the heavy main vine from falling.

The baffling question is how did the vine get to the tree top, what supported it as it grew. Most of these trees have no lower branches for the grape vines to climb.

I don’t have a clear snswer. Is it possible that these trees were much, much smaller, with low branches or thin trunks, when tbe vines first reached out their tendrils? Is it possible that these vines are roughly in the same age category as the trees they now dangle from?

There are many days when I learn something new about the flora and the fauna in Eliza Howell Park. There are many other days when I recognize that there is so much more yet to learn.

Starting Year 4: Endlessly Fascinating

I began this blog three years ago, in mid-December, 2017, and have now posted over 210 times. One of my reasons for starting this was to provide others with some information and observations on the natural wealth and beauty of Detroit’s Eliza Howell Park.

(This map of the Rouge River watershed, provided by Friends of the Rouge and found on a sign in Eliza Howell, shows the different branches of the Rouge River and the relationship of the Rouge to the Detroit River.)

Another reason for this project is that the blog’ provides incentive for me to learn more about what I am observing. Preparing to tell others about sonething is a great way to deepen my own understanding.

As I begin Year 4, the number of “research” questions is growing. Among others, I would like to get a I better understanding of the following.

Walking Sticks in Eliza Howell

I rarely see this insect, which is not surprising, since it is a highly camouflaged and a noctural feeder. This picture, taken this fall, is of one on the forest floor.

It will be very challenging to find out more about how common Walking Sticks are in the park and where I am most likely to find them.

The Life Cycle of Several Plants

It should be less difficult to get more detailed infornation on several plants that I have not previously focused on (when they bloom, when they drop their seeds, how common they are, etc.).

One is Teasel, which I think is only in small numbers here.

A more common wildflower that I want to pay more attention to is Horse Nettle, which usually catches my attention in the fall. I want to study it throughout the growing year.

A tree to know better as it grows in this particular locale — its numbers, the time of its flowering and seed dropping — is Northern Catalpa, known for its large heart-shaped leaves and long bean-like seed pods.

Use of Woodpecker Cavities by Other Birds

I recently watched a Hairy Woodpecker drilling a hole in a tree (in December). At this time of the year, the hole is likely to be used as a winter roosting location. a shelter from the cold. It reminded me that woodpeckers excavate, each year, more than the one or two cavities used for their own nests.

There are 4 species of woodpeckers that breed — and drill holes large enough for nests– in Eliza Howell. And there are at least 9 other bird species that nest in cavities in the park, in cavities that they do not make on their own. They use either natural cavities or ones that were made by woodpeckers.

I am hoping to locate several woodpecker-made cavities, at different heights and in different sizes, this winter, when they are easier to find, and then visit them regularly in the spring breeding season, to begin to learn more about which old woodpecker holes are likely to be used by which different species.

While I have a growing agenda for Year 4, I am aware that many blog topics are presented to me by something that I come across unexpectedly, not something that I was planning. This is one of the ways in which Eliza Howell nature walking is endlessly fascinating.

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Looking Under Decaying Logs

Attentive nature walkers can observe a lot walking slowly on a path through the woods, but there is much that is hidden – not visible or audible – that needs to be searched out.

On a recent cold morning, Charon (my collaborator on this project) and I searched for some of what is hidden by turning over a few logs in the woods of Eliza Howell Park.

We selected logs that were well started in the decomposition process, several inches to nearly a foot in diameter. As can be seen here, we rolled them just enough to be able to see what was underneath and what was on the underside.

The animals we found are more likely to be considered “creepy crawlies” than attractive by many, but worth getting to know better, especially in terms of their role in this micro habitat.

The most common were Woodlice.

Woodlice (also called a variety of other names, including “pill bugs,” “sow bugs,” “roly polies”) are crustaceans, not insects. Different from many other crustaceans, they can live their entire lives away from water, but do benefit from the kind of damp environment found under logs.

They feed on decaying vegetation and have a significant role to play in the decomposition of trees, turning the wood back into soil nutrients.

Millipedes also feed on dead / rotting vegetation, including wood, and are at home in the under-log habitat. In our sampling, they were not nearly so common as Woodlice (nothing was), but we found a few.

Millipedes are known for their great number of legs. Though they don’t have a thousand (the meaning of the name), they do have 2 pairs for each segment of the body.

Centipedes are also found under logs at times, but they are likely there for a differnt reason. They do not normally feed on vegetation and might possibly be hunting woodlice. Or perhaps they are sheltering there during the day before their noctural activities.

Centipedes are also named for their many legs. One way of distinguishing them from millipedes is that centipedes have (only) one pair of legs for each segment of the body.

We also found a number of Slugs, noctural feeders on vegetation that are sheltering here during the daytime. We let them get back to rest.

We were very conscious of the fact that we were disturbing these critters and their habitat, so kept our watching time short and rolled the logs back to their original positions after our brief moments of looking and picture taking.

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Nature is endlessly fascinating and there is always something more to learn. There are hundreds of logs on the ground in Eliza Howell Park and I wonder, I really wonder, what might be under the next one.

Common Redpoll: Bird Species #152

After walking a little closer today to get a better look at the small birds in the birch trees, a “Wow” escaped my lips. I was watching a flock of Common Redpolls, a species that I had not previously obseved in Eliza Howell Park in my 16 years of watching birds here.

I immediately called bird photographer Margaret. I know of her interest in photographing Redpolls and I was hoping she could provide a photo record of this special Eliza Howell occasion. Fortunately, she was able to come quickly.

Photo by Margaret Weber.

The Redpolls were energetically feeding on the copious birch seed — and in no hurry to leave.

Photo by Margaret Weber.

With their small bills, Redpolls are specialists at harvestong seeds from trees, flowers, and grasses. Birch tree seeds are a favorite winter food. I am always impressed by the ability of birds to locate scattered patches of desired plants after flying hundreds of miles in migration.

The Common Redpoll is a bird that breeds in the far North. While range maps indicate that this is part of their wintering grounds, they are not at all common here, usually rarely seen in southern Michigan. This is shaping up as an exceptional year, when they are much more common. Since “irruption” years, when more of the northern birds than normal head south, are thought to be caused by a diminished food crop back home, it is good to see these Redpolls finding an abundance of food here in Detroit.

(The map is from the Cornell Lab of Ornithology.)

Redpolls, both females and males, have black chins and red foreheads. (“Poll” is an old English word for head.) Males have a pinkish wash on the breast.

Photo by Margaret Weber.

Redpolls are almost always found in flocks, at least in winter. Today’s flock was made up of about 20 individuals, interacting with one another whenever they took a break from eating.

Photo by Margaret Weber.

It is always exciting to find a different bird species in Eliza Howell Park and doubly exciting when the new species is not common in southeast Michigan.

I lnow this flock will move on soon, but, since many seeds remain on the birches, perhaps they will be around for a few days.

How Vines Climb: Four Methods

There are a variety of tree-climbing vines in Eliza Howell Park and lately I have been examining the ways in which different species climb trees and shrubs. I am aware of four climbing methods used by different vines in the park.

1. Tendrils.

Some vines have tendrils, thin leafless growths, often in spiral form, that stretch out and wind around a support. Greenbrier, the green stem in this picture, is one example.

Wild Grape, one of the most common vines in the park, also climbs by tendrils. Grape tendrils tend to be forked. Here, it looks llike two different Grape stems are reaching out to each other for support.

Thick Grape vines can often be seen hanging from large trees, unattached to the tree trunks (different from Poison Ivy, which also grows high but adheres to the trunk — see below). The large and heavy Grape vines are attched high in the tree. In this picture, the Grape vine is on the right.

2. Twining.

A second method used by vines is twining, winding around a stem or limb or trunk like a rope. In Eliza Howell a good example of twining is Oriental Bittersweet.

Often several shoots of Oriental Bittersweet wind around the same tree or stem – and/or around one another.

3. Aerial roots.

Aerial roots are roots that grow from the plant above the earth surface. They are able to attach the vine to the surface of the tree trunk (or whatever surface it it climbing). In Poison Ivy, which clinbs with aerial roots, the effect is a hairy look.

Sometimes different vines grow on the same tree, providing a good opportunity to compare different climbing mechanisms. Here a Wild Grape is stretching its tendrils toward two large Poison Ivy vines. Note the hairy look of the Poison Ivy.

4. Adhesive disks.

Some vines climb trees by adhering to the trunks by using small adhesive disks. An example in the park is Virginia Creeper. Virginia Creeper grows right up the side of a tree, tight against it, as does Poison Ivy. but there are no “hairs,” no roots, visible. At first look, the vine’s support mechanism is not obvious.

Upon closer inspection, one can see the small tendrils that end in grasping disks. I have circled one side growth with adhesive disks that helps provide the support for this vine.

I usually identify the vines of Eliza Howell by their leaves and by their fruit (and sometimes by their bark). It is very helpful to have another method of identification in the leafless season, a season that is a great time to learn more about how the vines grow among the trees.

Frost on Flowers Gone to Seed

It was frosty when I started my walk today in Eliza Howell Park. Many of the wildflowers I have been observing during the summer and fall are still standing strong, topped with seeds rather than blooms, and today touched with frost.

Here are five pictures from this morning, each matched with a picture of the species in bloom earlier in the year.

Stagehorn Sumac: November 24 and July 19.

Ironweed: November 24 and July 18.

Queen Anne’s Lace: November 24 and August 19.

Rose: November 24 and July 7.

Culver’s Root: November 24 and July 22.

One cannot expect wildflowers to be as attractive in late fall as they are in their summer bloom but, with the frost visit today, these flowers-in-seed certainly have a beauty worth noting.