September 7 Nature Walk

The second of the annual Detroit Audubon field trips to Eliza Howell Park takes place on Saturday, September 7, 2019, starting at 8:00 a.m. The public is invited; there is no cost.

Timed to coincide with the early days of the Fall bird migration, this walk give special attention to birds, especially warblers headed from the North Woods to Central and South America. Depending upon the weather conditions, we are likely to see several warbler species, perhaps including these three. (Thank you to Margaret Weber for these three photos.)

Black and White Warbler

Nashville Warbler

American Redstart

The fall warbler migration begins at the end of August and continues into October, with individuals of some 20 different species making short stops at Eliza Howell. The find from one day to the next is almost always different.

If September 7 is a good day, the birds will keep us quite busy, but we will also stop for non-bird observations. This is about the best time of the year to note the variety and nature of spider webs among the wildflowers and the shrubs. They vary in sizes and shape; this is a small one on a thistle.

September is also the month when I most frequently see a Praying Mantis (or 2 or 3). They have reached maturity and may be seeking mates and/or laying eggs. (I wrote about “Praying Mantis Egg Laying” on September 13, 2018.)

Butterflies continue to be present. One of my favorite late-season butterflies is the Common Buckeye, which makes it appearance in Eliza Howell after the July butterfly peak.

I usually find several Bald-faced Hornet nests in the park each year, beginning about this time. We may want to stop for a look (through lenses) to watch the hornets enter and exit the hole near the bottom of these amazing constructions. (For more, see “Bald-faced Hornet Nests,” December 12, 2017.)

Blue Jays migrate in September and many spend days at Eliza Howell harvesting acorns, from the middle of September into October. (For more information, see “Blue Jays Harvesting Acorns,” August 27, 2018).

September 7 might be a little early to see them at work, but we will check (this photo also courtesy of Margaret Weber).

The seasons repeat themselves, so it is possible to predict what might be seen at any given time of the year. But it is also true that every day is different and almost every walk includes an element of the unexpected. Such is the nature of nature walks. September 7 should be fun.

Maple Sap Rising

There is a little different look in Eliza Howell Park at this time of the year. Some 8 trees have sap collection buckets (or plastic bags) attached.

The trees, of course, are maple trees and the sap is collected (in most cases) to boil down to syrup. Syrup can be made from the sap of different species of maple trees, but the preferred is clearly the Sugar Maple, because of the higher sugar content of Sugar Maple sap.

Even with Sugar Maples trees, however, making maple syrup is not easy. It takes about 40 gallons of sap to make one gallon of syrup (or 10 gallons of sap to make 1 quart of syrup). Depending upon the conditions, a little or quite a lot of sap can be collected in one day.

In southeastern Michigan, it is usually early March when the sap starts to flow, the best conditions being nighttime temperatures below freezing and daytime temperatures above – just the kind of weather that we have been having lately. The sap freezes when exposed to freezing temperatures.

Rising sap is a clear indication that maple winter dormancy is over. The process of new growth is beginning. The time to stop “sugaring” is when the temperatures are above freezing overnight or when the buds start to break open. As of now, the buds are not yet opening; they still appear as they did throughout the winter.

I have commented in other posts on Eliza Howell Park edibles like raspberries and hickory nuts. Maple sap is the edible that can be found in March.

Birds of Eliza Howell: Monthly Variations

Over the years, I have seen 145 different species of birds in Eliza Howell Park.

In January, 2018, I saw 22 species.

Both numbers are important. The total number of birds recorded is an important indication of the diversity of birds that visit the park. The monthly number is important for human visitors interested in observing birds at a particular time of the year.

The birds of Eliza Howell can be placed in the following categories:

(1) All seasons (or year-round residents). These species can be found in the park all seasons of the year (though not usually in the same numbers at all times). They do not migrate north-south or, if they do migrate, Eliza Howell is within both their summer and their winter range.

Approximately 21% of total species are all-seasons birds.

An example of an all-seasons EH bird is the Red-tailed Hawk.

          Photo by Margaret Weber

(2) Summer only. These species can usually be found in the park in the breeding season and are typically seen between spring and fall. They are birds that migrate south for the winter, but their summer range includes Eliza Howell.

Approximately 33% of total species are summer only.

The Rose-breasted Grosbeak is one such species.

          Photo by Margaret Weber

(3) Migrants. These are the migrating species that breed further north and winter further south. They are in this area only as they pass through and can normally be found in a short timeframe – a couple weeks to a month or so. The peak spring migration through Detroit occurs in May and the peak fall migration month is in September. Some species pass through in April and October.

Approximately 41% of the total species are migrants.

The Magnolia Warbler is one of many migrating warblers that stop briefly in Eliza Howell each year.

 

 

 

 

 

          Photo by Margaret Weber

(4) Winter visitors. These few species spend the breeding season further north and migrate south for the winter. The “south” for these species includes the Detroit area. They arrive in fall and leave in spring.

Approximately 5% of the bird species are winter visitors.

The American Tress Sparrow is one of the 5%.

          Photo by Margaret Weber

Group 3 is the only one referred to a “migrants” above, but species in groups 2 and 4 also migrate twice annually; however, they stay much longer. While the migrants that pass through in the spring and fall are the most numerous, they can easily be missed because they are in the area only for a short rest and refueling stop.

The most species are usually seen in September and May because all-seasons birds, most summer residents, and many migrants can be found in these months.

Average number of species seen per month over 13 years (2005 – 2017):

• January       = 19
• February    = 16
• March         = 31
• April            = 45
• May             = 64
• June             = 45
• July              = 42
• August        = 51
• September = 69
• October      = 55
• November  = 32
• December  = 24

Based on experience, I have a very good idea what birds to expect each time I visit Eliza Howell. But nature is always somewhat unpredictable, so I also expect the unexpected.

THE OLD ELM TREE: A Nesting Tree

For many years, the American elm tree along the road loop in Eliza Howell Park in Detroit was my usual starting point for bird-watching walks. It is located near the beginning of the nature trail that leads to and over the Rouge River and so is a convenient place to park and to meet others. I no longer park under the tree, however. It dropped its last leaves in 2014 and is now beginning to drop a few of its branches.

The elm tree was both a convenient place to park and the first place I would check for birds. In this location, it has been a stopping point as birds as they move back and forth from the wooded area by the river to the more open area inside the road loop. It has also been a destination, an attractive foraging and nesting spot.

Over of the years, Baltimore Orioles regularly nested in the elm. This made for a great beginning of the Detroit Audubon field trip at Eliza Howell in June. I would simply ask the participants to look up as they got out of their cars to find and watch the orioles – and the field trip was off to a good start.

Photo by Margaret Weber

My favorite memory of nesting birds in the old elm tree is from June 9, 2013. As usual, Baltimore Orioles had built a nest there. And, in an exciting development that year, a pair of Orchard Orioles was also nesting in the same tree, as were robins. Three species nesting in one tree at the same time is very unusual, but on that day I noted a Blue-gray Gnatcatcher high in the tree, moving out on a horizontal branch. It led my eyes to its tiny nest. The old elm tree was host to four nesting species at the same time!

The elm tree had survived decades after Dutch elm disease killed most of the American elms in Detroit, but in 2014 the tree was clearly dying. It leafed out, but the leaves began to fall shortly thereafter. Baltimore Orioles were again nesting there and the young had just fledged when the leaves were no longer present to shelter the hanging nest.

Though the orioles no longer nest there, the old elm tree continues to support life, from the perching birds to the shelf fungus that grew at its base in Fall, 2017.

As a large snag, still retaining most of its branches in 2107, the elm is now a popular perching tree, as well as a foraging spot for those birds that seek insects in crevices. During visits to the park in 2017, I observed 23 bird species in the tree, without any concerted effort to count them all. They included two hawks (Red-tailed and Cooper’s) and four woodpeckers (Red-bellied, Downy, Red-headed, and Norther Flicker). Male Red-winged Blackbirds watch over their territory from its branches during the breeding season. Whenever I am out with my binoculars, I check the tree from time to time, even from a distance, just to see what might have stopped by.

This year or next, assuming it continues to stand, woodpeckers will likely be drilling holes and the old elm tree will again be a nesting tree. I will be checking regularly.