Category Archives: Southern Illinois Ecology

How the Turkey Vulture Found the Raccoon

Coming up the driveway in the car a little before noon today (8 October 2011), I was surprised to see a very large bird flap out of the

Turkey Vulture in flight. Photo Kalamazoo MI by Tim Tesar. Used by permission.

trees, followed by a Blue Jay. I had just seen crows along the road, so it was evident that this bird was much larger than a crow and larger than any buteo. It was, in fact, a Turkey Vulture, the first I had seen actually within the woods in the 15-plus years since I arrived.

What, I wondered, was it doing here? Then the answer struck me.

The folk wisdom in southern Illinois, where I grew up, was that vultures, or buzzards, find carrion by the smell of rotting meat. But birds in general have a poor sense of smell, and the olfactory lobe of the brain, which is associated with smell, is large in mammals like us, but small in most birds. Then too, John James Audubon, an excellent naturalist as well as painter of birds, did a few trials in the early part of the 19th century, trying to assess how vultures found food. His observations of vultures failing to find hidden carrion led him to the conclusion that dead carcasses were located by sight. “The power of smelling in these birds had been greatly exaggerated,” he wrote.

Other observations didn’t always agree with Audubon’s conclusion. By 1964, an article by Kenneth E. Stager of the Los Angeles County Natural History Museum summarized his and other studies that pretty well established the main features of how vultures find their meals. In broad outline, Aububon wasn’t wrong, but he had worked mainly with Black Vultures (Coragyps atratus), which do locate food visually, either by spotting it themselves or watching Turkey Vultures (Cathartes aura). Turkey Vultures, it turns out, have a well-developed sense of smell which they can use to find even small animals that are not visible from the sky. They also have large olfactory lobes. Of course, they are not above gliding down to a dead animal they see lying out in plain sight.

There are some other details that may or may not have been decided in the last few years, such as whether either or both vultures can use the sight (or the sound) of carrion-feeding insects going to a dead animal as a clue to the corpse’s presence.

Earlier this morning before 9 AM, when I was walking down the driveway to get the newspapers, I had caught a strong smell of carrion. I left the driveway and only a few steps into the woods found a dead raccoon. I didn’t examine it carefully and have no idea how it met its death. When I had walked past the same spot several times yesterday, I had not smelled a dead raccoon. It was not there, or it was too fresh.

Finding a Turkey Vulture near a dead raccoon that it could not have seen from the sky doesn’t qualify as an important piece of evidence on the topic, Nevertheless, I was pleased that an observation of my own, right here in Oshtemo Township, is so nicely congruent with modern thinking on how the Turkey Vulture finds its food.

When I pulled up at the front door, I looked back and the Turkey Vulture had already returned to the trees above the dead raccoon. I ducked into the house, not wanting to interrupt the bird’s meal any longer.

Dead raccoon. Photo 8 October 2011 Oshtemo Township by Richard Brewer

A few hours later, I checked the carcass. The skull, vertebral column, and limbs had been stripped clean, and the skin was clean and much of it was inside out.

Hazelnut, Fire, Oak Openings, Nostalgia

Hazelnut catkins in Oshtemo Township, Michigan. Photo 10 April 2011 by Richard Brewer

Early this April, I saw a tall skinny shrub without leaves but with catkins. It reminded me that early last fall I had come across a clump of similar skinny trunks that bore pointed, toothed leaves. The leaves were more or less like leaves of several groups of woody plants–birches, elms, hornbeams, and conceivably a few others. I had been puzzled by the plant and hadn’t identified it for sure but had narrowed it down to a handful of possibilities. One of the possibilities had been American hazelnut (Corylus americanus). The books I was using commented that catkins are produced in the fall but don’t open to produce pollen until the following spring. These catkins weren’t quite open yet, but seeing them there tilted me toward thinking that the plants must be hazelnuts.

The plant was in a handy place to observe, so I was able to keep track of it over the next couple of weeks as the catkins lengthened and then opened, shedding pollen.

Hazelnut catkins, Oshtemo Township, Michigan. Photo 11 April 2011 by Richard Brewer

The pistillate flowers of hazelnut are tiny buds, but recognizable by the thin red styles–ready for pollen–poking out the end. The styles are easily seen with a lens. The hazelnuts when they ripen in the fall look like the European filbert of commerce, but smaller. They’re also similar in taste.

The first time I saw hazelnuts I was probably six or seven years old. My parents took me along when they went hazelnut picking one day in the fall. The spot wasn’t far from where we lived east of Murphysboro, Illinois, probably a quarter of a mile down the county road toward Route 13. I enjoyed eating the nuts at the time but never became a big filbert fan.

I’ve seen hazelnut fruits in the wild in Michigan a few times, but never in these woods. Two possibilities occur to me. The first is that the woods are too shady, especially with the increasing abundance of red maple, for the shrubs to accumulate enough energy to produce fruits. The second is that the nuts are so attractive to the squirrels, woodpeckers, and jays that they have always been eaten (or stored) before I chance to wander by in the fall.

Hazelnut in oak woods--former oak openings--in Oshtemo Township. Photo 21 June 2011 by Richard Brewer

Now that I’m attuned to the look of hazel even without catkins or hazelnuts, I’ve seen several clumps in both drier and wetter parts of the oak woods. Most of the clumps are between knee high and waist high, only a few head high or taller.

Since I’ve been in Michigan, I’ve associated hazelnut with the edges of prairies, and I think that’s apt. But now I’ve begun to understand (1) its remarkably wide ecological amplitude and (2) how widespread it must have been in almost every permutation of prairie and savanna that existed in pre-settlement southwest Michigan.

One indication of hazelnut’s wide habitat occurrence can be drawn from John T. Curtis’s The Vegetation of Wisconsin. This excellent book has a species list in the back (after the Literature Cited and before the index), that gives the plant community where the species most frequently occurs and also given the number of plant communities in which Curtis found the species in his studies. The community in which the species was found most often–the modal community–is presumably the most characteristic community; the number of communities from which the species is recorded is a measure of ecological amplitude of the species.

The book recognizes 34 plant communities. American hazelnut was reported most frequently from dry forest, but it occurred in 20 other communities, or 62 per cent in all.

I didn’t go through the species list line by line, but I did check on some species that I think of as occurring in a wide variety of situations. There were a few species in the 15-18 community range and at least one species that occurred in the same number of communities as hazelnut–21. This was Cornus racemosa, gray dogwood. Vitis riparia, river-bank grape, had a 22. There were only two species clearly ahead of the hazelnut, dogwood, and grape. These were Va. creeper, Parthenocissus quinquefolia, 1n 25 communities and poison ivy, Rhus radicans, in 26 (76%). It may not be accidental that all five of these species are woody and have animal-dispersed seeds.

Hazelnut’s broad distribution more or less centered on dry forest fits well with the conception of oak openings that Kim Chapman and I expressed in an article (“Prairie and Savanna in Southern Lower Michigan: History, Classification, Ecology”) in the January 2008 Michigan Botanist. We see oak openings in the pre-settlement landscape as a diverse community, the composition of which varied in space–different in low and high spots, north slopes and southwest slopes, sandy sites and gravelly sites. But it also varied in time at any given point based on the latest disturbance (fire, tornado, insect infestation) and how recent it was, but also on the historic frequency of disturbance. A north-facing slope running down to a pond in a small kettle might have included a set of plants much like mesic forest. A gentle loamy slope after a few years of near-annual fires might have been covered with dry-mesic prairie.

This is oak openings in the sense of Michigan pioneer botanist Ruth Hoppin’s description (quoted on pages 7-8 of Chapman and Brewer). In this view, most of the prairie and savanna types are just different faces of one big community type. Mesic prairie and bur oak plain, I would say, are different and so, of course, is mesic forest.

Hazelnut seems to have the life history traits to be a near-perfect fit to the oak openings habitat as it was. Hazelnut can get around readily by the nuts being carried, and often buried, by mammals and birds. Over short distances, it spreads readily by rhizomes. It tolerates a wide range of light intensities though it tends to decline in deep shade. It tolerates fire, but only up to a point. Most of its rhizomes and roots are in the upper six inches of soil. Light fires kill the above-ground parts of the plant but stimulate vigorous sprouting from the rhizomes. Fires hot enough to consume the litter often kill the underground parts. Hence, hazelnut might be at least temporarily eliminated by fire from certain habitats where hot, litter-consuming fires occurred.

I suspect most of the hazelnut plants I’ve been finding in the Oshtemo oak woods are just hanging on, waiting for the fires the openings used to have, the fires that would stimulate sprouting and open the canopy to enough sunlight to yield a good crop of nuts. One more reason why few of the hazel bushes grow tall may be the high populations of deer these days. Hazel is a favored browse plant of deer, so high populations may keep it pretty well clipped.

More About Aldo Leopold’s Subversive Ideas

@Dick Klade in Comment 3 to preceding post

Button found 14 April 2011 and reused

Thanks for restoring the interesting lost section of your comment.

It’s not surprising that Leopold’s ideas didn’t always suit the bureaucracy. Ecology is the subversive science, as Paul Sears said.

The game managers seemed to accept Leopold early. As an undergraduate in 1953 or 1954, I had a course in game management taught by Willard D. Klimstra, an Iowa Ph.D. from the period when Paul Errington, another game management great, was there.

Klimstra’s supplementary reading list for the class had at least one piece by Leopold. It was my first encounter with Leopold’s writing though I don’t remember just which of his articles it was. I’m afraid I didn’t read it as carefully as, later on, I would expect students to treat my reading lists.

Lots of people came to environmental issues in the 1970s from the humanities side. Many of them think highly of Sand County Almanac, but I have a suspicion that not all of them take the quote given in the earlier post (19 April) as literally as Leopold meant. It is a profoundly anti-anthropocentric idea.

Leopold had other heterodox ideas, some of which still haven’t had the attention they deserve. For example, he thought that conservation was everybody’s, and especially every land owner’s, duty. Hence, paying land owners to conserve would be counterproductive. If the government pays land owners for doing some reforestation or leaving second-rate cropland in perennial grass instead of planting corn, the incentive for the land owners to do it on their own will be lessened or lost. Likewise, if the government will buy conservation easements, fewer land owners will be willing to donate them. It’s a sound conclusion. At least, most of the people where I grew up would have thought that if somebody will pay for it, you’re a fool to give it away.

Darwin and the Tree of Life Vs. Science Illiteracy

A section of the Darwin shelf. Photo by Richard Brewer

I got an email message from Barack Obama today–well, maybe not from Barack personally. The heading of the message was, “What does your T-shirt say?”

The next message in my mail box was from the Center for Inquiry, Michigan chapter, reminding me not to forget Charles Darwin’s birthday, Saturday February 12th.

The Obama T-shirt is very nice, a pretty blue, and says, “We Do Big Things,” which I think may be from the State-of-the-Union speech. All in all, though, a better T-shirt to wear this time of the year would be one of the T-shirts you can get with the “tree of life” diagram based on gene sequencing. This is the diagram where the end branches of the phylogenetic tree are arranged to form a big circle. The primate branch or maybe it’s the hominid branch, has an arrow pointing to it and a label, “You are here.”

Wearing such a shirt might be a good way to start some conversations. We know from polls that many Americans doubt the existence of evolution. As to the specific question, Did human beings develop from other species of animals?, the figures for the U.S. (in 2005) were 40% yes and 40% no. Twenty per cent hadn’t decided yet.

In the 33 other countries where the same question was asked, the yeses were over 60% for most of them. I’m reading from a graph, but it looks like Denmark had yeses just over 80%, France just under 80%, followed by Japan, the UK, Norway, Spain, Germany and several others above 70%.

At least the U.S. isn’t the lowest on the list. Turkey is below us, with yeses below 30%. In fact, since only 34 countries were included it’s not impossible that some country omitted–Iraq or Afghanistan perhaps–would have been below the U.S. and Turkey.

The figures don’t give me much reason to believe that America has progressed a whole lot since my boyhood in southern Illinois. After the gospel quartet was done, the preachers in the little country churches, in tones rising toward hysteria, would fulminate against the idea that man had descended from the monkey.

But belief or non-belief in evolution is not America’s main problem. With or without our endorsement, genetic variation will go on, natural selection will do what it’s going to do, and adaptation will continue apace. Our poor showing on the evolution issue is an indicator of a bigger problem–America’s low level of scientific knowledge and, much more serious, our general lack of understanding of scientific reasoning.

Of course, that’s not news. The newspapers have all had reports recently telling us how poor we are in science. The National Assessment of Educational Progress (NAEP) tests say that 40 per cent of U. S. high school seniors function below the basic level in science and only 1 per cent perform at the advanced level. We also are confronted with a dismaying variety of other data showing the same deficiency: For example, 49 per cent of U.S. adults don’t know how long it takes for the Earth to circle the Sun.

The fact of the matter is that, despite our country’s many fine scientists and excellent research in most fields of human knowledge, America as a nation has rarely shown a strong interest in science. Figuring out what causes this and how to fix it are things Obama needs to work on. There’s not much evidence he’s on the right track as yet.

For my part, as a beginning, I’ll order a “You Are Here” tree-of-life shirt and wear it on Darwin’s birthday. Maybe for the whole week.

Christmas Bird Counts, Murphysboro to Kalamazoo

Buttonbush swamp in winter, Oshtemo Township. Photo by Richard Brewer

Whatever else Christmas may mean to a birder, it definitely means the Audubon Christmas bird count.

The National Audubon Society sponsors a continent-wide set of local counts to be taken some time around Christmas, specifically on a single day between December 14 and January 5. Local groups of birders count birds in circular areas 15 miles across. What most groups do is divide the circle up into sectors and maybe sub-sectors and assign a party to each. The party may be one person ambling ( or driving) along and censusing birds by himself or herself. Or it may be a small group, but if the group gets above about four, it would be more efficient to break it and the sector up.

A circle of 15-mile diameter doesn’t sound very big, but it is. It amounts to a little more than 175 square miles. A square mile is 640 acres. Except for a few sophisticated urbanites, most of us out here in the part of the US where the grid rules–where the land is laid out in townships, ranges, and sections–most of us have at least a vague idea of what 40 acres looks like. A square mile (640 acres) is one section, which can be divided into quarter sections–each 160 acres–and each quarter-section can be divided into quarters. These are each 40 acres, as in the back forty.

So if a local bird group divides its count circle into 20 slices or chunks, the average size will be between 8 and 9 square miles, or between 5000 and 6000 acres. The average bird club is making a good showing if it has 40 birders out and counting, or in other words, about 2 birders per sector.

The point of all these numbers, if there is one, is that most Christmas bird counts are a bit understaffed.

But that’s not a serious problem. First, the main point of the count is fun, of a sort. It’s fun to get out and brave the elements in the coldest, darkest part of the year. The Christmas count is the birder’s winter solstice festival. And it’s fun to see what birds are around, what birds are braving those conditions along with us. A few bird species have normal body temperatures around the same as humans, 98.6 degrees Fahrenheit, but most of the small birds we count at Christmas have temperatures up around 105-110 degrees. It takes a lot of feeding during the daylight hours, a lot of sunflowers seeds and suet or hibernating insects and fat from a deer carcass, for a chickadee to stay alive for 24 hours in winter.

Christmas Counts do provide data for scientific purposes. They provide a very accurate map of the winter range of the most of the bird species. They provide passable information on abundance of many of the species, expressed as an index value, usually number of birds per party-hour.

But except for a few species, a Christmas count almost never gives us the actual number of birds, Song Sparrows or Black-capped Chickadees or Cedar Waxwings, in our 15-mile circle. On a well-regulated count, it might be possible to arrange things to tally every individual of an uncommon, conspicuous species, especially one of a well-defined habitat. For example if there are only three areas of open water in a count circle and we cover all three, we can probably get a pretty good count for the ducks. A good count for the time when somebody visits the three areas of open water, that is. There’s no guarantee that some ducks from our circle didn’t fly a few miles to a different circle just before we counted.

The first Christmas Count I took was in 1949, when I was a sophomore in high school. Bill Hardy, Kenny Stewart and I took a Murphysboro, Illinois, count on December 27th. Hardy was the instigator. He was the oldest, the best birder, and also more of an organizer than Kenny or me.

Things were more casual then. We just decided to take a count, figured out our circle, took it, typed up the results, and sent them to Audubon Field Notes, which published ours along with the whole batch of counts from around the country. Audubon Field Notes is called American Birds now, and the figures that get sent in on forms go into a database and the published Christmas Count consists mostly of summaries for the different geographic regions. The total number of counts today is well over 2000, mostly in the U.S., but quite a few in Canada, and some in Latin America and the Caribbean, and a few elsewhere.

We took the Murphysboro count a few more times. I can’t remember when we stopped, but eventually Hardy went off to graduate school at Michigan State and a little later I went off to the University of Illinois.

I ought to mention that the Murphysboro count was not the first southern Illinois Christmas bird count. A few years before, William Marberry, a botanist and all-round naturalist on the faculty at Southern Illinois University, had taken a count south of Carbondale and, I think, including Giant City State Park, or part of it. He may have repeated the count another year, but I’d have to get to the library to look at the back issues of Audubon Field Notes to be sure.

I’ve occasionally gone on a couple of counts in a year, but I’ve also missed an occasional year. Ordinarily though, even if I’ll be away from home, I try to get in touch with the organizer of a count near where I’ll be at Christmas time and ask if I can join in. Most groups are happy to have visitors help out. Most of the other places where I’ve helped seem to be in places that are warmer in the winter than Michigan.

Most counts that have been running for a long time have a tradition as to when the count is held. The Kalamazoo count is supposed to be the Saturday after Christmas. When Christmas is on a Saturday, as is the case this year, this means that the count would be held on New Year’s Day. That would seem to be no problem, except that the tradition for the Southern Kalamazoo County Count (SKCC) is that it be held on New Year’s Day.

The SKCC is relatively young, started for the 1975-76 count. It’s odd in that it is a rectangle rather than a circle, hence it doesn’t qualify for the National Audubon database. One advantage of a rectangle is that, here in our gridded landscape, you nearly always know exactly whether a bird is in or out of the count area, depending on which side of the road it’s on. Sometimes you’re not so sure about a bird near the edge of a circular count area. On the other hand, circular count areas are the most compact shape and accordingly have the least amount of edge to worry about.

I understand that in the clash of tradition this year, SKCC won. The Kalamazoo Count is on Sunday, 26 December 2010, rather than on the Saturday after Christmas, 1 January 2011. What would Frank Hinds say, or Theodosia Hadley? Or Charlie Cook, or Helen Burrell, or Bob van Blaricom (Buckeye Bob), or Harold Wiles?