Winter Campfire 4

December 7, 2009 at 6:48 am (Winter Campfire series, methods)
Tags: , , ,

by Carl Strang

Winter is a time when we slow down and become introspective. Sitting and staring into the fire, we ponder the big questions. If you have been following this blog, you know that the focus here is science, science that can be done simply in outdoor settings. But we are more than scientists, and science has well defined limitations that need to be understood by everyone who does science or studies its findings. This winter I am using one post per week to develop my own viewpoint and biases, in particular sharing my take on the relationship between science and spirituality. In part this defines for me what these two realms of human experience are all about, and also develops the separate methods used for inquiry in each realm. I plan to place this paragraph in front of each entry in this series, so that those who are interested only in natural history or in scientific practice can skip these posts.

Advanced Awareness: Physical Techniques

I want to step away from physiology for a moment and describe what I call advanced awareness, sensory techniques which can compensate for some of our sensory limitations. I first was introduced to these by my martial arts teacher, and by survival and tracking teacher Tom Brown, Jr. These methods give us a more comprehensive grasp of our surroundings, and more.

A prerequisite for awareness is relaxation. Relaxation allows us to slow down and tune out everything but the process of awareness. Awareness requires us to let go of worries, of concerns about time, of thoughts of what we are going to do next. An example of a relaxation method I have used is to create a poem or phrase that will act as a reminder or trigger for awareness. For instance: “Let your shell of troubles collapse to the forest floor, and step away from it. Now take the reality of each leaf and wrap it around you.” 

The first of the sensory techniques is wide‑angle vision. Communications technologies such as print and television have provided many advantages necessary for the development of our civilization. But there have been costs, too, and one of these is the way we use our vision. Television screens are small, and a line of print occupies an even tinier portion of our visual field. These media train us to focus our vision narrowly, to look at only one small thing at a time. But when we do so, we miss most of what is going on around us. We use our vision like a flashlight beam illuminating the eyes of an animal at night. Everything else is darkness. The preferred alternative is to spend most of our time in wide‑angle vision, spreading our attentiveness over the entire visual field. A person using wide‑angle vision loses some detail, but there is nothing wrong with focusing narrowly for a short time, or for as long as is necessary to examine some particular thing. By seeing widely we see more, notice more.

Conventional, narrow vision is allied to the linearity of language. Notice how impossible it is to describe ecosystems in strings of words. Wide‑angle vision, considering many parts of an ecosystem at once in parallel, opens the door to a better understanding of how ecosystems really function. Wide‑angle vision is especially sensitive to movement, and is necessary for optimal seeing in dim light. This is because when we are focusing narrowly, we are using the fovea, small regions in our retinas composed almost entirely of cones, which do not function in dim light. With wide-angle vision we use the entire retina, which also has rods, the receptors for light intensity. 

The second physical awareness technique also is visual: seeing in three dimensions. We all know that our physical universe has three dimensions of space, but thanks to our current dependence on one‑dimensional print and two‑dimensional TV and movies, many of us don’t actually perceive in three dimensions. A demonstration of this is that urban-suburban people visiting wild places often look at the surface of a mass of vegetation, say a forest or clump of brush, without seeing into or through it, without noticing the three dimensional arrangement of the plants. But back behind that surface is where most of the action is.

We’ll come back to vision, but now I want to focus on sounds. Every sound, even the smallest and faintest, is significant in a wild setting. Deer teach this. On several occasions, watching deer who did not know I was there, I was struck by how sensitive they were to the slightest sounds. The small snap of a twig, barely noticeable to me, would stop a deer from feeding for several minutes while it peered in the direction from which the sound had come, sniffing and moving its ears to obtain more information. Out of this lesson I have profited many times by seeking the sources of little sounds.

The third dimension includes us. We need to be aware of what is all around us, not just in front of us, and to include ourselves in the environment. Scanning is a technique for accomplishing this. We need to turn our eyes to all directions, in wide angle vision, and with 3-D vision keep track of all depths as well.

1 Comment

Another One Bit the Dust

November 18, 2009 at 7:44 am (birds, methods, restoration)
Tags: , , , ,

by Carl Strang

Restoration work that clears ground, whether through controlled burns or brush removal, can reveal stories from the past in the form of skeletal remains. Last week Mayslake Forest Preserve restoration co-steward Jacqui Gleason showed me part of a skeleton exposed through recent brush clearing performed by Forest Preserve District staff in the prairie area near the stream.

Fuzzy brown feathers around the feet, as well as the size and proportion of the bones, identify the remains as belonging to a great horned owl.

I don’t have the skill to age the remains, either in the sense of when the bird died or how old it was. Most animals die young, so if I had to guess I would say this probably was a youngster that died in its first year. If so, it wasn’t from 2009. As I reported earlier, the most recent great horned owl nest on the preserve met with tragedy.

Leave a Comment

A Salute to the NYC Cricket Crawl

October 30, 2009 at 6:07 am (methods, singing insects)
Tags: , , , , , , , ,

by Carl Strang

When I began to study singing insects a few years ago, one of my hopes was that I would be able to develop protocols for a monitoring program. I was a participant in the dragonfly monitoring group, and I was aware of hearing-based monitoring programs for frogs and breeding birds. In subsequent years I have found that there is no clear way to comprehensive, all-species monitoring of singing insects. Because of the odd pitch ranges and harmonics, different people hear insect songs differently. For example, older people like me begin to lose their capacity to hear higher pitches, and need to rely on devices like the expensive Songfinder to hear some species. There are many insect songs to learn, in comparison to relatively few frogs and toads. Though the number of breeding bird species is greater, birds are popular. Few people will make the kind of effort needed to learn so many insect songs.

Fall field cricket female 1b

I was interested, therefore, to learn of a group in the New York City area which has come up with a different approach to singing insect monitoring. They call it the Cricket Crawl. They selected a date, September 11, on which they asked people to go out at night and listen to insect songs for one minute at one or more places, then report locations and species heard to the web site. Key to their plan was limiting the focus to seven species of insects with loud, distinctive songs that nearly everyone can hear. They acknowledged that others “form the background of soft churrs and trills that emanate from a series of different small ground and tree crickets.”

While results are not complete as of this writing, Sam Droege and other organizers immediately picked several patterns from the data. For instance, the fall field cricket (photo above of a female) proved to be the species most tolerant of the broad range of urban environmental conditions. The most common katydid was the greater anglewing (photo below).

Greater anglewing 4b

The species of greatest interest was the common true katydid, which historical data indicated at one time had become scarce or even extirpated locally. The September survey found several local populations, some of which may have become established from eggs transported on nursery stock from other parts of the country.

As I continue to ponder possibilities for insect song monitoring, the success of the Cricket Crawl will remain in mind as worth considering.

2 Comments

Gadget 2

October 16, 2009 at 6:47 am (methods, singing insects)
Tags: , , , , ,

by Carl Strang

In an earlier post I wrote about how the soprano recorder, a musical instrument, has been helpful in my singing insects research. This summer I acquired another gadget and began exploring its potential.

SongFinder b

This is the SongFinder. Microphones on each earpiece take in sounds, the electronic box alters them by reducing their pitch, and sends the results back to the earpieces. You can slow sound frequencies by one-half, one-third or one-fourth. You also can set threshold sound frequencies below which the device does no alteration. At several hundred dollars, this is not an impulse buy. I waited a couple years until I had made a good start on the insect songs I could hear unaided. But now I am at the point where I want to begin surveying additional species, mainly small meadow katydids in the genus Conocephalus, whose songs are too high-pitched for me to hear without help.

Short-winged meadow katydid 2b

This is a short-winged meadow katydid. I never had heard its song until I used the SongFinder. The song has the typical meadow katydid tick-and-buzz pattern. In this case the song is very brief, lasting one to two seconds depending on temperature. The songs repeat continuously with no gap between them. The buzz has an exceptionally rattling quality, and the 2-3 ticks are very fast. At Mayslake Forest Preserve on a recent day I heard dozens of short-winged meadow katydids whose songs vanished from my hearing when I turned off the SongFinder. Thanks to the stereo design, I found I can locate the direction from which an altered sound is coming and trace it to the singer.

I have done my best to protect my hearing. I avoid louder music concerts, and use ear plugs when necessary, for instance in 2007 when, at their peak, periodical cicadas at mid-day were chorusing so loudly that my ears hurt without protection. Even with these precautions, age gradually has eroded the upper range of pitches I can hear. The SongFinder was created for birders and other natural history enthusiasts for whom sounds are an essential part of our aesthetic.

Slender meadow katydid female b

As I continue to make use of this device in future years I look forward to hearing additional species, such as the slender meadow katydid (though not the individual in the picture, which is a female).

2 Comments

Union Township, 1830’s

October 13, 2009 at 5:50 am (botany, ecology, history (human), methods)
Tags: , , , , , , , , , , , , , , , , , , , , , , ,

by Carl Strang

Yesterday I began to recount my study of what my home township in Indiana was like in the 1830’s, before Americans began to transform it from wilderness to a predominantly agricultural landscape. Here is a more detailed line drawing of the final map.

Union_Township_presettlement_vegetation

The surveyors’ description provided enough information for me to rough out the map. Getting to the final version required another step. I acquired a soils map of Marshall County, and looked for correlations between soil types and vegetation categories as the surveyors described them. A specialist might have done it differently, but for my part I was satisfied that the correlations were good enough to draw the detailed boundaries of vegetation areas by combining the surveyors’ records with the finer-scale soils map.

Of the various communities defined by woody plants, swamps are the ones most absent from today’s Union Township. The characteristic swamp tree was the tamarack. Here is some foliage of that species, which is unusual in that it is a deciduous conifer.

Tamarack foliage b

I remember seeing a tamarack tree at the old state fish hatchery that was formed out of the south end of Moore Lake, but that tree died years ago and I know of none surviving in the township today. There are bits of shrub swamps here and there.

A relatively moist (mesic) forest occupied much of the east half of the township, on the rolling Maxinkuckee Moraine. Sugar maples and beeches were characteristic trees, though not necessarily the dominant ones. A remnant of this forest is preserved by the Culver Military Academy in its Bird Sanctuary.

Dry forests and savannas were dominated by oaks and hickories, which grew on more sandy soils. They represent a continuum, with the forests shading the ground fully in the summer and the savannas’ trees scattered enough that prairie-like vegetation grew between them. A forest of this type was the site of the town now known as Culver. Gradually over my lifetime I have noted the passing, one by one, of the town’s largest surviving old oaks that were part of that forest. Dry forests persist mainly in the many “wood lots” preserved by the township’s farmers.

I am grateful to all the individuals and organizations, from private landowners to The Nature Conservancy, who have made the commitment to preserve and restore these reminders of the wilderness that once was.

Leave a Comment

Ghost of a Landscape

October 12, 2009 at 6:24 am (botany, ecology, history (human), methods, restoration)
Tags: , , , , , , , , , , ,

by Carl Strang

The places we live and work all were wilderness at one time. National parks, state parks, and nature preserves protect and restore areas intended to represent the landscape as it was before large scale agriculture began the sequence of alterations that have brought us to the present day. A number of studies have produced maps showing, in some detail, what the counties of northeast Illinois looked like 200 years ago. In the late 1980’s I decided to do the same for my home area, Union Township in Marshall County, Indiana. Here is a watercolor rendering of my results.

Union Twp painting 2a

I was reminded of that project by Scott’s excellent recent post on Houghton Lake in his blog, Through Handlens and Binoculars. Houghton Lake is the small lake closest to the map’s upper left corner. Recently it was acquired by The Nature Conservancy, and is getting the attention needed to preserve the rare plants and vegetation communities that have persisted there.

My mapping study began with a visit to the County Surveyor’s office in Plymouth, the county seat, to copy the original survey notes. Two different surveyors explored the local wilderness in 1834 and 1836, marking out the land on behalf of the federal government for purchase by American farmers. The 1836 survey covered the Indian reservations east of Lake Maxinkuckee, the township’s largest lake. That land became available to eastern farmers after the forced removal of the Potawatomis via the Trail of Death in 1838.

The surveyors’ main job was to mark the section corners and quarter-section corners (a section is a square mile). They also described the land, so that potential buyers back east could make informed choices. For example, after passing through what is now the center of the town of Culver, on Maxinkuckee’s west shore, surveyor David Hillis wrote, “Land rolling. 3d rate. Hickory etc.” Usually the description was dispassionate, but sometimes a surveyor revealed the sweat and discomfort of the experience. After crossing an extensive marsh at the south end of Maxinkuckee, Jeremiah Smith allowed, “In Sec. 34, at 1.20 (an) inlet 80L. wide coming from S.E. A nasty place.”

One of the surveyor’s helpers blazed and inscribed two “witness trees” at each section corner. The surveyor wrote down the species of tree along with its distance and direction from the corner. The tree species suggests to us what kind of vegetation community occupied that corner, and the tree’s distance from the corner hints at how close together the trees grew in that spot.

The surveyors also were careful to map the edges of lakes and rivers. In Union Township only Lake Maxinkuckee and Lost Lake, off its west edge, still have their 1834 outlines. Houghton Lake, and Moore Lake beside it, today are remnants of the larger water bodies they were in the early 1800’s. Two other lakes in the west-central part of the township no longer exist. They were shallow and easily drained for agricultural purposes before 1900.

Plant communities described by the surveyors as “wet prairies” or “marshes” were extensive mixtures of cattail marshes, sedge meadows and wet to moist prairies. Some of these featured insect-eating plants, the pitcher plants and sundews. See Scott’s post for photographs of some of the botanical beauty preserved around Houghton Lake. I’ll continue this account tomorrow.

1 Comment

Whitefish Point Bird Observatory

September 22, 2009 at 6:28 am (birds, methods)
Tags: , , , , , , ,

by Carl Strang

Last week I traveled to the tip of Michigan’s Upper Peninsula. I had a few inquiry goals during the trip, which I’ll share over the next few days. The first was to spend some time with the migratory water bird counters at Whitefish Point. There are sites like this across the country, where dedicated people spend hours per day, for long stretches of days in the migration seasons, counting the birds of each species that pass by on their way south or north. Some such stations specialize in raptors, some are more general. This one focuses on water birds.

Whitefish Point 3b

I have heard that the elite birders who gather such data can be impatient with those less skilled than themselves. Such was not the case whatsoever at Whitefish Point. I felt welcomed, and my questions were answered with patience born not of tolerance but of willingness to share the observers’ own enthusiasm. The paid observer on the first, full day I spent there was Tom Prestby. Tom was skilled not only at identifying birds that to me were little more than dots even in the spotting scope, but he also clearly enjoyed sharing the experience, and his knowledge. Other, unpaid birders were there simply for the enjoyment, and some have been participating for years. I stopped by the observatory office and bought a membership. This kind of ongoing data collection is worth supporting. Check out the Whitefish Bird Observatory website. (Note that this site does more than count water birds; there are other programs, for instance a nightly owl banding project).

Whitefish Point office b

Curiously, for all the years of numbers recorded for various ducks, loons, grebes, jaegers and the like, no one knows for sure how the birds counted at Whitefish Point are getting there. They pass from west to east, along the shore, rounding the point and continuing south (Whitefish Point is near the tip of the Upper Peninsula on the Lake Superior side), but where are these birds crossing the lake from the north? No one knows: potential for more inquiry.

I spent part of a second morning at the observation site. The birds were different. For instance, where on the previous day there were lots of white-winged scoters, on this day the dominant ducks were American wigeons. Chris Neri, the lead observer on that day, taught me how at a great distance the steep forehead and relatively small bill on that duck gives the impression of beaklessness. We also were entertained by falcons. Once a peregrine streaked past at head level, just a few yards in front of us, only to land on the nearby beach where we could admire it at leisure. The resident merlin spent a long time persuading a persistent passerby that there was room for only one merlin on this point. The aerobatics of the chase elicited many exclamations of appreciation from our group.

Merlin 1b

Eventually the local bird triumphed, only to be pestered by a flock of blue jays.

Merlin 3b

More reports from this trip are forthcoming.

Leave a Comment

Gadget 1

September 13, 2009 at 10:04 pm (methods, singing insects)
Tags: , , , , , , , , ,

by Carl Strang

For the most part in this blog I am trying to model methods of inquiry that don’t rely on technology. Our human senses have their limitations, but we can gather enough information through them to answer a lot of questions about our surrounding wild world. Nevertheless, there are occasions when gadgets can help. Today I will feature one of those I have found useful in my field studies of singing insects: my soprano recorder.

Recorder b

I don’t have perfect pitch, but I have a reasonably good ear. I have found the recorder to be especially helpful as I tackle the problem of the arboreal tree crickets (outlined in my earlier post on one of them, the two-spotted tree cricket ). This season one of my goals has been to sort out the songs of the two-spotted, narrow-winged and Davis’s tree crickets. I was encouraged when I noticed that Elliott and Hershberger, in their recent book on singing insects, indicated that these three species should have distinct pitches in their songs. Highest should be the two-spotted, at 3.5 kHz (kilohertz, a quantitative sound frequency measurement), which translates to a pitch of A, the fourth A above middle C. In the middle should be the narrow-winged tree cricket, at 3 kHz or approximately F-sharp, the fourth F-sharp above middle C, 3 half-tones below the two-spotted. I noticed, incidentally, that the distinctive song* of the snowy tree cricket also is indicated to be at 3 kHz, and so I had hopes that this would provide a rough and ready field standard. The lowest of the arboreal tree crickets, according to Elliott and Hershberger, is the Davis’s tree cricket, at 2.5 kHz. This translates musically to the fourth E above middle C, distinctly lower than any of the others. So, recorder in hand, I set forth.

Snowy tree cricket 5b

Snowy Tree Cricket

Two caveats quickly became clear. First, the pitch of a given species is subject to change with environmental temperature, rising and falling as the temperature rises and falls. Second, I have to keep in mind that my own hearing may not well match the measuring devices used to provide the information in that book. In general all species sounded, to my ear, a good 3 tones lower than Elliott and Hershberger suggested.

I have found that to my ear, both two-spotted and narrow-winged tree crickets have songs distinctly higher pitched than that of the snowy tree cricket. At a given temperature, the two-spotted sings one-half to a full tone higher than does the narrow-winged. However, at a given general temperature, narrow-wings range over half a tone of pitch or more. Whether this is because the microclimate is different where individual crickets are singing, or whether this is something they are controlling, I cannot say. It means, though, that I have to rely as much or more on the temporal pattern of the song to distinguish these two species.

Narrow-winged Tree Cricket

Narrow-winged Tree Cricket

Narrow-wings sing with a steady pattern of trills and spaces, with trills of equal lengths and spaces of equal lengths, and the spaces are significant at a second or so duration. Two-spotteds sing at a little higher pitch on average, have trills of varying lengths including some often lasting well over 5 seconds, usually with at least some pauses that are very brief, as though catching a quick breath.

I recently heard, on my neighborhood block count, what I believe must have been a Davis’s tree cricket. The insect was high up in a tree. Its trills were variable but generally very long, with only occasional odd interruptions. Spaces were short. Significantly, the pitch was down at A-flat, low for the temperature, which was 70F. Based on my recorder tests, at that temperature I would expect snowy tree crickets to be singing at B or C, two-spotteds at the E above that, and narrow-wings at C to E. So, the recorder is a helpful tool, but in distinguishing the songs of these crickets I find that the pattern of their song is more reliable than the pitch.

*You know the song of the snowy tree cricket, even if you live outside its range. In the movies, whenever the director wants to convey a calm nighttime mood, there will be a snowy tree cricket in the sound track. The song is a pulsing tone, varying with the temperature so that if you count the notes in 15 seconds and add 40, you have the temperature in degrees Fahrenheit. Though the narrow-winged tree cricket’s song likewise is a regular pulse, the tones are on the order of 2 seconds’ duration with a 1-2-second space between. Unless the temperature is very cool, the snowy’s song is much faster.

3 Comments

Block Counts

August 21, 2009 at 6:08 am (methods, singing insects)
Tags: , , , ,

by Carl Strang

Sometimes I collect data without a particular question in mind, on the possibility that I may learn something that guides a future inquiry. My block counts of singing insects are an example.

Block count 1b

My mailbox is a block away from my home. When the singing insect season arrives in the latter half of July, I begin going around the block the long way to retrieve my mail. The above photo shows the first side of the block as I head north. Next, I turn the corner and head west.

Block count 2b

I vary the starting time, record that along with date and temperature, and count the number of individuals of each singing insect species I hear along the way. Here is the view as I turn south.

Block count 3b

This neighborhood may not look like much, but I have heard a total of 14 species here from 2007 to date, including field crickets, bush crickets, trigs, ground crickets, tree crickets, true katydids, false katydids and cicadas. These data allow me to get some understanding of how species vary in numbers between years, and how their singing changes over the season and with time of day. Once I have picked up the mail, here is the final block as I turn to home.

Block count 4b

One pattern I would have missed without the discipline of the block count is a pause in singing among the cicadas in late afternoon, followed by a big push as light fades toward dusk. I have documented the arrival of a new species, the jumping bush cricket, in the neighborhood. Striped ground crickets and greater anglewing katydids were the most abundant singers in 2007, but while the stripeds also were the top species in 2008 there was a big drop in numbers of singing anglewings. It’s a little early to say much about 2009, but so far there seem to be more Carolina ground crickets than in the previous two years.

3 Comments

Two-spotted Tree Cricket

August 17, 2009 at 6:24 am (methods, singing insects)
Tags: , , , , , , ,

by Carl Strang

One of the goals in my singing insects study this year is to sort out the songs of three arboreal tree crickets. In the field I have found that their songs are not as distinct from one another as reference recordings and descriptions seemed to suggest. Two of the three species I have seen, and so confirmed their presence in DuPage County. Today I begin with what I suspect may be the only one singing as early in the season as late July and early August: the two-spotted tree cricket.

Two-spotted tree cricket 1b

This photo shows a female, with the two large spots on her back that give the species its name (males lack them, and are pale). She sits on the arm of one of the 2006 Roger Raccoon Club  kids, who brought her to me for identification. Until two weeks ago, she was the only one I had seen. Certainly the references were correct in saying these are not easy to find. They live in trees, often well above the ground. The male’s song, which you can find here  or here, is a strained, often dissonant sounding trill that is interrupted fairly frequently by brief pauses that often are filled with stuttering sounds. Unfortunately, the same description applies more or less to the songs of Davis’s tree cricket and the narrow-winged tree cricket, though the tone of the last seems more melodic to my ear.

Two-spotteds begin to sing at dusk. On August 6 I was at Timber Ridge Forest Preserve, strolling the Great Western Trail with ears open for insect songs, when scattered tree crickets in this target group began to sing. All had identical songs, but one in particular seemed to be closer to the ground and just off the trail. After a short time I found him.

2-spotted singing b

He was on the underside of a big grape leaf. Here he is close up.

2-spotted singing cropped b

He was using a trick for which some of the tree crickets are known. He had chewed a circular hole in the leaf, and was using it to amplify and possibly direct his song (tree crickets sing by elevating their wings and vibrating them against one another).

2-spotted wings down b

I made a recording, then prepared to collect him for identification. But when I put my flashlight on him again I found this was unnecessary.

2-spotted pair 2b

A female had arrived on the scene, and there was no mistaking her identity. The male kept his wings elevated, and continued to vibrate them occasionally in song. She was palpating her way slowly up his back in search, I believe, of secretions that some of the tree cricket males provide as nuptial food gifts in a prelude to mating.

2-spotted pair 1b

The next evening at dusk I was at Springbrook Prairie Forest Preserve. I heard the same song coming from near the top of a 15-foot-tall bur oak beside the trail. Looking up toward the point from which the sound seemed to be coming, I noticed that one of the leaves had a circular hole in the middle. When I illuminated it with my flashlight, sure enough, there was another male two-spotted tree cricket. So, at least with plants having relatively large leaves, I now know to look for distinctive circular holes that may help me to find these elusive insects.

2 Comments

« Older entries