Friday, July 1, 2022

Is It Noise or Not Noise?

 

It’s July 1st, and the 2021-22 COVID academic year is eight weeks behind me. When I returned to the forests, meadows, and wetlands in May, I began my homecoming process by simply going to places I thought might be adequately quiet for listening and recording. That’s not very easy, of course, since there’s noise almost everywhere. Most of it is generated by humans, and some of these sounds are more disturbing to me that others.

So what is noise, what’s not noise, and what falls somewhere in between? It's somewhat subjective, and I hadn’t thought about it more specifically until now. I know noise when I hear it, and it’s almost everywhere.

I'll start in the backyard.

Wendy and I have a little woodland understory backyard in an old, inner-ring suburb of Cleveland. There are large pin oaks that provide abundant shade and acorns, and we expect that there are various caterpillars up in the leaves that are providing live bird food. We’ve planted smaller native trees and shrubs to create the understory and have ferns and an assortment of native plants creating layers of green broken only by wood chip paths and rocks. Birds are numerous, not surprisingly, as well as various cricket species, a couple of katydid species, and an assortment of other insects.

                                           There's a lot of life in this backyard

Sadly, I seldom record here. There is human-generated noise at almost any time of day and night. You know many of these sonic offenders: the roaring lawnmowers, whining weed whackers, and bellicose blowers of various sorts. Night brings unnecessarily loud motorcycles and cars plus necessary sirens for police, fire, and ambulance. Firecrackers – periodically including those that shake windows – startle people and other animals from late spring through at least October. Private and corporate jets destined for the county airport scream so low overhead that I can see the lights and landing wheels. 

There's typically more noise than I can edit out of any recordings I might make. It didn't used to be so obtrusive, but the noise level has increased significantly in the past 25+ years.

Even the closest park area I could call a “local patch” has a chronic problem with extensive processions of obnoxiously dominating motorcycles that obscure all sounds of nature along the road paralleling the river. It's a beautiful location that's full of birds, frogs, and singing insects, but noise from the motorcycles and cut-through traffic and from the air traffic to the Cuyahoga County regional airport make recording frustrating. (The one human-generated noise I forgive is the train whistles in the distance. I did state earlier that it's rather subjective.)

               North Chagrin Reservation, Oxbow Lagoon area, Cleveland Metroparks

So I often take my recording equipment out to the more rural parks and preserves, hoping it’s quiet enough to make some rather nice recordings for my programs and blog posts. I may have to do a certain amount of editing, but at least it seems possible…

…unless- or really, until the inevitable jet approaches. There’s no way to eliminate that wide range of frequencies from a recording. All I can do is wait impatiently, hoping the jet and the long trails of sound behind it will be gone before the bird or insect moves or stops singing.

Although I get frustrated and disgusted, noise significantly impacts the birds. This is how they communicate, especially when they can’t see each other. This is how many young birds learn the songs of their species. Males impress females with their virtuosity and repertoire.They challenge and set boundaries with other males of their species with their songs. Young birds need to learn their songs by ear – if they can hear the adults’ songs well enough to imitate them. For me, not hearing the songs clearly is angering, frustrating, and deeply sad. But for the birds, it affects their survival.

So how should I define noise? Is it everything humans do that affects birds, amphibians, and singing insects’ ability to be heard - and affects other humans as well? 

I recently drove almost 40 miles east to the Geauga Park District’s Observatory Park east of Chardon with hope that I'd find enough quiet to hear the bird song repertoire clearly.

 

At first, it seemed like it should be possible. There was no one around- just a couple of cars plus a few trucks on the road involved in some kind of maintenance work. I started walking and listening, and I was eventually able to record a Hooded Warbler in the foreground with an Eastern Wood Pewee in the background, If you look at the sonogram, you can see the distinct shape of each bird's song

But there was an unnatural droning sound that I couldn’t overlook in the background. I heard it when I was recording the Ovenbird, too. 


What was it and where was it coming from, anyway?

I finally tracked it down. It was a tractor! That’s one I don’t hear in the city, though some of the landscaping companies that come around have riding mowers as big as tractors filling up the small front yards they’re mowing.

So was this noise? It’s human-produced, so probably yes. But it’s a farmer – just one guy out on his tractor in an agricultural field. I was disappointed, but more resigned than actually angry.

 

The next day, I went to Swine Creek Reservation in an area of Geauga County with a large Amish community. I hoped that this time, I would just hear horse hooves and buggies. I started recording near a small parking area at the wooded edge of a field.


An Indigo Bunting broadcasting his song from his perch on a dead tree limb was subsequently joined by a Song Sparrow. 

I decided I’d walk down to the creek, cross, and hike up the ridge on the other side. 

I began recording before crossing the creek but stopped when a mom and her kids arrived to play in the water. Soon, another mom and kids followed. No one was quietly pondering the wonders of nature. These kids were in the creek, and they were yelling and occasionally shrieking. 


But they should be playing outside in a creek and kids are going to yell.  It may prevent my being able to record, but I decided it’s not exactly noise.

I crossed the creek and began my walk into the forest. Although I seldom actually saw birds, I could hear those that were close, others more distant, and the begging calls of nestlings. 

 

Recording is so much more than simply pressing the record button when someone is singing. It’s really about listening closely to the nuances of the songs I might miss otherwise. It’s also about context. What’s going on around this bird? Does he vary his songs? Is another male responding and challenging him? 

“Observation” isn’t only a visual term.

There are times when a habitat may look quite glorious yet is so dominated by human noise that birds are likely experiencing significant difficulty communicating with others of their species.  In addition, birds - and even smaller mammals - must be able to stay alert for avian alarm calls warning of an approaching predator. When the chipmunk starts calling, it's possible that the birds are paying attention as well. So as annoying as it may become after a while, this is not - in my opinion - noise.

 

Doesn't this look attractive? It's a vibrant location I recently investigated after coming across it on a park district website.

                          Strongsville Wildlife Area, Mill Stream Run Reservation.

 It was full of birds when I arrived, yet I couldn’t hear them clearly because...

 

Just look at the sonogram! Can you see how the birdsong is being obliterated?

On the other side of the trees is a major freeway. Sadly, this is not the first time I’ve had to walk away from what looked like an intriguing habitat to study simply because of relentless human noise. 

Park districts can save, restore, and create vibrant habitats, but they can’t move freeways.

 

During this same time period, I went to one of my favorite places in all of NE Ohio: Lake Erie Bluffs. 

 

 I walked the bluff trail that's typically filled with Yellow Warblers, Catbirds. and Song Sparrows.

 

 

This particular Catbird was having a sonic struggle with a speedboat, however. 

 

 

Then just as I was recording an especially splendid Song Sparrow, a brisk walker crunched past on the fine gravel. 

 

I was surprised by how far away she was when my microphone first alerted me to her approach and how long after her passing I could still hear her. But was that  noise? No. She was just out for a walk.

Although I deeply love this park, I tend to stay away in the summer because of the noise from speed boats, jet skis, and yachts. No verbal description is needed here. I’ll just offer this recording from May 30th. . 

 

Of course, I’m not going to leave you with that sonic obscenity. Here’s the song of an excellent Gray Catbird at Lake Erie Bluffs. There's a train in the distance, as is often the case there.

 

I’ll close with the song of Swine Creek itself. 



What are your biggest noise offenders? What are the sounds that are loud or annoying but not noise? (To me, that would be Common Grackle fledglings outside the window as I write, the whining Blue Jay fledglings, and the crowd of European Starling fledglings that have finally moved along from their residency at the backyard feeders.) And what gets a pass because there’s a certain connection for you, like train whistles for me?

You can leave messages on this blog (listeninginnature.blogspot.com), on my Facebook page if that’s where you found this blog post, or even by email if that's how you received an update from me. (Lisa.rainsong@listeninginnature.com.)

Shall I add some of your responses to the end of this post? Check back and see!  


                                                Observatory Park, Geauga County
 

 

 

Sunday, November 21, 2021

Taking Attendance

 

 

NE Ohio did not have a gentle autumn decrescendo this year. I thought it might be yet another warm fall after the hot weather in the first half of October, but a dramatic change in late fall brought early winter temperatures and an end to the singing insect season that often lasts into early November near Lake Erie. Instead of late-season field explorations, I sat inside with crickets and katydids singing in the dining room and considered what felt so odd about this year’s field season.


It wasn’t the crickets. All the various crickets I expected to find were present everywhere I went.

Previous blog posts have detailed my documentation of the northward advancement of Handsome Trigs and Jumping Bush Crickets. They certainly continued their steady progress into the lakeshore counties and the snow belt this year. Parts of Geauga County are even beginning to sound like Portage and Summit Counties, where Jumping Bush Crickets can obscure other members of the singing insect chorus.

 Jumping Bush Cricket (Orocharis saltatur) female. Geauga County, NE Ohio.
 

 Later in the season, I was able to learn a little more about the look-alike and sound-alike Black-horned Tree Crickets and Forbes’s Tree Crickets whose ranges overlap here. I’ve improved my ear training skills for identifying the two species by sound, especially when both are in the same location. The more familiar I become with them, the easier it becomes to hear the difference in the overtones of their songs. 

Forbes's Tree Cricket (Oecanthus forbesi)

I added a new aspect to my search this year: investigating habitat preferences for these two species.  

It appears that the Black-horneds, where present, prefer edge habitat with a mix of shrubs, blackberry, and goldenrod. They seem far less likely to be in the large, open, goldenrod-filled meadows that are the typical habitat of large numbers of Forbes’s Tree Crickets. In fact, I have found Black-horneds several feet up in shrubs and small trees that are out of reach of the tip of my shotgun microphone. This can make photographing and catching them more of a challenge for a 5’3” inch human.

Forbes’s are less of a problem. I just need to be willing to push and plod through dense stands of goldenrod that are at least as high as I am tall.

I noticed a possible habitat division at The Rookery in the Geauga County park district. This park is unusual in that it supports a much higher percentage of Black-horneds than of Forbes, but I didn’t have any idea why that might be. I decided to try refining my search by observing  where each species was concentrated.

How did I do this? By ear. I later checked my accuracy by recording a number of these crickets, noting the habitat and the temperature on their individual plants, and then counting the number of wing strokes per second in my sonograms

Next, I decided to  revisit a preserve that had plenty of both species. The Buttonbush Trail area of Summit County Metroparks’ Pond Brook Conservation Area was an obvious choice. I’d surveyed this area for singing insects in 2013 and subsequently searched specifically for Black-horned and Forbes’s Tree Crickets in 2018. 

Black-horned were somewhat more common than Forbes’s at that time (about 60% and 40%). My field notes even indicated that along Pond Brook itself, one species was on the left side of the trail and the other was on the right. You can hear Pond Brook in my 2018 recording of these two species - Forbes's first, then Black-horned.

 

I’d simply noted their occurrence at that time, but now I wanted to know why they seemed to be separated instead of mixed together. Was the vegetation the difference? I had the beginning of an idea.

It seems to be my pattern to get compelling ideas late in the season when time is short. This one was no exception, and I knew I wouldn’t have time for an extensive study. I had to begin to pursue my intriguing idea, though, so I decided to search for Black-horneds, as they are less common overall in my region.

I applied my developing ear training skills to my habitat hypothesis and recorded the ones I thought were Black-horned. In fact, I even brought three probable Black-horneds home so that I could record all of them at exactly the same temperature. 

                                 Black-horned Tree Cricket (Oecanthus nigricornis) 
 

 

Every one of my three indoor residents and all the others I recorded in the field were indeed Black-horneds. I’d found all of them in intimidating thickets of shrubs, blackberry and young trees. 

 

 Black-horned tree Crickets were singing here along Buttonbush trail at Pond Brook

Black-horned Tree Crickets were in the blackberry, the shrubs, and a few were even in the smaller trees up to 8 feet high. Any goldenrod was mixed in with the blackberry and shrubs.

 A few were even in this tangle, including well above my head!

 

Edge habitat or clumps of shrubs and small trees in a more open area? Look for Black-horned. Wide-open goldenrod-filled meadow? It will be filled with Forbes’s as far as the ear can hear. 

 A festival of Forbes's Tree Crickets will be singing here at Frohring Meadows,

This isn’t a definitive discovery, of course; it’s an engaging first step that could be the beginning of my plans for next year.

 

But what about the katydids?

 


 The season began with a very encouraging number of Broad-winged Bush Katydids and Rattler Round-winged Katydids. Broad-winged Bush Katydids are an expected species beginning in the first week of July. 

 

Broad-winged Bush Katydid (Scudderia pistillata) male, Geauga County, 7-19-21 

 

Rattler Round-winged Katydids are occasional, and they seem to mature in mid-July. I discovered substantial numbers of them as well and felt quite optimistic about what I’d find later in July and in August.  

 

The reality was even more troubling as a result.

It started with the Curve-tailed Bush Katydids.

 A Curve-tailed Bush Katydid female's ovipositor is her "curved tail."
(Recording below also includes a Fall Field cricket)

 

I expect to find Curve-tailed Bush Katydids in strong numbers everywhere shortly after the Broad-wingeds mature, but where were they this year?

They are by far the most common of the Scudderia in NE Ohio, yet I only occasionally saw or heard even one in the counties I visited. Some species like the Oblong-winged Katydid have abundant years followed by sparse ones, but not Curve-taileds. It would never have occurred to me that they wouldn’t be widespread. What was different?


 Curve-tailed Bush Katydid (Scudderia curvicauda) female

The subsequent lack of Texas Bush Katydids in August was also concerning. While there may be more individuals some years than others, I saw none in 2021 and possibly heard just one. I visited multiple parks and preserves in counties both east and west of Cleveland, yet there were no Texas Bush Katydids and only one or two Curve-taileds. 

Texas Bush Katydid (Scudderia texensis)
  

 

Fork-tailed Bush Katydids, perhaps? I don’t see the as adults as often as the nymphs, yet I only encountered one Fork-tailed nymph this year.

Fork-tailed Bush Katydid (Scudderia furcata) male nymph
 

What about the other katydids that typically can be found at eye level?

The bounty of Rattler Round-winged Katydids was very brief, corresponding with the Broad-winged Bush Katydids in early and mid-July. I did not find any after this time. 

 
Rattler Round-winged Katydid (Amblycorypha rotundifolia)  female. Geauga County, 2021

 

Oblong-winged Katydids are more common in some years than others and I didn’t expect a large number after 2020’s outstanding season. But even in slower years, they’re always present – except in 2021. 

Oblong-winged Katydid (Amblycorypha oblongifolia) emerges from the vegetation

Meadow katydid numbers were neither plentiful nor alarmingly low, though there weren’t as many Black-legged Meadow Katydids in the wet areas as I would typically find. Our ever-present Sword-bearing Coneheads did not form the usual dense wall of sound along every trail, but at least scattered coneheads were singing. 

 


 Sword-bearing Conehead (Neoconocephalus ensiger)

 

True Katydids and Greater Angle-wings were plentiful up in the trees, but Scudderia and Amblycorypha? Except for the first half of June, they simply were missing.

What changed?

Could weather have been a factor? I didn’t notice a shortage of crickets this year. When there are storms and heavy rains, both katydids and crickets seem to be amazingly resilient. There were definitely periods of hot weather, but the range of our common Amblycorypha and Scudderia extends to the Gulf Coast. (The one exception is the Broad-winged Bush Katydid, whose range is from southern Ohio northward.)

 

Curve-tailed Bush Katydid range map from Singing Insects of North America

 

What I heard – and didn’t hear or see – reminded me of parks I’ve studied with less singing insect diversity. These parks typically have the arboreal katydid species and perhaps some of the most common meadow katydids such Short-winged and Slender Meadow Katydids. There may also be at least some Sword-bearing Coneheads, though not the typical loud and cheerful abundance one normally finds in NE Ohio. Crickets are more common than katydids.

What I find obvious in these parks is the significant lack of bush katydids in the edge habitats, meadows, edges of wetlands.

The general deficiency this year was obscured by all the tree crickets, ground crickets, and trigs. The crickets, Common True Katydids, and Greater Angle-wings can create an impressive chorus without any bush katydids but listening for diversity quickly reveals their absence. There is a gap in the orchestral texture. 

Here's an example from our backyard: the rich sound you hear is comprised almost entirely of of crickets. Only Common True Katydids and Greater Angle-wings up in the oaks are present, yet it sounds like a complete ensemble. This is to be expected in a more urban area, even when gardening for wildlife. Katydids, however, should be - and usually are - in our parks and preserves. 

 

This was just one season. I guess I’ll need to see and hear what happens in 2022 and think through what kinds of records I should keep and how I will do this. But in a changing climate, how can I not feel uneasy?


 
Texas Bush Katydid