Wednesday, November 15, 2017

Straight-lanced Surprises

My last post recounted my story of recording a Fork-tailed Bush Katydid, which in 2017 was still an unaccomplished goal I'd set for myself years earlier. But the Fork-tailed wasn’t the only singing insect I still needed to record. 

I also needed my own recording of a Straight-lanced Meadow Katydid (Conocephalus strictus). This is a meadow katydid I see in a couple of locations every year, although they’re not especially common and only seem to show up in scattered little groups. I’m more likely to find them in drier habitat than in the dense goldenrod/blackberry/dogwood meadows and fields so typical of my area. 

Except for their diminutive wings, they’re a little more substantial than other members of the Conocephalus genus. 

The males’ cerci are noticeably longer and straighter than those of other meadow katydids... 

...and the females’ long, blade-like ovipositors set them apart from most of the other members of their genus. 

I don’t know which characteristic gave the species its "Straight-lanced" name, but it seems appropriate either way. 

Their wings, however, are even shorter than those of the soft-singing Short-winged Meadow Katydids (Conocephalus brevipennis), and I think that’s been part of my challenge in recording them: I can’t really tell if the males are singing. 

With other meadow katydids whose songs are difficult to hear, I can watch their wings move and try to get my microphone so close that it almost touches the singing katydid. But the Straight-lanced? I seemed perpetually unable to correct this gap in my field recording collection. 

I brought a male home a few years ago but never saw or heard him sing. I was convinced he was just too miserable to perform, so I eventually took him back to his birthplace. The following year, I borrowed both a male and a female, thinking that the female would inspire the male to make a statement about his impressive genetic material. I didn’t hear a thing from him. If he did sing, I simply couldn’t tell. 

My “studio recording” success with the Fork-tailed Bush Katydid encouraged me to try the same procedure with a male Straight-lanced Meadow Katydid. When I eventually found one to bring back here for an overnight recording session, it was exactly the right technique for this project! He not only sang – he sang nonstop for extended periods of time. From the changes in volume level during the recording, he apparently walked all around the terrarium, singing as he traveled. 

When I looked at the overnight recordings, I also learned there was more to these singing sessions than I realized. He sang for up to a half an hour without even pausing, but it wasn’t just a single repetitious song. There were variations within it that did not seem to follow any kind of pattern that I could determine. Here are the two kinds of trills in the song – one fast and concentrated, and the other slower with more separation between wing strokes. 

(Did you have to turn up your speakers a little when you clicked on the arrow - or maybe a lot? You would not be the only reader/listener who found this to be necessary. We'll talk more about those vanishing high frequencies in a future post.)

This Straight-lanced singer would apparently alternate between them seemingly at random, although there certainly must have been some kind of organization that simply wasn’t obvious to me. After all, I didn’t know his musical score or how he was responding to his environment. 

The fast trill would go directly into the slower one and then back. In addition, he'd sometimes stop for less than a second, then immediately produce an energetic burst of song that continued right into one of the two kinds of trills. It's visible on the sonograms. 


Both my recording success and unexpected song observations were quite rewarding, and I assumed this would be my Straight-lanced Meadow Katydid story for the season.

An unexpected chapter began a month later.

Lake County Metroparks biologist John Pogacnik, well-known and highly respected for his field observations, shared a intriguing discovery with me: brown Straight-lanced Meadow Katydids at a park property in Lake County that’s not open to the public. He offered to show them to me, and I was delighted to meet them.

I saw green individuals first, then some that were a darker olive green, 

lighter brown ones, 

and then very dark brown ones all within one small area! Look at him! Isn't he gorgeous?

The dark katydids resembled their green counterparts, but the color was so different that I thought it would be good to document their songs. Would they be the same as those of the green male I recorded the month before? John invited me to bring a few home to photograph and record, since I would return them to their home as soon as I was able to obtain this documentation. 

First, I needed to get some closeup photos of the cerci (the male's posterior projections that can be used to determine the species). Katydids are not necessarily gracious and cooperative about letting humans photograph their anatomy, but my experience with meadow katydids has been that both males and females will ascend to the terrarium’s screen lid and walk upside down along it. 

I was right about the screen lid, but the male whose cerci I tried to photograph simply wouldn’t stand still and pose. I was persistent and eventually obtained a clear enough photo to show that the cerci were indeed the same as those of green males. 

And a recording? I used the same home studio recording process that worked with the green male and with the Fork-tailed Bush Katydid. Yes, both of the visiting males sang what was clearly a Straight-lanced song. There was a fast “whirr” followed by the slower, more decisive pattern.  In one lengthy proclamation, I counted the pulses at 24 per second for the fast whirr and only 8-9 per second for the slower passage. In others, the whirr was about twice the speed of the slower song.

The split-second pauses were present, and so were the bursts of more intense song illustrated by the dark brown individual's song above. The songs of the the brown males were consistent with those of the green male I'd recorded a month earlier.

Now that John and I both had photo documentation and I had recordings, it was time for these little beauties to return home. However, I had limited confidence in my ability to get them into traveling containers, as they are very accomplished jumpers. 

Instead, I took the terrariums themselves right to the exact spot where we'd caught these katydids, and then I removed the lids. The brown katydids leaped out and disappeared into the plants they knew so well.

How fortunate I am to have had the opportunity to see, photograph, and record them!

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