Monday, July 16, 2018

A Spring Field Cricket Named Lincoln and his Log




As I was working on my new online field guide, “Listening to Insects: NE Ohio’s Crickets and Katydids,” I realized I had no pictures of adult Spring Field Crickets. 

Fall Field Crickets – yes. In fact, we’ve had Fall Field Crickets in our terrariums for at least the past two years, so there are pictures from there as well as a few from the field.  So why would Spring Field Crickets be a problem? 


They look identical and sound identical. They live in similar – and often the same – habitats, but not at the same time. Spring Field Crickets mature around the third week of May and live until about mid-July. Fall Field Crickets take over at the end of July and continue through at least mid-September and longer closer to Lake Erie, as a freeze will occur later there due to the warm waters of Lake Erie.


Spring Field Crickets don’t seem to be as common. They're an expected – and in some places, abundant – species in the sandy soil closer to Lake Erie. Otherwise, they are scattered here and there, often seeming to favor the areas next to railroad tracks. I’ve started keeping a Google map of where I’ve located them, and it’s primarily near the lake.


In addition, they hide very well in cracks, beneath leaves, in clumps of grass, and under stones and pieces of driftwood on the beach. They emerge to sing at night, but are generally well-concealed.
 


I really just wanted some photos. That’s all. Time was going to run out for this year.


I decided to check a couple of beach areas for crickets and anything else of interest. (There’s always something of interest when I go out at night.) One year in late November, I looked under a driftwood log where the beach meets shrubs and trees and found…







…Spring Field Cricket nymphs! How could they survive under there through a stormy NE Ohio winter? I know it’s not quite as cold right at the lake shore as even a little ways inland, but under a log against some small trees and shrubs just didn’t seem possible. But you saw that cricket’s tiny wing buds. He was not going to mature any time soon. 


So at the end of June I went to one of the beaches I know and heard a scattering of Spring Field Crickets. They weren’t just singing from hiding, either. They were up on driftwood as if singing from wooden stages, on stones, and in the sand! 



Maybe I could actually catch one, transport him back to our house for a photo shoot, then return him in a day or two. I periodically bring a cricket or katydid home for a recording session, then take the insect right back to his exact location. 


I managed to catch one of the singers, who was proclaiming his desirability from a large driftwood log. 



I created a terrarium that mimicked his habitat, as I typically try to do for my guests and residents. 

I put a thin layer of beach sand on the floor of the terrarium, added little pieces of driftwood and beach stones, a few dead leaves, a clump of grass in the corner, and made sure I arranged these objects so that he’d have places to hide under and between. Then I added one little cap filled with cricket water cubes, another of dry cricket food, and a little lettuce. 





When I slid him into his temporary apartment, he instantly went straight to the cricket food, stood right in the tiny dish, and lost all fear. I figured he’s be OK – and he was. He went to his hiding places for naps, but has been out in the open most of the time, singing from his pieces of wood, his rocks, and occasionally even from his food dish. 


I returned to the beach a couple nights later after considerable heavy rain. I didn’t hear any crickets. There were some at higher elevations with more vegetation, but no one down where he had been. I wasn’t sure it would be right to take him back there now, even though it had only been two or three days. I went back again shortly thereafter, and there were definitely no Spring Field Crickets left anywhere in the vicinity.


If he would be staying, he was going to have a name instead of just “the cricket.” Since he’s a Spring Field, Wendy named him Lincoln. (I did not remember the connection, but maybe you do.)


There was one thing he still needed, though: a miniature log. I’d brought home a wide, smooth, rounded piece of a branch that looked appropriate, and I negotiated its placement among  the smaller pieces of driftwood. I consistently learn a great deal from watching crickets and katydids sing in a terrarium that approximates their natural habitat.




It was perfect. He loved it. He continues to sing up there every day and night. Lincoln the Spring Field has his log.


That’s the story. Now for what I learned from him: 


He doesn’t just sing the standard, cheerful chirp-chirp-chirp I associate with his species.





Sometimes, his rhythm is erratic. At first, I thought he was just getting old. However, it’s actually a choice, as he switches back to the steady pacing whenever he is inclined to do so. The erratic rhythms and pauses are rather catchy and I find myself making up tunes with the rhythms he uses.


But there’s something else much more interesting. Listen:





He’s alternating phrases of chirp-chirp-chirps with a different sound altogether. It’s much softer, scratchier, and sometimes faster. The primary accent follows the pattern and spacing of the chirps, but what are those continuous little strings of tiny wings strokes between them? Here's a sonogram that shows the two different song types:




Once he begins to shift into that alternate song pattern, he may increase the amount of dense, soft song (sotto voce, as singers would say). It sounds almost mechanical, like a very soft engine.

 




While he may still include chirping calls, the continuous, soft song can become a larger part of what he sings until it is the majority. 




His wing movements are smaller, and his body seems to quiver. He occasionally does a subtle dance on his log as if it were a courtship ritual, though there’s no female cricket. 



I feel very fortunate to have been able to watch and listen to this level of detail.



Oh, and Dmitri, the Guardian of the Terrariums, adores Lincoln. He sits next to the terrarium, purring, for extended periods of time. 

But our beloved little gray cat is getting older and currently requires medication in his food to manage two chronic health conditions. These conditions result in his being uninterested in eating much of the time, yet the only way he might consider accepting medication is in his food. 

And guess when he’s most likely to eat? 



When I put his food dish next to the terrarium with Lincoln, his health coach.
 


I don’t know how much longer Lincoln will be here, but I did see a couple of Fall Field Cricket nymphs in a park near the lake last night. They were not too far from maturity.



He's still sounding quite good as of today, but I’ll definitely miss Lincoln when his time is up. 

So will Dmitri.


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