Sunday, October 5, 2014

Jumping Beyond the Range Map

I’ve been out in the field every chance I've had, but now with today's afternoon temperatures fluctuating between 43-50 degrees, I am returning to Listening in Nature with more stories of range-expanding crickets and katydids.  Remember those Jumping Bush Crickets with the beautiful, bell-like trills?  Let’s start with them.

As I wrote last year, Jumping Bush Crickets are well established beyond where they have been reported for the range map in the Singing Insects of North America. (see below).  

I’ve listened to them expand very rapidly throughout the Greater Cleveland area; they’re now abundant in the city.  They’re not on the range map for Akron, either, yet they are widespread in Summit County.  These crickets are moving northward so quickly that it does indeed seem that they jump over each year’s boundary the following year!

So where are they as of October 2014?  Would you believe that they’ve made it all the way to Erie, PA? 

First, a reminder about who they are.  These crickets are seldom seen because they look just like the twigs and branches where they live.  

They are in trees and shrubs, where males run and jump from one twig or branch to another, pop up their beautiful, wood-colored wings, sing a few songs, and then dash to another nearby location to repeat the performance.  I seldom see them, but now that they live in our yard, I can watch closely enough to occasionally get photographs.

My back yard wildlife journal of the past 20 years starts noting their regular appearance in 2007, though a small number had been here a few years earlier.   By 2010, I was writing, “This has been an amazing year for Jumping Bush Crickets in the back and front yards!  In 2011, I wrote, “Jumping Bush crickets are everywhere – so many of them singing!”  The exclamation marks indicate that this was a new phenomenon, though now it’s the norm.

Are they spreading through ornamental plantings, or by gradual dispersal? I have heard them singing in ornamental trees and shrubs in a Home Depot parking lot, so that’s definitely one route.  The Jumping Bush Crickets on Kelleys Island in Lake Erie had to have taken the ferry over like everyone else. 

They weren’t in the NE Ohio “snow belt” counties, though.  Until very recently – the past few years - I simply did not find them in Geauga County and Lake County.  Now, they’re gradually taking on the coldest, snowiest part of the state.  (In case you don’t know what I mean by the NE Ohio snow belt, see the map below.)

Each year, I record Jumping Bush Crickets in locations I had not heard them before. They are now beginning to get established in Chardon, Chesterland, and Chagrin Falls.  While not generally heard in the outlying areas, they can be heard in trees that are “in town.” These aren’t ornamental plantings, either; they are older, established trees.

Jumping Bush Crickets are also singing in the woods east of Summit County in the Aurora area of Portage County.  Small numbers are in Lake County at the Holden Arboretum, and I’ve heard them at a rural Lake County intersection that seems to have been an apple orchard.

And they’re spreading east along the lake shore.  That’s where Erie, PA come in to the picture.

I assume that Jumping Bush Crickets do well in Cleveland because it’s a city – and a heat island.  Evenings are at least 10 degrees warmer here than in rural areas.  There are ornamental plantings that undoubtedly aid in their dispersal, but the maturation/reproduction season also has to be long enough for them to become well established. 

Maybe it’s not only the heat island effect of the city, though.  Lake Erie has major effect on temperatures here, both in the spring (when it stays cold much longer than elsewhere in the state) and in a longer period of above-freezing temperatures in the fall.  The milder fall temperatures allow for a longer growing season, and this benefits the crickets and katydids as well.  After a couple of freezes south and east of Cleveland, I always head up to the lake shore because I know there will still be some singing insects hanging on.

Clearly,  I needed to track these crickets along the lake shore to the east.  When my partner Wendy was in Erie, PA this past week doing a presentation for work, she told me she was hearing Jumping Bush Crickets in Erie’s historic district. 

That did it.  I had to go, but I was just about out of time.  It would have to be after work on the last relatively warm evening before a strong cold front shut down the singing insect ensemble.

Sure enough - they were singing exactly where she said I would find them!  They were
right on West 6th Street and Sassafras near the Erie County Court House. 

Excellent!  But how was I going to get some kind of documentation?  I couldn’t photograph them up in the trees next to the historic buildings.  I’d have to record them at a rather busy intersection with considerable foot traffic as well as car traffic.   How was I going to look unobtrusive with my headphone and shotgun microphone? I wasn’t in a park or preserve!

This had already been a challenge when I needed to record them in Chardon and Chesterland.  Keep in mind that I am doing this after dark. 

In Chesterland, I stood at the edge of an empty parking area for a couple of shops that may no longer have been open.  Since I needed to record crickets that were singing in the trees of the adjoining residence without looking too suspicious, I wore a headlamp to be visible and frequently spoke into the microphone in hope of looking like I was a reporter doing some kind of story on something up in the trees.  No one stopped me.

In Chardon, however, I could only access the large redbud tree on that home’s property by standing near the drive-through lane of a Taco Bell next to a privacy fence.  There were a number of Jumping Bush Crickets singing over the idling cars, so I played the same reporter role as I approached their tree.  Some people watched while they waited to place their orders, and others just seemed focused on getting their food.  I could only hope that no one was calling the police while waiting for "welcome to Taco Bell - may I take your order?"


But in Erie, I was standing in a busy historic district next to Gannon University with people walking around me and looking at me – and sometimes looking twice.  

I had to watch for traffic as I went back and forth across the street, trying to determine where the Jumping Bush Crickets actually were singing over the urban noise. 

On the way home, I stopped at the first rest area across the Ohio line and heard…lots of Jumping Bush Crickets!  Again, they were not in ornamental plantings.  This rest area was in what must recently have been a woodlot, and there were trees everywhere.  I pulled over on exit drive near a light (where I’d be visible) and recorded them singing in the woods on the other side of the drive.  There were numerous other singers with them too: Narrow-winged Tree Crickets, Greater Anglewings, Oblong-winged Katydids, possibly Four-spotted Tree Crickets… this wasn’t just a few individuals in an ornamental tree by the rest rooms.  This was a singing insect community.

As I continued east, I began hearing them in the trees along the freeway even while driving.  I pulled off at Route 45 in Austinburg and recorded more of them in areas just behind stores and other structures.  I left the freeway to record yet again at the rest area west of Route 44.   I was filling in the gap between Cleveland and Erie as I traveled west to Cuyahoga County!

 (You can access this map with all its points here if you'd like to see each location)

I’m not sure that how they got there really matters so much.  They’re living, reproducing, and forming established populations.  Although last winter was very snowy and miserable and spring chilly and wet, other winters have been very mild.  Once these and other northbound insects arrive in the area, many seem to be able to make their homes here.

I’m happy about the Jumping Bush Crickets – I love their sweet songs.  Those songs will be slower (and lower in pitch) now because it's getting cold, but they can sing even when temperatures are in the 50s. 

If – and when – you hear them during this month or next year, please let me know!

1 comment:

  1. Great work, Lisa. In northeast Illinois I found them about half a mile farther north than last year.