Site Map Project

January 30, 2019 at 9:09 am (singing insects)
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by Carl Strang

Up to this point I have reported singing insect distributions in the Chicago region at the county level. For instance, here is an Allard’s ground cricket (Allonemobius allardi) and its species distribution by county.

Male Allard’s ground cricket

The black dots simply show that I have found Allard’s in every county of my study region.

But I have a lot more data than that which I wanted to share. Also, I thought that maybe a finer grained mapping approach might reveal new questions for me to investigate. I had a spreadsheet with a species list for every site I have visited. So, I recently created a series of maps showing the sites where I have found each species over the years. Here is the resulting map for Allard’s ground cricket:

Filled circles indicate sites where I have observed Allard’s ground crickets. Open circles are places I have visited where I haven’t (yet) noted that species.

As you can see, this is a widespread and frequently encountered cricket. The map reveals significant areas with no sites. Some of these are vast empty (from a biodiversity standpoint) agricultural regions, but still I should give them more attention.

One more example for today. The long-spurred meadow katydid (Orchelimum silvaticum) reaches its northern range limit in the Chicago region.

Long-spurred meadow katydid, male

The county-level map showed this, but the site level map makes it even clearer.

The northernmost sites where I have found long-spurred meadow katydids line up impressively at the same latitude.

These two examples simply emphasize conclusions I had drawn previously. Some intriguing questions were raised in other cases, as I will share in upcoming posts.

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Shaking Out the Photo Bag

January 26, 2019 at 8:57 am (reptiles and amphibians, singing insects)
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by Carl Strang

Before I get going on a new series of posts, I want to share a few photos that didn’t fit into last year’s topics.

This seemed to be a good year for gray treefrogs across the region. I frequently ran into small ones.

Gray treefrogs can change colors, making themselves green to blend in.

For some reason, they often rested on milkweed leaves.

It was a good year of singing insect field work. Plenty of questions remain unanswered.

One of the smaller ones was the identity of this grasshopper nymph at the Indiana Kankakee Sands. My best guess is sprinkled grasshopper, which I found there in adult form later in the season.

An interesting observation in the Tefft Savanna Nature Preserve (within Indiana’s Jasper-Pulaski Fish & Wildlife Area) was that short-winged green grasshoppers (Dichromorpha viridis) were the usual green color in wetlands but were brown in the savannas.

A mating pair of brown variants.

Late in the season I visited my friends Lisa Rainsong and Wendy Partridge, who live in the Cleveland suburbs. One goal was to see jumping bush crickets out in the foliage and branches of trees and shrubs. In the Chicago region they almost always stick to the trunks of trees and are difficult to see.

Sure enough, within a few minutes of searching I found a singing male in a bush.

They have an odd angular appearance, as though roughly carved from wood.

That’s it for now. Soon I will share results of a productive winter project.

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