Riding the Great Lacuna

by Carl Strang

One of the many little mysteries I puzzle over is the spotty local distribution of field crickets. We have two species, the spring field cricket and the fall field cricket, in northeast Illinois. They look alike, sound alike, and are active in different parts of the season. Though they prefer much the same habitat, and more often than not occur together, sometimes one of the two species (usually the fall field cricket) occurs alone.

Green circles mark DuPage County locations where I have found both spring and fall field crickets. Blue circles indicate where only spring field crickets occur, and yellow circles mark spots exclusive to fall field crickets. The red area and blue star are explained below.

You can see that in east central DuPage County I found only fall field crickets through 2010. The yellow circles mark York Woods Forest Preserve (the northernmost circle), and in a row from east to west: Fullersburg Woods, Mayslake, Lyman Woods and Hidden Lake Forest Preserves. Together they seem to define a space, or lacuna, where spring field crickets may be absent. On Monday I rode my bike between these locations, listening as I went for field cricket songs. Though much of this area is occupied by gated residential communities, the city of Oak Brook also maintains a fine system of bike paths which allowed me to zigzag through much of the zone marked in red on the map.

I found mainly mowed lawns, residences, woodlands and businesses (including the McDonald’s corporate headquarters and “Hamburger U”), but there were plenty of places just like ones in which I have heard numbers of spring field crickets elsewhere, with unmowed grasses or mixed grasses and forbs. In all that area, though, I heard only two crickets singing, close together in the location marked by the blue star on the map. That spot marks the northern extent of a zone I should investigate further, between the Fullersburg and Mayslake preserves.

Still, it seems the lacuna is indeed largely empty of spring field crickets. Next steps will be to find how far the boundaries of this area extend, and to look at old aerial photos for clues as to why this region might be different, keeping in mind that fall field crickets are present. I may repeat yesterday’s bike ride in the late summer or fall to see if fall field crickets occur in the spaces between those preserves.

Advertisements

1 Comment

  1. August 22, 2011 at 6:04 am

    […] Earlier this season I reported on my search for spring field crickets in the Oak Brook area, where except for one little spot there is a curious lacuna in the distribution of that species in DuPage County. On Tuesday afternoon I followed the same route on my bike, listening for fall field crickets along the way. I photographed this male fall field cricket last Monday at Mayslake Forest Preserve, which has no spring field crickets. […]


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: