Eric R. Larson

Handshake meme - "Me doing a CAPTCHA" and "THE THIRD POLICEMAN by Flann O'Brien" uniting over "Is the guy riding the bicycle part of the bicycle?"

Visit Nachusa Grasslands Consisting of 4,000 acres of restored, remnant prairie, Nachusa Grasslands is home to 180 species of birds, more than 700 native plant species and a herd of bison.

A little farther from Chicago, but The Nature Conservancy also has bison herds on restored prairies at both Nachusa Grasslands in Illinois (www.nature.org/en-us/get-in...) and Kankakee Sands on the Indiana border (www.nature.org/en-us/get-in...). Both are ~1.5 to 2 hour drives from the loop.

The show is very funny, but when Garfield is explaining the omission of his Civil War service to his daughter? Devestating stuff, Michael Shannon is incredible.

Maybe recency bias, but "I've Made Up My Mind to Give Myself to You." I had to see it live before it hit me that the "you" was us, the audience - a justification for the last few decades of Dylan's life and their relentless touring.

"I Shall Be Released" one of those songs that feels like it's been around for centuries

An irrigation ditch centered in the image that has dried to a single, isolated pool in the foreground. There are grassy banks on either side of the ditch, with two men standing on the right bank in an orange sweatshirt and blue shirt.

New invasion note from southern Idaho, where we've rediscovered the non-native red swamp crayfish after a half century without detection (doi.org/10.3391/bir....). Intensive burrowing by red swamp crayfish could be a risk to canals and other irrigation infrastructure.

I think the exhibit on Lincoln as a circuit lawyer in central Illinois is interesting. It's a nice but smaller county museum. The restored prairie on the west side of the property is interesting, but gets some spillover noise from the interstate.

Big Lincoln exhibit, blacksmith shop, small botanical garden, connects west to a restored prairie and east to a forested river corridor. It is very convenient off I-74.

He was just great. Everyone on Stax had the same excellent backing musicians, but Redding completely elevates the sound as a singer. I'm never tired of it.

Mr Pitiful for the origin story of flipping a radio DJ dig about his sad ballads into a great song

An entire government of and for excitable boys

A prairie with a wetland in the middle distance and a tree line on the horizon under low, scattered clouds

New faculty position in the University of Illinois Department of Natural Resources and Environmental Sciences for an assistant or associate professor of agroecology: illinois.csod.com/ux/ats/caree.... Position closes October 31st. Happy to answer questions about the dept / university / town.

ecoevojobs.net 2025-26

UPDATE: The 2025-2026 list of faculty and postdoc positions in ecology and evolutionary biology is out! Be sure to check out this active and helpful community run resources! docs.google.com/spreadsheets...

A slightly out of focus rusty crayfish (Faxonius rusticus) held between a thumb and forefinger with the calm surface of a lake in the background

Two boats docked in the foreground of a large lake with a yellow floating platform in the middle distance and a forested shoreline ~2 miles back on the horizon

Sunset on a large, calm lake as a band of orange below emerging stars

A square white bucket with ~16-20 rusty crayfish (Faxonius rusticus) waiting to be counted and measured

Completed my annual trip to northern Wisconsin, continuing population monitoring of invasive rusty crayfish (Faxonius rusticus) that extends back to the 1970s. Populations remain down, at only ~25% of past peak abundances, with surprising catches of large native snails in our traps.

It was a real pleasure to participate in the Mazama Newt Workshop at Crater Lake hosted by the @oregonzoo.bsky.social and the National Park Service. Discussions focused on a recovery plan for the Mazama newt in light of an exploding invasive signal crayfish. Great to see @ericrlarson.bsky.social!

New database catalogs plant species in latest effort to restore prairies The RELIX catalogues every plant species in 353 prairie remnants — parts of the native grasslands of the midwest that were not converted to farmland during colonization.

The RELIX catalogues every plant species in 353 prairie remnants — parts of the native grasslands of the Midwest that were not converted to farmland during colonization.

An olive brown crayfish held between a thumb and finger with a drying stream pool out of focus in the background.

A small but rocky stream below a blue sky, flowing through sagebrush steppe.

A view from a bridge crossing down into a stream bed of cobble and fine sediments, where one crayfish is visible crawling on a rock.

This pool was packed with non-native virile crayfish; we recovered >120 in only four traps. It will likely dry out by the end of summer, but virile crayfish have dispersed through this intermittent reach. We found them abundant in the permanent stream higher up the watershed (photos 2 & 3).

This is a good prediction.

A drying stream pool above a culvert, with a researcher collecting crayfish traps. Five gallon buckets, crayfish traps, and a clipboard are visible on the stream bank.

So ... any crayfish in this small and declining habitat?

An isolated stream pool above a culvert (not visible, where the photographer is standing) with a dry bed upstream. The pool is turbid and surrounded by dry steppe, with mountains visible in the distance under a mostly sunny sky.

Our search for invasive crayfish barriers includes more than just dams or irrigation diversions. Because the virile crayfish is intolerant of stream drying (doi.org/10.1086/725318), intermittent reaches could present barriers to upstream spread to permanent streams in the mountains.

They always are, from Australia to Madagascar to Canada

Two researchers hold a seine downstream of them in a moderately wide, rocky river

Two researchers check hand nets while overturning rocks on the shoreline of a reservoir

Two researchers check dip nets along the shore of a stream impounded behind an irrigation diversion

Crayfishing.

A pile of debris on grass that features many obvious crayfish claws and carapaces, cleared from a filter on center pivot irrigation that had clogged

Here an abundance of crayfish claws and carapaces have been cleaned out of center pivot irrigation filters that had clogged. In our study region, many farmers and ranchers identify this as a problem, but I don't think anyone has quantified these type of impacts of invasive crayfish to agriculture.

A map from the United States Geological Survey's nonindigenous aquatic species database showing the native range of the virile crayfish (Faxonius virilis) as light brown and non-native watersheds as a dark red. The species has a broad native range spanning the Great Plains, upper Mississippi River, and Great Lakes basin, but now occurs as a non-native species west of the continental divide and in Atlantic-draining watersheds of Appalachia. It's probably the most widespread non-native crayfish in North America, but is minimally studied relative to invasive crayfishes with more global distributions like the red swamp crayfish (Procambarus clarkii).

The non-native virile crayfish (Faxonius virilis) in particular has boomed in regions of the western US without any native crayfishes like the Colorado River (nas.er.usgs.gov/queries/Fact...). Given its abundance in irrigated lands, I wonder if we're missing damages and costs as an ag pest?

An irrigation diversion with sloughing banks that, on closer inspection, were full of crayfish burrows. Mountains and patchy clouds are visible in the background behind dense grass.

I routinely get calls from water management districts in southern Idaho concerned about damage to canals from burrowing by this same non-native crayfish. In estimates of economic costs of invasive crayfish (doi.org/10.1016/j.sc...), I think we're missing effects on agriculture in the western US.

The manager at this property noted they have problems with the invasive crayfish clogging irrigation infrastructure downstream of the diversion. Economic damages to agriculture from invasive crayfish are well-known on other continents, but I wonder if we've missed an impact in the arid western US.

A cat door-sized panel in a water control structure or dam that is partially open but clogged with debris, letting out a small flow of water.

A close-up of a small panel or gate in a water control structure that is clogged with both aquatic plant debris and noticeable crayfish carcasses, including visible walking legs and abdomens

This was another barrier where non-native crayfish passage was obvious before we started sampling. Here a small gate in one of the water control structures was clogged with carcasses from the upstream pool. I think this barrier is open to flow at times of the year when crayfish are moving around.

Disturbance and species displacement: different tolerances to stream drying and desiccation in a native and an invasive crayfish 1. Crayfish are among the most threatened taxa in the world and invasive crayfish are the primary cause of the decline of native crayfish. Most research has emphasised biotic interactions as the mech...

Crayfish in the genus Faxonius (formerly Orconectes) differ enormously in their desiccation tolerance (e.g., doi.org/10.1111/j.13...). Terrestrial locomotion by crayfish also requires moderate temps w/high humidity (www.jstor.org/stable/1549337). That's rare in our study region in the summer.

Winners and losers over a ½ century of change in crayfish assemblages of Wyoming, USA | Freshwater Science: Vol 42, No 2 Abstract Crayfish have experienced extensive assemblage reorganization as a result of global change, with some species becoming globally invasive and others becoming rare or extinct. We combined histo...

However, the invasive crayfish we're working with is really intolerant of desiccation. Faxonius virilis is usually excluded from intermittent or ephemeral habitats by other species (doi.org/10.1086/725318). I think it's going to be reluctant to go over-land in this very arid region.