Living Things: Jeff Skrentny is trying to peer identify 2,500 this year in Cook County

Jeff Skrentny is on a mission to peer identify 2,500 living things in Cook County this year on iNaturalist.

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Jeff Skrentny, who is on a quest to peer identify 2,500 living things this year in Cook County, in his iNaturalist photo.


Jeff Skrentny mentioned desire to document 2,500 living things in Cook County at the showing of Bob Dolgan’s documentary, “Monty and Rose,” at Martyrs’ on North Lincoln.

That caught my attention. It seemed unlikely enough that I asked why.

“I will be attempting to see and have peer identified via iNaturalist, as many species of all living things as I can in Cook County this year,” he emailed. “I foolishly said I had hoped to document 2,500 living things in the county in the year, but further research shows me that such a number will be a heck of a stretch goal.”

Stretch? Last year all observers had 2,472 living things in Cook County and just over 3,500 things in all the years of iNaturalist. Since he joined iNaturalist in June of 2016, Skrentny has made 9,000 observations of 1,700 living things.

On Tuesday, I reached Skrentny at a Toyota dealership.

“Just so happens that I am stuck getting my Prius, `The Belafonte,’ cleaned and checked at the shop, so I can continue my exploration from one end of Cook County to the other,” emailed Skrentny, who noted it is 74 miles from northwest to southeast in Cook County.

He set a high bar. His living things count only if peer identified on iNaturalist. A joint initiative by the California Academy of Sciences and the National Geographic Society, the iNaturalist app helps users identify plants and animals around them while also building data.

One reason he values iNaturalist beyond data is that, “You respect a thing by naming it. [Then] you can have a respect for the thing and the ecosystem it is a part of it.”

File photo

File photo of Jeff Skrentny of Chicago, who is a volunteer with both the Chicago Ornithological Society and the Friends of the Cook County Forest Preserves, looking for some things to photograph at the LaBagh Woods Forest Preserve in 2015.

Michael Schmidt/Sun-Times

He is good at identifying. At LaBagh Woods, near their Northwest Side home and where he does restoration work 15-25 hours a week, he has identified 1,000 living things. As of Tuesday, he had entered about 400 things this year from Cook County, 310 of which have been peer identified.

“They only count if I get it peer reviewed,” he said.

Birds, mammals, fungi, slime molds, mushrooms, insects, spiders and such count.

“If it is alive and not super microscopic, it counts,” he said.

He thinks 250 birds, 1,000 plants and 1,000 insects (his weakness) and the rest mammals, frogs, snakes and so on would get him to 2,500.

“A great year would include seeing a species never before recorded in Cook County,” he emailed later.

Things he would love to see this year in Cook County are a North American river otter, a massasauga, an American eel, a muskie and a few rare plants he has yet to find in the county.


Greg Remec with the muskie he caught near the Adler Planetarium on April 8, 2017; Jeff Skrentny hopes muskie will be one of the 2,500 living things he documents and gets peer-reviewed in Cook County this year.


The idea came up between Skrentny and Paul Sweet, a biology instructor at College of Lake County, who is doing something similar in Lake County.

Skrentny knows long lists and this one he plans to be a book.

“On Jan. 1, 2006, I decided I was going to be birder.” said Skrentny, who started with “The Sibley Field Guide to Birds of Eastern North America.”

He became keeping life lists. His Cook County list is 333 or 331; his Illinois list is 379 and his world list is 602, nearly all (565) from the United States.

“I am really focused on what we have in Illinois,” he said.

Every night, he spends 35 minutes seeing what somebody has seen and see if he can find it.

“I am not going to find all of these things myself,” he said. “I know where about a 1,000 plants were seen. Plants usually grow back in the same place.”

Insects usually come back to the same place.

“I can get 1,700 to 2,000 on my own, but I will need community support,” he said. “It is hard to sustain motivation for a whole year.”

Skrentny said the biggest possible obstacle is “There’s life. Life can interfere. I am still the Dad, which means I am an Uber driver for them.”

But he has experience. Twice he has done a Big Year in birding. In 2009, he tied the then Illinois record. In 2013, he did a Cook County Big Year and broke the record, but somebody the same year had two more.

“I like long arduous journeys,” he said.

You may not see Skrentny on his searches, he can disappear for hours, even in the heavily populated Cook County. But, he is rather distinctive.

As is his quest.

“In this day and age, it is a message that needs to be reinforced,” Skrentny said. ``It is a message that seems to be getting lost. I want them to care more. It is, in my small way, a protest as much as raising awareness.’’

In the end, Skrentny said, ``Maybe people will give a darn more than they do, even in this most urban of urban counties.’’

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