by Patrick McShea
Whether you participated in the recent City Nature Challenge (CNC) or not, the results of the Pittsburgh Region’s broadest annual citizen science biological survey might be of interest.
The visually rich and geographically referenced compilation is a record of 1,219 different species of free-living plants, animals, and fungi documented, via the iNaturalist phone app, by 446 observers within six southwestern Pennsylvania counties during four mid-spring days. It’s a site where anyone with an interest in local natural history can spend a lot of time exploring.
Participation in Pittsburgh’s 2021 CNC was 16% lower than during the 2020 event, a reduction resulting in a similar-sized decline in total observations, yet only a 10% drop in the total number of different organisms documented. This year’s event was held April 30 – May 3, nearly a full week later in the spring than the 2020 CNC, a modification that might have increased the likelihood for some organisms to be observed.
Garlic mustard (Alliaria petiolata), a highly invasive plant introduced to North America in the mid-1800s for its herbal value and erosion control properties, was the most commonly documented organism, accounting for 98 of the Pittsburgh Region’s 7,045 total observations. On the results page, where visitors can further explore every documented species, there’s information to be gleaned beyond the common and scientific names of each entry. Far down the rankings, for example, all four images of organ-pipe mud-dauber nest chambers show the wasp-build tubes attached to human-built walls, and both seal salamander images appear to be illuminated by flashlight or headlamp.
As a category, plants, and frequently their blossoms, account for over half the total species documented. Birds, which included some migrants passing through the Pittsburgh region, led the vertebrate class with 111 species documented. Mammals followed with 21 documented species, and documented species for amphibians and reptiles numbered 16 and 13, respectively. 197 species of insects were documented, as were 137 species of fungi.
Participation levels are also carefully recorded in the results, with CMNH’s own Mason Heberling, Assistant Curator of Botany, leading the pack with 403 recorded observations of 208 different species. He explains his level of activity as a response to the scientifically sound parameters established by the CNC organizers. “Because it is roughly the same time each year, I have made a habit of going back to the same several sites each year, mostly ones that are convenient and nearby to me, and ironically, ones I don’t often get to as much as I wish I could. I do that with hopes of after going back to the same handful of sites around the same time, year after year, we can look at year-to-year and longer-term differences.”
And CMNH’s own Bonnie Isaac, Collection Manager in Botany, was among 397 identifiers who contributed time and background knowledge during a critical six-day second phase of the CNC to review and identify the observations of other participants. In fact, Bonnie identified 872 observations during the challenge. Within the operations of the iNaturalist app, observations with GPS coordinates that are identified by two separate reviewers are termed “Research Grade,” meaning they can contribute to the data sets of future studies. Nearly 54% of the Pittsburgh Region’s CNC observations earned the research grade mark this year, a very slight increase over last year’s mark.
Through the CNC and other citizen science survey projects, the contributions of observers and identifiers enables the powerful image recognition software of the iNaturalist platform to increasingly transform our phones into broad spectrum field guides. As you scroll and click through this year’s CNC results it’s also worth reflecting upon what is both gained and lost through a digital interface.
In a 2015 New York Times essay titled Identification Please, naturalist Helen Macdonald pays homage to the low-tech field guide by first calling out their flaws:
Out in the field, birds and insects are often seen briefly, at a distance, in low light or half-obscured by foliage; they do not resemble the tabular arrangements of paintings in guides, where similar species are brought together on a plain background on the same page, all facing one way and bathed in bright, shadowless light so they may be easily compared.
She later explains the great value of field guides in preparing our eyes and minds for what we hope to observe:
Field guides made possible the joy of encountering a thing I already knew but had never seen before.
Patrick McShea works in the Education and Visitor Experience department of Carnegie Museum of Natural History. Museum employees are encouraged to blog about their unique experiences and knowledge gained from working at the museum.
Carnegie Museum of Natural History Blog Citation InformationBlog author: McShea, Patrick
Publication date: May 19, 2021