City Nature Challenge Starts Friday

Over four days starting this Friday, which cities worldwide will engage the most people to record the most observations of wildlife and plants, and find the most species? This is the City Nature Challenge, and it’s open to all, including you. Last year, 68 cities participated and tallied 441,888 observations by 17,329 people. This year, more than 160 cities around the globe will join this citizen science effort.
The free iNaturalist app ( is how data is recorded by those participating in the City Nature Challenge. First, install the app, or the even snazzier Seek version ( on your smart phone or tablet. Second, with a fully charged device, go outside from Friday, April 26 through Monday, April 29 and photograph living things with the app. Seek will tell you instantly what you have seen. The standard version can be asked to suggest possibilities. Third, be sure to upload your photos to iNaturalist. Save precious battery power by uploading your images from your home computer. Scientists and researchers will help identify your findings. To reduce their burden, do not submit photos of your pets, common birds or commonly cultivated flowers. No fido, no robins, no tulips. A short instructional video about how to use iNaturalist can be found here:
If you plan to focus on trees, take several photos: one with the entire tree and its surroundings, one of the branching pattern (alternate or opposite), one of the bark, one of the leaves and any flowers or fruit, and be sure to include any evidence of pests or disease. Submit all of the images of the same subject so that scientists have a better chance of correctly identifying what you saw. Your aim is to get “research grade” status for your work. Sometimes a piece of white paper or foil can help illuminate your subject, such as bark or a stationary salamander, so that researchers can see more detail of telltale markings.
For those fascinated by fungi, a good technique is to take a mirror with you and place it under the subject so that in one shot you can capture the base, stem, connection to the cap, gills and top of the mushroom. Detail of the area where the stem connects to the cap is crucial in identifying fungi with photos, so be sure to focus on that.
This type of crowd sourcing allows scientists worldwide, including many at our own Smithsonian Institution, to mine the data for information they need to track species. You might even find a new species! It has happened in our area before with insects, so go chase some bugs with your phone and see what turns up.
Last year, the DC Metro area did well during the City Nature Challenge, according to Alonso Abugattas, writing on the Capital Naturalist blog. He said the area’s 22,809 observations ranked it fifth overall, behind San Francisco—which with Los Angeles started the competition three years ago—(41,737 observations), Dallas/Fort Worth (34,218 observations), San Diego (33,448 observations), and Klang Valley/Greater Kuala Lumpur (25,287 observations). Just behind DC were Houston and New York. Coming in last was Palmer Station Antarctica, whose three participants had 36 observations of 27 species. Globally 124 new species were added to the iNaturalist data base that had not been present before.
     Participation by 876 individuals ranked our area fourth, behind San Francisco (1,532 observers), San Diego County (1,211 observers), Boston (992 observers), and just ahead of Los Angeles (855 observers).
The DC area came in eighth last year with 1,855 verified species observed during 40 planned events, 25 of them in Arlington. This year, more than 124 local events are planned. Check them out and sign up for events sponsored by Arlington County at Those under the auspices of Arlington Regional Master Naturalists are at For area-wide events, go to

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TreeStewards of Arlington and Alexandria, Virginia, are trained volunteers who work to protect, preserve, and enhance urban tree canopy through public education and volunteer activities such as planting, pruning, and caring for trees.
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