Orange, Oily Sheen in Streams: Iron Oxidizing Bacteria Published on July 25, 2025 You may notice an oily sheen along the edges of a stream, or along the sidewalk if groundwater or water from a sump pump discharges to that area. This is very common when it’s wet and the groundwater levels are high.
City Nature Challenge 2019 Results Published on May 10, 2019 This year’s friendly global citizen science competition, the City Nature Challenge, ended up with 159 cities competing!
Just What is Citizen Science? Published on January 17, 2019 iNaturalist Makes it Easy to Participate in Citizen Science
Rare Dragonfly Spotted in Arlington (and Virginia) for First Time Published on November 28, 2018 There was quite the discovery at this year’s Bioblitz in Glencarlyn Park.
2018 Arlington BioBlitz: 762 Observations of 362 Different Species Published on October 16, 2018 The second ever Arlington Bioblitz that took place on Sept. 15, 2018 had always been planned as a smaller and more focused event than the first one conducted last May.
City Nature Challenge 2018 Wrap-up Published on May 08, 2018 A friendly global challenge was issued this year: Which cities could engage the most people to record the most observations of wildlife and plants, and find the most species over 4 days, April 27-30?
Crows – Of Mobbing and Murder Published on December 22, 2017 We have two species of crows in the DC area: the common American Crow (Corvus brachyrynchus) and the slightly smaller Fish Crow (Corvus ossifragus), which is usually associated with water.
These are the Champions: Our biggest trees Published on December 14, 2017 Champion trees are the largest of its kind, in that species.
Daylight $avings Time Approaches Published on October 24, 2017 It’s no secret that fall is kicking in. Average temperatures are dropping, the sun is setting earlier and earlier and soon Daylight Savings Time will be upon us.