Maryland Ornithological Society (MOS) is a nonprofit organization focused on birds and birding in Maryland and the Washington, DC area, promoting conservation, education, and science through chapters, events, field trips, and resources. It provides tools for birders and educators—official bird lists and checklists, breeding bird atlases, field guides, and programs such as YMOS for young birders and scholarships for educators. MOS also runs an annual convention, coordinates counts and other outreach activities, partners with groups like the Maryland Bird Conservation Partnership, and publishes periodicals such as Maryland Yellowthroat and Maryland Birdlife.
AI named Maryland Ornithological Society from December 2025 to January 2026.