The phrase "gray catbirds" refers to birds that are predominantly gray in color and are known for their ability to mimic the sounds of cats. Full definition
Summarizing a recent study of gray catbird fledglings in the Washington, DC area, the SMBC claims that cats were responsible for «alarmingly high rates of nest predation and fledging [sic] mortality.» (voxfelina.com)
«A study recently published in the Journal of Ornithology says such cats were the No. 1 killer «by a large margin» of baby gray catbirds in three Washington, D.C., suburbs.» (voxfelina.com)
Data from the Atlas indicate that Maryland's gray catbird population declined perhaps 7 percent between 1966 — 1989, a period during which the state's human population grew approximately 35 percent. (voxfelina.com)