Which bird is commonly described as outcompeting local species and transmitting diseases, consistent with the given description?

• A. House Sparrow
• B. European Starling
• C. Common Grackle
• D. American Crow

Answer: (A)

The idea being tested is how an introduced or invasive bird can disrupt native bird communities by both competing for limited resources and helping spread disease. The House Sparrow fits this pattern especially well: it was brought into many regions near human settlements and has become incredibly abundant and aggressive. It readily takes over nesting sites and food resources that native cavity-nesting birds rely on, often outcompeting species like bluebirds and other small songbirds. The high densities and close contact in urban environments also increase the potential for disease transmission via shared feeders, droppings, and contaminated surfaces. While other invasive species can show similar effects, the House Sparrow is the classic example of this combo—outcompeting locals and contributing to disease spread.