Why Birds Matter: Conserving the World’s Birds and Their Ecosystem Services Cagan Sekercioglu, Department of Biology Birds play critical roles for ecosystems and human well-being worldwide.  Birds consume pests, pollinate flowers, disperse seeds, scavenge carrion, cycle nutrients, and modify the environment in ways that benefit other species. However, the ecological importance of birds and the economic value of their services are not widely appreciated, and many face extinction due to climate change, habitat loss, and introduced species. By studying birds' ecological functions and ecosystem services, we can understand the environmental consequences of bird declines and extinctions for ecosystems and for the people that benefit from birds’ services.