Thanks Scott.
The "canary in the coal mine". I've watched the decline of birds and bird species throughout the Colorado region for 48 years. My observations are not strictly scientific I admit, but yearly and monthly trips to favored areas have led me to see and believe that many species are in decline. Pawnee Grasslands, Rocky Mt. National Park, Boulder Mt. Park, Indian Peaks Wilderness, Boulder County Open Space, among many other places all are showing some species rapidly decreasing, including the following:
Flycatchers - all
Vireos - all
Black Headed Grosbeaks
Lazuli Buntings
Tanagers
Green Tailed Towhees
Bluebirds
Western Meadowlarks
Yellow Breasted Chats
Cassin's Finches
Woodpecker species - especially Williamson's Sapsuckers and Red Napped Sapsuckers
and many other species.
In my observations, habitat is being lost at a rapid rate, both north and south along end-point migratory routes. Some species though, are adapting to these changes by nesting in suburban-urban areas. Not because they want to, but because they are forced to. Examples include:
Say's Phoebes
Great Horned Owls
Coopers Hawks
Red Tailed Hawks
Swainson's Hawks
etc, etc.
48 years ago, you would almost NOT see any of these species' nesting near human habitats.
And note that this isn't just birds - its many species of wildlife and plant life.
Just my two cents.
John T (Tumasonis)