Karl Grantmyre and John Campbell have been teaming up since 1986 to find, build and record Prairie Falcon nests along a 100 mile stretch of the Bow River.  

 Prairie Falcons are currently listed as a "species of special concern" by the Alberta government. There are roughly 20-25 active nest sites along this stretch of river in a good year. Some years there are less than 10.

What We Know About Prairie Falcon Nest Sites

Over the last 30+ years we have drilled new nest sites in rock faces, cleaned out rock crags/ledges and reinforced them with concrete, painted cliffs with white paint to encourage nesting, renovated historic natural sites and built hack boxes to hang over eroding cliffs. We have learned that the most productive site on the Bow River is an artificial site. Chicks have been produced reliably every year at this particular location. 
Maintaining historic sites is very important. They are still the most reliably used nest sites.