Nest territories are essentially equivalent to what are called core-use areas, which are areas used more frequently than any others by wildlife. These areas contain homesites, refuges, and the most dependable food sources. These areas contain homesites, refuges, and the most dependable food sources. Since core-use areas for bald eagles are commonly calculated based on usage pattern for a much larger home range—well beyond visual tracking—telemetry is commonly used. However, the equivalence of core-use areas for nesting eagles can also be reliably determined by careful field studies that integrate geospatial data for perch locations and defended distances against other eagles. These core-use-equivalent areas are defined our studies as nest-territories, and here we’ll discuss how we map them and what they tell us about our territorial bald eagles.
Not only are prairie dogs a vital prey source for bald eagles but are they crucial for many other avian and non-avian wildlife in the Colorado Front Range, and thus considered a keystone species.
One of the questions many eagle lovers often have is “could that bird be the offspring of the territorial pair of bald eagles?”
Please join FRNBES and our partners at Colorado Sierra Club, Rocky Mountain Wild, and host of Colorado Audubon Chapters in advocating of for the protection this treasured pair of golden eagles and their habitat.
The Stearns nesting bald eagles have been repeatedly impacted by human activity and development. This appears to be occurring again in the summer of 2020, as a result of loud construction activity in close proximity to one of their most common use areas. In addition, the City and County of Broomfield plans to allow oil and gas remediation work near this site during September, 2020, a time when the Stearns eagles begin nest-building.
In the initial two weeks post-fledge, the adult and juvenile eagles focused most of their activity in an ~130-acre area of the hay fields north and northeast of their nest. The adults were busy tending to the two active juveniles in what we call the early “herding cats” phase of the post-fledge dependence period (PFD).
FRNBES filed two federal lawsuits versus U.S. Fish and Wildlife Service regarding permitted allowances for a construction company to build a large apartment complex in close proximity to an active Bald Eagle nest (the Stearns nest in Broomfield, Colorado).
There are two very different ways in which an eagle nest is lost due human causation.
In Colorado’s Front Range – specifically in Weld County – Bald Eagles are in trouble. Weld County is among the fastest human growth areas in the state, and residential and commercial development continue to threaten existing eagle territory.