Dear Robert and Justin,
Our citizen science bald eagle nest monitoring team has recorded three observation sessions during the past week at the Hygiene Road nest (July 21, 24, and 26). In previous emails, I have emphasized the importance of prairie dog colonies adjacent to all of 14 nests in the Front Range that we have studied. The Hygiene nest is no different. The fields generally north, north east, and perhaps northwest of the nest are important foraging resources to the Hygiene bald eagles, and this is well demonstrated by their behavior in our observation sessions just this week.
These recent observations are simply examples that show the importance of these foraging fields and the adjacent prairie dog colony in a time period that many researchers consider to be one of the most critical in the development of young eaglets.
In terms of time budgets:
July 21-Adult male 31% of observation time, ~0.25 miles north, northeast of nest foraging. Fledgling 1, 10% of time at same position (153 total observation minutes)
July 24-Fledgling 1, 18% of observation time, 0.2 miles NE of nest foraging; Fledgling 2, 13% same position (120 total observation minutes)
July 26-Fledgling 1, 53% of observation time, 0.2 miles NE of nest foraging; Fledgling 2, 10% of time at nearby positions and caught live prairie dog (90 total observation minutes).
Finally, contrary to current misconceptions, nesting and other Bald Eagles in this part of the Front Range commonly capture live prairie dogs. The attached photo shows one of the Hygiene nest fledglings on July 26th, 2017, just after capture of a small prairie dog during foraging about 0.2 miles NE of nest (my apologies for the atmospheric distortion during yesterday’s conditions).
This photo and the above documentation are being utilized here just to give examples of the importance of these foraging fields and prairie dog colonies, where gravel mining is being considered. In the fledgling phase, prior to dispersal, the young eaglets are notoriously inept hunters, and depend on most of their food to be provided by the adults. The opportunity for the fledglings to stalk and actually catch their own prey—as shown in the attached photo—is important, so I encourage all parties to make sure this planning is done right, so that this important foraging resource area isn’t displaced. I believe it is critical in the sustainability of this nest.
Please see attached (also note prairie dog in background for scale):