Great Blue Herons

Great Blue Herons in Broomfield

Great Blue Herons are protected by international treaty under the Migratory Bird Treaty Act of 1918. These herons congregate during the breeding season in rookeries for the purpose of courtship, nest building, egg-laying and incubation and chick rearing. Great Blue Heron colonies are dynamic and can vary annually, especially in areas of high disturbance. Small colonies are less stable and relocate more frequently than colonies with more than 50 nests. Colony size and location are related to the quality and quantity of nearby foraging areas.

In Broomfield, a small heron rookery occurs on the southeast shore of the Lower Pond. In spring 2012, open space amenities were built near the rookery, including construction of a new trail. The open space amenities contributed to increased recreation and the number of visitors to the area. Monitoring surveys of the rookery were conducted 2013 through 2023 heron breeding seasons to assess the status, activity and viability of the rookery and to note any signs of disturbance associated with the increased recreational activities around the rookery.

Great Blue Heron Monitoring Efforts

The Broomfield's biologists (ERO Resources) monitor the heron's behavior to ensure they are not disturbed by activities in the area. Please feel welcome to approach these experts and ask questions about the eagles.

Great Blue Heron Monitoring Reports

• 2023 Annual Great Blue Heron Rookery Monitoring Report

For a copy of a monitoring report not listed above please email openspace@broomfield.org.