Colonial Waterbirds | Reporting in Iowa

One of the most unique groups of birds to occur in Iowa are the Colonial Waterbirds. Colonial Waterbirds are birds that depend on water for their food source and who nest in colonies called rookeries. These rookeries can have as many 100 or more nests and as few as two. The rookeries most often occur adjacent to or very close to water and depending on the species may be in a tree or on the ground. Great blue herons will often take over several trees in an area building somewhat flimsy looking platform nests.

The colonial waterbird species we are most interested in for Iowa are the following:


+ Double-crested cormorants
+ Black-crowned night-herons
+ Yellow-crowned night-herons
+ Green herons
+ Little blue herons
+ Cattle egrets
+ Great egrets
+ Great blue herons

Only conservative estimates of the number of rookeries in the state are available, because Iowa DNR staff does not have the resources to monitor many of the Iowa nests, nor to adequately search for new colonies. Great Blue heron rookeries are by far the most common and can be found statewide. Monitoring these rookery sites is important as it provides data on the reproduction and population of these important species which among other things serve as indicators of our water quality. Monitoring of nests is left mostly up to volunteers and concerned citizens. Therefore, the discovery of new nest sites, which is often by chance, is primarily by volunteers, other citizens, and agency staff.

If you or anyone you know locates a Colonial Waterbird Rookery, please report your findings to the Iowa Department of Natural Resources Wildlife Diversity Program, 1436 255th Street, Boone, IA 50036. Reporting forms with instructions can be downloaded below as well as instructions on how to get good coordinate location data on a rookery. Thank you for helping in the conservation and monitoring of a unique Iowa resource! Enjoy the outdoors!

Realize the birds are easily spooked and could abandon the nest if disturbed. Please remain 300 meters from the rookery and view them from afar. Realize that rookeries are often on private land, so please do not trespass unless permission from the landowner has been granted.

Colonial Waterbird Rookery Reporting Instructions and Form
Colonial Waterbird Rookery Reporting Instructions and Form

Questions? Contact Stephanie Shepherd at vwmp@dnr.iowa.gov for assistance.


Bald Eagles | Reporting in Iowa

The DNR is always interested in receiving reports of Bald Eagle Nests in the state. We maintain a database of nests and are interested in keeping it as up to date as possible. The information we are interested in is the exact location of the nest, whether the nest is being used by eagles and if young are present how many and the date of your observation. Please download and use the form below to report on an any Eagle nest:

Bald Eagle Nest Reporting Instructions and Form
Bald Eagle Nest Reporting Instructions and Form
How to Identify a Bald Eagle Nest

If you are interested in “adopting” and formally monitoring the nest as a volunteer for the DNR, please visit the Volunteer Wildlife Monitoring Program webpage for information on bird nest monitoring.

To talk to someone about reporting eagle nests in Iowa contact:
Boone Wildlife Research Station
1436 255th St., Boone, IA 50036
515-432-2823 or vwmp@dnr.iowa.gov