Black-crowned Night-heron photo by Tony Yee.
Exciting news! Black-crowned Night-herons will be getting some much-needed attention from researchers and conservationists. Dr. Michael Ward’s lab at the University of Illinois, Urbana-Champaign has partnered with biologists at the Illinois Department of Natural Resources, and Lincoln Park Zoo to develop techniques to encourage some birds to set up additional rookery locations.
Black-crowned night-herons (BCNH) are a colonial wading bird that historically nested throughout Illinois. They have been listed as endangered in the state since 1977. The largest remaining breeding colony in Illinois nests right in the middle of Chicago, in and around Lincoln Park Zoo. Having such a large proportion of the state population in a single breeding colony could expose the birds to further threats (e.g., avian influenza or a storm), as well as damaging the nesting trees as the concentration of guano increases.
The team has identified a peninsula in Big Marsh Park in Calumet that has suitable nesting habitat. Up until the early 2000s, BCNH used to nest in this area and in the surrounding wetlands until nesting trees died and widely fluctuating water levels exposed nests to predators. Now, they hope to encourage some birds to return to this site through a method called “conspecific attraction”.
The team placed 19 BCNH decoys at Big Marsh, around the base of the peninsula and in many of the trees, and set up callboxes that play BCNH vocalizations at dawn and dusk when the birds are likely to be flying overhead. If you are out birding in Big Marsh and see some unusually large, unmoving BCNH, those are the decoys! However, if you see any real BCNH or other wading birds interacting with the decoys, please contact Sarah Slayton at slayton4@illinois.edu. .
Additionally, urban BCNH foraging behavior and habitat use throughout the Chicagoland area is being studied. If you are interested in other potential volunteer opportunities, please send an email to Sarah (above). The team is excited to learn from Chicago birders, and to work with us towards their conservation.
Four adult Black-crowned Night-herons nesting at the Lincoln Park Zoo and three fully flighted juveniles were successfully captured and fitted with special satellite transmitter “backpacks”. Researchers now receive data uploads that provide information about their daily movements across the Chicagoland area and will allow us to learn about their wintering grounds. Additional birds received leg bands. This information will help guide conservation efforts for this state-endangered species within Illinois, and beyond.
Please keep an eye out for BCNH throughout the Chicago area, and follow this link to report any banded heron sightings: https://arcg.is/0vKHPW0. Please look closely at its left leg for that alphanumeric tag and include it in your report if you can! This work would not be possible without the support of the Chicago Black-crowned Night-Heron Project, Bird Conservation Network, and the Chicago Parks District. These groups were critical in providing financial, volunteer, and logistical support throughout this field season