BBCU Surveys on the Missouri River

Black-billed Cuckoo and avian surveys along the Missouri and Madison Rivers are in full swing again this summer after the cancellation of the 2020 field season due to the COVID-19 pandemic. For nearly a decade, we have carried out this monitoring project in partnership with the UM Bird Ecology Lab and MTFWP. Every year we try to both refine the project and increase it’s scope in order to gain a better understanding of Black-billed Cuckoo, as well as other species, and their distribution in the state. 

At every survey point we conduct a 10 minute bird survey which is followed by a vegetation assessment, with an emphasis on important riparian species that appear to be in decline (such as the plains cottonwood) and noxious species, which, unfortunately, are generally not in decline. Black-billed Cuckoos are known to prefer cottonwood galleries with dense understory, so survey points in areas that have this habitat also include playback surveys in which we broadcast Black and Yellow-billed Cuckoo call recordings with a speaker. Cuckoos are very territorial, so if they’re present anywhere within hearing distance of our playback they typically respond and make themselves known very quickly. In most of the playback sites we also deploy Automated Recording Units (ARU’s) sensitive enough to detect and record Cuckoos from 150 meters away.

Although results from our ARU’s won’t be available until later this fall, the season has already been a success. We found two Black-billed Cuckoos at the end of our first multi-day survey float on the Missouri River! Two individuals of this highly elusive species is great, but our success didn’t end there. A playback survey on a small Missouri River island between Loma and Coal Banks yielded a territorial Black-billed Cuckoo to our surprise (they are more likely to be found further east). This individual stayed and coo-cooed for about 20 minutes, allowing us to get several good photos and video recordings. Several days later we went on another beautiful multi-day float from Coal Banks to Judith Landing, and found an incredible total of five Black-billed Cuckoos along the way, in the large cottonwood galleries near the confluence of the Judith River and the Missouri. The ARU’s we left around that area will hopefully record the vocalizations of these individuals and may give us insight into how, and for how long, they use that great stretch of habitat before leaving the area in fall. It will be interesting to see how many of the ARU’s we deployed in areas where we did not detect Cuckoos will actually capture the calls of this unique species. 

Stay tuned for the results of our ARU recording analysis later this fall or winter!

Written by Bo Crees, Avian Specialist