If you would have gone to Goose Pond within the last couple months in the hopes of seeing Northern Harriers, you would’ve been lucky to see one. If you did see one, it would’ve most likely been the slate-gray male gliding over the prairie in search of prey. However, if you walked around Browne Prairie today, it would be hard to miss multiple brown Harriers clumsily flying over the prairie, not quite mastering the steady glide of their parents. These four once-fuzzy, gray chicks have left their nest in Browne Prairie on approximately August 1, and have begun to explore the surrounding areas.
Northern Harrier. Photo by Mick Thompson
On May 19 and 20 Neil Rettig and Laura Johnson came to Goose Pond to film grassland birds for the Cornell Lab of Ornithology (read more here: Filming Grassland Birds at Goose Pond). On Neil and Laura’s first visit, the Northern Harriers were in the early stages of breeding: the male was bringing nesting material to the female, who would ultimately choose the location for and build the nest. At this time, we deducted the general location of the nest, but couldn’t be sure as male Northern Harriers are known to bring nest materials to multiple ‘cock nests’ before the female settles on one location.
A goal of Cornell’s grassland bird project was to film multiple stages of nesting behavior, so Neil and Laura planned to come back in July to film nestlings if we could confirm a nest. So on July 5, Mark, Graham, and I set out in the Browne Prairie to locate the Harrier’s nest. We walked in tight transect lines, ten-fifteen feet apart, within the area we remembered the male bringing nest materials. It was important to walk close together because Northern Harrier nests are expertly concealed in the tall grass and one has to get surprisingly close to the nest before the female flushes. It was a brutally hot and humid afternoon and we had already walked back and forth a discouraging amount of times, but it was the kind of weather that if you’re going to spend any time in, you’d better succeed, so we decided to walk another line. We were halfway through the transect, Mark in the middle, and Graham and I on each side, when a large brown raptor erupted from the prairie just a few feet in front of us. Mark looked over with a grin, “I think I was the one who found it”.
Northern Harrier chicks defend their nest in Browne Prairie. Photo by Graham Steinhauer
Mark and Graham carefully tiptoed forward to find the nest, count the young, and mark the location. There were four downy chicks, mouths agape, trying to look extra scary despite their size. On our way out, Mark was laughing and told me that he didn’t want to tell me this before searching for the nest, but that Northern Harriers are highly territorial, so there was a risk of being attacked. I read about their aggressive and territorial behavior in Frances Hamerstrom’s book, Harrier, Hawk of the Marshes, and didn’t say anything either. I guess it was a risk we were both willing to take!
Neil and Laura came back twice to film the nestlings. They captured footage of the parents feeding the chicks, and observed the male flying back and forth after a successful hunt. However, the well known nest in Browne Prairie did not appear to be the male’s only stop: Laura observed the male leave the nest after delivering prey, catch a blackbird about 40-50 yards from the nest, and fly to the south and out of sight. Perhaps our male Northern Harrier has more mouths to feed than we thought!
One juvenile Northern Harrier with prey is closely followed by its sibling. Photo by Arlene Koziol
Watching the young harriers fly around the prairies and learn to catch prey mid-air from their parents has brought so much joy and excitement to Goose Pond staff, but soon we must wish them well on their journey south. In her book Harrier, Hawk of the Marshes, Hamerstrom hypothesized that age, rather than parental influence, triggers the onset of migration. She and her colleagues observed that young harriers typically head south on their migration about 3 weeks after fledging. Our harriers were first seen flying on August 1, so it will be interesting, and a little sad, to see if our harriers we see gliding through the air dwindle next week. However, we expect to see other harriers migrating through the rest of fall.
We last wrote a Northern Harrier Friday Featured Feature in 2016 but we have accumulated a lot of data since then.
In the 2015-2019 Breeding Bird Atlas II, Northern Harriers were “confirmed breeding” in eight of the 85 atlas blocks and “probably nesting” in an additional five. The atlas volunteers' main focus was on 18 priority blocks where harriers were “confirmed” in five and “probable” in two of the 18 priority blocks.
We are developing a nice data set for nesting chronology for Goose Pond. There were nests or fledged young that we probably missed including at the Benade tract.
Northern Harrier range map. Cornell Lab of Ornithology, All About Birds
Northern Harriers like to nest in large grassland areas, so we are fortunate to have large blocks of grassland in Columbia County thanks to Madison Audubon, the Department of Natural Resources, and the Fish and Wildlife Service. The adjoining table shows nesting locations at Goose Pond. In the Breeding Bird Atlas II, volunteers including JD Arnston, Charlie Luthin, and Jim Otto found nesting harriers at Jennings Creek, Lodi, Mud Lake, Peter Helland Wildlife Areas and at the Hinkson Creek, and Schoenberg Marsh Waterfowl Production Area.
Thanks to everyone that provided data and photos on nesting harriers.
Written by Emma Raasch, Goose Pond Sanctuary seasonal employee
