Over the last few days, while having morning coffee in the backyard, I’ve had the impression there were more blue jays in town. Their calls seemed to be more frequent and from groups of two or more, unlike the summer months when long periods would pass with only scattered calls. But at any season, when a hawk or owl is around, jays seem to come in from every direction to harass the patient raptor, who endures the bullying for quite a while before being chased off, usually followed by several jays and other species of birds. After witnessing such activity, I am surprised by the actual number of birds around that until then remained hidden. Soon, though, all of them melt back into the shadows, and all becomes relatively quiet and calm again.
Morning view from the back door
On these late September days, there is a different feel in the air: goldenrod is in full bloom; many trees show signs of fall colors; and there might be the occasional migrant bird from the boreal forest foraging nearby for only a short time before moving on. On one such morning, I heard more than a few jays calling, and thought maybe they were after the local Cooper’s hawk. As I looked upward, thirty to forty jays flew overhead in a loose formation moving toward the southwest. They flew not in a serious energetic flight, but in a smooth almost coasting manner, flapping their wings like gentle fans rather than with high power thrusts. It was a pace that could probably be kept up for a long time. So from this behavior I determined that these were migrating jays—quite likely from faraway origins, maybe even southern Ontario—clearly on their way further south than my Macomb town. Other migrant jays from the North might stay around Macomb and nearby woodlands all winter; at the same time, many of the local jays may have moved on, possibly out of Illinois entirely, or not.
The reason why the jays engage in what might be termed “relay migration” is unclear. If there were a lack of food resources in the area, then all of the jays should move on. If some local jays traveled south to avoid cold Macomb winters, why would others tolerate that same winter? If the motivation to migrate is not food availability or habitat suitability, what other factors might indicate to a jay that it has gone far enough or that it does not even need to leave its breeding area? (Banding studies have provided some insight, but there are still many unknowns.)
Migrating is a risky adventure, but clearly worth the effort; otherwise, the behavior would not have been favored by natural selection. At Hawk Ridge in Duluth Minnesota, I recall watching a constant stream of blue jays in flight around the southwestern edge of Lake Superior, clearly heading for a destination that was not northern Minnesota. These birds were in serious power flights, warily sprinting over open areas from cover to cover. They used caution because great numbers of migrating sharp-shinned hawks that prey on small birds also used the same flight strategy of going around the lake, rather than across, to avoid being caught in weather with no place to land. I remember thinking of the jays as sharp-shinned hawk food, although I had not actually seen a hawk capture a jay in full flight.
Lake Superior at Hawk Ridge, Duluth, MN
In terms of bird activity, there is always something happening in the neighborhood, especially when overwintering flocks of blue jays patrol the streets. But to see most of it usually requires some attention, noticing small movements and sounds that are necessarily ignored or downplayed because of the myriad small demands of daily life. If I had not taken the time during morning coffee to simply sit and observe, I would have missed the migrating jays. Much later on that same day, I happened to look up from reading a book just as a small kettle of broad-winged hawks soared among the clouds in a patch of sky only visible between the canopies of several backyard trees; the hawks slowly circled and drifted to the southwest and out of sight in the same direction as the earlier jays. Two important memories on the same day, and each lasted less than a minute.
References
Cornell Lab of Ornithology. 2020. All about birds, https://www.allaboutbirds.org/guide/Blue_Jay, referenced 24 September 2020.
DeVore, S., S.D. Bailey, and G. Kennedy. 2004. Birds of Illinois. Lone Pine Publishing, Auburn, Washington.
Stewart, P.A. 1982. Migration of blue jays in eastern North America. North American Bird Bander 7(3): 107-112.