Bill made a number of interesting comments and observations concerning Common Nighthawks that parallel my own observations over the years. Other than a few scattered individuals, I cannot remember seeing any fall migrant flocks of nighthawks until late afternoon and through the evening. I'm pretty sure all of the large flocks I have seen during the fall migration have occurred between 3:00 p.m. (usually later) until about dusk.

 

Joe Bens and I were just discussing this very same subject last Sunday night when we were driving home after seeing 75+ Common Nighthawks milling around above the Great Miami River at Shawnee Lookout Park between 7:00 and 7:30 pm.

 

"Birds of North America" states that Common Nighthawk migration is "not well studied and that migration flights occur both day and night but most are observed during evening in the fall".

 

Joe and I both thought that it was possible that when we see these fall migrants at low altitude (tree-top levels) in the evening they often seem to be foraging, taking advantage of the insects found at the low altitude, before either moving on and continuing they're migration into the night or possibly before coming to roost for the night.

 

We also felt it is quite possible that when they are strictly migrating (not foraging), they may do so at extreme elevations making them difficult or nearly impossible to detect. I remember once seeing a tight flock of nighthawks numbering 500~ birds kettling and moving slowly south over the Cincinnati Zoo around 7:00 pm some years ago (during a Cincinnati Bird Club picnic). These birds were so high they were barely visible. Is it possible that early evening is a preferred time to forage at lower altitudes and that when they are set on direct migration they do so at higher altitudes beyond our notice?

 

A couple of times I got the distinct impression that some large fall flocks (200+) I have seen, especially at Winton Woods, in the early evening may have spent the day there and as evening approached began moving off of they're day roost and began foraging right above those same woodlands. This is just speculation, but it seemed to me that they didn't so much as move into the area as they just materialized and began their activities right there. The birds we saw at Shawnee Lookout the other night gave me that same impression. We had a good view of several miles of skyline as we were looking at shorebirds in the Oxbow looking east towards Shawnee. Even though we were looking at shorebirds we made constant scans of the sky, looking for raptors and migrating nighthawks. After standing in that same spot for over an hour, Joe noticed this large flock of nighthawks milling very low, just above the treetops in the valley at the base of the Shawnee Lookout hill. We did not notice them arrive to this point and I feel it is possible, even likely, that they came up from a day roost in those very woodlands where we saw them foraging. After watching them for a while many seemed to gain elevation. We decided to drive over that way to get a closer look but when we got there 10 minutes later they were gone.

 

Jay Stenger

Cincinnati, Ohio

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