The strong cold front on September 20-21st brought what was probably the last major push of Broad-wings over Hawk Ridge this season, including 1148 on September 20th and 2975 on the 21st, which gives us only a little over 10,000 for the season, which is much lower than average. The vast majority of this species flies through in a very narrow window from about September 8-22, and if we don’t get the right weather conditions to push them to Lake Superior during this period, they simply fly elsewhere.. This season a series of low pressure systems, with south and east winds, including rain days on the 18th and 19th, appeared to disperse the flight.
Good numbers of Peregrines have been flying through this week, but almost all of them have been adults, at a time when I would expect the flight to be mostly juveniles. This is true also for Red-tails, which have just started to increase in numbers, but most have been adults, and it appears we may not have any significant flight of juveniles, which generally would come through in late August and September. These species may have had poor production of young this season. The first adult dark (“rufous”) morph Red-tail of the season flew through on September 19th, which seemed earlier than normal.
This was another great week for songbird migration, with another mass movement on September 20-21st as a strong cold front came through the region, and what was probably the last major push of neotropical migrants departed.
This has the been the week of the Blue Jay, with over 18,000 seen in the last seven days, including single day counts of 5627 on September 16th and 5434 on September 21st, bringing the season total to about 25,000. This has also been a great week for large numbers of warblers, including a great flight of 4270 warblers on September 20th. Although this flight started out with a good diversity of warbler species in the morning, including good numbers of Nashvilles, Palms, and American Redstarts, by the afternoon when the warblers were still flying, the flight appeared to have shifted to mostly Yellow-rumps, which was also true on the 21st.
With the departure of many neotropical migrants, the diversity of species moving through is dropping. Interestingly, the overall number of migrant songbirds will increase the next few weeks, as very large numbers of primarily more diurnal, shorter distance migrants become more common, such as American Robins, Rusty Blackbirds, and finches. As the number of Blue Jays decrease, these other species will become the most abundant migrants of the fall. On the 21st, thousands of Blue Jays were joined by hundreds of robins and Rustys, which made for an excellent flight.
Sandhill Cranes, American White Pelicans, American Golden-Plovers, American Goldfinches, American Pipits, and Common Grackles have all been increasing in numbers as well. Luckily American Crows don't start moving in numbers until October, because that would be just too many Americans.
The funniest sighting of the week was a single Ross’s Goose that tried to join a flock of 35 American White Pelicans on 21 September, falling into the V and even staying in formation as the flock of pelicans began circling, but then as the flock continued circling it realized it didn’t know what to do with these giant, soaring birds, so it finally gave up and broke off.
|juvenile Red-tailed Hawk attacking the owl decoy at Hawk Ridge|