The migration continues to amp up during week 5 of the Mackinac Straits 2024 Fall Raptor Watch. Our strongest day of the year so far occurred on 9/15 with a total of 455 raptors counted. The total number of raptors this week amounted to 2,168. Sharp-shinned Hawks and Broad-winged Hawks remain the two most numerous species, at 37% and 33% of the total count respectively.
The week started strong on 9/15, as mentioned previously, being the highest count day of the season thus far. The first dark-morph Red-tail was recorded on this day. The first Cooper’s Hawk of the season was also recorded.
September 16 saw another strong day of 433 birds, with light and variable winds that settled in the afternoon. The calm weather also allowed Calvin and the visitors to hear Horned and Red-necked Grebes from the count site.
The next day on 9/17 was another calm day with light winds, though the migration slowed significantly to only 133 raptors. September 18 had more haze and humidity, with more birds than the previous day at 283. The migration started out slow in the morning and picked up between noon and 2pm, with birds flying quite high.
Warmer weather characterized 9/19, with high cirrus clouds then cumulus building late in the day, and moderate winds coming from the east and south-east. The winds had the raptors coming in pulses on kettles, often coming back and forth over the count site as they attempted to cross the Straits. Broad-wings saw their highest day of the season thus far at 203 individuals, with one group numbering over 60 birds.
September 20 was significantly slow with showers and overcast weather. Only 30 birds were sighted, although over 200 American Pipit were seen along with 10 duck species.
Finally on 9/21, the migration bounced back again with 418 total birds observed. Sharpies, Turkey Vultures, and Bald Eagles all had their best days of the season. The weather was calm, with light winds building to moderate in the afternoon, and a foggy morning followed by full sunshine. Much of the flight occurred in the afternoon, tapering off around 3pm. The Monarchs also had an excellent day, with 135 being counted at the count site and still moving when Calvin left for the day.
Overall week 5 has been very exciting with numbers of birds continuing to build. It will be interesting to see what the second month of the fall migration has in store in the next couple of weeks. Stay tuned and make sure to visit us at the St. Ignace count site!
