The line graph below represents the annual frequency of Ruby-throated Hummingbird (RTHU) sightings in Alachua County, FL. There is a full discussion of the six points here but we'll jump to the section between points 1 and 2 today because that's our current status as we head into the final month of summer. RTHU has already passed it historical peak in Alachua County but I want to bring your attention to the little shoulder on the line graph notated by point 2. That shoulder represents an increase in the average frequency of RTHU caused by storms that affect the ability of birds to migrate across the Gulf of Mexico and through the Antilles. Because we have had so many active storm seasons in the past 10-20 years, Ruby-throats will "bottleneck" in the Florida Peninsula as birds continue to migrate from points further north but are temporarily unable to fly across the water because of storms. Depending upon the severity, location, and duration of each storm event, bottlenecks and the resulting spike in the graph can be significant. To illustrate the point, see the second graph below.

The "Bottleneck Effect" of storms illustrated - The graph below shows Ruby-throated Hummingbird activity in Alachua County in 2017 when we had three major storms in the Gulf of Mexico and the Antilles from late August through early October. The effects of Hurricanes Irma and Nate on in-season frequency of RTHU are noted along with the historical peak. Hurricane Maria also affected activity on most of the dates between Hurricanes Irma and Nate. We have already experienced a few smaller bottlenecks of RTHU activity in the county this summer and with the busiest part of the hurricane season yet to come, we stand a good chance of seeing at least one more.

I recorded this footage during the Bottleneck Effect caused by Hurricanes Irma and Maria in 2017. There were five or more hummingbirds visible around my firespike at all times over the course of about a week. Experts will tell you that, during migration, the ratio of birds that you can see to birds that you can't see is about 1:6. That means we could have had about 30 birds in the yard during this particular bottleneck. That's not a lot of hummingbirds for places like Arizona, California, or Texas but it is a lot for Florida. So, enjoy those birds now!!!