For 77 evenings, between August 6 and October 24, I left my home to count Chimney Swifts that were seeking a nightly roost site as they migrated through Central Ohio on their way to Columbia, Ecuador, Peru and the northwest corner of Brazil. Swifts showed up for 75 counts while two of the 77 evenings were spent counting zero swifts to make sure that there were no mistakes determining their latest date for the year.
In Milton and Mary Troutman’s Annotated List of the Birds of Ohio (1968), they list the swift’s fall migration period as July 25 through October 8. During the previous 15 years that I have counted swifts, their earliest last date was October 6, 2005, and their average last date during those 15 years is October 12. Their latest date had been October 18, 2006.
This year, the sixteenth year of counting, four days were added to the latest annual date as seven swifts dropped into their chimney on October 22, a record date confirmed after no swifts were seen during the next two nights.
So, why was the swift migration so late? My first guess is that their food supply, flying insects, is lower due to warm winter temperatures that encourage insects to emergence too early from hibernation. Then, in today’s world, there are multiple chemicals applied for multiple reasons, including agriculture, lawn care, forest health, and human health. Also, I can’t help wondering about cell tower radiation that is everywhere. If radio waves can cause reactions in their intended receptors, why can’t the same waves occasionally affect biological receptors in living cells.
By the end of the swift’s migration, I had visited seven chimneys. I visited two chimneys only once. I did not count at the Sells Middle School in Dublin as hundreds of swifts dropped in its chimney; I only visited and played the role of naturalist to a program led by Darlene Sillick. The other lone visit was at the Galena Village Hall where hundreds of swifts confirmed that its chimney continues to be a very popular roost.
The remaining five chimneys are all inside Delaware. I sat in a canvas director’s chair as I watched Gray Chapel on the campus of the Ohio Wesleyan University, and I used my chair on the sidewalk in downtown Delaware when I counted swifts entering the chimney at the First Commonwealth Bank.
My Chevy Spark was my sanctuary at three chimneys. For Edward’s Gym at OWU, I parked my car in their van parking lot across the street, and parking lots at Carlisle Elementary School and Zion United Church of Christ were usually accessible, but when I found parking lots filled with cars, it was a short distance to other options within the city.
I always download a sunrise/sunset chart from the Internet and arrive on site one-half hour before sunset, then the swifts are usually in their chimney within an hour after my arrival.
As I launched the 2018 season, the Carlisle chimney was quite active, so I checked it on alternate days as I entered other swift counts from other chimneys into my data book on alternate nights. By September, I stayed with the elementary school’s chimney every night until the chimney “died,” or became inactive by the third week in September.
Chimneys can become inactive for more than one reason. Exhaust chimneys become inactive when they kick into gear, and intake chimneys are abandoned once temperatures drop and the roosting swifts find the breeze drawn over their bodies to be too cold.
Chimneys are built to drain after rainstorms, but if drains become plugged, wet swift guano decomposes to release ammonia gas. As swifts enter the chimney, they produce enough turbulence until the ammonia gas slowly rises to reach the roosting birds, and they flee the chimney. I have seen this happen several times, all within several days after saturating rains.
Unlike most birds, swifts can smell odors, so when swifts die inside chimneys, their odors of death will repel other swifts seeking a roost. Also, swifts can smell raccoons and other critters that are already using chimneys for their own.
After the Carlisle chimney became inactive, I focused on the Zion United Church of Christ chimney for all of October’s observations. Since the previous season, tree limbs had been trimmed away from the chimney, making it easier for the swifts to negotiate a more accurate drop into their roost. I was so obsessed with the season that I skipped an important meeting, and days later, managed to arrive in Delaware on October 20 early enough for a swift count after an enjoyable day at the Ohio Avian Research Conference held at Denison University. The old record of October 18 had already been surpassed and I’m glad that I made the effort to return to Delaware to count ten swifts at the church. Excitement grew for two more nights as I counted one and seven swifts, respectively, as the new record late date became October 22 for the swifts. And, once I counted zero swifts on October 23 and 24, the season ended for me.
Migrating Crows made October extra special as they would arrive in the northeast corner of Delaware at the same times that swifts were selecting roosts. I think the crows were trying to avoid Great Horned Owls by roosting in trees within a City. During many of October’s nights I would see flocks of more than fifty crows, North America’s most intelligent birds.
So, I list my data below with the first and last entry times in the last column. Subtract 12 from each military time to find the local time. I hope the numbers promote questions and thoughts of your own. I have more to report on, and I plan to do so in a later newsletter to better prepare additional swift counters. In addition, more and more swift towers are going up to help this valuable bird procreate and find safe shelters to roost in. There’s a lot of information on the Internet to checkout. And, lastly, next year at this time, I hope to report on a new fancy brick tower on the campus of Ohio Wesleyan University. Swift on!
2018 Fall Chimney Swift Counts, N=77
Carlisle Elementary School, 746 West Central Ave., Delaware, n=29
August 6 195 swifts 20:32 – 20:59
August 8 293 swifts 20:36 – 21:09
August 9 362 swifts 20:23 – 21:04
August 11 343 swifts 20:15 – 21:00
August 12 314 swifts 20:08 – 20:57
August 14 319 swifts 20:28 – 20:55
August 16 325 swifts 19:57 – 20:43
August 18 362 swifts 20:06 – 20:54
August 20 634 swifts 19:58 – 20:47
August 22 515 swifts 20:18 – 20:45
August 24 613 swifts 19:57 – 20:41
August 26 455 swifts 20:32 – 20:41
August 27 498 swifts 20:07 – 20:41
August 28 493 swifts 20:09 – 20:37
August 29 760 swifts 19:49 – 20:31
September 1 910 swifts 19:38 – 20:29
September 3 844 swifts 20:11 – 20:30
September 5 834 swifts 19:57 – 20:20
September 7 693 swifts 19:43 – 20:11
September 8 51 swifts 19:29 – 19:59
September 9 379 swifts 19:27 – 20:06
September 10 879 swifts 19:18 – 20:02
September 12 692 swifts 19:50 – 20:15
September 14 468 swifts 20:05 – 20:17
September 16 675 swifts 19:56 – 20:08
September 17 492 swifts 19:24 – 20:05
September 18 599 swifts 19:51 – 20:06
September 20 one swift 19:55
September 26 zero Watched 18:55-20:00
Sells Middle School, Dublin, a program planned by Darlene Sillick and sponsored by the Columbus Audubon Society, n=1
August 10, I did not count. I only interpreted.
Hundreds of swifts entered…
Zion United Church of Christ, 51 West Central Ave., Delaware, n=32
August 17 76 swifts 20:29 – 20:44
August 21 44 swifts 20:29 – 20:44
August 25 16 swifts 20:16 – 20:35
August 30 9 swifts 20:16 – 20:30
September 6 8 swifts 19:50 – 20:11
September 15 37 swifts 19:52 – 20:12
September 23 138 swifts 19:37 – 19:50
September 27 460 swifts 19:22 – 19:46
October 1 275 swifts 19:27 – 19:39
October 2 270 swifts 19:25 – 19:33
October 3 309 swifts 19:27 – 19:39
October 4 467 swifts 19:17 – 19:31
October 5 322 swifts 19:23 – 19:33
October 6 221 swifts 19:27 – 19:33
October 7 292 swifts 19:20 – 19:31
October 8 198 swifts 19:17 – 19:28
October 9 212 swifts 19:17 – 19:24
October 10 187 swifts 19:07 – 19:15
October 11 52 swifts 19:14 – 19:18
October 12 24 swifts 18:41 – 18:56
October 13 39 swifts 18:51
October 14 36 swifts 18:56 – 19:09
October 15 43 swifts 18:51 – 19:05
October 16 36 swifts 18:42 – 19:01
October 17 17 swifts 18:46 – 19:04
October 18 5 swifts 18:51 – 18:54
October 19 10 swifts 18:24 – 18:48
October 20 10 swifts 18:12 – 18:40
October 21 one swift 18:28
October 22 7 swifts 18:47 – 18:54
October 23 zero watched 18:10 – 19:10
October 24 zero watched 18:10 – 19:10
Edwards Gym, OWU, 105 South Sandusky St, Delaware, north chimney on east face, n=4
August 15 4 swifts 20:29 – 20:47
September 4 10 swifts 20:13 – 20:20
September 21 15 swifts 19:36 – 19:58
September 28 33 swifts 19:29 – 19:39
First Commonwealth Bank, 41 North Sandusky St, Delaware, n=5
August 19 11 swifts 20:26 – 20:45
September 2 91 swifts 20:07 – 20:31
September 13 372 swifts 19:56 – 20:16
September 19 117 swifts 19:44 – 20:11
September 30 257 swifts 19:12 – 19:29
Gray Chapel, OWU, 61 South Sandusky St, Delaware, west chimney on north face, n=4
August 23 55 swifts 20:29 – 20:43
September 11 8 swifts 19:50 – 20:02
September 22 193 swifts 19:26 – 19:48
September 29 210 swifts 19:23 – 19:38
Galena Village Hall, 109 Harrison St, Galena, n=1
August 31 879 swifts 20:18 – 20:30