(707) 431-5100 (707) 431-5100

Vaux's Swift Migration

2023 Swift Information

We will be open the following days from 6 PM – 8 PM:

Sept. 2-3

Sept. 9-10

Sept. 23-24

We are a gated closed campus, When you arrive at the gate, please use the call box to call the school office so administration can open it for you. Please respect our campus rules of no alcohol or substances (including tobacco, vaping, etc.), and remain in the area set aside for viewing the Swift Chimney (watch for the bird signs pointing the way). 

Vaux’s Swifts have been roosting in the Rio Lindo Adventist Academy chimney since 1989, the first year the school’s boiler wasn’t producing steam year-round. The chimney is still used in the winter when the boiler generates heat for the school campus, but that’s after the fall migration. The first small groups of migrating birds usually appear in mid-August. The numbers increase and generally peak between September 10 and 20. In an average year, the count peaks between 5,000 and 10,000 birds for a few evenings. The highest numbers that have been observed were in 2015 when a couple of evenings the estimate was between 35,000 and 40,000 birds. We believe this was because of the Middletown fire which may have narrowed the migration path. The lowest was in 2005 when the highest count was only 300. This was a West Nile year.

The sight of thousands of birds flying in a tornado-like pattern against the dusk sky is simply awe-inspiring. Bird and nature enthusiasts travel from all over the world to see this unforgettable, natural phenomenon. Most years, the birds arrive in small numbers by the first of September and leave by the end of September. Check back with this website as numbers are posted on a regular basis.


Visitors are welcome to visit Rio Lindo Adventist Academy for viewing the Swifts. We ask you to remember that this is a high school campus with faculty and students present 24 hours a day, seven days a week. Please leave alcohol and substances (including tobacco, vaping, etc.) at home — we are a Seventh-day Adventist school and believe in a pure and healthy lifestyle. See this link for more information about the why behind our abstinance from mind-altering substances: What Adventists Believe About Christian Behavior –

Please keep dogs on a leash, even friendly ones. Also, please stay in the area around the chimney and do not roam around campus. Generally, the best time to arrive is 30 minutes before sundown. We’ve observed that the time they begin entering the chimney is connected to the air temperature (the colder it is, the earlier they enter the chimney), the time of sundown, and the number of birds present to roost in the chimney (the higher the number, the earlier they begin their descent). Please be prepared to leave campus within 15 minutes after the birds have finished their chimney roost.

Swift Count

Thank you to our bird counter, Star, for getting these numbers up.

Swifts are counted by timing from the moment the swifts enter until they finish and multiplying the number of minutes by 360, which is determined by a video calculation that was performed by the Audubon Society in the early 1990s. The number is only an estimation and not precise.

2023 Swift Numbers

Date Estimated Number of swifts
August 31 300
September 1 360
September 3 1000
September 4 1440
September 5 1980
September 6 2200
September 8 2340
September 9 3000
September 10 5000
September 11 6500
September 12 4680
September 13 8280
September 14 8640
September 15 10080