COMINGS AND GOINGS FROM HERE, THERE, & THE ARCHIVES
This week’s blog starts with a summary of recent St Adolphe nest site activity. To provide a long-range geographical comparison, we’ll look at a news flash from London, ON, which also includes roost site intel. A terrific video by Glenn shows just how challenging monitoring at large roost sites can be. The video provides an opportunity to go down memory lane via a re-post of a link to an old blog about counting Chimney Swifts in a photograph.
I also have a couple of other resource links to share. One link is for an info-rich reference book written by Paul and Georgean Kyle. There is another old blog you can head to for a refresher about moulting. Recognizing moulting in adults is one of the key elements in distinguishing an adult vs a fledgling. The flight behaviour of newly launched fledglings is the other important characteristic to identify Chimney Swifts taking their auspicious first flights. As some fledging dates are approaching, let’s review the past week and look ahead to the exciting developments that will come next week…
Friday, July 15th was one of those days with developments on both ends of the happiness continuum. Sadly, when I showed up to monitor the Brodeur Bros./Daycare site, the swifts were no-shows. Thursday, there had been no activity over the chimney and I didn’t manage to catch sight of any entries/exits as I cast an eye about during monitoring sessions elsewhere in town. On Saturday and Sunday mornings, a similar lack of activity confirmed that a nest failure had taken place. The Brodeur Bros./Daycare site has an accessible cleanout. In September, after the Chimney Swifts have migrated south, I will be able to look at debris to see if the nest has fallen etc.
Elsewhere in town on Friday, the breeding pairs at the SE Club Amical and Main St nest sites continued to incubate eggs. The NE Club Amical pair were busy feeding non-brooded young on Day 15. All was well.
The happiest development noted on Friday was the hatching of eggs at the Church chimney! So, three different stages of nesting and one apparent nest site failure were evident on one day. That was a wide range of variation in nest site activity.
Within two days of Friday, eggs hatched out at the remaining nest sites. On Saturday, the SE Club Amical pair were feeding young – quite vigorously for Day 1 at a rate of 3 X hour. It was an exceptionally good day generally for local feeding. On Sunday mid-day, the snoop squad did repeat peer ‘n’ veer flyovers of the Main St chimney. In the evening, the homeowner noticed “crazy flying – the birds just kept swooping low over the roof and chimney”. All that action translated into a 2 X hour entry/exit cycle on Monday morning, which confirmed my suspicion that eggs had hatched.
As a recap, hatching day = Day 1 of feeding; the young are brooded for 6-7 days; and the non-brooded young fledge or take their first flight outside the chimney on Day 28-30. The NE Club Amical eggs hatched on July 1, so those young will fledge July 28-30; the eggs at the Church site hatched on July 15, which makes for a fledging date range of August 11-13; the SE Club Amical hatchlings appeared on July 16 and they will fledge August 12-14; and the Main St young emerged on July 17 which makes liftoff outside the chimney between August 13-15. Do you remember that the magic date for the latest known fledging in St Adolphe is August 16th? This year, all of the breeding Chimney Swifts are coming in just under the wire. Let’s hope conditions and the food supply remain favourable for those juveniles to reach liftoff.
That segues nicely to the Rainmageddon event which hit Manitoba on the day I started to draft this blog. Tuesday July 19th started with torrential rain and horrendous electrical activity and high winds in many areas of the province. Storms continued in the evening. It is important to check nest sites in the aftermath of such deluges. Continued daytime activity indicates that no nest slippage has occurred and the parents have foraged successfully despite the weather – energy budgets have to be maintained in those voracious youngsters.
There is one last noteworthy developmental milestone to mention. At Day 20-21, the juveniles transfer from the bowl of the nest to the interior wall of the chimney. Wing flapping begins in earnest to strengthen flight muscles. Practice flights up and down the shaft of the chimney take place. All this activity prepares the young swift for its debut flight outside the chimney on Day 28-30. As of this blog’s posting, the NE Club Amical juveniles should be making that transfer.
Now some very interesting observations have flown in from Winnie Wake who, along with Dave & Sandy & Glenn, spearheads the amazing London, ON, Chimney Swift Monitoring Program. Winnie summarizes things best in her July 12th report:
Another hot, humid, rainless week preceded the Jul 12 counts. The combined tally of 489 was up slightly from Jul 5 (467) …This might be a fluctuation related to inherent imprecision in counting. Or it may reflect movement of swifts among roosts and/or from nest chimneys to roosts. Most swifts continue to be located at four roosts – Huron (151), Hunt’s (127), Phoenix (117) and King’s (64). All except Hunt’s increased in size. Smith Fruit hosted a mini-roost of 13, and 6 chimneys held from 1 to 6 swifts. Very troubling is that 7 of 18 chimneys reported 0 swifts in for the night. It is unprecedented for so many chimneys to be empty this early in the season. The question is why. Possibilities are that swifts in some chimneys retired earlier or later than our monitoring hour, or spent the night elsewhere and will be back next week. Regardless, reduced evening attendance at nest chimneys and intermittent overnight use are not promising signs for successful fledging of young. A more plausible explanation is swifts are abandoning chimneys after nest failure (perhaps due to weather negatively affecting food supply). Early in the season, reports from most sites showed at least some behaviour indicating a possible nesting attempt. During the week or two prior to Jul 12, monitors reported negative or ambiguous nesting evidence at many chimneys. This came at a time when frequency of entries and exits should have been increasing as nests hatched and young needed to be fed.
The situation at a nest site can change on a dime. One day young are being fed and the next day the site may be abandoned. That toggle of site use is important to remember when evaluating data from opportunistic monitoring sessions. Current lack of activity at a site does not necessarily mean a site has been unused previously during the season. However, an indication of daytime activity at a nest site – especially if young are being fed – does reflect a lot of previous site use to get to that stage! This is part of the challenge in documenting chimneys as critical habitat.
Not to leave you roost site monitors out, Winnie also provided a link to a great video posted by Glenn. It was from his July 12th monitoring session at Hunt’s (a century-old former flour mill); the footage was shot from the ground towards the building top which is six storeys tall. Glenn offered: While at Hunts Warehouse this week, Susan and I saw almost half of the swifts enter in less than one minute. This was not exactly “fireworks”, but “rush hour”. Note: 127 birds came in to roost that night!
Check Glenn’s video out at: https://youtu.be/qu8t3OQcFH4
While nest site monitors are happy to get their “2 in for the night”, monitors counting roosting birds face a very different challenge…Rob wraps it up in an understated comment – “It’s hard, isn’t it?”. I easily dissolve into a puddle of excitement and find counting roosting swifts rather overwhelming. Many folks use a video camera or take footage with a phone etc. to review counts and tally a final number of roosting birds.
While single photos of Chimney Swifts swirling around a roost can’t capture the total number of roosting birds, they can document what the set-up to the final roosting entries looks like. Years ago, Rob & I were gifted a lovely photo taken at a Kingston, ON, roost site. Rob developed a challenge for folks wanting to try to count Chimney Swifts in the air. Go back down memory lane to our July 27, 2014 blog to see how you fare: https://www.mbchimneyswift.com/counting-chimney-swifts-on-the-wing/
If all this swift activity has piqued your curiosity, head to this link Frank has installed on the MCSI Resource & Link page: https://www.mbchimneyswift.com/resources-and-links/ Then, go down to the section on “Some Books about Chimney Swifts” to find a hot link for the bible on Chimney Swifts written by Paul and Georgean Kyle:
Chimney Swifts: America’s Mysterious Birds above the Fireplace
152 pp., 41 color photos., 4 b&w photos., 28 line drawings., Map. Pub Date: 2005
The Kyle’s natural history book covers the historical investigations of breeding swifts using artificial towers (in the US), various flight behaviours, vocalizations, and descriptions of breeding activities etc. The book is enriched with drawings and photographs.
Now for a recent and important observation. On a beautiful sunny day last week, with just the perfect backlighting of low and slow-flying Chimney Swifts overhead at the Church, I saw the first moulting adult of the season.
Moulting does not render Chimney Swifts incapable of flight – they must continue to be airborne to harvest insects from the air column. Yet another trip back in time will land you at the July 15, 2015 blog which details plumage replacement. Some stunning photos by Dave Lavigne give you a terrific visual of what adult trailing wing margins look like during the different phases of the moult. https://www.mbchimneyswift.com/july-update-field-identification-of-adult-chimney-swifts-in-the-summer-range/
It is important to get a handle on how adults fly generally and how their wing margins change with moulting. Next week we will welcome some new fliers to the Manitoba airspace as fledglings start popping out of nest sites. As there are fundamental differences between adult and fledgling flight behaviour and wing margins, here’s a segment from the 2015 blog to explain it:
“For monitors in Manitoba, moult characteristics become an important way to distinguish fledglings from adults. Most fledging takes place toward the end of July and into the first week of August, and it is useful to identify juveniles to help estimate nesting success. The flight of newly fledged chimney swifts is characterized by: flying at low altitudes, rapid wing beats for slow air speed, large banking turns, and, occasionally, difficult entries to chimneys (yes, they do miss the opening and tumble down the outside face!). However, within several days post-fledging, young swifts are proficient fliers and they are not easy to distinguish from adults based on flight competency alone. So how do you distinguish juveniles vs. adults? The best way is to look for evidence of moulting on the trailing wing margins. Juveniles will have intact margins while adults will have discontinuities and gaps due to worn and missing feathers.”
Now, the range of estimated fledging dates in St Adolphe is very protracted this year ~ the estimates range from July 28-30 (NE Club Amical) to August 11-13 (Church), August 12-14 (SE Club Amical), and August 13-15 (Main St). The clump of 3 mid-August dates for possible fledging is the biggest and latest since monitoring began in 2007. How do you think your nest sites fit into this range of estimated fledging dates?
That’s a wrap for this week. Keep your monitoring sheets flying in and Ariel, our summer student, will sort through them and enter your all-important observations into our database. Thanks for helping us help our Chimney Swifts through our various MCSI conservation efforts!
— Barb Stewart, for the other MCSI Steering Committee members: Christian Artuso (Co-Chair), Tim Poole (Co-Chair), Frank Machovec (Webmaster), Lewis Cocks (Founding Father of MCSI), Ron Bazin, Neil Butchard, Ken DeSmet, Jack Dubois, Nicole Firlotte, Rob Stewart, Joanne Tuckwell, and Ashleigh Westphal
