Oct. 15: So Long, Farewell, and Thanks for all the Saw-whets!

Photographer’s Pose. Photo by Courtney

I would like to begin this my final post of 2023 by acknowledging all of you our readers for following along with us on our journey over the past two and a half months that has marked the 17^th season of migration and Northern Saw-whet Owl monitoring at the TLBO. I also would like to express my deepest gratitude for all of you who have contributed in many differing ways to the success of yet another season up here in the beautiful Tatlayoko Valley. To each of our volunteers who gave of their time, energy, and enthusiasm to help us execute both the songbird and owl extension into October, many thanks to you as well. It is always bittersweet to say goodbye to this place and begin my late migration south and east down to my own abode on the cliffs overlooking Kootenay Lake.

The view looking south towards the lake from our MOTUS Tower on Skinner Ridge

Back in July when a friend of mine up here contacted me asking if she could borrow our live trap as she had a bigger than usual mouse problem in her house, I should have clued in that it would be a good year for Saw-whet Owl reproduction. Alas, it wasn’t until our tally of indoor captures at the field station started to take up an alarming amount of space on the white board that it occurred to me that despite this only being two years after our last big year (2021) this could be an even bigger one. For those of you who are new to the blog, to the best of our knowledge Northern Saw-whet Owl’s favoured prey items like most other owls are rodents and as such their population trends mirror that of their prey species which is thought to peak every four years. As a quick aside we collaborated with Dr. Laura Grieneisen at the University of British Columbia Okanagan this season in a pilot study where we collected 50 fecal samples with the aim of better understanding the microbiome of these mysterious little owls. Who knows, perhaps by this time next year we will have new information on what unknown delicacies these lovely owls feast upon in the darkness of night.

Ready for a band in the “Reverse Grip”. Photo by Courtney

Based on our limited scope this four-year population boom appears to be a little more fluid as our first “big” season was in 2017 (59 owls banded) but then only two years later in 2019 (62 owls banded) we broke that record. The following year was more on trend as we would band only 22 owls with 2021 showing the spike which we had all expected albeit somewhat lower with 54 owls banded. Incidentally, it was that season when we embarked on our first attempt at our October extension to our owl banding program as we had always suspected that we were missing the peak of owl migration in October. Those two weeks proved to be very fruitful as despite exceptionally foul weather we would band an impressive 79 owls in just six nights for a season total of 133. The next September (2022) would surprise us as we would go on to band 56 owls for our third highest total ever albeit with our largest effort ever as these were spread over 14 nights. October that year proved unseasonably warm and calm as Sachiko would get out on 14 of the 15 nights banding 42 owls for a season total of 98.

Figure 1. September Owl banding totals by year

As September arrived, I prepared myself for what I expected to be another “slow” season despite the fact that I couldn’t walk two paces without nearly stepping on a live or dead mouse. Despite the mercurial nature of the weather this past September, we would surprise ourselves by banding a record breaking 88 owls in just 11 nights which is an average of eight per night, five more than our long-term average of three. I had high hopes for October and even with the poor weather it didn’t disappoint. We were able to get out on eight nights (an improvement on 2021) and banded one better than the previous month with 89 (average of 11 per night) for a season total of, are you ready for it, 177!

Figure 2. Owls banded by season (September – October 15)

To shift to age ratios for a moment, in a large breeding season we would expect to capture a far larger percentage of young (hatch-years) versus adults. An example of this is in our first two big seasons, namely 2017 and 2019 our ratio was 92% hatch-years to 8% adults and 95% hatch-years to 5% adults respectively. This is quite a stark contrast compared to our last three years of data which include the addition of the owl extension into October where the ratios are quite similar between 2021 (84% hatch-year: 14% adult), 2022 (89% hatch-year: 11% adult), and 2023 (89% hatch-year: 11% adult). You probably noticed that though the volume was nearly double that of 2022 this season the ratios were exactly the same. One possibility is that due to the warm weather in 2022 we actually missed the peak movement of these owls or they were less in a hurry to start moving. The other factor is that with the extension into October we are likely to capture more adults as if owls are anything like songbirds the adults tend to begin their migration later than their young. Only by continuing to run our October owling extension can we collect more data to better answer these questions.

Mae basking in the glow of the northern lights. Photo by Courtney

Switching to the songbird front, it has been a fantastic season for visual migration and species diversity as in the two and a half months that we have been here we have recorded 153 species, four of which are new to the hotspot’s list! Since my last post I added one more species, American Coot which is historically sparse at the TLBO as this is only our fourth record. For those Swan fans out there, the Trumpeter Swan was still present when Courtney, Mae, and Keith were at the lagoon on the 14th.

The American Coot followed close behind an American Wigeon in the lagoon

Since my last post I have no new species to recount on the banding front. The final tally for the month of whimsical songbird banding this October was 28 new birds banded comprised of 11 species with four recaptures which were all Black-capped Chickadees. I do have one last experience to relate for as I was taking down the owl nets amidst the nearly leafless alders late this afternoon, I heard the barking song of a Barred Owl. I can do a passable impression of this particular owl and have been known to duet with them from time to time in March from my deck back home. Needless to say, we sang to each other for a time as I secretly hoped that it would come for a closer inspection which it did deign to do. It was a lovely send off and I was quite content that it was indeed time to pack up the station for another season as very few birds were present along the trail.

Thank you all again for your attention and devotion to my ramblings as the pleasure is all mine. With any luck we will all meet again here next spring for the Birdathon reports of our team, “The Wandering Tatlers”.

All my recent checklists can be seen at: https://ebird.org/hotspot/L989990?m=&yr=cur&changeDate=

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2023 Nothern Saw-whet Owl Banding Stats  (Sept. 3 – Oct. 12)
Banded	177
Recaptured	5
# of Owling Nights	19
Physical Hours of Owling	59.75
Owls per Hour	3
Volunteer Hours	87.25

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October Non-standard Banding
Species	Banded	Recaptured
White-crowned Sparrow	8
Golden-crowned Sparrow	4
Ruby-crowned Kinglet	4
Varied Thrush	3
Fox Sparrow	2
Lincoln’s Sparrow	2
Wilson’s Snipe	1
Yellow-rumped Warbler	1
Dark-eyed Junco	1
Savannah Sparrow	1
Hairy Woodpecker	1
Black-capped Chickadee		4
Total	28	4

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Oct. 11: The Owling Continues

Photo by Courtney Jones

We are now two thirds of the way through the two-week extension of our Northern Saw-whet Owl monitoring program and thus far this season has found the middle ground between 2021 and 2022 with respect to nights of effort. During the second third (October 6^th-10^th) we have been able to owl on three nights, the 6^th (16 banded), 8^th (8 banded), and 9^th (14 banded) for a total of six nights out of 10 in October. Our numbers the last three outings are up from the first three with a total of 38 banded versus 32. That said our total for October now sits at 70 owls banded and one recapture in six nights. For comparison in 2021 due to foul weather we were only able to get out and owl on six nights in total out of 15 yet we still banded a record total of 79! In 2022 the weather was far more cooperative as Sachiko was able to get out on almost every evening save the 10^th for a total of 42 owls banded and three recaptures. By this stage there were 61 owls banded in 2021 and 26 in 2022, so it goes without saying that Saw-whets had an extremely successful breeding season in 2023. In the bigger picture October 6^th saw us beat our previous record of 133 owls banded in a season set in 2021 (which was the first owl extension into October) when we banded 16 for a total of 136! Since then, we have owled twice more and now sit at a record 158 new owls banded and five recaptures!

Sunrise behind the Field Station

Now switching to songbirds I have continued to open the nets up on a whimsical basis which has translated to three 1–2-hour sessions. Over these three sessions I have banded nine new birds of eight different species along with three recaptures which were all Black-capped Chickadees. As migration slows and the residents become more prevalent in and around the net loop my perspective on what is “exciting” shifts as well. A hatch-year female Hairy Woodpecker who happily added to the numerous superficial nicks and cuts on my hands was a total delight. My second Fox Sparrow of October along with three members of the Zonotrichia clan, two White-crowned and one Golden-crowned Sparrow were subtly beautiful each in their own way. Of the three Black-capped Chickadees that I recaptured one had been first banded this season as a hatch-year whilst the other two were long-term residents of the valley. Both of these older birds were first banded in the first few days of the 2018 season as hatch-years which means that they are both exactly six years old! One of them I recaptured on the 3^rd and thus have already written about what we know of its past on the previous post. The second one however also has a colourful history in our banding records which is worth elaborating on. This feisty little individual has been recaptured in every season since 2018 except 2020 and had the good fortune to be caught in August, September and October of 2021! Its only recapture in 2022 was on October 1^st so it has been a year and 10 days since we last set hands on it. This is some of the most valuable data that we collect at the TLBO as it is easy to lose sight of our hardy residents in favour of the more colourful migrants.

Hairy Woodpecker (left) and one of the long-time resident Black-capped Chickadees (right)

As it neared midnight while I was owl banding on the evening of the 6^th, I heard the barking calls of two Barred Owls as they made their way down the valley which marked our first detection of the season and the 151^st species for the station’s hotspot in 2023! On the daytime observational front, the hordes of Yellow-rumped Warblers and Ruby-crowned Kinglets have thinned out with much smaller numbers still coming through and calling out to me as I wander along the census route. With this shift the waterfowl numbers of both species and individuals have increased making my outings to the lagoon all the more enjoyable as I scan through the rafts looking for something new and exciting. October 7^th would mark our 152^nd species of 2023 as I was able to pick out a female Eurasian Wigeon as she foraged amidst a raft of 58 of her cousins (American Wigeons). The distinction between these species is fairly straightforward if you are comparing males as a Eurasian Wigeon stands out like a sore thumb with its red head, light forehead and grey flanks. Females on the other hand are much more subtle as you have to first notice the rusty tones on their heads and then confirm that it does not contrast with their neck and flanks. If you are lucky enough to get one in flight then be sure to pay close attention to the underwing coverts which are dusky in Eurasian and pure white in American. Otherwise, Northern Shrikes and Lapland Longspurs (both scarce during our songbird monitoring season) have continued to be semi regular visitors over the past 10 days.

Female Eurasian Wigeon

 For those subspecies hybrid enthusiasts out there, I was visited by another interesting “Intergrade” Northern Flicker on the 8^th. This is the closest to a pure “Yellow-shafted” individual that I have observed this season as all of the traits (peachy face with grey cap and red nape patch) pointed to “Yellow-shafted” except for the flight feathers which appear to begin as an orangish-red near the base and shift to yellow halfway to the tips. The other sighting of note was our second record of a Black-billed Magpie as I watched one flying north over the lake to briefly stop atop a large cottonwood before continuing on. Is this one of the trio from September 23^rd and will they stay and attempt to breed in the valley next spring? That remains to be seen.

The intriguing female “Intergrade” Northern Flicker

All of my recent checklists at our Station’s Hotspot on eBird can be seen at: https://ebird.org/hotspot/L989990/activity?yr=all&m=

The forecast looks promising tonight although it has misled me many times in the past, including last evening where it appeared to be calm but once we reached the nets the intermittent gusts were too strong for us to open up. Stay tuned for the final blog post of the season on the 16^th or sooner if the weather turns too foul for mist-netting.

Let us hope for more rounds like this one!

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Nothern Saw-whet Owl Banding
Date	Banded
October 6, 2023	16
October 8, 2023	8
October 9, 2023	14

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Non-standard Banding – Oct. 07 to 11
Species	Banded	Recaptured
Ruby-crowned Kinglet	2
White-crowned Sparrow	2
Savannah Sparrow	1
Lincoln’s Sparrow	1
Golden-crowned Sparrow	1
Hairy Woodpecker	1
Fox Sparrow	1
Black-capped Chickadee		3
Total	9	3

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Oct. 06: Welcome to the 3rd Owling Extension

The lovely view of the Niuts from the Field Station

Even though it was just over a week ago that we were still operating our migration monitoring program it now feels like a very distant memory. With the end of September, the gears shift at the TLBO from juggling both morning songbird monitoring and nighttime owl banding to a full focus on the latter. Our regular season owl banding program wrapped up on the evening of September 30^th when we caught 14 owls (second highest count of the season) for a total of 88 banded and four recaptures in 11 nights over the course of the month. This is by far our highest total on record as it is a full 26 owls higher than the previous record of 62 (2019) which had the exact same amount of effort with 11 nights of banding.

With five nights gone in October I have been able to get out on three of those namely, the 2^nd (12 banded), 4^th (9 banded) and 5^th (11 banded) for a total of 32 owls banded and one recapture! That is a grand total of 120 new owls banded and 5 recaptures which is only 13 shy of 2021’s record of 133. Of the 120 owls that we have banded thus far only 15 were adults (11 second-years, one after-second-year, one after-third-year, and two fourth-years). This is a bit of a higher percentage (12.5%) than we traditionally see in a big reproductive year but one possibility is that many of these adults bred locally. It is heartening to see so many second-years as the first year of a Northern Saw-whet owls’ life is the most fraught with high mortality rates. With a volunteer gap in this week’s schedule I have had the pleasure of being joined first by Krista and Iain and then by my good friend and local resident Jim Sims on the last two evenings.

I spy a Trumpeter Swan

As we have done in the past two seasons Sachi and I packed up half of the songbird mist-nets and left the rest in place so that I am able to do some daytime non-standard songbird banding whenever the mood takes me. I have opened up nets on four days this month for roughly 1-2 hour sessions for a total of 19 new birds banded and one recapture. The bulk of these have been sparrows namely, Golden-crowned and White-crowned who have been making their way through the valley. The highlights so far for me have been our second Fox Sparrow, sixth, seventh, and eight Varied Thrushes and our second Wilson’s Snipe (fifth overall) which had been evading me all week until today!

Wilson’s Snipe!

Another routine that I have continued has been birding the census route every day so far this month except for on the 5^th when I spent the day helping a neighbour dismantle an internet tower in the next valley over. It is exciting to spend my second October birding in the valley as there is so little data on what birds are present during this period. Lapland Longspurs are a notoriously tricky species to detect so it has been a pleasure to have observed an individual on four separate occasions (October 1^st, 2^nd, 4^th, and 6^th). As I was walking the census route on the 2^nd, I had the good fortune to first hear and then observe two Long-billed Dowitchers as they were foraging in the shallows. The next day I had a brief but delightful encounter with the post fire specialist, Black-backed Woodpecker and our first October detection of an immature Ring-billed Gull.

A duo of Long-billed Dowitchers

Two years ago, when I stuck around for the inaugural October owling extension, I was witness to a spectacle of Snow Goose migration on the 4^th when I logged 357 individuals as they flew south in Vs of varying sizes over the course of nearly seven hours. With this in the back of my mind I headed down to the station early on the 4^th in the hopes that perhaps I would get lucky again. As fate would have it the overcast skies and intermittent rain must have been a signal for goose migration as I would log 161 Snow Geese, 307 Canada Geese, along with the hotspot’s first record of Cackling Goose as I was able to pick out two amidst a V of 60 Canada’s!

Snow Geese on the move South!

I had three more surprises today the first of which was my first sighting of a Greater Scaup in our study area, which are the rarer of the two Scaup species in the Cariboo, as it loafed amidst a mixed species raft in the lagoon. Out on the lake I spied our first Barrow’s Goldeneye of the season which is rather unusual as over the past five or so years this has been the species of Goldeneye that we more often encounter during monitoring. An adult Northern Shrike topped the day off as I was packing up to head home to begin to draft this post.

The weather is looking near perfect again this evening for owling so with any luck we will surpass 2021’s total tonight!

Stay tuned for another update in five days or so.

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Northern Saw-whet Owl Banding
Date	Owls Banded	Owls Recaptured
02-Oct	12
04-Oct	9	1
05-Oct	11

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Non-standard Banding – Oct. 01 to 06
Species	Banded	Recaptured
White-crowned Sparrow	6
Golden-crowned Sparrow	3
Varied Thrush	3
Ruby-crowned Kinglet	2
Wilson’s Snipe	1
Yellow-rumped Warbler	1
Fox Sparrow	1
Lincoln’s Sparrow	1
Dark-eyed Junco	1
Black-capped Chickadee		1

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