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The same procession of September and October cold fronts that send you scurrying for your fleece jacket also acts as a subtle reminder for birds of all shapes and sizes that it is time to move south in search of sustenance and shelter. We dress warmer and turn on our furnace....they move to survive.
During the familiarity of daylight, it is easy to determine when the songbirds and raptors are moving: warblers flit visibly among the pines and spruce, dining on the last insects of the year, and kettles of broad-winged and sharp-shinned hawks soar overhead with wing's set on updrafts of warm air. But what happens at night? There's only one way to find out...... Swets in My Nets...2006....... |
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Saw-whets: 2006 |
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Saw-whets: 2005 | ||
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Saw-whets: 2004 | ||
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Boreal owl: 2004 | ||
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Swets in my nets 2000 (Maine) Swets in my nets 2001 (New York; Maine) |
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Saw-whet Measurements:
Wing Chord: a measurement of the owl's closed wing, taken from the bend at the "wrist", to the tip of the longest primary feather. Northern saw-whet owls exhibit moderate sexual size dimorphism (females are larger than males) and in general, wing chords >145 mm are most likely female birds.
Tail, or Deck Length: the central pair of tail feathers is measured using a metric scale.
Molt Pattern: Saw-whet owls exhibit observable patterns of molting. Hatch year birds have uniformly-colored, new feathers; second year birds exhibit new primary and secondary feathers while retaining old feathers in an "inner block" of primaries and secondary feathers; third year and beyond owls drop their feathers in irregular patterns (see photos below). |
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Typical, second year molt pattern (After Hatch Year: AHY). Inner block of primary and secondary feathers are retained. |
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Typical, after second year (ASY) molt pattern. Irregular pattern of old and new primary and secondary flight feathers. |
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Weight: Trapped owls are weighed using a hand-held Pesola scale. Males generally weigh between 70 and 90 grams, and females weigh between 90 and 110 grams. Of course, if the owl has recently eaten a 15-gram vole, the scale sags a little more.
Bands*: I use USFWS Size 4 ("shorts"), butt-end bands, placed on the tarsus (lower leg of the owl). After approximately 5 minutes following capture and recording measurements and weights, the owls are released in a nearby, thick stand of cedar and shortly thereafter, are back on their nocturnal journey.
Net Hours: I typically use 2, 12 m "CTX" mist nets arrayed in a "t" configuration. Net hours provide a standardization of effort and therefore, allow me to compare my results with my earlier, annual efforts, or with other banders across North America. A simple rule of thumb: 1 net + 1 hour = 1 net hour; 10 nets + 1 hour = 10 net hours.
Audiolure: Although I have little regard for "playback" (especially in the hands of the overzealous and uninformed), in the fall, it is a critical tool for bringing in saw-whets. I use a digital playback system built by Wildlife Technologies, Inc. with the speaker placed right at the "t" of my two nets. |
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USFWS leg band in place, prior to release. |
| A Tofte saw-whet weighing in at a whopping 83 grams (9/20/03). |
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*Trapping and banding authorized by permits provided by the USFWS Bird Banding Laboratory |
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11 September 2006: Each successive fall gets a bit more automatic. I make one trip to the nets and stay there until I make one trip to bed. I am just testing the waters so far. I don't want to feel the drag of exhaustion for a couple of more weeks...or when it gets really busy. Yesterday, the winds blew off the lake for most of the day and there was a cold, damp chill along the north shore. East winds typically slow saw-whets down and such was the case last night, although I did band 2 owls. It is very relaxing without nets dripping with owls. The 110 owls I banded on 9 October 2004 seems impossible to comprehend now. 12 September 2006: After an hour of nothing, all of the sudden, owls moved in. For the next hour I was busy, trapping 12 owls, including a "foreign recapture"...meaning an owl with someone else's band on its leg. That's pretty exciting, but just having owls around was a welcome respite from the monotony of early (or late) season banding. Temps are supposed to warm up over the next couple of days, and I imagine things will slow down a bit, but that is just owlers conjecture. 13 September 2006: It was about 10 degrees warmer last night and for the first hour, I was bathed in oily perspiration. The moon is no longer a factor in the early evening sky and until it reappears, I should gradually see an increase in owls. I don't know where they all come from, but it sure seems like they're going someplace important. So many mice in the woods this fall. The swets should be fat. 14 September 2006: An uneventful evening that balanced between boring and not-so boring. Six owls in 3 hours. Weather is looking dicey, with warm temps. and winds. Once the typical fall weather pattern returns, it'll get nutz. 15 September 2006: At 20:00 last night, the temperature was 60 degrees. At 22:00, it was 63. The humidity followed a similar ascendance and by 23:00, I felt as though I was trapping in Manila. I was down to shirt sleeves and flip flops...and still, a slow trickle of swets came in. 16 September 2006: All was good last night until the lightning moved in. Once it did, all nocturnal acitivities came to a grinding halt. Temps ranged from 60 at the start and it got warmer....64 by the time I "bagged it". Nine saw-whets in the first hour, then only one in the next two. A front is moving in Sunday and that should really get things busy. 17 September 2006: At sunset, the sky was clear and for the first time in two evenings, the temperature dropped below 60. I was prepared for banding bliss, but then the wind started up and I was forced to toy with the idea of folding shop. I persevered and lo and behold, saw-whets appeared and in 3 hours, I picked up 14 owls. The cold front is now upon us and once it clears, it's going to get hectic in Tofte. 18 September 2006: There was truly nothing going on last night. It rained until the wee hours and when it stopped, a bullying wind blew in and ruled the Laurentian Shield until daylight. I welcomed the respite because I was a bit weary. When you are an owler, weariness often wins the battle. 19 September 2006: Last night was the first big push of the migration. I ended up with 42 swets, including one recapture. It got a bit windy but evidently, not enough to slow down the owls. A hard frost covered my deck when all was said and done and the Jotul was fired up for the first time this season. 20 September 2006: Any doubt I am full-on into the owl migration has been removed....I feel sluggish, my fingers are developing a puncture wound motif', and my house is turning into a unique collection of plates and dirty clothes. I have been here before. It was another good flight last night and were it not for my daytime job, I would have explored a bit longer. Still, 30 owls is a good night for any owler, wherever he or she are. 22 September 2006: Rain and wind kept Billy at bay last night. 23 September 2006: As the sun set, the auroras started their nocturnal dance. I sat and enjoyed them for a moment, but then the first owl showed up and thereafter, auroras were something for someone else to enjoy. I ended up with 72 saw-whets, including another foreign recapture. I finally folded the nets at 01:00, even though there were more owls around. Yah gotta sleep, man. 24 September 2006: I never thought 33 owls would feel like a night off, but it was a bit more relaxed last night. The winds picked up an hour into my nocturnal sortie, but a steady stream of owls kept me company. Not in the groups 5's and 6's of Saturday though. In fact, for a couple of minutes, I was actually able to absorb my surroundings. 25 September 2006: My 8th owl last night was a long-eared. Usually, they don't show up until early October. I don't catch many, probably because my nets are in some pretty thick stuff, but when they come in, beauty has arrived. Another night, another 55 owls. I'm on a roll. Work all day, band for a couple of hours, sleep, and do it again. 27 September 2006: At 22:00 last night, my nets were dripping with saw-whets. A wave of birds moved through and I had to extract 10 owls from one net. Other than that, it was a steady, busy evening. The winds picked up around 23:00, but didn't really deter the owls. I am close to a 3:1 ratio of hatch year to adult birds. All those saw-whets I heard during my surveys in March and April obviously had some success in reproducing and I don't think the success was confined to northern Minnesota. 28 September 2006: It was a relaxed evening at the nets last night. Thirty-eight saw-whets and all arriving incrementally, rather than in waves. Last night's flight was evenly divided between youngsters and adults. 3 October 2006: My nets have been reopened and thankfully, the push has slowed considerably cuz I'm just kind of stumbling around now. It's been a rough week but the owls foohet me anyway. Tonight appears to be a wash-out. Not that there's anything wrong with that. 5 October 2006: After a rain night, the nets were opened again and although overall it was quiet, at one point, there were 8 saw-whets to process. There were owl interactions and tail chases and all sorts of good things. It was an enjoyable evening. I'll top 500 owls tonight. Wow!!! 6 October 2006: A bright, beautiful evening with not a lot of swets, but enough to keep me from falling asleep in my crappy camp chair. 8 October 2006: Is the paint dry yet? Goodness...such tedium and monotony in the beginning of October. Only 8 new owls during 6 hours of net time Friday and Saturday nights. Today, a substantial cold front is pushing through and when it is finished, I am anticipating a substantial push from the little owls. 10 October 2006: By about my second net check, I knew I was into owls. Eleven saw-whets awaited extraction. Were it not for the moon, it could have been an enormous owl evening. As it was, 57 owls were banded, with one foreign recapture. After the s-l-o-w previous evenings, I was happy to be gainfully engaged in owls. 15 October 2006: I think the only reason there is bad weather is so we appreciate good weather. At sunset the winds ground to a halt and owls took to the wing. My nephew flew solo to Tofte and helped me record data and managed to earn some frequent footing miles from uncooperative saw-whets. Still a couple of weeks left and my season total is at 631. It's been an amazing fall. 16 October 2006: Two nights and nearly 100 owls. I have eclipsed my total from last year and now am hoping things slow down a bit cuz man...it's getting to be a chore. It's like everything in owling though...the fun only lasts till daylight. 20 October 2006: The rain-outs have come more frequently as winter approaches, and the dryness of the summer of tomatoes and peppers is now but a stain on the road of life. The owls keep coming, however, and a tally over 800 seems highly likely. I am so glad I ordered 1000 bands this summer. 22 October 2006: Two long-eareds hit my nets last night, but only one is adorned with a USFWS band this morning. Meanwhile, the saw-whets continued to move in persistent waves through Tofte. If bell curves define the migration, then maybe 900 owls is within my reach. 24 October 2006: Two nights in the bone-rattling cold of mid-October and the owls keep coming. Last night, I began to have my doubts. In the first 90 minutes of trapping, only one owl graced my evening. In the subsequent 90 minutes, 18 owls met the charming, ebullient, insightful, owlman. I am at 818 owls and have already caught more hatch-year birds than the total number of owls from all of last year's efforts. The second batch of 5th graders arrives at my humble abode this evening. 25 October 2006: It was another cold night in the boreal forest. The sky was crystal clear and nary a breeze stirred. Mrs. Russ' second group of 5th graders were my guests last night. We banded 7 owls while they were here and hopefully, they learned a bit about owls and habitat and all the things that leave the youth of our world asking for more. Then again, they were with me so....maybe not. |