CAPTAIN SAMS
The birds just keep coming! We had another busy day out on the spit capturing a total of 239 birds (228 new, 11 recaptures). Common Yellowthroats just won't stop this year as we banded 140 more of them today. To date, we have banded 1,361 Common Yellowthroats just at Captain Sams. Looking back at the last 15 years since we began banding, the highest number of Common Yellowthroats banded during a fall season was 1,339 back in 2012. Their numbers will start to slow down soon but I bet we still have a solid 2-3 weeks left of decent numbers of Common Yellowthroats. In addition to all the new Common Yellowthroats, we also had 4 recaptures. Two of those recaptures turned out to be banded at other banding stations. The first one was a male that was banded as a second-year on 4/29/2020 at Foreman's Branch Bird Observatory in Chestertown, Maryland. The other yellowthroat was banded on 5/17/2019 as an adult near Newberry, Massachusetts.
The highlight of the day came when I pulled a small "Gray-cheeked Thrush" out of the bird holding bag. The wing chord measured in at 94.0 mm which raised an eyebrow and prompted an additional measurement - tail length which was 65.0 mm. Plugging those numbers into a formula, we determined that this bird was a Bicknell's Thrush. Bicknell's Thrush is a very rare migrant with a small breeding population that is isolated to the disturbed high elevation forests in the Northeast. In the field, Bicknell's Thrushes are indistinguishable to Gray-cheeked Thrushes. The songs are differ in minor details but with experience can be reliably separated. Flight calls also differ slightly, although the differences are so subtle that spectrogram analysis might be the only way to distinguish them.
 |
| Bicknell's Thrush (hatch-year, sex unknown) |
 |
| Bicknell's Thrush (hatch-year, sex unknown) |
 |
| Bicknell's Thrush (hatch-year, sex unknown) |
-Aaron
LITTLE BEAR
North winds graced us with another wave of new migrants today; we banded a total of 104 new birds and captured two new species for the year. Blue-gray Gnatcatcher finally made an appearance and we also caught an early migratory Ruby-crowned Kinglet. We are just starting to see Kinglets appear in our nets and this marks the first wave of some of the earliest individuals to migrate this year. We joked amongst each other at the banding table quoting Ricky (RCKI) Bobby's famous one liner from Talladega Nights, "If you ain't first you're last". Although this Will Ferrell classic has nothing to do with birds or migration, the quote does reflect the importance of a speedy migration as early migrants often have an advantage over those who show up later to their wintering grounds. It is a common misconception that the wintering grounds are a relatively stress-free part of a songbird's life. However, this is not entirely true as many migrant passerines defend territory on the wintering grounds similarly to how they do during the breeding season. Spending the winter in high quality habitat, with an abundance of food resources, and little competition sets them up for success the following spring.
To elaborate on this point more, let's take a look at the annual cycle of American Redstarts and how establishing winter territories in the tropics will go on to benefit their future success during the spring breeding season. American Redstarts are what we call neotropical migrants, meaning they spend their summers breeding here in North America but will undergo a long-distance migration in the fall to spend their winters in Central and South America. During the summer certain populations will breed as far north as British Columbia or Alberta, but they can also be found as far south as Louisiana, Alabama or Georgia. These widespread warblers only spend a short two and a half months breeding in these locations before heading southbound. During their fall migration, the destination for these warblers varies from Mexico's Yucatan peninsula all the way to places as far south as Venezuela, Colombia or Ecuador.
One thing to note about American Redstarts is that when they reach the tropics in the winter, they will defend territory almost as aggressively as they will during the breeding season (this also applies to females). A study by Ryan Norris et al. (2004) found that males occupying high quality habitat on the tropical wintering grounds arrived sooner the following spring to breed compared to males that had wintering territory in lower quality habitat. Similarly, females in high quality habitat during the winter months were predicted to fledge young the following spring a month earlier than their counterparts that wintered in poor habitat. For birds heading southbound this fall, it is likely that the earliest arrivals will get the best selection of the highest quality wintering habitat... if you aren't first, you're last!
 |
| American Redstart (after hatch year, male) |
-Noah Nei
| Species | Captain Sam's | Little Bear | ||
|---|---|---|---|---|
| New | Recaps | New | Recaps | |
Green Heron | - | - | 1 | - |
Northern Flicker | 1 | - | - | - |
Downy Woodpecker | - | - | - | 1 |
Eastern Wood-Pewee | 1 | - | 3 | - |
White-eyed Vireo | - | - | 1 | - |
Red-eyed Vireo | 3 | - | - | - |
Ruby-crowned Kinglet | - | - | 1 | - |
Blue-gray Gnatcatcher | 1 | - | 1 | - |
House Wren | - | - | 1 | - |
Marsh Wren | 1 | - | - | - |
Carolina Wren | - | - | - | 1 |
Gray Catbird | 27 | 6 | 12 | 3 |
Brown Thrasher | - | - | - | 1 |
Bicknell's Thrush | 1 | - | - | - |
Gray-cheeked/Bicknell's Thrush | 1 | - | - | - |
Swainson's Thrush | 6 | - | 1 | - |
Ovenbird | - | - | 1 | - |
Northern Waterthrush | - | - | 1 | - |
Black-and-white Warbler | 3 | - | - | - |
| Nashville Warbler | 1 | - | - | - |
| Common Yellowthroat | 140 | 4 | 46 | 1 |
| American Redstart | 16 | - | 4 | - |
| Northern Parula | 1 | - | 2 | - |
| Magnolia Warbler | 2 | - | 1 | - |
| Cape May Warbler | - | - | 2 | - |
| Black-throated Blue Warbler | 9 | - | 4 | - |
| Palm Warbler (Western) | 9 | - | 10 | - |
| Pine Warbler | 1 | - | - | - |
| Yellow-rumped Warbler (Myrtle) | 1 | - | - | - |
| Summer Tanager | - | - | 1 | - |
| Scarlet Tanager | - | - | 1 | - |
| Indigo Bunting | - | - | 1 | - |
| Painted Bunting | 3 | 1 | 8 | 9 |
| Today's Banding Stats | Captain Sams | Little Bear | TOTAL |
|---|---|---|---|
| # Birds Banded | 228 | 104 | 332 |
| # of Recaptures | 11 | 17 | 28 |
| # of Species | 20 | 23 | 33 |
| Effort (net-hours) | 201.6 | 166.4 | 368.0 |
| Capture Rate (birds/100 net-hours) | 118.6 | 72.7 | 97.8 |
| # of Nets | 32 | 26 | 58 |
| 2024 Fall Cumulative Banding Stats | Captain Sams | Little Bear | TOTAL |
|---|---|---|---|
| # Birds Banded | 3,234 | 1,982 | 5,216 |
| # of Recaptures | 608 | 493 | 1,101 |
| # of Species | 69 | 61 | 84 |
| Effort (net-hours) | 8,665.1 | 5,229.4 | 13,894.5 |
| Capture Rate (birds/100 net-hours) | 44.3 | 47.3 | 45.5 |
| # of Days | 53 | 45 |
Banding Staff
Aaron Given (CS)Michael Gamble (CS)
Kristin Attinger (LB)
Natalie Miller (LB)
Lisa Viviano (LB)
Noah Nei (LB)
Garrett Rhyne (CS)
Nancy Raginski (CS)
David McLean (CS)
Ann McLean (CS)
Note: All banding, marking, and sampling is being conducted under a federally authorized Bird Banding Permit issued by the U.S. Geological Survey’s Bird Banding Lab.
No comments:
Post a Comment