Point Blue Conservation Science: Monthly Banding Summary, January 2020
May 31, 2020
This summary was compiled by Point Blue’s Palomarin banding interns Samantha Chavez and Hannah Roodenrijs with help from Renee Cormier, Banding Supervisor.
About Point Blue: Our mission is to conserve birds, other wildlife, and ecosystems through science, partnerships, and outreach.
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Exciting Captures and Observations:
Happy belated new year! Another year of banding at Palo has passed, meaning we’re heading into our 54th (?) year of banding at this station! With a new year often come reflections of what has happened over the past year, so we thought we would do a little recap of birds we caught and banded in 2019.
At Palomarin, we recaptured 1,414 previously banded birds and banded 1,801 new birds throughout the whole year, for a total of 3,215 birds! We banded 58 different species and our top captured species at Palomarin included: Ruby-crowned Kinglet (459), Wilson’s Warbler (321), Swainson’s Thrush (282), Western Flycatcher/Pacific-slope Flycatcher (227), and Wrentit (204).
At all of our remote banding sites combined, we recaptured 833 previously banded birds and banded 1,257 new birds for a total of 2,090 birds for the year. We banded 57 different species and our top captured species for our remote banding sites were: Song Sparrow (347), Wilson’s Warbler (314), Swainson’s Thrush (271), Ruby-crowned Kinglet (190), and Wrentit (89). What a busy banding year 2019 was and we hope to catch plenty more birds in 2020!
January was a very slow month for banding at Palo. Capture rates typically slow down at this time of year, with January and February having the lowest average capture rates. With the colder weather and no active migration there tend to be fewer birds moving around the area, which may help explain why we catch fewer birds in the winter time. Despite the slow banding days, spring feels like it’s just around the corner! Many new birds are starting to gear up for the breeding season by singing. Some of the new singers in January included the incessant single note of the Hutton’s Vireo (https://www.natureinstruct.org/dendroica/spec.php/Dendroica+USA), the complex and wild gibberish of the Pacific Wren (https://www.natureinstruct.org/dendroica/spec.php/Dendroica+USA), and the occasional melodic Song Sparrow song (https://www.natureinstruct.org/dendroica/spec.php/Dendroica+USA). We even had our first evidence of nesting: we caught a female Anna’s Hummingbird who had a brood patch (a featherless and fluid-filled patch on the belly that helps transfer heat to eggs during incubation)!
For the first time since November, Ruby-crowned Kinglets were no longer crowned as our “Highest Captured” bird at our Bolinas Lagoon Open Space Preserve banding site. Instead we hailed a new champion, the Yellow-rumped Warblers! Yellow-rumped Warblers are colloquially known as “butter-butts” for the distinct yellow patch on their rump that looks like a sunny pat of butter. These birds can be split into two discrete subspecies, the Audubon’s Warbler and the Myrtle Warbler. The Myrtle Warbler has a white throat and pale eyebrow line while the Audubon’s Warblers lack the eyebrow line and they have yellow throats, though some young Audubon’s Warblers can have a pale creamy throat that will yellow as they age. Of the captured Yellow-rumped Warblers, 31 were Myrtle Warblers and 4 were Audubon’s Warblers. These birds are relatively easy to extract from nets, which is convenient since they were often found in a single net in groups of three to eight!
We had a unique Song Sparrow visit us at the Palomarin Field Station this month. Most Song Sparrows caught at the Palomarin Field Station are resident birds that belong to the subspecies gouldii. But one particular bird in the net had rustier streaking and was overall darker and larger than our resident gouldii. Based on this evidence we determined the Song Sparrow probably belonged to the morphna subspecies of Song Sparrow. These Song Sparrows are typically found in Northwest Oregon and the central coast of British Columbia. As a non-resident bird, we do not expect to see this particular Song Sparrow again throughout the summer, but it will hopefully return next winter.
Let’s Do the Numbers:
In 14 days (1465.25 net hours) of mist-netting at Palomarin in January, we captured 24 new birds and recaptured 26 previously banded birds. A total of 50 birds of 17 species were caught. Approximately 3 birds were caught per banding day.
At our Bolinas Lagoon Open Space Preserve site, Pine Gulch, we captured 56 new birds and recaptured 35 previously banded birds. A total of 91 birds of 13 species were caught over 4 banding days in January (205.59 net hours), an average of approximately 17 birds per day.
The highest capture rates at Palomarin and our other West Marin banding site were on January 2nd at Palomarin with 10 birds, and January 14th at Pine Gulch (Bolinas Lagoon Open Space Preserve) with 25 birds.
At Palomarin, the following species were caught in the highest numbers: Ruby-crowned Kinglet (7), Song Sparrow (7), Spotted Towhee (7), Bushtit (6), Wrentit (4), and Anna’s Hummingbird (4).
At Pine Gulch, the highest numbers of captures by species were: Yellow-rumped Warbler (35), Ruby-crowned Kinglet (20), Hermit Thrush (9), Song Sparrow (8), and Lincoln’s Sparrow (4).
About these Summaries:
Point Blue interns and staff at our Palomarin Field Station share these blog posts in an effort to further engage the public in our science. We are grateful to our partners at the Point Reyes National Seashore and to our surrounding Bolinas and West Marin County community for their support of our work.