Monthly Banding Summary, October 2013
By Palomarin Field Station
This summary was compiled by Palomarin banding interns Navit Reid and Elena Daggett with assistance from Palomarin Banding Supervisor Renée Cormier, and Conservation Educator Lishka Arata.
Exciting Captures and Observations:
Exciting Captures. While fall migration has wound down, we still had quite a few exciting captures this month. Among them were 10 Sharp-Shinned Hawks, 8 Red-Breasted Sapsuckers, 2 Nashville Warblers, 2 Swamp Sparrows, and a Slate-colored Junco.
Geolocator Update. It’s that time of year again…now that our winter resident birds are back we’ve begun recovering many of the geolocator tags (lightweight tags that record time and light intensity) we put out last winter. Two species, the Golden-crowned Sparrow and Hermit Thrush, were fitted with tags prior to their northward migration to summer breeding grounds. Now that they are back, we can retrieve the tags, download the information, and find out where they went! This month, we have recovered 4 tags from our coastal Golden-crowned Sparrows, 2 from an inland site in the foothills of the Sierra, and 1 tag from a Hermit Thrush at Pine Gulch Creek (Marin County Open Space District Land). Each tag provides a wealth of information about where these birds breed and how they migrate improving our ability to inform conservation efforts.
Banding and the Government Shut-down. Looking at our “Numbers” section below, you might notice our banding days were fewer than normal. During the federal government shutdown, all research was suspended on federal lands, including our banding at Palomarin and 4 out of 5 of our other field sites in West Marin County. We will have a two week gap in our data for the first time in our history. On the bright side, although not necessarily correlated, after the shutdown ended we captured surprisingly high numbers of birds during the second half of October.
Let’s Do the Numbers:
In 16 days (1,840.5 net hours) of mist-netting at Palomarin in October, we captured 426 new birds and recaptured 106 previously banded birds. A total of 532 birds of 34 species were caught this month. Approximately 33 birds were caught per banding day.
At our other West Marin banding sites, we captured 287 new birds and recaptured 82 previously banded birds. A total of 369 birds of 37 species were caught over 16 banding days this month (815.64 net hours), an average of 28 birds per day.
The highest capture rates at all sites were on October 30th at Palomarin Grids Uppers and October 26th at Palomarin, with 74 and 62 birds, respectively. At “Uppers”, this was the most captures in one day since we initiated surveys at that site, 21 years ago. At Palo, this was the most captures in one day since 1986!
At Palomarin the highest numbers were captured for the following species: Fox Sparrow (212), Ruby-crowned Kinglet (93), Oregon Junco (53), Townsend’s Warbler (13), and Wrentit (13).
Across all of our other banding sites in West Marin County, the highest number of captures by species were: Fox Sparrow (99), Ruby-crowned Kinglet (74), Hermit Thrush (34), Song Sparrow (25), Pacific Wren (20), and Bushtit (17).
Fox Sparrows, Fox Sparrows, Fox Sparrows!
2013, contrary to what other calendars might say, is the year of the Fox Sparrow. After banding 379 of these spunky, medium-sized birds at Palomarin this fall (and counting!), we took a look at previous capture rates to compare whether this was an exceptional number, and if so, how exceptional. What we found revealed this year to be quite the anomaly, with more than four times the number of Fox Sparrows caught this year than the highest record in the history of the Palomarin Field Station. For a comparison of October rates, see Figure 1 below.