Monthly Banding Summary, September 2016
By Palomarin Field Station
This summary was compiled by Palomarin banding interns Lila Fried and Kate Maley, with help from Renée Cormier, Banding Supervisor.
Exciting Captures and Observations:
September was a busy month for Palomarin. We were still catching mainly hatch-year (young birds that hatched in 2016) birds, many of whom would soon depart on the first of hopefully many journeys to their wintering grounds. Wilson’s Warbler captures all but ceased, Hermit Thrushes replaced Swainson’s Thrushes in our nets, and the first Sharp-shinned Hawk of the season was caught on the 16th, followed the very next day by the season’s first Golden-crowned Sparrows, who returned from their Alaskan breeding grounds. Thanks to recent geolocator tagging work by Point Blue biologists, we now know that Golden-Crowned Sparrows from coastal wintering populations tend breed along the Gulf Coast of Alaska, while more inland-wintering populations are likely to migrate to interior sites in western Canada!
Mid-September saw a major movement of Fox Sparrows as we started getting slammed with them in the nets after the first one was caught on the 6th. The “Sooty” subspecies of this large sparrow is a common winter resident at Palomarin, and can be distinguished from its “Thick-billed,” “Slate-colored” and “Red” counterparts by its bicolored bill, and uniform chocolate brown coloring.
One particularly exciting capture for the month was a hatch-year Northern Waterthrush, caught on September 15th at Palomarin. This large, streaked warbler breeds in Alaska, Canada and the northeastern U.S., and winters from Southern Florida and Mexico to northern South America. It is regularly seen east of the Rockies during migration, but is a vagrant (a bird outside of its normal range) for the West Coast and interior west.
A hatch-year Hermit Warbler that was captured at Palomarin on September 5th was another major highlight of the month. This species is a regular visitor during migration but is rarely caught in our nets, due to its preference of foraging in the forest canopy. It can hybridize with the closely-related Townsend’s Warbler where their ranges overlap, and so an extra careful examination is required when either of these two species is captured!
Let’s Do the Numbers:
In 27 days (2995.67 net hours) of mist-netting at Palomarin in September, we captured 137 new birds and recaptured 41 previously banded birds. A total of 178 birds of 29 species were caught. Approximately 7 birds were caught per banding day.
At our other West Marin banding sites, we captured 259 new birds and recaptured 108 previously banded birds. A total of 367 birds of 36 species were caught over 21 banding days in September (1130.98 net hours), an average of approximately 17 birds per day.
The highest capture rates at Palomarin and our 5 other West Marin banding sites (the “off-sites”) were on September 27 at Palomarin with 17 birds and September 29 at Redwood Creek with 32 birds.
At Palomarin the highest numbers were captured for the following species: Pacific-slope Flycatcher (27), Fox Sparrow (27), Oregon Junco (15), Hermit Thrush (15), and Wrentit (14).
Across all off-sites, the highest numbers of captures by species were: Song Sparrow (87), Fox Sparrow (45), Pacific-slope Flycatcher (35), Pacific Wren (23), and Wrentit (21).
About these Summaries:
In an effort to share our science with the public, Point Blue interns and staff at our Palomarin Field Station (Palomarin or “Palo”) in Point Reyes National Seashore near Bolinas, CA produce these monthly bird-banding summaries. Our science interns create these summaries as part of their science outreach training.
Our Palomarin Field Station is open to the public. Consider visiting us! Learn how by visiting our mist-netting demonstrations web page.