Taking the Long View: An inside look at the goings-on at the longest running avian ecology field station west of the Mississippi.

Monthly Banding Summary, September 2015

This summary was compiled by Palomarin banding interns Hannah Conley and Rhianna Stavish with help from Renée Cormier, Banding Supervisor.

Exciting Captures and Observations:

Every September we banders watch the days get shorter and the crisp autumn air creep in, while we wait, anticipating many of our winter resident bird species to return, and many of the first fall migrants to start making their way back south. September marks the first big push of migration, and is perhaps the height of this beautiful movement of birds. At the Palomarin Field Station this September, many of the birds we captured were migrants, fueling up on their way south. We also welcomed back Golden-crowned Sparrows, Fox Sparrows, Hermit Thrushes and Ruby-crowned Kinglets to the station, all species that spend their winters here in West Marin and breed north of us in the spring and summer. By the end of the month, many of the early migrants (e.g., Wilsons’ Warblers) that we had been capturing frequently started to peter out, as a new wave of later-migrating species (e.g., Fox Sparrows) started to pick up.

This Ruby-crowned Kinglet, a winter resident, was our first capture of the fall at Palomarin on 9/23. Photo by Hannah Conley.

Swainson’s Thrushes, one of our most commonly caught breeding birds, have been replaced by the wintering Hermit Thrushes. Townsend’s Warblers are now our most frequently caught warbler, while Wilson’s Warblers, so common in the spring and summer, have seemingly all left for their wintering grounds. Winter regulars have returned in numbers, while some species like Yellow Warblers passed through in a matter of weeks. Yellow Warblers are an example of a passage migrant here in West Marin: they neither breed nor winter in the area, yet many are detected here in the fall, making this an important stopover region during their migration.

A striking adult male Yellow Warbler caught at one of our West Marin banding sites, Redwood Creek in the Golden Gate National Recreation Area. Photo by Hannah Conley

A few of our interesting captures were either regular west coast migrants that we don’t catch very often, or vagrants (birds that get off course during migration and find themselves outside of their normal range). In September we caught some of these vagrants, such as a Canada and Blackpoll warblers, and migrants that we don’t catch often, such as Black-throated Gray Warbler and Yellow-breasted Chat.

A vagrant, this first-year Canada Warbler caught at Muddy Hollow in the Point Reyes National Seashore was just our 8th capture ever of this species. Photo by Hannah Conley.

A hatch-year Blackpoll Warbler – much different in appearance than an adult breeding male, for which the species is named – was a very exciting vagrant to catch! Photo by Hannah Conley.


Let’s Do the Numbers:

In 26 days (2801.56 net hours) of mist-netting at Palomarin in July, we captured 166 new birds and recaptured 36 previously banded birds. A total of 202 birds of 37 species were caught this month. Approximately 8 birds were caught per banding day.

At our other West Marin banding sites, we captured 274 new birds and recaptured 129 previously banded birds. A total of 403 birds of 38 species were caught over 22 banding days this month (1163.33 net hours), an average of approximately 18 birds per day.

A hatch-year Blackpoll Warbler – much different in appearance than an adult breeding male, for which the species is named – was a very exciting vagrant to catch! Photo by Hannah Conley.

The highest capture rates at Palomarin and our other West Marin banding sites were on September 20th at Palomarin with 15 birds and September 25th at Redwood Creek with 29 birds.

At Palomarin the highest numbers were captured for the following species: Pacific-slope Flycatcher (22), Fox Sparrow (22), Swainson’s Thrush (21), Yellow Warbler (18), and Townsend’s Warbler (13).

At our other five banding stations in West Marin (excluding Palo), the highest numbers of captures by species were: Song Sparrow (100), Pacific-slope Flycatcher (32), Swainson’s Thrush (31), Pacific Wren (26), and Wilson’s Warbler (24).

Lincoln’s Sparrow (left) is another winter resident that has reappeared at a few of our banding sites. Sometimes confused with the year-round resident Song Sparrows (right), it is easy to see the differences in coloration and patterning in a side-by-side comparison. Photo by Hannah Conley.

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.