Winter Banding Summary, November 2024 – January 2025

May 8, 2025

This summary was compiled by Point Blue’s Palomarin banding interns Mason Avelar and Paul Kessler, with help from Banding Supervisor Larissa Babicz.

Exciting Captures and Observations

November marked the beginning of the winter season and the beginning for a new crew of apprentice banders! The incoming apprentices got plenty of practice with their bird banding skills on Ruby-crowned Kinglets, a common winter resident in the area of which 124 were caught at the Palomarin Field Station in November alone. We can sometimes tell how old a Ruby-crowned Kinglet is by looking at the shape of its feathers, so it was a great opportunity to see so many of them in the hand. Golden-crowned Kinglets, a year-round resident species, were another common capture.

 

In November, we also resumed banding more frequently at our additional banding sites across Marin County, known as “off-sites”. These riparian sites can yield species that we are unlikely to observe at the Palomarin Field station, including Marsh Wrens, Common Yellowthroats, and wintering Swamp Sparrows.

 

On December 18th, we caught two species of jay… in the same net, at nearly the same time! Steller’s Jays and California Scrub-jays are both common around the station but are not captured very frequently because our nets are designed to capture smaller birds. Large birds like jays tend to escape easily, so to catch one of each in a single day was exciting!

 

The most exciting capture of December by far was a Merlin caught at our banding site at Marin County Park’s Bolinas Lagoon Preserve, along Pine Gulch creek, on New Year’s Eve! Merlins are a small species of falcon and are uncommon winter residents to the area. Our capture was not the usual kind of Merlin we might expect here, either. The pale coloring of our bird (pictured below) tells us that it was a Prairie Merlin, a subspecies that breeds in the Great Plains region of the United States and is not commonly seen in our area! This was the first Merlin ever caught at any of Palomarin’s sites and an amazing sendoff to the year 2024.

 

The number of captures began to decline in January, but the month was not without excitement. On January 4th, we captured a very unusual “white morph” Varied Thrush! This species is typically blue-black and vibrant orange (in males) or orange and brownish-gray (in females). This black-and-white look is rare, and after some research, we still aren’t sure what causes it.

 

One of the exciting things we can determine when we band and recapture birds is their age. On January 23rd, we recaptured a banded Fox Sparrow with what appeared to be an older band. After checking our database, we discovered that the bird was first banded on November 5th, 2014, which means it has been banded for 10 years and 4 months. Because it was an adult when it was first banded, we estimated its true age to be closer to 11 years and 6 months. According to longevity records kept by the USGS’s Bird Banding Laboratory, this bird may be the oldest Fox Sparrow ever captured in North America!

 

In addition to catching and banding birds, we try to observe all species at our banding sites and keep note of what we see. Some species we saw but that evaded our nets included Pileated Woodpeckers, a Red-breasted Sapsucker, Pygmy Nuthatches, and even a Ferruginous Hawk at our Muddy Hollow site in the Point Reyes National Seashore.

Let’s Do the Numbers

In 42 days (4925.2 net hours) of mist-netting at Palomarin from November to January, we captured 223 new birds and recaptured 205 previously banded birds. A total of 428 birds of 26 species were caught. Approximately 10 birds were caught per banding day.

At our other West Marin banding sites, we captured 186 new birds and recaptured 119 previously banded birds. A total of 305 birds of 31 species were caught over 17 banding days from November to January (958.98 net hours), an average of approximately 18 birds per day.

The highest capture rates at Palomarin and our other West Marin banding sites were on November 12th at Palomarin with 34 birds, and November 26th at Muddy Hollow (in Point Reyes National Seashore) with 38 birds.

At Palomarin, the following species were caught in the highest numbers: Ruby-crowned Kinglet (173), Golden-crowned Kinglet (68), Hermit Thrush (32), Wrentit (29), and Townsend’s Warbler (25).

Across all off-sites, the highest numbers of captures by species were as follows: Ruby-crowned Kinglet (131), Song Sparrow (46), Hermit Thrush (29), Bewick’s Wren (17), and Chestnut-backed Chickadee (11).

About these Summaries

Point Blue apprentices 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.

Early-career bird banders are part of a rigorous training program at Point Blue’s Palomarin Field Station, where they learn to capture birds safely using mist nets and record data on each bird caught. The information collected allows us to better understand how populations of birds are doing and in turn gives us insight into the health of the systems we research. Learn more about our seasonal apprenticeships by visiting the careers page on our website (link).

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 Laboratory.

Our Palomarin Field Station is open to the public. Consider visiting us! Learn how on our contact & visit us web page (link).