Summer Banding Summary, May-July 2023

October 5, 2023

This summary was compiled by Point Blue’s Palomarin banding apprentices Samantha Hagler and Andrea Robles with help from Mike Mahoney, Banding Supervisor.

Exciting Captures and Observations:

May to July marked the busiest time of the season for the spring-summer banders at Palo, and as the summer went on, a shift in captures to mostly young (hatch-year) birds. Blackberry vines and stinging nettle began growing faster than we could trim, bush lupine and bush monkeyflower lit up the hillsides in purple and orange, and we started finding more and more fledgling birds in our nets, all signs of the local wildlife reaping the benefit of the winter rains.

Like a harbinger of summer, an adult male Western Tanager appeared in the Palomarin nets on May 6. Western Tanagers aren’t uncommon in Marin County (albeit mostly as a “passage migrant”, e.g., those that do not stick around), but this bird dazzled everyone at the station nonetheless with his sunset-colored plumage and glossy black wings. Later in the same day, banders caught a warbler that looked similar to the familiar Orange-crowned Warbler, but with grayer plumage, pale undertail coverts, and a wash of greenish on its back– a Tennessee Warbler, and the first vagrant capture of our spring season!

 

 

 

 

 

 

 

 

 

 

 

The second vagrant of the season, on June 9, was a hummingbird with a touch of red at the base of her bill, a white eyebrow, and a flash of blue in her tail. Banders realized that they had captured a Broad-billed Hummingbird! Although females are less flashy than males, which are a glossy blue and green, the bold face pattern and patch of blue in the tail still sets females of this species apart from the other hummingbirds expected in California.

 

This species is native to arid landscapes in Mexico and southeastern Arizona, so this female was certainly out of place on a fog-shrouded hillside in coastal California, hundreds of miles from even the northern edge of the species’ breeding range! She is only the second Broad-billed Hummingbird ever captured at the Palomarin Field Station, a species first caught at the station in 2011 and a very rare species for the county.

As the days lengthened and spring settled into summer, we started hearing the buzzy songs of Hermit Warblers around the Palo net trail and even captured two beautiful adult females on May 8 and June 17 and a hatch-year female on July 14, suggesting that these warblers might have nested just upslope of the Palo nets this season. Other fun captures for the summer at Palo included a family of California Quail on July 23, a Band-tailed Pigeon on June 2, and two adult California Towhees on May 31, the first capture of this species at Palo since 2012. At least two pairs of California Towhees spent the summer around the field station, and likely nested nearby. It was exciting for all Palo staff to welcome back a familiar breeding bird species to Palo after 11 years. The banders and staff were also surprised to find no less than four separate House Finch nests at the station, including one pair nesting on top of the old pay phone by the offices.

 

 

 

 

 

 

 

 

 

 

 

Offsite banding kept us busy as well this summer, with what at times felt like a flood of hatch-year Wilson’s Warblers, Swainson’s Thrushes, and Song Sparrows, especially in July. Other fun offsite captures included a Cooper’s Hawk at our site Muddy Hollow in Point Reyes National Seashore, on May 19, a Mourning Dove at our site at Redwood Creek in the Golden Gate National Recreation Area near Muir Beach on July 13, and a Savannah Sparrow at our site Pine Gulch on Marin County Parks Land at the Marin County Bolinas Lagoon Open Space Preserve on May 18.

The banding apprentices were joined from mid-June to early August by two interns with the Doris Duke Conservation Scholars Program, Jedi Casas and Alejandro Vazquez Rodriguez. Jedi and Alejandro joined us to learn about bird banding and about other research with Point Blue, and by the end of their internship were already extracting and banding birds like pros. We were so lucky to have them join us this summer!

 

 

 

 

 

 

 

 

 

 

 

Our full crew also enjoyed color-banding newly fledged Wrentits, Spotted Towhees, and Song Sparrows around Palo. It was so fun getting to know the local birds around the net trail by their color-band combos! The banders were especially fond of the local cohort of hatch-year Wrentits. It was fitting that the Palo crew and Spotted Owl crew came together to create a Wrentit float for the Bolinas 4th of July parade, where they won an award for being the Crowd Favorite.

Let’s Do the Numbers:

In 80 days (8,723.58 net hours) of mist-netting at Palomarin in May, June, and July, we captured 363 new birds and recaptured 356 previously banded birds. A total of 719 birds of 37 species were caught. Approximately 9 birds were caught per banding day (8.2 birds per 100 net hours).

At our other West Marin banding offsites, we captured 614 new birds and recaptured 495 previously banded birds. A total of 1,109 birds of 37 species were caught over 38 banding days in May, June and July (2,034.18), an average of approximately 29 birds per day (54.5 birds per 100 net hours).

The highest capture rates at Palomarin and our other West Marin banding sites were on July 10 at Palomarin with 20 birds, and July 20 at Muddy Hollow with 82 birds each. At Palomarin, the following species were caught in the highest numbers were Song Sparrow (37), Allen’s Hummingbird (72), Wrentit (72), Swainson’s Thrush (75), Oregon Junco (82), and Wilson’s Warbler (89).

Across all off-sites, the highest numbers of captures by species were: Bewick’s Wren (27), Wrentit (37), Orange Crowned Warbler (46), Wilson’s Warbler (219), Song Sparrow (233), and Swainson’s Thrush (295).

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