Point Blue Conservation Science: Monthly Banding Summary, July 2020
August 21, 2020
This summary was compiled by Point Blue’s Palomarin banding interns Mary De Aquino, Mary Kate Lisi and Bernarda Vasquez with help from Mark Dettling, Banding Supervisor.
A quick note that while the field station was closed to the public in June, we were still able to conduct our research activities. We always take the safety of our team seriously, and the COVID-19 pandemic is no exception. Our team has developed protocols to maintain the interns and staff supervisors as a family unit, allowing us to continue to work together closely. Please check the Point Blue Facebook page for announcements on dates and times for live banding demonstrations. Please check here for updates on when the field station will reopen to the public.
Exciting Captures and Observations:
Similar to June, July banding kept the banders at Palo very busy! As nestlings continue to fledge and become active outside the nest, we were having the busiest banding days of the year. There were 10 (out of 26) banding days at Palomarin with over 30 birds, and 3 (out of 9) days at our offsites with over 50!
Over the past few months, we have been observing a Barn Swallow nest right on the side of our Palo bunk house! This is the second successful nest on our building this year. We tracked the nest since finding the eggs in the beginning of the month, and a few weeks after hatching we banded them as nestlings! We were surprised to see how short their legs were compared to the rest of their body. We expect them to fledge in August! (Update: They fledged August 6!)
With some exceptions, many birds have begun to molt (grow) new feathers. Hatch-year birds (ones that hatched during the current calendar year) are changing from the juvenile plumage they left the nest with and into their first-winter plumage, which in some species looks similar to that of adults, while adult birds gain fresh feathers to get them through the winter. The order in which birds molt their flight feathers can be helpful in identifying an individual’s age. Birds molt only a few feathers at a time to avoid losing all their feathers at once to ensure there are enough fully grown feathers present to retain their ability to fly. Once these late summer or fall molts are complete, it can be difficult to differentiate hatch-year from adult birds, since many will appear identical!
In the end of July, the nest searching season came to an end as the breeding season for most birds stopped. Gridders finalized their season by creating maps and write-ups of the pairs and territories they have been studying the past four and a half months. This data will be helpful in the future to track particular individuals and provides valuable data about bird behavior and breeding at Palo. Individuals of some of our study species (Song Sparrow, Nuttall’s White-crowned Sparrow, California Scrub-Jay, Spotted Towhee, and Wrentit) will continue to receive unique color band combinations in the fall and winter so they can be identified in the field during future breeding seasons.
We had several exciting, rare captures at Palomarin in July! We were surprised to capture a Sharp-shinned Hawk, MacGillivray’s Warbler, and California Scrub-Jay in our mist nets. It is not every day you find a hawk in the net! Large birds, like hawks and jays, are typically easy to extract because they are so big and do not get very tangled, but can be difficult due to their strong legs and sharp claws. Although they are commonly seen around Palo, this was the first California Scrub-Jay to be captured since March!
Let’s Do the Numbers:
In 26 days (2915.68 net hours) of mist-netting at Palomarin in June, we captured 446 new birds and recaptured 229 previously banded birds. A total of 676 birds of 28 species were caught. Approximately 26 birds were caught per banding day.
At our other West Marin banding sites, we captured 228 new birds and recaptured 93 previously banded birds. A total of 329 birds of 19 species were caught over 9 banding days in June (486.0 net hours), an average of approximately 37 birds per day.
The highest capture rates at Palomarin and our other West Marin banding sites were on July 8 at Palomarin with 43 birds, and July 23 at Muddy Hollow (in Point Reyes National Seashore), with 80 birds.
At Palomarin, the following species were caught in the highest numbers: Swainson’s Thrust (168), Wilson’s Warbler (115), Oregon Junco (52), Brown Creeper (51), and Wrentit (50).
Across all off-sites, the highest numbers of captures by species were: Swainson’s Thrush (97), Song Sparrow (81), Wilson’s Warbler (52), Bewick’s Wren (23), and Wrentit (21).
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.