Breeding Season Banding Round-up, March-July 2022
August 24, 2022
This summary was compiled by Point Blue’s Palomarin banding apprentices Larissa Babicz, Naomi Burns, Hope Caliendo, and Doris Rodriguez with help from Mark Dettling, Banding Supervisor.
Exciting Captures and Observations:
The breeding season is a very exciting time of year for bird banding! Towards the end of spring migration, we started catching more birds and the overall bird activity increased drastically. Singing, establishing territories, finding mates, and collecting nesting materials all became increasingly important for birds in March and April. Some species started this process earlier in the year, especially hummingbirds. Therefore, it was not surprising that our first chick caught was an Anna’s Hummingbird on April 13th! Breeding condition such as brood patches and cloacal protuberances indicated that our other birds were also raising young, yet we didn’t catch our first fledgling passerine (perching birds), an Orange-crowned Warbler, until May 4. After that, fledglings were showing up all over the place, and by June and July, the vast majority of birds caught were juveniles!
At Palo, the California Quail families provided plenty of entertainment as the chicks slowly started showing themselves more and more. At first, they looked like tiny fuzz-balls with legs, but pretty soon they grew in some flight feathers and stubby little top-knots (the feathers dangling at the top of their heads). A family of Hermit Warblers was also hanging around the net trail for a few days, and we were able to catch the adult female. This was exciting since Hermit Warblers usually only nest in higher elevations in Marin County. A pair of Red-breasted Nuthatches tried nesting on our trail as well, but after their branch fell down, they moved upslope where we could no longer watch them. We were delighted when they came back later on with their chicks… and then more came… and some more… until we had banded 27 nuthatches at Palo! Along with the nuthatches came an explosion in the number of Brown Creepers (32 in total). What was previously an occasional treat in our nets somehow became one of our most frequently captured birds! Nesting birds were also around the Palo buildings. Two pairs of Barn Swallows each raised two broods of chicks that created massive piles of poop right outside our doors. Meanwhile, we discovered that House Finches prefer to keep all their poop inside the nest – how considerate. Very few White-crowned Sparrows nest around Palo because of the encroachment of Douglas Fir on their preferred scrubby habitat, but we were delighted to catch one adult and one fledgling. In July, an adult female Ruby-throated Hummingbird decided she needed a holiday far, far away from her home in the east and headed to the Pacific Ocean, only to be caught by those pesky Palo banders. This was quite a rarity and the first one in Palo’s 56-year history!
The banders run four off-site banding locations in addition to the field station. The first off-site hatch-year (birds hatched this calendar year) was caught at Pine Gulch (in Bolinas Lagoon Open Space Preserve) – an Allen’s Hummingbird, and the first young passerine was a Chestnut-backed Chickadee at the same location. The first day of banding at Redwood Creek (in the Golden Gate National Recreation Area) was May 5th, and it was a frenzied rush of hummingbirds overwhelming nets and banders alike! That day had our highest capture rate of the season – 93 birds total, including 52 hummingbirds!!! Whoa. July 6th was another special day as a wave of WAVIs (the four letter banding code for Warbling Vireo) flew into one of our nets at Pine Gulch. Since we don’t catch these guys very often, having five in one day was exciting! A hatch-year Black-headed Grosbeak and a breeding Pygmy Nuthatch were two more highlights from Redwood Creek. The nuthatch was the only one of this species we caught all season, as they usually hang out higher up in the trees and don’t fly into our nets below. Even better, this bird was a female with a brood patch, so we know she was raising a family! Another cool brood-patchy bird was a Hooded Oriole at Pine Gulch. Why she wasn’t hanging out in her palm trees, we have no idea, but we sure appreciated her willingness to explore the area and fly into a net! The second-ever American Crow was also caught at Pine Gulch (although this had nothing to do with the breeding season – we just thought it was awesome and had to mention it!).
Let’s Do the Numbers:
Let’s take a look at some numbers for March through July! At our beloved Palomarin Field Station, we had 381 recaptured birds and 486 new birds. At our off-sites, we had 595 recaptures and 928 new birds. This sums up to a grand total of 2,390 birds! Whoa, that’s a lot of birds! At Palo, 274 of these were hatch-years of 23 species, while at the off-sites, 482 hatch-years of 27 species were caught.
Palomarin top 3 species by number: Wilson’s Warbler – 113, Oregon Junco – 82, Swainson’s Thrush – 69
Off-site top 3 species by number: Swainson’s Thrush – 321, Song Sparrow – 266, Wilson’s Warbler – 184
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.
Our Palomarin Field Station is open to the public by appointment. Consider visiting us! Learn how on our contact & visit us web page.