Point Blue Conservation Science: Monthly Banding Summary, October 2019
November 28, 2019
This summary was compiled by Point Blue’s Palomarin banding interns Samantha Chavez and Hannah Roodenrijs with help from Hilary Allen, Banding Supervisor.
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Exciting Captures and Observations:
October was another exciting month of banding at Palomarin! We continued to experience fall migration of both songbirds as well as raptors. Although our nets aren’t specifically designed to capture raptors, fall is the time when we often start to capture Sharp-shinned Hawks. Primarily we catch hatch-year (young, hatched earlier this year) males who tend to be around the same size as a Steller’s Jay. We caught and banded 4 Sharp-shinned Hawks in October: three males and one female, all hatch-year birds in their juvenile plumage. In raptors, females are generally larger than males so we can typically determine the sex of the bird based on the length of their wing. Surprisingly, we also caught another Cooper’s Hawk this month! That makes two so far in 2019, a high number considering the last Cooper’s was caught in 2015. This month’s Cooper’s Hawk was already banded and we determined that it had been banded a week earlier at the Golden Gate Raptor Observatory which is located in the Marin headlands in the Golden Gate National Recreation Area!
In another example of the changing of the guard, we caught our first Varied Thrush of the season as well as the last Empidonax flycatcher (a genus of the flycatcher family). No Empidonax flycatchers have been caught since October 5th, a sign that most have finally finished passing through Palo and are continuing on their way to Mexico and Central America. Meanwhile, the Varied Thrushes have finally arrived. These gorgeous orange and slate gray birds will stay at Palo for the winter season.
A rare capture that became surprisingly common this month was the Pileated Woodpecker. We caught 3 different individuals within a two week period during October! Of the three individuals, the first capture was a hatch-year female, the next a male of unknown age, and the last was an after-hatch-year (adult) female. The males and females can be distinguished based on the extent of red in their crown. Males have red that extends into their forehead, and in females the red is only on the back of the head; males also have a red mustache, that is absent in females. Another Pileated Woodpecker was caught back in March of this year, so that makes 4 so far for 2019! Interestingly, before this year we had only ever caught 9 other Pileated Woodpeckers at Palomarin! That means that in 2019 we have banded about one third of all Pileated Woodpeckers that have ever been banded at Palomarin. Pileated Woodpeckers prefer forest habitats, and the succession of Douglas Firs into the study area at Palomarin may be creating more suitable habitat for these large woodpeckers. When we first started banding at this site in 1966, much of the study area was dominated by coastal scrub habitat and over the years it has begun to turn to early succession Douglas Fir forest as the trees move down the hill and encroach into the scrub. The first Pileated Woodpecker banded here was in 1991, so it may be that before then the forests in the area that were mature enough for this species were less extensive, and thereby the area near the nets less appealing to them.
Another very exciting capture this month was a young male Yellow-bellied Sapsucker caught on October 22. Only two other Yellow-bellied Sapsuckers have been caught here previously. The Yellow-bellied Sapsucker is similar to the Red-breasted Sapsucker, but the face pattern has much more white striping. The Yellow-bellied Sapsucker we caught still had some juvenile plumage that it will continue to replace until it is in its formative (first winter) plumage. In the United States, these sapsuckers are primarily found on the east coast, though occasionally one will find itself on the west coast. They are able to hybridize with the more common west coast species, the Red-breasted Sapsucker, and in fact the Red-breasted, Red-naped, and Yellow-bellied Sapsuckers were all once considered the same species. They were split into three separate species in 1985 by the American Ornithological Union. We also caught our first Red-breasted Sapsucker of the season in October. The difference in amount of red is quite striking!
A couple of traditional Palomarin events took place in October this year. The first was our annual Golden-crowned Sparrow party, a party to celebrate the changing of seasons and the return of Golden-crowned Sparrows to their wintering grounds. The Palomarin team of interns, staff, and friends also participated in Point Blue’s 41st annual Rich Stallcup Bird-A-Thon fundraiser. Our team, called “The Lookers” spent 24 hours birding together throughout West Marin trying to find and identify as many species as we could, all while donning binoculars and fancy clothes. The Lookers motto is “Bird hard, stay focused, and look good”. We ended up with a final tally of 152 species! It’s not too late to donate to The Lookers team! You can find more information here.
Let’s Do the Numbers:
In 25 days (2706.99 net hours) of mist-netting at Palomarin in September, we captured 248 new birds and recaptured 131 previously banded birds. A total of 379 birds of 31 species were caught. Approximately 15 birds were caught per banding day.
The highest capture rate at Palomarin was on October 20th with 23 birds.
At Palomarin, the following species were caught in the highest numbers: Ruby-crowned Kinglet (97), Fox Sparrow (45), Hermit Thrush (38), Wrentit (33), Golden-crowned Kinglet (22), and Townsend’s Warbler (21).
No banding occurred at any of the Palomarin off-sites this month, but tune in next month for capture rates for one of our off-sites, Pine Gulch.
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.