Monthly Banding Summary, September 2013
By Palomarin Field Station
This summary was compiled by Palomarin banding interns Navit Reid and RJ Roush with assistance from Palomarin Banding Supervisor Renée Cormier, and Conservation Educator Lishka Arata..
Exciting Captures and Observations:
One of the many exciting captures we had at Palo this month was a young Black-chinned Sparrow. While these birds are often found in and around scrubby vegetation, the Palomarin Field Station is at the northern-most tip of their range and they are rarely detected here: they “invade” Marin County at irregular intervals, and we have a few recorded breeding attempts on the study area over the past few decades, but, in the last 42 years of banding, we have only caught three other Black-chinned Sparrows.
Another fun capture we had at the Palo nets was a Band-tailed Pigeon. While this bird is not uncommon for the area, they rarely get caught in our nets due to their large size and tendency to stay high up in the canopy. It was a real treat to get to handle such a large species, especially since we have only caught nine others before.
With September being prime fall migration time, we need to be ready to identify any vagrants (birds far out of their typical range) we might catch in our nets. This month, our offsite locations tested our identification skills with three rare species for the west coast. First, at Pine Gulch we caught a Red-eyed Vireo which are usually found in the eastern half of the U.S. and up into the northern states, and Canada. Then, a few days later we caught a Canada Warbler at Redwood Creek. As the name implies, this species is typically found in Canada as well as throughout the eastern U.S. during migration. Finally, we caught a Northern Waterthrush at Muddy Hollow which can be found throughout the middle and eastern U.S. during migration. Pine Gulch is part of the Marin County Open Space District’s Bolinas Lagoon Preserve, Redwood Creek is a banding site located near Muir Beach in the Golden Gate National Recreation Area and Muddy Hollow is a site located near Limantour Beach in the Point Reyes National Seashore.
Finally, with all the northern birds heading south, we started catching many of the migratory species that winter here. Species such as Puget Sound White-crowned Sparrows and Hermit Thrushes began showing up much more regularly, and the number of Fox Sparrows and Golden-crowned Sparrows we caught seemed to skyrocket overnight. It was as if all the migratory birds chose to show up all at once here in West Marin.
Let’s Do the Numbers:
In 27 days (2,674 net hours) of mist-netting at Palomarin in August, we captured 197 new birds and recaptured 34 previously banded birds. A total of 231 birds of 37 species were caught this month. Approximately 8 birds were caught per banding day.
At our other West Marin banding sites, we captured 250 new birds and recaptured 106 previously banded birds. A total of 356 birds of 39 species were caught over 22 banding days this month (1,184 net hours), an average of 16 birds per day.
The highest capture rates at all sites were on August 22nd at Redwood Creek and August 23rd at Muddy Hollow, with 33 and 38 birds captured, respectively.
At Palomarin the highest numbers were captured for the following species: Fox Sparrow (37), Pacific-Slope Flycatcher (22), Warbling Vireo (17), Townsend’s Warbler (14), and Song Sparrow (13)
Across all off-sites, the highest number of captures by species were: Song Sparrow (80), Swainson’s Thrush (32), Fox Sparrow (27), Pacific-Slope Flycatcher (25), and Pacific Wren (21)