The Fall Season Begins
September 5, 2009
August 22nd marked the start of PRBO Conservation Science’s Fall Season here on Southeast Farallon Island, when focus shifts from the spring and summer breeding seabird monitoring, to the Passerine migration and Great White Shark monitoring of the fall. PRBO Biologists that arrived on the Island yesterday were Jim Tietz, Ryan Terrill, Jill Gautreaux, and Matt Brady. One Seabird intern, Jordan Casey, will be staying with us to continue seabird breeding effort monitoring.
During this transitional time, several late-nesting seabird breeders linger on the island to feed their downy chicks. While others that either already fledged their young or failed at nesting, return to socialize and perhaps prospect for next year. Tufted Puffins are particulary abundant at this time of year and we frequently see them flying closeby the lighthouse and land around crevices in small groups and then appear to discuss its potential.
Although the weather over the last two weeks has not been condusive for many migrant to find the island, we have had a smattering of West Coast migrants and a handfull of vagrants from the East Coast. For the first few days after our arrival, we experienced decent weather with high cloud cover and light northwest winds. This allowed a few of the western birds to find the island such as a Dusky Flycatcher on Aug 23rd which is actually an unusual bird to the Farallones in the fall. In fact, there are fewer than 40 records of Dusky in the fall which is odd when you consider that we have over 100 records of Least Flycatcher – a very uncommon bird along the California Coast. It is believed that most Duskies fly along the inner mountain routes and mostly avoid the coastline.
During late August and September, we typically capture large numbers of Yellow Warblers and Townsend’s Warblers in our mistnets. We then colorband them so that we can better determine the number of days that each individual is present and better estimate the number of each species on the island.
In addition to these birds, a few other western birds were present such as a Rufous Hummingbird, a couple Hermit Warblers, Black-throated Gray Warbler, and both Western and Eastern Kingbirds.
On the first of September, a few more migrants found the island including a Tennessee Warbler and a Virginia’s Warbler – the Tennessee is a vagrant from the northeast while the Virginia’s is a vagrant from the desert southwest.
In addition to birds we also collect data on sharks, insects, bats, whales, fur seals, and anything else of interest. We’ll give some information about these other taxa in future blogs.
