Docenting and Birding on Patos Island

[Stephen Chase]

Hi Whatcom Birds,

This week my wife Jes and I volunteered as docents for Keepers of the Patos Light, an organization which opens the historic lighthouse for visitors during the summer months. Patos Island is the northernmost of the San Juan Islands, and is just a mile south of Whatcom County - and a mile east of B.C.'s Gulf Islands. Between hosting visitors and completing volunteer responsibilities, I did some thorough birding of the island and scoping of the waters of the Salish Sea. A few notable sightings:

• I documented a fledgling Sooty subspecies of Fox Sparrow, along with at least five adults around the island. This confirms that Sooty Fox Sparrow nests on Patos. This subspecies is a winter resident of Whatcom County which heads north to Alaska in the summer. Surprisingly, it is known to nest on a few select islands in the San Juan Archipelago, although I had never seen confirmation that they nested on Patos. 
• A pair of Black Oystercatchers were raising two fledglings, and preferred to forage and roost on the rocks below the lighthouse at Alden Point. The oystercatchers proved particularly useful for spotting raptors, as they would raise a ruckus anytime a predator showed up. A Peregrine Falcon and a Cooper's Hawk both made tries for the young, and a Bald Eagle made many low flyovers. On our last day, a third adult oystercatcher flew in, and was immediately chased off by an adult (I presume the male). However, they both returned about a half hour later and the interloper was accepted, although generally the resident adults would scare it off a few yards with a wing display.
• Other confirmed nesters on the island included White-crowned Sparrow, Northern House Wren, Belted Kingfisher, Song Sparrow, Western Flycatcher, Canada Goose, Red-breasted Nuthatch, and American Robin. I'm certain there were more, but at a minimum I was able to confirm fledglings of all of these species. I also saw fledged Brown-headed Cowbirds, but they may have flown in from elsewhere after leaving their host parents.
• On our second day, a large flock of Bonaparte's Gulls flew in and began successfully harvesting small fish (herring?) off the north shore of Alden Point. Soon a number of other species joined them, including three Red-necked Phalaropes, two Rhinoceros Auklets, and others. I found this example of  interspecific reliance fun to watch.

Here's a link to my eBird trip report, which includes the photos I took during the trip. You can click on individual checklists within the report to see notes and comments about the avifauna of Patos Island. I really enjoyed getting an in-depth look at the goings-on of the wildlife on and around the island!

Finally, a panorama of the lighthouse at sunset on our last evening on the island. You can find a larger version of this image in one of my eBird checklists in the link above.

It was a unique and rewarding birding experience!

Back on the mainland USA, in Everson,

Stephen Chase