Alix Arthur d'Entremont: Cerulean Warbler on Bon Portage

Hatch-year female Cerulean Warbler at Bon Portage, Shelburne County, September 3, 2016. Photo by Alix d'Entremont.

Status & Recent Sightings
McLaren (2012) rates the Cerulean Warbler as a rare vagrant to Nova Scotia with about 45 reported as of the end of 2010. The first was found on Sable Island on June 6, 1968 by C. Bell (Nova Scotia Birds Society Newsletter Vol. 10 No. 2). Sightings since 2010 are listed below:

Aug. 17, 2011 - Bon Portage Island - Lucas Berrigan
Oct. 2, 2011 - Chebucto Head, Halifax - David Currie (ph.)
Oct. 2, 2011 - Hartlen Point, Halifax - Dennis Garratt, fide David Currie (3 BIRDS!)
May 18, 2012 - Halifax Public Gardens - Dennis Garratt (female)
Sep. 2014 - Lower Sackville, Halifax - Don Robar (fide Clarence Stevens, no details)
Sep. 3, 2016 - Bon Portage Island - David Bell & Alix d'Entremont (imm. female, ph.)
Sep. 2016 - Pleasant Hill Cemetery, Halifax - Dennis Garratt (imm. female)

*The Oct. 2012 Ceruleans above were part of a larger fallout due to a low-pressure system that moved up the U.S. coast towards us. This system propelled migrants offshore and then directly to Nova Scotia. (NS Birds Vol. 54 No. 1)

Field Encounter
Chloe, Molly and Ben Symons joined me on a Zodiac trip to Bon Portage on September 3, 2016. I brought them to the island to show them the bird banding done by the Atlantic Bird Observatory staff.

We watched a few birds get processed and then made our way south towards the lighthouse. I pulled out an immature Leach's Storm Petrel from a burrow to show the group. While observing the few shorebirds in the pond near the lighthouse, a bat flew in and landed on one of the buildings. I was able to get a few photos and Andrew Hebda (Curator of Zoology at the Nova Scotia Museum) as well as Hugh Broders (Professor of Biology at Saint Mary's University) believe it is likely a Silver-haired Bat.

Silver-haired Bat at Bon Portage, Shelburne County, September 3, 2016. Photo by Alix d'Entremont.

We then made our way back to the cabins near the wharf. The area around the cabins is often one of the busiest places for passerines on the island. Chloe and I observed a warbler that I first took as a Bay-breasted, but wasn't quite sure so I pulled out the camera and snapped a few photos. Bay-breasteds don't have a pale supercillium, so it wasn't quite right for that species.

Hatch-year female Cerulean Warbler at Bon Portage, Shelburne County, September 3, 2016. Photo by Alix d'Entremont.

I asked David Bell (bander-in-charge) to check my photos and he was glad to share that he thought it was a Cerulean Warbler. David soon re-found the birth north of the wharf while walking to check the mist nets. David had actually briefly seen the Cerulean earlier in the day, but the brief views weren't enough to confirm its ID. I had never seen a Cerulean Warbler and wasn't quite ready for such a pale coloured and blandly patterned bird. Had it been an adult male, I'd have known right away. The lack of blue tones or streaking above along with the extensive yellow below make it a hatch-year female.

Below are a few photos of a hatch-year Yellow-bellied Flycatcher that I took after the banding and processing was complete.