Bell's Vireo

 

                                                        Bell's Vireo    [Photo by Mark Morse]

A Bell's Vireo was seen and photographed on October 2, 2023 by Mark Morse, previously found by Karen Miller across from the Anchorage Road on Grand Manan.  This is a significant event because it is the first record of this species for New Brunswick.  The photos above and below in this post were taken by Mark Morse.  Birds of New Brunswick: An Annotated List lists six vireos found in New Brunswick and, of course,  Bell's Vireo is not one of them.  The story of its discovery follows.

Sometime in September Jim Wilson and his birding friends were discussing vireos and commented that we were overdue for a rare vireo.  Specifically they were thinking about Bell's Vireo and Cassin's Vireo.  If Maine and Nova Scotia have had autumn records of these species over the years, why not us?  Well, fate would have its way.

On September 28, 2023, a vireo was seen on Grand Manan by Karen Miller which was not easy to identify.  She thought at first it was a Blue-headed Vireo and thus did not report it since that species is common.  She saw it again over the weekend and then thought that it might be a juvenile White-eyed Vireo.  That was when Mark Morse decided to get some photographs for identification.  We are thankful they were able to get them!  The bird was identified as a Bell's Vireo.

                                                   Bell's Vireo   [Photo by Mark Morse]

So what is a vireo that is supposed to be in the southwestern US doing in New Brunswick?  The range of this species is expanding but we are way off its normal range.  The Bell's Vireo's normal breeding range includes southern California, Colorado, the Dakotas and Indiana southward.  It is not found at all in the eastern third of the US.  It winters along the Pacific coast from northern Mexico south to northern Nicaragua.  Its preferred habitat is thickets in forests and along streams.  It also likes woodland edges and overgrown fields.

                                                   Bell's Vireo   [Photo by Mark Morse]

The Bell's Vireo is a small vireo, 12 cm long, compared to the Blue-headed Vireo which is 13 cm long and the Red-eyed Vireo which is 15 cm.  The plumage varies geographically, the eastern population being yellower and the western population grayer.  Two indistinct wing bars are present, the upper one sometimes very indistinct.  The white spectacles and lores are also sometimes indistinct.  Both of these features are seen in the photos above.  Notice that the eyering is broken.  The bill is thick and slightly flattened.  The bird's upper parts are green to gray and the underparts are white with a wash of pale yellow on the sides.  The Eastern race has more gray-green on the upper parts and distinctly yellow on the underparts.  The bird flicks and bobs its tail frequently.  Both genders are similar.  

                                                   Bell's Vireo   [Photo by Mark Morse]

The photo above gives a clear view of the gray-green on the dorsum.  Notice the gray head.  The Bell's Vireo is a very active species.  It feeds low to the ground in dense underbrush.  It eats insects, spiders and fruit.  Given the indistinct plumage features, this species can be difficult to identify.  Its song, however, is the way it is mostly identified.  The song is distinctive among vireos.  It is described as rapid, complex, harsh, squeaky, sharp.  We, here in NB, have not heard this species but would quickly learn it.  Given that the bird prefers dense thickets and is reluctant to show itself, the song is the best way to identify it.  

Karen has already told us what species we might mistake this one for, Blue-headed Vireo and White-eyed Vireo.  In the west one would have to distinguish it from the Hutton's Vireo and the Gray Vireo. The Bell's Vireo was named by John James Audubon after John Graham Bell (a taxidermist from Tappan, NY) who was with him on a trip up the Missouri River in the 1840s.  The Least Bell's Vireo is an endangered subspecies in southern California and is endangered due to habitat loss and parasitism by the Brown-headed Cowbird.

Bell's Vireos nest in dense shrubbery often along streams.  The nest is well camouflaged and made from grasses, leaves, bark and spider webs.  It is lined with fine grasses, coarse hairs, feathers and wool.  Brown-headed Cowbirds often parasitize the nests of this species throughout most of its range.  Three to five white eggs are laid and incubated for 14 days by both adults. 

                                                   Bell's Vireo   [Photo by Mark Morse]

We are unlikely to see a Bell's Vireo nest here in NB but the appearance of this individual will make us all look more closely at vireos in the future.  It has been a learning experience for all serious birders.  Thanks go to Karen and Mark!