Bullock's Oriole

Rare Oriole Visits New Brunswick

Bullock's Oriole [Marbeth Wilson Photo]

For the last week in October there has been a rare oriole visiting a bird-friendly home near Centreville, NB.  There it is eating suet and oranges and managing to keep healthy in spite of the rain and cold weather.

What is a Bullock's Oriole?  The Bullock's Oriole is the western cousin to the Baltimore Oriole.  It normally inhabits the western part of North America from southern British Columbia and southern Alberta south to southern California and northern Mexico and east to the mid-western US.  It spends its winters in southern Mexico and sometimes southern California.  It prefers open woodlands, shade trees, parks, and riparian zones.  So what is it doing here?  Well, this individual is undoubtedly a victim of the severe storms recently hitting the US.  It is amazing that a small bird can survive travelling so far off course!

Bullock's Oriole

If you look up Bullock's Oriole in a bird book, it shows a very brilliant orange and black bird.  This present individual is in its winter plumage.  It is either a female or juvenile male so it looks very different from the brilliant orange and black of the male in breeding plumage.  The adult male in breeding plumage looks much like our male Baltimore Oriole, brilliant orange and black.  The Bullock's Oriole does show more white, however on the wing bars and the orange placed in different areas from the Baltimore.  The female is much more subdued with yellow-orange on the head and tail, gray on the back and much lesser white wing bars.  

It is in winter that they are difficult to tell apart.  A dull immature Baltimore is similar to a female Bullock's.  But these Baltimores tend to have more yellow on the underparts which blends  into the gray belly.  In the Bullock's the transition from the yellow to the grayish white belly is more abrupt.  The backs (mantles) are different, too.  In the Baltimore the mantle feathers have dark centres and those of the Bullock's are mostly unmarked gray.  The rump of the Baltimore shows yellow but that of the Bullock's is gray.  Looking at the under tail coverts also helps.  They are yellow in the Baltimore but more often gray but sometimes yellow in the Bullock's.  A more subtle difference is the wing bars.  They are distinct and separate in the Baltimore but seem connected by white edges on the greater coverts in the Bullock's.  None of the aforementioned features are absolute but one must look at all the identifying features to make a true identification.  No wonder we birders often seek expert opinions when faced with such an individual.  (Thanks to Stuart Tingley and others).  

Bullock's Oriole

Notice in the top photo how the wing bars are connected by white-edged feathers from the coverts.  And, in the photo immediately above, notice the mostly gray mantle feathers.  The middle photo and the photo below show the abrupt transition from the throat feathers to the grayish white belly feathers and the grayish yellow under tail coverts.  This individual does not have solid gray under tail coverts.  

Bullock's Oriole

A good description of winter-plumage Bullock's and Baltimore Orioles can be found in National Graphic, Complete Birds of North America, 2006, pp. 624-625.  

Bullock's Oriole is rarely seen in New Brunswick.  According to Birds of New Brunswick:  An Annotated List up until publication in 2004 there had been only 2 accepted sightings, one at Bathurst from Nov. 2001 which stayed at a feeder area until Feb. 2002, and one at Saint John in 2003.  Since then I have also seen one at Hampton in Dec. 2011.  So they are rare, they usually come in late fall or winter and they usually remain at feeder areas for a few weeks.  I think we can assume that they die of our severe winter weather.  They are very unlikely to turn around and fly south to warmer areas.  Given that they arrived here due to severe weather or a disturbance in their navigation systems, they are very unlikely able to return to their normal range or even warmer geographical areas.

 

Bullock's Oriole

Shown above is the Bullock's Oriole which arrived at a feeder in Bathurst 2001-2002.  Notice it also shows winter plumage.  We can see the gray under tail converts and the grayish white belly clearly.  The yellow throat does not show a sharp transition to the breast feathers but the white wing bars are tied together with white edges to the coverts.  Unfortunately we cannot clearly see the rump and back of this bird.

At one time the Baltimore Oriole and the Bullock's Oriole were lumped together as one species, the Northern Oriole.  That was because in the central area of the continent where their ranges overlap, some individuals interbred producing hybrids.  In recent years, the two species were again given full species status so they again became Bullock's Oriole and Baltimore Oriole. 

 

Bullock's Oriole

We are fortunate to have this bird visit us.  It is a delight to see a visitor from afar both for its beauty and for the challenge to identify it.  We hope it does well at the excellent area it has found.