Mountain Bluebirds, Mountain Bluebirds, Mountain Bluebirds.

It is clear that 2015 has been a tremendous year for Mountain Bluebirds in Nova Scotia. Many of our birders were able to add this western open-habitat thrush to their provincial list. These visiting rarities have been long-staying and have for the most part stuck to small areas making them easy to find.


2015 Timeline
Important observations of Mountain Bluebirds this year are listed below in chronological order:

• Nov 15 - Simon-Paul d'Entremont photographed two bluebirds at Mavillette, Digby County. They were assumed to be Eastern Bluebirds at the time.

• Nov 22 - David Bell and Dominic Cormier discover a hatch-year (HY) female Mountain Bluebird at Freeport, Digby County. See the eBird Checklist for photos.

• Nov 22 - David Bell and Dominic Cormier find a HY male Mountain Bluebird at Mavillette, Digby County. See my eBird Checklist for photos from that day.

• Nov 28 - Richard Hatch saw three bluebirds at Mavillette, Digby County, that he identified as two Mountains and one Eastern. No photos were taken that day and multiple birds were not observed again at Mavillette until Dec 26, see this item below.

• Dec 2 - Cal Kimola Brown found a HY male Mountain Bluebird at Fish Plant Rd, Cape Sable Island, Shelburne County. The bird at this location was never resighted.

• Dec 6 - Alix d'Entremont got two HY male Mountain Bluebirds (Fig. 1) at Church Hill Rd, Cape Sable Island, Shelburne County (only 0.5 km away from the Dec 2 sighting). One is likely the same that was photographed nearby on Dec 2 by Cal Kimola Brown. See my eBird Checklist for photos.

• Dec 26 - Simon-Paul d'Entremont photographed two Mountain Bluebirds at Mavillette, Digby County. One is a HY male, and the other, a HY female.

A few questions arrise from the list of observations above.

What explains the lack sightings of multiple birds at Mavillette after Nov 28 and before Dec 26? The Mountain Bluebird at Mavillette was consitenty found at the Cape View Motel and Restaurant, but would sometimes dissapear to the south-east in the large expanse of coastal alders. Was this where the others were spending time?

Were the three bluebirds seen on Nov 28 comprised of the one HY male Mountain Bluebird and one Eastern Bluebird photographed on Nov 15 in addition to the HY female Mountain Bluebird from Freeport (Fig. 2)? Freeport is only 25 km from Mavillette, so that seems very possible also given that the age and sex of the bird is the same. In order to survive, vagrant birds will linger at good locations where they can find enough food. Mavillette, with its open landscape, appears to be an appropriate place for these bluebirds.

Figure 1. Two hatch-year male Mountain Bluebirds at Cape Sable Island, Dec 6, 2015. Photo by Alix d'Entremont.

Figure 2. Hatch-year females at Mavillette (Dec 26, 2015) and Freeport (Nov 22, 2015) that might be the same individual. Photos by Simon-Paul d'Entremont and David Bell.

There is precedence in Nova Scotia of different bluebird species in one location. On Jan 18, 1999, a Mountain Bluebird (present since Jan 16) in Centreville, CSI, was joined by an Eastern Bluebird. Both birds remained until at least Feb 7, 1999.

Historical Sightings in NS

I've combined all issues of NS Birds (previously named the Nova Scotia Bird Society Newsletter and later Nova Scotia Birds) into a 1.6 Gigabyte PDF complete with searchable text. This allows me to search by species name and find all occurances quickly.

• Oct 25, 1989 - possible female at Hartlen Point, HRM.
• Jan 27 - Feb 10, 1992 - our first fully confirmed, a HY male in Brooklyn, Queens County.
• Jan 10, 1995 - female at Sable Island, HRM.
• Jan 3, 1999 - immature at Port Morien, CBRM.
• Jan 16, 1999 - female at Cape Sable Island, Shelburne County.
• Nov 14-15, 2002 - female at Cape Sable Island, Shelburne County.
• Dec 22-24, 2002 - one at Little River Harbour, Yarmouth County.
• Jan 15-17, 2003 - one at Cape Sable Island, Shelburne County. *same as the Nov 2002 bird?*
• mid-April, 2005 -  one at Long Island, Digby County. (7th)
• May 23, 2007 - one in Upper East Green Harbour, Shelburne County.
• May 10, 2009 - one in Dartmouth, HRM.
• Dec 31, 2011 - one in Glace Bay, CBRM.

The above results in a total of 12 reports. There is a high probability that the Jan 2003 sighting was the same bird that was seen in Nov 2002. We are now left with 11 historical occurances of Mountain Bluebird in Nova Scotia. There have been at least 4 during 2015 (assuming the Freeport and Mavillette HY females are one in the same), the conservative total becomes 15. Twelve records have been during fall/winter and the remaining 3 in spring.

Migration and Vagrancy

Mountain Bluebirds are the most migratory of the bluebirds. They breed from east-central Alaska in the north to extreme west Texas in the south. They winter as far south as central Mexico and north to north-central Oregon. Depending on the severity of winter, they concentrate in the nothern of southern potion of the winter range. Autumn migration begins in August and extends into November. (Power & Lombardo, 1996)

The unprecedented number of Mountain Bluebirds in Nova Scotia during late fall and winter 2015 are mirrored by multiple sightings in other parts of eastern North America. Below are the number of Mountain Bluebirds reported to eBird in other eastern provinces and states.

• Ontario - 2
• Quebec - 1
• New Brunswick - 1
• Massachussetts - 1
• Florida - 1

Figure 3 compares the eBird reports from fall migration 2014 to those of 2015. These maps allow us to visualize a phenomenon of vagrant Mountain Bluebirds that was not confined to NS. It is fair to say that a specific weather pattern at a particular latitude, altitude and time played a role in the arrival of the Mountain Bluebirds to eastern North America. During August and early September, we get airflow from the southwest. October through December is characterized by zonal airflow across North American from west to east, directly towards our province. This wind pattern contributes to the yearly arrival of birds from the west. (McLaren, 2012)

Another cause of vagrancy is misorientation, but the effect would be more consistent from year to year. A quick look through eBird shows that significant numbers of Mountain Bluebirds in the east, similar to the 2015 event, don't occur on a regular basis. The last time that we saw large numbers was during fall/winter 2011/2012.

Figure 3. Late fall/winter Mountain Bluebird eBird reports from 2014/2015 (left) vs late fall/winter 2015. From eBird.org.

Fall and winter 2015 were characterized by many other notable western vagrants to our province; these include Hermit Warbler, many Western Kingbirds, Bullock's Oriole, two American White Pelicans, an apparent "western" Marsh Wren and Western Flycatcher (Pacific-slope or Cordilleran).

One Mountain Bluebird in Nova Scotia is thrilling enough, but two separate locations with two individuals is amazing. Nova Scotia keeps providing evidence that it is truly a great place for vagrant birds. Its location (halfway between the north and south poles) and geography (surrounded by water and comprised of many headlands and islands) are great for producing exciting birding. (McLaren, 2012)

References

McLaren, I.A. 2012. All the Birds of Nova Scotia: status & critical identification. Gaspereau Press Ltd, Kentville, N.S., Canada

Power, Harry W. and Michael P. Lombardo. 1996. Mountain Bluebird (Sialia currucoides), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/222

doi:10.2173/bna.222

A Three Lifer Day

At 5 am on Dec 5, 2015, I picked up Ervin Olsen and Mark Dennis by car and we drove east on Highway 103. The plan was to drive up to Shubenacadie to twitch on three good birds that had been reported in the area. These three species were all lifers for me, so a long day of driving would be worth it. Eight Sandhill Cranes (Grus canadensis), and one each of Greater White-fronted Goose (Anser albifrons) and Cackling Goose (Branta hutchinsii) were within a 15 minute drive of each other.

We made great time and reached Snides Lake, a 29 acre water body near Exit 10 in Shubenacadie, by 8:15 am. We were on the northern side and all of the waterfowl were on the opposite end (Fig. 1). After a bit of searching, Mark found the Greater White-fronted Goose. We looked around a bit more for the Cackling and decided to drive closer to the geese and try for a photo.

Figure 1. Mark Dennis and Ervin Olsen looking through the hundreds of geese at Snides Lake, Hants Co., Dec 12, 2015. Photo by Alix d'Entremont.

This new vantage point provided much better views of the rare goose. It appeared fairly small compared to the Canada Geese that surrounded it (Fig. 2). The orange bill is very obvious through the scope, even at a distance of over 600 m. Mark shared with us that Greater White-fronted is quite easy to spot by checking for its orange legs when in a standing group of Canadas.

Figure 2. Greater White-fronted Goose with Canada Geese at Snides Lake, Hants Co., Dec 12, 2015. Photo by Alix d'Entremont.

This individual is a juvenile and lacks the adult's distinctive white band around the bill and on the forehead. The most expected subspecies in Nova Scotia is the "Greenland White-fronted Goose" A. a. flavirostris. This population normally migrates to Europe, but increasingly occurs in n.e. US and Atlantic Canada.  This bird fits for flavirostris as it shows a distinctly orange bill and lacks the grayish back tones and pinkish bill shown by A. a. gambelli, the subspecies that breeds across n.w. Canada (Fig. 3). (McLaren, 2012)

Figure 3. Juvenile Greater White-fronted Goose at Snides Lake, Hants Co., Dec 5, 2015. Photo by Alix d'Entremont.

Timing was right when I received a call from Andy de Champlain as he stood on the Milford Rd admiring the group of eight Sandhill Cranes (Grus canadensis). Merridy Rankin accompanied Andy and Fulton Lavender and offered to meet us at Snides Lake and lead us directly to the cranes. We arrived at the Milford Rd location and the flock of eight was my second lifer of the day.

Figure 4. Eight Sandhill Cranes on the Milford Rd, Halifax Co., Dec 5, 2015. Photo by Alix d'Entremont.

Both the Greater (G. c. tabida) and Lesser Sandhill Cranes (G. c. canadensis) are reported to have occured in the province. Most references warn that subspecific indentification should only be attempted on individuals that are on the extreme ends of the proportional differences between subspecies (McLaren 2012, Alderfer 2014). Compared to Greater, Lesser Sandhill Cranes are smaller and have relatively shorter legs and neck. McLaren (2012) gives us a rule of thumb: the bill of tabida is about twice the length of the head, that of canadensis about the length of the head. G. c. rowani represents a population that is between canadensis and tabida in both breeding location and structure.

The bill length of most birds appear to be closer to the length of the head than twice the length of the head. There has been some subspecific discussion of these cranes on the NSBS Facebook Group, but nothing that I would call concrete. For some "light" reading regarding Sandhill Crane subspecies, there is a 2001 article that Maxine Quinton forwarded to me named Mitochondrial Phylogeography, Subspecific Taxonomy, and Conservation Genetics of Sandhill Cranes (Grus Canadensis; Aves: Gruidae) that is interesting.

Twitching birds often provides opportunities to see birders from other parts of the province that you don't often get to spent time with. We took the opportunity to grab a few photos, like the one in Figure 5.

Figure 5. Andy de Champlain, Fulton Lavender and Alix d'Entremont (me). Photo by Ervin Olsen.

Once we had our fill of photos and scope views of the Sandhill Cranes, Andy and Fulton followed us to the next water body where we hoped we'd find a Cackling Goose. It had been seen at at a pond just south of Shubenacadie near the railroad tracks. Eric Mills called it Shaws Pond on eBird, so that is what I'll go with. The five of us arrived and soon after we were joined by another Nova Scotia Bird Society member, Donna MacNeil. We crossed the railroad tracks (carefully looking both ways) and Mark soon found our target bird.

Once I got my binoculars onto the Cackling Goose, I first noticed how how pale it was and then how small it was in comparison to the Canada Geese (Fig. 6). Switching optics often resulted in the temporary loss of the subject. I finally was able to get my camera on it and get a few photos.

Figure 6. Cackling Goose among Canada Geese at Shaws Pond, Hants Co., Dec 5, 2015. Photo by Alix d'Entremont.

Cackling Goose (Anser hutchinsii) was only split from Canada Goose (Anser canadensis) in 2004 in the 45th Supplement of the AOU Checklist. The split occured due to differences in size, voice, habitat and timing of migration (Mowbray et al., 2002). In general terms, it looks like a small Canada Goose, almost how Ross's Goose is a tiny version of a Snow Goose. If you were to shrink a typical Canada Goose, you still wouldn't have a Cackling. In comparison to Canada Goose, Cackling Goose has a relatively shorter neck, smaller bill and steeper forehead (Alderfer, 2014).

The only subspecies of Cackling Goose that is expected in Nova Scotia is "Richardson's Cackling Goose" A. h. hutchinsii (McLaren, 2012). This population breeds from the Mackenzie River Delta to Baffin Island and south to n. Hudson Bay, migrates mid-continent and spends the winters in the south-central US (Mowbray et al., 2002). The other three subspecies breed west of hutchinsii and also winter further west (Alderfer & Dunn, 2014).

A three lifer day in Nova Scotia is getting harder as my species list climbs. I may have to wait for a storm during spring or fall migration for this to happen again.


References:

Alderfer, J., J.L. Dunn. 2014. (Ed). Complete Birds of North America, 2nd Edition. National Geographic Society. Washington DC, USA.

McLaren, I.A. 2012. All the Birds of Nova Scotia: status & critical identification. Gaspereau Press Ltd, Kentville, N.S., Canada

Pyle, P., S.N.G. Howell, R.P. Yunick, and D.F. Desante. 1997. Identification guide to North American Birds, Part 1, Columbidae to Ploceidae. Slate Creek Press, Bolinas, California.

Mowbray, Thomas B., Craig R. Ely, James S. Sedinger and Robert E. Trost. 2002. Canada Goose (Branta canadensis), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/682
doi:10.2173/bna.682

Mountain Bluebirds and Other Western Rarities

Figure 1. Mountain Bluebird at Mavillette, Digby, November 22, 2015. Photo by Alix d'Entremont.

On November 22, 2015, David Bell and Dominic Cormier found two Mountain Bluebirds, one at Freeport and another (Fig. 1) in Mavillette, both in Digby County. Paul Gould and I had just found a Yellow-breasted Chat in the multiflora brambles near Prospect St in Yarmouth when I received the good news about the Mavillette bird via text. We said our goodbyes to the chat and drove up Highway 101 towards my next lifer. Just north of Salmon River we noticed an interesting bird on the wires. We stopped to investigate and found that it was a Western Kingbird (Fig. 2).

Figure 2. Western Kingbird at Salmon River, Digby, November 22, 2015. Photo by Alix d'Entremont.

David and Dominic were still in Mavillette keeping an eye on the bluebird when we arrived. We quickly shook hands and thanked them as they had to leave to do maintenance on more radio bird tracking systems. The Mountain Bluebird was my 294th bird for the province.

The Mountain Bluebird breeds in western North America and is migratory in most of its range. It is a rare but regular vagrant to the East. There had previously been at least 11 reports of this western thrush in Nova Scotia, most during fall and winter. The last sighting was on 10 May 2009 in Dartmouth. (Mclaren, 2012)

Identification Tips

Lets begin by looking at structure to identify this bird to species. Compared to Western Bluebirds and Eastern Bluebirds, Mountain Bluebirds are longer-winged, longer-legged and thinner-billed (Alderfer, 2014). Figure 3 is very useful to compare structure between the Mountain Bluebird and Eastern Bluebird as both birds are in a similar position.

Figure 3. Mountain Bluebird (L) and Eastern Bluebird (R) at Mavillette November 15, 2015. Photos by Simon-Paul d'Entremont.

Mountain Bluebirds only have one moult per year, the pre-basic moult completed on the summering grounds. Therefore, there is no extreme difference in plumage between seasons. An adult male would be almost entirely sky-blue - clearly not matching our bird. A hatch-year male would be similar, but duller blueish to mixed brown and blue. Hatch-year males show strong moult limits in the greater secondary coverts - the inner ones having bright blue centres. The first pre-basic moult includes 1-8 inner greater coverts. A single bright blue replaced inner greater covert is visible in Figure 4. This replaced feather creates strong contrast with the remaining retained greater coverts. (Pyle, 1997)

Figure 4. Mountain Bluebird at Mavillette, Digby, November 22, 2015. Photo by David Bell.

Adult females are dull bluish gray and hatch-year females are dull brownish to grayish. The amount of blue on the bird combined with the presence of a strong moult limit in the greater coverts make it a hatch-year male. Some photos show more pure blue on the upperparts than others (Fig. 5).

Figure 5. Mountain Bluebird at Mavillette, Digby, November 23, 2015. Photo by Ellis d'Entremont.

Multiple Recent Western Vagrants

 Five western rarities were in s.w. Nova Scotia on November 22, 2015:

-Mountain Bluebird at Freeport, Digby
-Mountain Bluebird at Mavillette, Digby
-Western Kingbird at East Ferry, Digby
-Western Kingbird at Salmon River, Digby
-Western Kingbird at Louis Head, Shelburne

One could hypothesise that the weather system that brought hundreds of Franklin's Gulls to the eastern US mid-November contributed to the recent arrival of western birds to Nova Scotia. The track of the mid-November storm seemed favourable to bring some exciting birds to the Maritimes.

The Mountain Bluebird at Mavillette was actually present since mid-November. Simon-Paul d'Entremont had photographed two bluebirds at Mavillette on November 15 that were, at the time, passed off as Eastern Bluebirds. Once the November 22 bird was identified as a Mountain Bluebird, Simon and I reviewed his earlier images and were surprised that the rare bluebird was in fact present on November 15. One of the Simon's bluebirds was a Mountain Bluebird and the other was an Eastern Bluebird.

The Western Kingbird at Louis Head, Shelburne, was originally reported November 15. A Franklin's Gull was sighted briefly at Hall's Harbour, Kings, on November 19. The number of western vagrants concentrated in such a brief period provide evidence supporting a weather-driven arrival.

References

Alderfer, J., J.L. Dunn. 2014. (Ed). Complete Birds of North America, 2nd Edition. National Geographic Society. Washington DC, USA.

McLaren, I.A. 2012. All the Birds of Nova Scotia: status & critical identification. Gaspereau Press Ltd, Kentville, N.S., Canada

Pyle, P., S.N.G. Howell, R.P. Yunick, and D.F. Desante. 1997. Identification guide to North American Birds, Part 1, Columbidae to Ploceidae. Slate Creek Press, Bolinas, California.

Yellow-throated Warbler

The Yellow-throated Warbler (Setophaga dominica) is an annual vagrant to Nova Scotia in small numbers. Most are reported in autumn, mainly during October (McLaren, 2012). One to four have been reported during fall migration in the last five years. This warbler breeds in the eastern US; the population nearest to our province is in Delaware, however its breeding range is expanding northward (Alderfer, 2014).

On the morning of Oct 25, 2015, Paul Gould and I found a Yellow-throated Warbler in Arcadia, Yarmouth County. It was only my second sighting of this species, the first being a yard bird during the fallout of April 2012.

Figure 1. Yellow-throated Warbler in Arcadia, Yarmouth County, Oct 25, 2015. Photo by Alix d'Entremont.

McLaren (2012) describes two subspecies that can be expected in Nova Scotia; the western S.d. albilora and the eastern S.d. dominica. Alderfer (2014), Pyle (1997) and Sibley (2014) all describe the geographic variation in this species. Alderfer (2014) lists three subspecies, the two already mentioned above and an additional S.d. stoddardi that is found nesting in the Florida panhandle and an adjacent portion of Alabama.

Recent research (McKay 2008, 2009) suggests recent expansion of this species and shows that the morphological differences between the subspecies are clinal. Sibley, in his blog post regarding identifiable subspecies, explains that Coastal (eastern) and Interior (western) forms differ slightly in plumage and bill length, but extensive variation makes identification of many birds uncertain. Some believe that this species should be treated as monotypic (Alderfer, 2014). The continued inclusion of subspecific field marks in recent publications (Alderfer 2014, Sibley 2014) indicate that, even if morphological differences are clinal, it is still useful to investigate these varying features of the Yellow-throated Warbler. These differing characteristics might still provide information on the likely origin of a vagrant bird, but possibly only for individuals on the extreme ends of the continuum. It is still interesting to study the features of vagrant Yellow-throated Warblers that arrive to our province. Patterns of occurance will be statistically stronger when backed by more information. For the remainder of this article, I will use the terms western birds for albilora and eastern birds for dominica - this will better represent recent understanding of the variation within this species as a cline.

Western birds show white above the lores (rarely yellow) and often a small white spot at the base of the chin. Eastern birds show yellow above the lores (rarely white) and rarely shows a small patch of white on the chin (Alderfer, 2014). Bill length increases from west to east, although birds breeding along the Gulf Coast and on the Delmarva Peninsula have markedly longer bills (McKay et al., 2012).

This bird shows a patch of white feathers on the chin (Fig. 2), especially when viewed from below. The supraloral area seems to show a very slight hint of yellowish, but is predominantly white. Bill length is difficult to assess without measurements in the hand, but this bird appears somewhat short billed (see Fig. 3 as well).

Figure 2. Yellow-throated Warbler in Arcadia, Yarmouth County, October 25, 2015. Photo by Alix d'Entremont.

Figure 3 compares this bird to one with slightly more yellow in the supraloral area and another with still more yellow. All three of these birds show some amount of white on the very upper chin.

Figure 3. Yellow-throated Warblers. Photos by Alix d'Entremont (left and middle) and Ronnie d'Entremont (right).

Individuals breeding in the western portion of the range show more white in the outer tail feathers (McKay et al., 2012). Dunn and Garrett (1997) state that the white on the outer rectrices of western birds appears to meet the white undertail coverts. Figure 4 seems to show extensive white under the rectrices - similar to that of a western bird.

Figure 4. Yellow-throated Warbler in Arcadia, Yarmouth County, October 25, 2015. Photo by Alix d'Entremont. 

McKay (2008) concluded that there was a strong west-to-east clinal change in bill length and proportion of yellow in the lores. He goes on the say that a discriminant function analysis failed to correctly assign most individuals, especially those collected near the subspecies border. The analysis did however correctly group individuals from the extreme east or west part of the range into subspecies. This provides evidence that in actuality only the extreme individuals in the continuum can be confidently assigned to a geographic area.

This Yellow-throated Warbler shows mostly white above the lores, only slight white on the chin, what looks like a relatively small bill and extensive white on the underside of the outer tail feathers. Due to the lack of a strong delineation between currently accepted subspecies, I believe that we can assume that this bird isn't from the far east, but might be from the intermediate zone. A quick Google Image search produces photos of birds with an entirely white supraloral area and a wide white patch on the upper chin. These are likely a good representation of the appearance of the birds from the far west.

It will be interesting to see if the recommendation of McKay (2008) to eliminate the subpecies S.d. albilora and S.d. stoddardi will widely be accepted by the birding and ornithological communities.


References:

Alderfer, J., J.L. Dunn. 2014. (Ed). Complete Birds of North America, 2nd Edition. National Geographic Society. Washington DC, USA.

Dunn, J. and K. Garrett. 1997. A Field Guide to Warblers of North America. Peterson Field Guide
Series. Houghton Mifflin Co., New York.

McKay, B. D. 2008. Phenotypic variation is clinal in the Yellow-throated Warbler. Condor 110(3):569-574.

McKay, B. D. 2009. Evolutionary history suggests rapid differentiation in the Yellow-throated Warbler Dendroica dominica. Journal of Avian Biology 40(2):181-190.

McKay, Bailey and George A. Hall. 2012. Yellow-throated Warbler (Setophaga dominica), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/223
doi:10.2173/bna.223

McLaren, I.A. 2012. All the Birds of Nova Scotia: status & critical identification. Gaspereau Press Ltd, Kentville, N.S., Canada

Pyle, P., S.N.G. Howell, R.P. Yunick, and D.F. Desante. 1997. Identification guide to North American Birds, Part 1, Columbidae to Ploceidae. Slate Creek Press, Bolinas, California.

Sibley, D.A. 2014. The Sibley Guide to Birds 2nd Ed. Alfred A. Knopf, New York, N.Y.

AHY Male Yellow-rumped Warbler

Finding a deceased bird is not the most joyous experience, but it offers an opportunity for detailed study. The following image (Fig. 1) shows the vibrant yellow patch that the Yellow-rumped Warbler is named for. A hint of the yellow in the crown is also visible.

Figure 1. Yellow-rumped Warbler dorsal view. Photo by Alix d'Entremont.

All Yellow-rumped Warblers have mostly brownish upperparts in fall, but AHY (after-hatch-year) males typically show the greatest amount of blue-gray (MBO). Figure 1 shows blue-gray on the coverts, scapulars, mantle, nape, and the rump area. Notice the wide dark centres to the uppertail coverts which is more extensive on older birds and males (Pyle, 1997).

AHY males show on average the greatest amount of yellow on the breast and crown (Fig. 2). AHY males are the only age/sex class in fall to sometimes show traces of black in the lores or auricular (MBO). Black lores are clear in Fig. 3.

Figure 2. Yellow-rumped Warbler underside. Photo by Alix d'Entremont.

Figure 3. Yellow-rumped Warbler head. Photo by Alix d'Entremont.

The wing of AHY males show very little contrast between feather groups - it is dark overall (Fig. 4). A hatch-year bird would show contrast between the greater coverts and the rest of the wing (primaries, primary coverts and secondaries). This contrast in young birds is due to the dull, retained juvenal feathers compared to the newer and darker greater secondary coverts. AHY females have browner and duller wings than those of AHY males. (MBO)

Figure 4. Yellow-rumped Warbler wing view. Photo by Alix d'Entremont.

Figure 5 shows that white is present on on the outer 3 tail feathers (r4-r6) and that the base colour of these is blackish. Pyle (1997) cautions that there is more overlap in rectrix shape by age in Yellow-rumped Warblers than in other Dendroica warblers. Nevertheless, the tail feathers of this bird appear fairly blunt-tipped like an AHY bird.

Figure 5. Yellow-rumped Warbler tail. Photo by Alix d'Entremont.

References:

McGill Bird Observatory (MBO). (n.d.) [Photo Library: Yellow-rumped (Myrtle/Audubon's) Warbler / Paruline à croupion jaune (Dendroica coronata)]. Retrieved October 9, 2015. http://www.migrationresearch.org/mbo/id/mywa.html

Pyle, P., S.N.G. Howell, R.P. Yunick, and D.F. Desante. 1997. Identification guide to North American Birds, Part 1, Columbidae to Ploceidae. Slate Creek Press, Bolinas, California.

Pubnico Pelagic 2015

The annual Pubnico Pelagic is the birding highlight of the year for me. A visit offshore offers wonderful opportunities for close up views of species that are typically kilometres away when observed from the mainland. A trip report of the previous year's pelagic can be found at Pubnico Pelagic 2014.

Northern Fulmar at German Bank, Nova Scotia on August 29, 2015. I consider fulmars to be one of the best looking seabirds. Photo by Alix d'Entremont.

Ronnie d'Entremont once again organized the trip this year. The vessel was the Captain Derek, a commercial lobster fishing boat, with Rodney d'Entremont at the helm. All 25 birders are listed below.

Ronnie d'Entremont

Ted d'Eon

Raymond d'Entremont

Paul Gould

Eric Ruff

Barbara Ruff

Eric Mills

Ian McLaren

David Currie

Bruce Stevens

Richard Stern

Rick Whitman

Jake Walker

Judy O'Brien

Gisele d'Entremont

Alan Covert

Ken McKenna

Mike King

Kevin Lantz

Larry Neily

Mark Dennis

Mike MacDonald

Jane Alexander

Keith Lowe

Alix d'Entremont



The route for this year's pelagic trip. The water depth at German Bank was from 50 to 70 metres.

I had been checking the sea surface temperature maps prior to departure. On August 21 the nearshore waters were up to 20°C, but this warm water abruptly left a few days before the trip along with the high hopes of spotting more southern warm water species (Audubon's Shearwater, White-faced Storm-Petrel, Black-capped Petrel...).

SST on August 21 from Rutgers Coastal Ocean Observation Laboratory

SST on August 29 from Rutgers Coastal Ocean Observation Laboratory

We left Dennis Point Wharf in Lower West Pubnico shortly after 5 am on August 29, 2015. Out of Pubnico Harbour, we took a hard right and headed west towards the Mud Islands. We passed near to Round Island where we were able to see Black Guillemots and Atlantic Puffins in the water and Black-bellied Plovers and Whimbrel on the island.

Kevin Lantz (upper right) armed with the chum chucker as the rest of the group scans for birds of interest at German Bank, Nova Scotia on August 29, 2015. Photo by Alix d'Entremont.

As we headed past the Mud Islands, out of Lobster Bay, we were surrounded by fog. This is when Mark Dennis spotted the first Great Shearwater. At 8:23 am we peered through the fog at a dark figure on a direct path with strong wing beats. David Currie and Kevin Lantz were the only two that were lucky enough to snap a few shots of this bird. Most were thinking skua, but no one called it out at the time. A quick view of the photos after this brief encounter made it obvious that we just had a skua. The bulky body, short tail and thick, hooked bill were clear. The thick fog and low light made it so that the characteristic white flash on the skua's wings were invisible. The photos are simply silhouettes and confident identification is likely not possible. There are primary molt timing differences between South Polar Skua and Great Skua, but the age of the bird must be known for this information to be useful. The Sibley Guide to Birds 1st ed. (2000) provides details on these molt timings.



Skua species at German Bank, Nova Scotia on August 29, 2015. Photo by Kevin Lantz.

Skua species at German Bank, Nova Scotia on August 29, 2015. Photo by Kevin Lantz.

Skua species at German Bank, Nova Scotia on August 29, 2015. This photo shows the white bases to the primaries that were invisible to the birders observing with binoculars. Photo by David Currie.

After the skua encounter we ran into a Cory's Shearwater which provided life list ticks to a few aboard. We examined photos of all Cory's seen and none showed the required amount of white on the underside of P8-P10 to be Nova Scotia's first Scopoli's Shearwater. Scopoli's Shearwater (Calonectris diomedea diomedea) is currently considered by the American Ornithologists Union at subspecies of Cory's Shearwater and is much rarer in the w. Atlantic Ocean than is Cory's Shearwater (Calonectris diomedea borealis). A bird photographed on July 4, 2015 off of Grand Manan, New Brunswick has been confirmed by Steve N.G. Howell as being a Scopoli's Shearwater. A later issue of NS Birds will contain an article that will provide more details on this taxonomic issue as well as discuss identification.

Cory's Shearwater at German Bank, Nova Scotia on August 29, 2015. Photo by Alix d'Entremont.

Cory's Shearwaters molt their primaries outward towards P10 from the inner feathers (Howell, 2012). Wing molt is evident in photos of the Cory's above. Below are expanded views of the wing. Monteiro and Furness (1996) explain that breeding Cory's Shearwaters (C. d. borealis) spend from late-Feb to late-Oct at the breeding sites. This would mean that any Cory's seen in Nova Scotia at this time of the year is a non-breeding individual. Howell (2012) states that non-breeding birds start molting their primaries mid-Jul to mid-Oct and likely finish Dec-Feb after having left North American waters.

Cory's Shearwater at German Bank, Nova Scotia on August 29, 2015. This photo clearly shows a molt limit in the primaries and primary coverts. The new feathers are much more grey than the old ones that are more solid brown. Photo by Alix d'Entremont.

An underside view of the wing of the same Cory's Shearwater. This perspective gives a better appreciation of the amount of wear on the tips of the outer primaries. Photo by Alix d'Entremont.

The most amazing encounter of the day for most was of the Pomarine Jaeger that appeared shortly after 9 am and kept circling the boat offering amazing views. The all-dark unbarred underwing coverts of this jaeger indicate that it is an adult. Prebasic molt in Pomarine begins soon after leaving the arctic (Haven Wiley and Lee, 2000). Primary molt is visible in that it has dropped P1 and P2. The sharply demarcated facial pattern and yellow nape have been replaced by a more mottled and less contrasting appearance.

Pomarine Jaeger at German Bank, Nova Scotia on August 29, 2015. Photo by Alix d'Entremont.

Pomarine Jaeger at German Bank, Nova Scotia on August 29, 2015. Photo by Alix d'Entremont.

Pomarine Jaeger at German Bank, Nova Scotia on August 29, 2015. Photo by Alix d'Entremont.

This Pomarine Jaeger has straight and short central tail feathers compared to the relatively longer central rectrices that are twisted 90° of a Pomarine that I photographed in 2012 (see below). Pomarines in alternate plumage show longer (7-11 cm past the rest of the tail) and twisted central rectrices while birds in basic plumage have ones that are shorter (1-6 cm past the rest of the tail) and straight (Haven Whiley and Lee, 2000). It can then be assumed that the 2012 bird had not molted its central rectrices while the 2015 bird has already replaced them.

Pomarine Jaeger at Southeast Bank, Nova Scotia on August 25, 2012. Photo by Alix d'Entremont.

The first of two Manx Shearwater were seen at 9:22 am. This my first view of a Manx on the water. I paid attention to the short bouts of flapping and quicker wing beats compared to the larger Great Shearwater as it took flight. Observed on the water, the bird showed the white undertail and wings projecting past the tail (unlike Audubon's).

Manx Searwater at German Bank, Nova Scotia on August 29, 2015. This photo shows the wing projecting past the tail and the white undertail coverts. Photo by Alix d'Entremont.

We got nice views of hundreds of Great Shearwaters and had up to 6 Northern Fulmars that were visible at the same time. The southern hemisphere breeding Wilson's outnumbered Leach's Storm-Petrel, as is expected.

Great Shearwater at German Bank, Nova Scotia on August 29, 2015. Photo by Alix d'Entremont.

The upperparts of Northern Fulmars always look like they are in a state of disrepair. This one shows wing covert molt and is growing the outer two primaries. Photo taken at German Bank, Nova Scotia on August 29, 2015. Photo by Alix d'Entremont. 

Leach's and Wilson's Storm-Petrels at German Bank, Nova Scotia on August 29, 2015. Photos by Alix d'Entremont.

I had to capitalize on the chance of getting my photo taken with Dr. Ian McLaren, a man that I admire greatly. He continues to inspire and contributes immensely to birding in Nova Scotia. If you don't already own a copy of his tremendous publication named All the Birds of Nova Scotia, I suggest that you do yourself a favour and add it to your birding book shelf.

Dr. Ian McLaren and myself during the Pubnico Pelagic on August 29, 2015. Photo by Mike King.

The following day (August 30) we all headed to Yarmouth County's warbler hotspot to see if we could find any interesting migrants or vagrants. We were not disappointed. Three (and maybe four) Warbling Vireos, a Prairie Warbler, a Cape May Warbler, two Baltimore Orioles and an Orchard Oriole were great finds on the Thomas and Gerry Roads at Cape Forchu.

Standing left to right: Jake Walker, David Curie, Alan Covert, Mike King, Bruce Stevens, Ian McLaren, Ellis d'Entremont, Richard Stern, Ken McKenna, Rick Whitman, Judy O'Brien, Sharron Marlor, Ronnie d'Entremont and Keith Lowe. I am kneeling on the ground. Not all participants of the pelagic are present in this photo. A few that did not take part had joined our group at Cape Forchu. Photo by Gisele d'Entremont.

Jake Walker had the difficult task of record keeper for the trip. He was the right man for the job. eBird checklists (ordered chronologically, 24 hour clock) are found below.

0600-0730 Pubnico Harbour to the Mud Islands
0730-0900 Mud Islands to German Bank
0900-1300 German Bank
1300-1400 German Bank to Mud Islands
1400-1500 Mud Islands to 2 miles offshore
1500-1600 2 miles offshore to Pubnico Harbour

Next is a list of all species seen with counts.

American Black Duck  1

Common Eider     11

Common Loon   1

Northern Fulmar 12

Cory's Shearwater 8

Great Shearwater 227

Manx Shearwater 3

Sooty Shearwater 2

shearwater sp. 4

Wilson's Storm-Petrel 13

Leach's Storm-Petrel 3

Northern Gannet 60

Double-crested Cormorant 80

cormorant sp. 80

Great Blue Heron 1

Bald Eagle 1

Black-bellied Plover 4

Greater Yellowlegs 9

Willet 1

Whimbrel 1

Sanderling 5

Red-necked Phalarope 32

Red Phalarope 46

Phalarope sp. 180

skua sp. 1

Pomarine Jaeger 2

Black Guillemot 9

Atlantic Puffin 20

Herring Gull 300

Great Black-backed Gull 150

Common Tern 2

Sterna sp. 17

Ruby-throated Hummingbird 3

Common Raven 2

References:

Howell, S.N.G. 2012. Petrels, Albatrosses & Storm-Petrels of North America. Princeton University Press, Princeton and Oxford.

Monteiro, L.R. and R.W. Furness. 1996. Molt of Cory's Shearwater during the breeding season. Condor 98:216-221.

Haven Wiley, R. and David S. Lee. 2000. Pomarine Jaeger (Stercorarius pomarinus), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/483

Blackbeards Cove

My co-pilot, Bertin d'Eon, and I had been discussing a trip to Blue Island, Shelburne County, for a while. We often fly virtually around Nova Scotia on Google Maps in search of interesting coastal areas and islands to visit. Online we could see that Blue Island is a 1 km by 0.5 km island with a great landing area on the northern side and large cliffs the rest of the way around. The most interesting features are the deep crevices on the eastern cliffs and Blackbeards Cove on the southern shore, facing the open Atlantic.

On July 5, 2015, Bertin and I left the wharf at West Green Harbour, passed the tiny rocky island named the Thrum Cap and after a short, but choppy ride, we reached the northern beach of Blue Island. We lugged the 200 pound inflatable Zodiac up far enough so that we could leave it for a few hours without risk of it washing away. It was decided to try to circle the island clockwise by foot. Once we left the northern open area, the woods constituted of short coniferous trees and short grass. We noted the fact that there was no understory and that walking was easy. We thought that this island likely has sheep on it, or at least had in the past. There is a narrow trail that led the way south along the eastern coast that we were happy to follow. We soon made it to the tall cliffs that we had seen from above on Google Maps.

The first view of the eastern coast cliffs on Blue Island.

Bertin looking down one of the many crevices on the eastern side of Blue Island.

Most large wooded islands that I visit in s.w. Nova Scotia are home to Swainson's Thrushes, this island was no exception. As we approached the southeast corner of the island we got a brief glimpse of two goats as they vanished around the bend. I was later informed that these goats as well as a sheep were placed on the island by Leroy d'Entremont.

The vista at the southeast corner of Blue Island.

The most impressive feature of the island is Blackbeards Cove. It is a large cove created by a grassed headland to the east and a formidable, almost vertical, rock structure to the west. This western border is almost unnaturally straight. This is very evident in the satellite image above once it is zoomed in.

The impressive Blackbeards Cove on Blue Island.

Bertin on a swing crafted from a large buoy at Blackbeards Cove on Blue Island.

We completed our trek around the island before 10 am, so we decided to head towards Jordan Bay Gull Rock. This is a substantial sized rock and is similar in length to Yarmouth County's Gannet Rock, but looks much taller. On our way we got great looks at a sunfish which wasn't much smaller than our boat. Gull Rock is home to hundreds of Double-crested Cormorants. I was pleased to also find four Razorbills and a colony of Great Cormorants also using this impressive rock. I've submitted a checklist to eBird with all of my observations.

Razorbills on Jordan Bay Gull Rock.

Great Cormorants on Jordan Bay Gull Rock.

Eric Mills had sent me a paper a while back entitled The Nesting of the Great Cormorant (Phalcrocorax carbo) and the Double-crested Cormorant (Phalacrocorax auritus) in Nova Scotia in 1971 (A.R. Lock and R.K. Ross). Jordan Bay Gull Rock was known as Blue Gull Rock back then and the paper states that there were 20-30 Great Cormorants and 400-430 Double-crested Cormorants. It is wonderful to know that the Great Cormorant colony on this gigantic rock of an island still has numbers on par with the 1970s.

Before summer's end I'd like to visit another Gull Rock east of Ingomar. It looks like more good habitat for Great Cormorants. Click here to view this island on Google Maps.