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