It is that time of year when the neotropical migrants are rapidly rushing south, giving way to the true denizens of autumn in Michigan: the Myrtle and Palm Warblers, Hermit Thrushes, White-throated Sparrows, and kinglets, among others. Waterfowl, also in this category, can begin to appear surprisingly early as well, such as this September 4 Cackling Goose from Grand Rapids and this September 14 Snow Goose from Muskegon Wastewater, both present well before the last Magnolia Warblers and Bay-breasted Warblers are south of us.
Cackling Goose is decidedly uncommon in Michigan (contra Wisconsin and Illinois, where flocks can outnumber Canada Geese at times). But it is not its rarity which causes us to flag all observations in Michigan, as we currently do. It is its very difficult identification, something not always recognized when looking at overly simplistic representations in field guides and apps. This species is thus similar to Iceland and Thayer’s Gulls, Greater White-fronted Goose, Sharp-shinned Hawks (midwinter and midsummer in the southern lower peninsula), and Northern Goshawks (anywhere in the southern lower peninsula). Each of these species represent underrated identification pitfalls, requiring a great deal of knowledge and excellent views/study to identify. We ask all eBirders to carefully document all individuals of these species, which allows us to apply a consistent standard to all of the records in the Michigan eBird database. We do consider part of our job to help users work through such identification quagmires, so we’d like to begin this quest by tackling Cackling Goose.
Cackling Goose used to be thought of as just a small subspecies of Canada Goose, one of many subgroups within this complex species. But Cackling Goose was split from Canada Goose in 2004 by the AOU, and subsequently birders began to take a much closer look at them here. As it turns out, there are at least eleven populations of Canada/Cackling (hereafter “White-cheeked Geese”), represented in this excellent summary map from David Sibley’s blog (the map is clickable):
©David Sibley (http://www.sibleyguides.com/)
Here is another visual representation of these groups by the Irish Rare Birds Committee.
Currently, Cackling is comprised of four of these taxa: hutchinsii, taverneri, minima, and leucopareia, while Canada is composed of the other seven: maxima, moffitti, canadensis, interior, parvipes (“Lesser Canada Goose”), fulva, and occidentalis.
Subspecies occurrence in Michigan
The only well-documented white-cheeked goose taxa to occur in Michigan are maxima (“Giant” Canada Goose, which nests here), interior (“migrant” Canada Goose: smaller birds, many of which have orange neck tags from banding efforts at Akimiski Island, Hudson Bay), and hutchinsii (“Richardson’s” Cackling Goose). Neither moffitti (which is not identifiable with certainty from maxima except by range) or canadensis are known from Michigan. The status of parvipes (also known as Lesser Canada Goose) in Michigan is more complicated. As in Ontario, it is likely that the subspecies occurs, but no confirmation of its occurrence has been shown to date. An apparent Michigan specimen of parvipes is rumored to exist at the University of Michigan Museum of Zoology, but cannot currently be located in either the database or specimen drawers (Janet Hinshaw, pers. comm.). So we do not know of any confirmed records for Michigan currently. This subspecies also has an uncertain occurrence anywhere in the east, but has been reported by reputable birders multiple times, such as by David Sibley in New Jersey. Also see the eBird map for this group here, which shows dozens of records east of the Mississippi. For clarification, there is some confusion over the definition of Lesser Canada Goose, with most authors using it only to refer to parvipes, but others lumping interior into this category as well. For the purposes of this article, we use it to refer only to parvipes.
The task in Michigan is seemingly pretty simple: if a bird can be shown to possess the classic characters of hutchinsii, it is a Cackling Goose, and if not, one can assume it is a Canada Goose of either interior or maxima. This works much, if not even most, of the time here in Michigan. But the problem is that there is an immense amount of variation within each of these taxa, with multiple intermediate appearing birds showing up annually in Michigan, all of which appear obviously smaller than any Canada Geese they are with. Further, hutchinsii reportedly hybridizes throughout Northwest Territories and Nunavut with parvipes (though citations clearly documenting this are frustratingly hard to locate), adding another layer of uncertainty and confusion. A final twist comes with the knowledge that some ‘runt’ interior individuals suffering from nutritional deficiency on the nesting grounds appear nearly or fully as small as normal hutchinsii (see the 2nd and 3rd photo of a banded runt interior at this link)! Just what are we to do given this set of facts?
Examples from Michigan
Here are some examples of what we consider to be classic hutchinsii from Michigan. Note the squared forehead and pale chest, in addition to body size being perhaps 1/4 the bulk of maxima (and 1/3 to 1/2 that of interior), or just larger than a Mallard:
These birds also typically show a frostier appearance to the upperpart feathers than Canada Goose does, and usually (but not always) have an indentation in the front of the white cheek patch. Very importantly: these birds have very small bills, distinguishable from Canada Goose only by size, not shape, as eloquently demonstrated by David Sibley. The juxtaposition of the very knobby/squared forehead with the extremely small bill creates the appearance of a differently shaped bill, with Canada showing a sloping, Canvasback-like forehead, and Cackling a tiny, pinched-in bill. But it is actually the vertically-oriented forehead that is responsible for this difference, not the shape of the bill itself.
Variation in hutchinsii
Some hutchinsii have darker breasts than these classic birds above (See Fig. 6 in Mlodinow et al.), and hutchinsii regularly shows a prominent white line at the base of the black neck. Neither of these traits disqualify a potential hutchinsii in Michigan, in our opinion. Let’s now look at some contentious birds.
Bird #1) http://ebird.org/ebird/view/checklist?subID=S13187894 (eBirded as parvipes)
This well-documented individual fails to show a classic bill size for hutchinsii and is clearly on the large end of the spectrum for this subspecies, rightfully giving the observers pause and moving the discussion in other directions. While we agree this bird may indeed be parvipes, we argue that the lack of at least one of the classic traits of this taxon (the long, thin bill giving a sleek, almost Canvasback-like profile to the forehead; see Figs . 7, 8, 11, and 12 in Mlodinow et al. ) argues for conservatism and that birds such as this be eBirded as Cackling/Canada Goose. Detailed notes, photos, and analysis should always be included in the species comments box, such as these observers have done (kudos to them!). For clarity, we are not saying we know this bird isn’t parvipes, just that confirming this taxon in Michigan for the first time should require a very high standard of evidence, expert commentary, or perhaps even a specimen.
This bird was clearly smaller than all of the Canada Geese it was with, and it had a relatively sleek bill profile and lacked the white cheek indentation typical of most hutchinsii (but not diagnostic for it, see Mlodinow et al. Fig. 8, 14 and 16). This bird may represent a good candidate for parvipes, but wasn’t as small as one would expect, and its bill seemed to lack the typical fine-tipped appearance of that subspecies. Again, we recommend birds such as these be eBirded as Cackling/Canada.
This excellent North American Birds article by Mlodinow et al. is the single best source we have found for separating the white-cheeked goose taxa . We strongly recommend all eBirders read this article several times over before eBirding Cackling Geese in Michigan, and in particular study the captions and photographs very carefully.
Final Notes & Identification Criteria for Michigan Cacklers
It is often thought that photographs are necessary to get difficult records such as Cackling Geese accepted. This is not true! Of course, photos can be very helpful, but we urge folks not to get caught up just taking photos, and to make sure they study the bird carefully while it is still in view. Of 501 overall eBird reports of Cackling Geese in Michigan, fully 98 were validated without any photographic or video documentation. If you can get photos, please do, but if not (and even when you do), focus intently on studying the bird in the field, as these views very often offer a better opportunity to accurately assess the needed traits, especially on distant birds or in difficult lighting/weather conditions.
Based on the all of the above information, these are our recommended criteria for identifying Cackling Geese in Michigan:
Perched birds must be shown to have the following traits:
1) Very small body size, approaching the size of Mallard. Again, these birds will appear larger if they are with interior, smaller if they are with maxima. It is helpful to record the subspecies of the birds they are with. Be specific about impressions of size, focusing on bulk vs. length in relation to nearby birds.
2) Knobby/squared forehead with vertical area at bill base. Parvipes types and intermediates very often will lack this, and possess a more sloping forehead like Canada Goose.
3) Very small bill. This is frustratingly hard to quantify or describe in words meaningfully, but again, intermediate birds often lack a bill as small as classic hutchinsii, so be on the look out for anything not quite as small as expected, and don’t be afraid to let birds go when they aren’t classic!
4) Frostier (grayer) upperparts compared to Canada Geese, especially the mantle, scapulars, and upperwing secondary coverts. These feather tracts should appear grayer and paler than those of any interior or maxima they are with. Runt interior and parvipes types will lack this, appearing the same color of brown as nearby Canadas.
5) The indented cheek patch is not obligatory, but it a very helpful supporting feature if possessed. Please note whether or not this was shown.
Small white-cheeked geese seen in flight only offer a particularly daunting challenge as most of these above traits are not likely to be evident. We recommend only calling Cackling Goose in flight if the following traits are noted:
1) Very small size around the bulk and mass of Mallard (same caveat for the bird being with interior vs. maxima).
2) Frostier, paler upperparts in comparison to larger birds they’re with.
3) Beyond this, it is not likely one will be able to assess any other traits. But of course, please make every attempt to view and amply describe any of the other traits should the bird allow close enough study. And if you have photos, please embed them into your eBird checklist automatically.
Identifying Cackling Goose in Michigan is one of our most underrated identification challenges, with numerous individuals not fitting neatly into any of the various categories currently recognized. As with any such challenge, we strongly recommend that birders get used to letting more birds go unidentified (Cackling/Canada Goose). For birds offering sufficient views, birders should spend ample time carefully studying each individual in the flock for all of the field marks we have laid out for classic hutchinsii above. Take photos when possible (which will doubly help us to fine-tune our understanding of these taxa in Michigan even when your bird isn’t an identifiable hutchinsii). Study whether impressions of size and head shape change with posture or wet/dry head feathers. And above all, please offer us reviewers abundant details in the species comments box for any claims of Cackling Goose. We hope this post emboldens all eBirders to better identify Cackling Geese this fall and in the future, and welcome comments for discussion.