The Greater White-fronted Goose (Anser albifrons) occurs throughout much of North America, but is found in largely disjunct populations. Only two North American subspecies are listed by Ely and Dzubin (1994), four by Pyle (2008), but five well-defined “population units” have occurred in North America, and there may be more. Banks (2011) recognizes four of […]
Distribution of Greater White-fronted Goose subspecies Read More »
Click here for the complete list of identifiable subspecies of North American birds Some background on subspecies Subspecies are a common focus of debate among birders and ornithologists. The subspecies concept exists as a way to record and classify variation below the species level. The problem is that once we venture below the species level
About the List of Field Identifiable Subspecies Read More »
Summary The two subspecies of Purple Finch are fairly distinctive with well-defined ranges. They are best distinguished by overall impression of color and pattern, and more objectively by details of back and head pattern. Virtually all individuals should be safely identifiable in the field, but the frequency and extent of intergradation is unknown. Eastern Purple
Distinguishing the subspecies of Purple Finch Read More »
Not really. Only under ideal conditions and with reference to location. Mountain Chickadee is found throughout much of the montane coniferous forest of the west, and up to seven subspecies have been described and named. These were sorted by Behle (1956) into Rocky Mountain, Great Basin, and California groups which differ in a complex mosaic
Can subspecies of Mountain Chickadee be identified in the field? Read More »
Caribbean Coot Fulica caribaea (found sparingly and locally in the West Indies from Hispaniola south and east to the coast of Venezuela) is virtually identical to American Coot except for its all-white frontal shield (Roberson and Baptista, 1988). ((The claim by Brisbin and Mowbray (2002) that American and Caribbean coots can be distinguished by the
The ‘Caribbean’ Coot in North America Read More »
Michael Butler of Marathon, Ontario sent me the remarkable photo below, showing all four taxa of redpolls (four subspecies, two species) in one view (see more at his blog here: http://northshorenature.blogspot.com/ The Hornemann’s Hoary is the most distinctive – larger than the “typical” birds and very pale, also looking exceptionally fluffy and “well-padded” which is
Four redpoll taxa in one photo Read More »
A favorite activity among avid birders is speculating and pontificating about which species should be “split” into new species (and new checkmarks on the life list). Another way of stating the question is “which subspecies should be elevated to full species status?” I’ve always tried to emphasize the value of paying attention to subspecies even when they don’t
The next 10 North American bird splits Read More »
In early March 2009 it was my pleasure to spend a few days in California at the San Diego Bird Festival. On my first morning in San Diego I headed straight out to the Tijuana River National Estuarine Research Reserve hoping to spend a few hours studying Savannah Sparrows (who wouldn’t, right?). I had seen
Identification of Belding’s Savannah Sparrow Read More »
Coincidentally, just days after my last post about the two White-fronted Geese in Concord, two White-fronted Geese showed up in Amherst, Massachusetts (about 60 miles west of Concord, but not the same birds) that appear to be one Greenland and one North American type. James Smith has some discussion and really nice photos on his
More on identification of Greenland White-fronts Read More »
The Greenland Greater White-fronted Goose (Anser frontalis flavirostris) is known to be a rare visitor to northeastern North America, but I have never been satisfied with a reliable, objective way of distinguishing it from the North American subspecies of Greater White-fronted Goose, also a rare visitor to the northeast. Bill color is the most frequently-mentioned
Identification tips for Greenland Greater White-fronted Goose Read More »