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 »
It’s early morning and you’re out on a bird walk following your guide under a gray sky. A flock of small songbirds flits over the distant treetops. The birds reveal no field marks (or so you think), so you’re surprised and mystified when the birder leading the group says matter-of-factly, “Eight House Finches.” “How is
Identifying songbirds by flocking behavior 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 »
In a previous post I wrote about differences in the black-and-white pattern on the neck of Downy and Hairy Woodpeckers, and in comments there Dan Lane reminded me of a difference in the pattern of red on the nape of males, that I’ve heard about over the years but never really investigated. Male Downy Woodpecker
Another clue for identifying Downy and Hairy Woodpeckers Read More »
It’s easy. Experienced birders do it subconsciously, using clues from the wingbeats, rhythm, and path of a bird’s flight. These are usually described in vague terms – the roller-coaster flight of a goldfinch, the slightly undulating flight of a blackbird – but I don’t know of any published effort to really define what is different
Identifying small songbirds by flight style Read More »
New birds are being added to the North American list at a steady rate, and there is no reason to think that the pace of discovery will slow. Some birds are expanding their ranges or pioneering new patterns of occurrence. Some species are being discovered in places like pelagic waters or the Bering Sea islands,
Bird species new to North America – a summary Read More »
Instead of song, most woodpeckers use a mechanical drumming sound as their audio advertising display. It’s easy to tell when you hear a woodpecker, harder to tell which species. Nevertheless there are distinct differences between species, and with practice most drumming sounds can be recognized with a high level of confidence. I’m comparing just Downy
Identifying Downy and Hairy Woodpeckers by drumming sounds Read More »