Downy Woodpeckers are found throughout the state of Idaho, at almost every elevation and habitat with necessary trees for nesting and foraging. As one travels across the state from west to east there is a noticeable morphological difference in this species, so much so that in 1972 when Thomas Burleigh published his then definitive work, The Birds of Idaho, he assigned two subspecies to the state. One is found throughout the state, from north to south and then east to almost the border with Wyoming. It is near the eastern border, that he designates another subspecies, one then found continuing on all the way to western Nebraska.
Burleigh assigned the subspecies Dendrocopos pubescens parvirostris to the vast majority of the state. The AOU never recognized this subspecies, and while clinal, it is morphologically distinct. Later the Downy Woodpecker was officially renamed on the Family level to Picidae, thus changing its binomial to Picoides pubescens, and in turn designating the race of all Downy Woodpeckers found in Idaho P.p.leucurus. In other words, the current accepted taxonomy gives us only one recognized subspecies which stretches from east of the Cascades through the Great Basin and Rockies and on to western Nebraska.
Regardless of official subspecies recognition or not, we cannot lose sight of the undeniable fact that Burleigh’s statewide parvirostris is visually distinct from the extreme eastern Idaho (though apparently not northern Idaho birds) of leucurus, especially when we are looking at birds near the western border of the state as opposed to those viewed in the east. If I’m losing you, let's just say that the birds of this species which I regularly see around Boise in the southwest look different from birds seen near the eastern border by observers aware of the color and structural differences.
View these photos, making sure to read through the caption explanation under Photo #1:
http://picasaweb.google.com/jhkrueger/DownyWoodpecker
Of interest to some might be a generalization called Bergman’s Rule, which simply stated is that birds of a species are larger from the north and higher, cooler elevations, while smaller from the south and lower, warmer elevations. This understanding is applicable to the seven recognized subspecies of Downy Woodpecker, although size can be a very difficult characteristic to gauge in the field for a species like this.
Downy Woodpeckers have not been shown to be migratory, but there is strong evidence for dispersal of birds during migration times (they would have to return to place of origin to be considered truly migratory, and that has not been shown to be the case). Whether this dispersal, sometimes for very long distances, and not just altitudinally, is in response to food needs and/or changes of season and vegetation, particularly deciduous trees losing their leaves, is also unclear. There are no areas where this bird breeds that it is not also present at any other particular season of the year.
Identifiable specimens of parvirostris have been taken as far north as Bonner County south to Owyhee County. As with Horned Larks, banding data would be interesting and informative to gather from various areas of the state…even examining data already gathered from Idaho Bird Observatory stations in the west and east could make a difference in our understanding… if any such morphological differences were ever noted or photos taken.
Could we possible find other Downy Woodpecker subspecies in Idaho? Reasonable possibilities would be P.p.turati (smaller and paler gray, not immaculate white below as Idaho birds tend to be), which is resident from north central Washington to central Oregon, all east of the Cascades, or P.p.gairdnerii, resident from south west British Columbia to northern California, mainly west of the Cascades (and is actually similar in wing appearance to Burleigh’s parvirostris, with few spots, but with underparts usually a very dingy white, sometimes even a brownish gray).
Confused? Frustrated? Don’t really care? But just think of the upside, the enjoyment, of getting to know this bird, and for that matter any bird, so well. If you’ve come this far with me…and even studied the pictures with their captions, I am willing to bet that you will never look at a Downy Woodpecker in the same way again! And this is a great time of the year to really start looking, because drumming birds are so much easier to locate in spring and early summer.
Thursday, February 28, 2008
Monday, February 25, 2008
Should We Bother with Subspecies? or "I'm Tired of the Listing Game!"
[The following was first written by me in 2005 in answer to many questions from fellow birders and others about my obvious deep fascination with subspecies, and the attendant identification and distribution problems and issues which inevitably are the object of so much of my attention. I believe that it was a good apologetic for subspecies investigation then, and I believe it is still such today...perhaps even more so. Furthermore, I believe this direction of effort has made me a more detail oriented and careful field observer...and in the process increased my ultimate satisfaction and joy in studying birds.]
Photo: North Park, C.J.Strike Dam, Elmore County, ID
16 February, 2008
When I first started birding the challenge was to see as many “new birds” as possible…. birds to check on, check off, and then check out from. If it was pictured in my Peterson’s or Golden Bird Guide, it was an undeniable object of desire. And like the addict which I was, I’d visually “use it up” for its instant gratification value and hurry on to my next avian fix. Concern about range, age, and plumage variation was almost non-existent. To me there were only eastern and western birds, a few immatures (that I would probably never see anyway), and those magical “arrows of identification” that gave me the necessary assurance to put that coveted check mark next to the object of my feathered lust.
Then a strange but ultimately wonderful thing happened: I moved to a very different and geographically removed part of the country and noticed that some birds that I had been used to seeing and that usually didn’t merit more than a casual look in my previous area of residence, looked a bit different than I remembered. For instance, Red-tailed Hawks were still recognizable as to species, but something had changed. But what was it? Although I did not realize it at the time, I was experiencing my first wonderful introduction to the "world of the subspecies."
It can be pointedly and rightfully asked: “Why bother?” And the answer definitely depends on if one’s interest in birds goes beyond the “lure of the lists"… the potentially endless, and often sterile daily statements of what species were seen, on which trip, sometimes even without a quantity notation, hurriedly jotted down on some soon to be lost scrap of paper. If this is where birding ends, then so does my interest level…and even mentioning subspecies is both needless and ultimately inhabiting.
But maybe, just maybe, there is another dimension to birding… an amazing “new frontier” whose understanding focuses us on distribution and dispersal and detail in a manner as never before.
First, let’s look at the basics of classification or taxonomy. All living organisms are classified into a hierarchy, with standardized Latin or Latinized names. There are seven main levels of classification in this hierarchy. From the most to the least inclusive they are: Kingdom, Phylum (of Division), Class, Order, Family, Genus, and Species. Subspecies are a grouping of organisms that differ from other members of their species by a possible combination of color, size, or various morphological and genetic characteristics. Often these subspecific groupings are called a “race.” What makes subspecific birding a bit tricky is the reality that sometimes races of a species are distinguishable and therefore recognizable in the field… and quite often they are not, only being classified by “in hand” examination, or through DNA sample comparisons, both obviously unavailable to the average birder.
Additionally, and hopefully not to confuse, there are what we call “morphs,” which do not necessarily represent different subspecies. A morph is an observable typing, quite often characterized by the color of a species, and may be inclusive of more than one subspecies. So for instance, a dark morph Red-tailed Hawk may be a possibility in various subspecies of the one species, namely Red-tailed Hawk.
Confused yet? Still hanging in there with me? OK, let’s dig a bit deeper.
Let’s say that one fall season you notice Mountain Chickadees showing up at your backyard feeder and also unexpectedly on you weekend lowland forays. You know that they belong in the mountains, and make the easy and reasonable assumption that they have “come down” for the winter. But what if it were possible to identify the chickadees you are seeing as to subspecies and thereby be able to tell what maintains they had come down from? Maybe they are not from the population of birds closest to home, but because of some trigger event in their normal area of residence, they have moved to your town and your backyard to seek food and ensure survival? Wouldn’t that make for a much more satisfying identification than to just mark down another “generic” Mountain Chickadee seen?
And consider the much taken for granted “I see them every day, without even looking for them” Canada Goose. Somewhere on their subconscious mental snapshots taken, most birders knew that this ubiquitous waterfowl came in different sizes, shapes and shades. But it has only been since the American Ornithologists Union and the American Birding Association pronounced that “science” has demonstrated that there are really 11 subspecies of 2 distinct species, that the birding fraternity has started paying attention. [You didn’t thank that a Brantaphile like me would get through this piece without mentioning my beloved white-cheeked geese subspecies, did you?] That wonderful bonus of listing, “the split,” always involves previously recognized subspecies. Remember the “species origins” of Juniper Titmouse, Cassin’s Vireo, Cordilleran Flycatcher, and others? And what about when taxonomists reverse the process and "lump" species, making them subspecies, as with Red-shafted Flicker, Oregon Junco, and Audubon’s Warbler? And in case you think it's all finished, just around the corner are nine subspecies of Red Crossbill clamoring for full-fledged species status (one endemic to Idaho), to say nothing of the Fox Sparrow.
Who is there that lifts binoculars to follow the flight of that unidentified treetop denizen or squints through a scope at mere blobs bouncing in the waves that doesn’t want to increase and fine-tune their powers of identification? Believe me when I state that there is absolutely no better way to make that happen than to practice the careful attention to detail that subspecies id requires. Subtle differences in color or pattern, bill shape, feather extension, even vocalization differences make up the wonderful world of the subspecies.
Do I have your interest yet? Are you willing to give it a try? Obviously, you will need an id source to give you an idea of what to look for. A very simple (and to be noted, often over-simplified) place to start is with the differences noted by Sibley in his field guides. Going a small step further would be to look at his website pages dealing with subspecies www.sibleyguides.com/subspecies.htm Pull out your book and compare it to names and comments on the web.
Are you hooked yet? Want to go further? Get a copy of the AOU Checklist (1957) with Supplements, or subscribe to Birds of North America online (Cornell Laboratory of Ornithology). Begin taking notes and photos… even of the “common stuff”…and then compare as you travel to different geographical areas or diverse habitats. Note if there are species in your state or region which comprise more than one race, and then as you travel begin taking note of the visual or vocal differences. In so doing, often the common becomes rare, and the rare finally becomes geographically placeable.
But some words of caution are in order, now that you’re all ready to go “subspecies hunting.” First, get to know the birds well, even the very common ones, in your area. Take notes, draw sketches, and snap photos. Second, when you see that bird that looks a bit different, or is in an area where a distinct subspecies should occur, understand that many subspecies are clinal, that is they have overlapping characteristics, often poorly understood or documented. Finally, continue to carefully note differences from your home population when looking at as wide a slice of birds as possible which may be present in a new area.
Here it would be wise to note that some have taken a fancy to using – and even listing or counting – “identifiable forms.” This is not necessarily the same as subspecies identification. An identifiable form may be inclusive of more than one subspecies, or conversely more than one identifiable form may comprise a single recognized race, as where locally distinct, yet consistent, clinal differences are present.
So in summary, why should birders bother with subspecies?
1. As an alternative to traditional listing
2. As a tool for new and expanded awareness of species distribution and dispersal patterns
3. As a path to a more careful attention to plumage and vocal details, and thus an attendant increase in overall identification skills
4. As a potential addition to developing a species/subspecies knowledge base
5. As a facilitation to a more thorough understanding of actual and potential “splits” and “lumps,” before, after, and as they occur.
So if you’re looking for a new challenge in birding, try entering the wonderful world of the subspecies. You won't regret taking the plunge!
Then a strange but ultimately wonderful thing happened: I moved to a very different and geographically removed part of the country and noticed that some birds that I had been used to seeing and that usually didn’t merit more than a casual look in my previous area of residence, looked a bit different than I remembered. For instance, Red-tailed Hawks were still recognizable as to species, but something had changed. But what was it? Although I did not realize it at the time, I was experiencing my first wonderful introduction to the "world of the subspecies."
It can be pointedly and rightfully asked: “Why bother?” And the answer definitely depends on if one’s interest in birds goes beyond the “lure of the lists"… the potentially endless, and often sterile daily statements of what species were seen, on which trip, sometimes even without a quantity notation, hurriedly jotted down on some soon to be lost scrap of paper. If this is where birding ends, then so does my interest level…and even mentioning subspecies is both needless and ultimately inhabiting.
But maybe, just maybe, there is another dimension to birding… an amazing “new frontier” whose understanding focuses us on distribution and dispersal and detail in a manner as never before.
First, let’s look at the basics of classification or taxonomy. All living organisms are classified into a hierarchy, with standardized Latin or Latinized names. There are seven main levels of classification in this hierarchy. From the most to the least inclusive they are: Kingdom, Phylum (of Division), Class, Order, Family, Genus, and Species. Subspecies are a grouping of organisms that differ from other members of their species by a possible combination of color, size, or various morphological and genetic characteristics. Often these subspecific groupings are called a “race.” What makes subspecific birding a bit tricky is the reality that sometimes races of a species are distinguishable and therefore recognizable in the field… and quite often they are not, only being classified by “in hand” examination, or through DNA sample comparisons, both obviously unavailable to the average birder.
Additionally, and hopefully not to confuse, there are what we call “morphs,” which do not necessarily represent different subspecies. A morph is an observable typing, quite often characterized by the color of a species, and may be inclusive of more than one subspecies. So for instance, a dark morph Red-tailed Hawk may be a possibility in various subspecies of the one species, namely Red-tailed Hawk.
Confused yet? Still hanging in there with me? OK, let’s dig a bit deeper.
Let’s say that one fall season you notice Mountain Chickadees showing up at your backyard feeder and also unexpectedly on you weekend lowland forays. You know that they belong in the mountains, and make the easy and reasonable assumption that they have “come down” for the winter. But what if it were possible to identify the chickadees you are seeing as to subspecies and thereby be able to tell what maintains they had come down from? Maybe they are not from the population of birds closest to home, but because of some trigger event in their normal area of residence, they have moved to your town and your backyard to seek food and ensure survival? Wouldn’t that make for a much more satisfying identification than to just mark down another “generic” Mountain Chickadee seen?
And consider the much taken for granted “I see them every day, without even looking for them” Canada Goose. Somewhere on their subconscious mental snapshots taken, most birders knew that this ubiquitous waterfowl came in different sizes, shapes and shades. But it has only been since the American Ornithologists Union and the American Birding Association pronounced that “science” has demonstrated that there are really 11 subspecies of 2 distinct species, that the birding fraternity has started paying attention. [You didn’t thank that a Brantaphile like me would get through this piece without mentioning my beloved white-cheeked geese subspecies, did you?] That wonderful bonus of listing, “the split,” always involves previously recognized subspecies. Remember the “species origins” of Juniper Titmouse, Cassin’s Vireo, Cordilleran Flycatcher, and others? And what about when taxonomists reverse the process and "lump" species, making them subspecies, as with Red-shafted Flicker, Oregon Junco, and Audubon’s Warbler? And in case you think it's all finished, just around the corner are nine subspecies of Red Crossbill clamoring for full-fledged species status (one endemic to Idaho), to say nothing of the Fox Sparrow.
Who is there that lifts binoculars to follow the flight of that unidentified treetop denizen or squints through a scope at mere blobs bouncing in the waves that doesn’t want to increase and fine-tune their powers of identification? Believe me when I state that there is absolutely no better way to make that happen than to practice the careful attention to detail that subspecies id requires. Subtle differences in color or pattern, bill shape, feather extension, even vocalization differences make up the wonderful world of the subspecies.
Do I have your interest yet? Are you willing to give it a try? Obviously, you will need an id source to give you an idea of what to look for. A very simple (and to be noted, often over-simplified) place to start is with the differences noted by Sibley in his field guides. Going a small step further would be to look at his website pages dealing with subspecies www.sibleyguides.com/subspecies.htm Pull out your book and compare it to names and comments on the web.
Are you hooked yet? Want to go further? Get a copy of the AOU Checklist (1957) with Supplements, or subscribe to Birds of North America online (Cornell Laboratory of Ornithology). Begin taking notes and photos… even of the “common stuff”…and then compare as you travel to different geographical areas or diverse habitats. Note if there are species in your state or region which comprise more than one race, and then as you travel begin taking note of the visual or vocal differences. In so doing, often the common becomes rare, and the rare finally becomes geographically placeable.
But some words of caution are in order, now that you’re all ready to go “subspecies hunting.” First, get to know the birds well, even the very common ones, in your area. Take notes, draw sketches, and snap photos. Second, when you see that bird that looks a bit different, or is in an area where a distinct subspecies should occur, understand that many subspecies are clinal, that is they have overlapping characteristics, often poorly understood or documented. Finally, continue to carefully note differences from your home population when looking at as wide a slice of birds as possible which may be present in a new area.
Here it would be wise to note that some have taken a fancy to using – and even listing or counting – “identifiable forms.” This is not necessarily the same as subspecies identification. An identifiable form may be inclusive of more than one subspecies, or conversely more than one identifiable form may comprise a single recognized race, as where locally distinct, yet consistent, clinal differences are present.
So in summary, why should birders bother with subspecies?
1. As an alternative to traditional listing
2. As a tool for new and expanded awareness of species distribution and dispersal patterns
3. As a path to a more careful attention to plumage and vocal details, and thus an attendant increase in overall identification skills
4. As a potential addition to developing a species/subspecies knowledge base
5. As a facilitation to a more thorough understanding of actual and potential “splits” and “lumps,” before, after, and as they occur.
So if you’re looking for a new challenge in birding, try entering the wonderful world of the subspecies. You won't regret taking the plunge!
Friday, February 15, 2008
Horned Lark Subspecies in Idaho
This is a follow-up to my post on IBLE of 25 January, 2008 which began to deal with the complexities of Horned Lark subspecies present and identifiable in Idaho during the winter months.
Photo: Bob Martinka, taken
in Helena Valley, MT
2/4/08. Probable E.a.
merrilli intergrade.
Let me say, right off the top, that the more I investigate this situation the more complex and not straight forward it becomes. Although there are 21 subspecies recognized by the American Ornithologists Checklist, 5th edition (1957), it must be understood that this species exhibits much intra-population variability, with numerous intermediate populations between the established races. What we have are endless variation possibilities, with micro-populations based on color and size differences resulting from a blending of the typical forms of each subspecies population. Clinal variations and differences are the rule rather than the exception, with “typical” being a nice technical term that has difficulty finding much viability in the realities of field observation with this species.
With that said, let’s look at what identifiable subspecies have been documented to be present in Idaho, where they can be expected to be found (based on recorded, available data), and how these subspecies can reliably be identified (perhaps) by observers in the field, especially outside of the breeding season.
(Let it be it noted here that there is a dearth of banding data available, which if it were systematically gathered by knowledgeable personnel at strategic and appropriate habitat locations throughout the state during the winter months, when conditions are unfortunately most unfavorable to human activity, many of the missing pieces of Horned Lark dispersal and distribution would become available. )
Subspecies that have been observed and/or collected in Idaho:
Eremophila alpestris arcticola
This race is the largest of the western subspecies and regularly migrates from its breeding grounds in Alaska, the Yukon and through the mountains of British Columbia south to Northern California and east to Wyoming. This is the only western race that does not intergrade with adjacent forms, therefore we do not see the potential variation here that is the bane of other subspecies field identification.
It has a white throat and eyebrow stripe, a pale, neutral gray back, boldly streaked with dusky brown, a pinkish-buff nape which bisects the streaking of the dorsum which continues onto the crown, a trait unique to this subspecies and not detailed in field guides. Its larger size is noticeable with careful comparative observation, especially appearing somewhat plumper than any of its potential winter associates.
It has been recorded by both collection (first record, Coeur d’Alene, 1897) and observation along the north/south length of the state. Specimens in the Colorado Museum of Natural History document 109 records from southern Idaho, spanning the area from Ada County to the eastern state border, from 4 November to 20 February.
The subspecies is possible anywhere in the state beginning at about the start of October until the beginning of March.
With that said, let’s look at what identifiable subspecies have been documented to be present in Idaho, where they can be expected to be found (based on recorded, available data), and how these subspecies can reliably be identified (perhaps) by observers in the field, especially outside of the breeding season.
(Let it be it noted here that there is a dearth of banding data available, which if it were systematically gathered by knowledgeable personnel at strategic and appropriate habitat locations throughout the state during the winter months, when conditions are unfortunately most unfavorable to human activity, many of the missing pieces of Horned Lark dispersal and distribution would become available. )
Subspecies that have been observed and/or collected in Idaho:
Eremophila alpestris arcticola
This race is the largest of the western subspecies and regularly migrates from its breeding grounds in Alaska, the Yukon and through the mountains of British Columbia south to Northern California and east to Wyoming. This is the only western race that does not intergrade with adjacent forms, therefore we do not see the potential variation here that is the bane of other subspecies field identification.
It has a white throat and eyebrow stripe, a pale, neutral gray back, boldly streaked with dusky brown, a pinkish-buff nape which bisects the streaking of the dorsum which continues onto the crown, a trait unique to this subspecies and not detailed in field guides. Its larger size is noticeable with careful comparative observation, especially appearing somewhat plumper than any of its potential winter associates.
It has been recorded by both collection (first record, Coeur d’Alene, 1897) and observation along the north/south length of the state. Specimens in the Colorado Museum of Natural History document 109 records from southern Idaho, spanning the area from Ada County to the eastern state border, from 4 November to 20 February.
The subspecies is possible anywhere in the state beginning at about the start of October until the beginning of March.
E.a.hoyti
Although not mentioned in Birds of Idaho (Burleigh, 1972), it undoubtedly occurs regularly during winter, most probably throughout the length of the state. One of only three races that are entirely migratory, it breeds from northern Baffin Island to northern Alberta, across Canada to Ontario, wintering south to Nevada (including Idaho) and across to Michigan (Beason, BNA, #195). Burleigh does cite records of E.a.enthymia from the southeastern portion of the state based on identifications by provided Oberholser of specimens in the Colorado Museum of Natural History. I question this based on Beason who contends that E.a.enthymia is a Great Pains breeding bird whose range extends a bit further south in winter, but is a long distance from Idaho (and inconsistent with the numerous records cited). Further fitting into the picture of misidentification is that enthymia is morphologically very similar to hoyti, and would be difficult to visually tell apart…and as mentioned, Burleigh does not even reference hoyti as a visitor to Idaho, which it is undoubtedly.
This race is primarily identified visually by its white eyebrow and yellow throat.
E.a.utahensis
This is one of three breeding races of this species in Idaho, this one primarily in the southern portion of the state, documented as far north as Custer County. Although most of the population moves out of Idaho during the winter months (this is the northern boundary of it breeding range), there are scattered remnants of the population that overstay the winter, often being most readily found in larger mixed flocks of the species.
Unique to this race (for Idaho) is its matching yellow eyebrow stripe and throat (although the stripe may be a bit lighter). Additionally it had a drab nape and crown, and dusky brownish back.
E.a.alpina
Breeds in the coast mountain ranges of western Washington, and primarily winters in the lowlands surrounding those mountains. Apparently it does occur regularly in northern Idaho, most often reported in association with flocks of E.a.arcticola. Specimens have been taken primarily in February, although there is one September record from Lewiston, and one southern Idaho record on November 23 from Emmett.
According to Beason it resembles the migratory arcticola but “E.a. alpina is smaller and less brownish than E. a. arcticola with a darker back and more pinkish nape, uppertail-coverts, and upperwing-coverts. (This may be a difficult one to separate in the field.)
E.a.lamprochroma
Another Idaho breeder, this one in the southwestern corner of the state, according to specimens not north of Ada County nor east of Owyhee County…a very restricted breeding range in the state. It apparently can (and does) occur in the winter months also, while occasionally also being present in northern Idaho during that period, apparently moving from its breeding grounds on the arid sagebrush plains of eastern Washington.
Similar to E.a. arcticola in appearance (along with E.a. alpina), the base color of the back is darker (less gray) than arcticola, with the striping and base color blending together, lacking the dramatic contrast of arcticola. Also, to my knowledge, the dorsum striping pattern is not seen on the crown.
E.a.merrilli
This is the third breeding population in Idaho, most common in the north, and found from the Canadian border to as far south as Washington County. In most areas it is absent during winter, retreating to the southern portion of its range (n. California), although there are two Moscow, Latah County specimen records from December. Apparently it is resident in the Lewiston area all year long, at times very plentiful and easy to find in “flocks of 20-200” (Burleigh, 1972).
This is the darkest of all the subspecies, with the back being blackish brown, nape brownish, extending around the wing wrist, the throat yellow, and a lighter yellow eyebrow line. It is fairly easy to pick out of any mixed group because of it contrasting dark color.
To date five subspecies of Horned Lark have been documented in Idaho. Few, if any, birders or researchers out in the field have paid much attention to plotting subspecies presence, therefore there is still much to learn of the movements of these groups, especially during migration and winter. For the amateur who likes identification challenges…and for the professional wanting to add some important pieces to the body of knowledge of this species, opportunities abound.
Some photos of Horned Lark subspecies in Ada County:
(Be advised that this is far from a completed work.... Much field work remains to be done. Photos of Horned Larks are always welcome.)
Harry Krueger
Boise, ID
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