Archivos de diario de diciembre 2019

02 de diciembre de 2019

November Summary

The month of November is over and I'm sad to say we are one month away from closing this project down and it's finished. If you've enjoyed it as much as I have, let me know and I may think about doing a breeding season count. Here's the summary for the month.

Top Five Species Observed (Overall):
Red-tailed Hawk -- 326 obs
American Kestrel -- 60 obs (+2 spots)
Swainson's Hawk -- 48 obs (-1 spot)
Great Horned Owl -- 45 obs (+1 spot)
Cooper's Hawk -- 43 obs (-2 spots)

Top Five Species Observed (November):
Red-tailed Hawk -- 116 obs
Rough-legged Hawk -- 27 obs (first time in Monthly Top 5)
American Kestrel -- 25 obs
Bald Eagle -- 20 obs (first time in Monthly Top 5)
Northern Harrier -- 19 obs

Total Species Overall: 29 species (+3)
Total Species November: 18 species (+3 from last month)

Top 5 Observations Submitted: @birdwhisperer 280 obs, @peterolsoy 192 obs and @cgates326 101 obs, @masonmaron 67 obs and @jnelson 37 obs
Top 5 Most Species: peterolsoy 18 species, cgates326 18 species, birdwhisperer 18 species, masonmaron 9 species and @nightjar09 8 species

Species Still Not Observed: White-tailed Kite, Broad-winged Hawk, Barn Owl, Flammulated Owl, Snowy Owl and Spotted Owl

Counties Still Needing Observations: 3 in OR -- Gilliam, Morrow and Wheeler

What to Expect in December: This is last month so I want the project to go out in a bang. We have 5 species that are "expected" in our search zones but we already know we've lost our chance at seeing a Broad-winged Hawk or Flammulated Owl. Though a Broad-winged Hawk was observed in Asotin County, WA last December, doesn't mean it will happen again. Spotted Owls will be incredibly difficult to find along with White-tailed Kites east of the Cascades. I am fairly shocked Barn Owls haven't been photographed/found yet as I find them one of the more common species. My lack of finding them has nothing to do with it. :P

Anyway here's what to expect. Snow will keep raptors in the same general area so keep your eyes open for similar looking hawks. A few days ago I found a Northern (abieticola) x Western (calurus) Red-tailed Hawk in Union Co, OR, so obviously seeing an odd-ball Red-tailed is not out of the question yet. @peterolsoy has proven that Gyrfalcons have returned to at least Asotin despite my envy and disbelief, so keep your eyes open for large pale falcons and don't confuse them for Prairie Falcons and have an embarrassing moment like I did this January. The Columbia River Basin will provide a great opportunity to see a Black Merlin (F. c. suckleyi) but remember that female Taiga Merlins (F. c. columbarius) can be incredibly similar. If you are anywhere in Washington, this is the month to find a Snowy Owl. I have found them in Walla Walla, Yakima and Spokane but can be anywhere in the basin.

A final note, on Friday, December 20th is the IPNRM field trip and I have sent a message to those that are members of the project and others I would like to attend. I have not received any word however if invited persons can attend nor have I received preferred departure times. If you are planning on attending, please get back with me as soon as possible. If you have not received an invitation or lost it, I will resend to you if you forward me a message. Good luck hawkwatchers!

Publicado el diciembre 2, 2019 12:32 MAÑANA por birdwhisperer birdwhisperer | 0 comentarios | Deja un comentario

03 de diciembre de 2019

Northern Red-tailed Hawk (Buteo jamaicensis abieticola) as a Distinct Subspecies

Introduction and Background
One of the most complicated discussions in the world of Red-tailed Hawks is the validity of the Northern Red-tailed Hawk (Buteo jamaicensis abieticola). Ever since it was described over seventy years ago (Todd 1950), the Canadian Red-tailed population has been on a seesaw of being a separate distinct subspecies or a heavily marked type of the Eastern Red-tailed Hawk (B. j. borealis).

The subspecies was described in 1950 by W.E. Clyde Todd where he collected 10 abieticola and borealis specimens in Canada and noted how the northern populations was like borealis but "underparts more heavily streaked; throat and upper breast darker colored (more brownish, less rufescent); upperparts (including wings externally) darker colored (more blackish); and subterminal black band on tail averaging wider."

The American Ornithological Society declined the acknowledge of the subspecies in their last subspecies assessment in 1957 and ending the age of looking for geographical variation in field work. Thirty years later, Dickerman and Parkes (1987) published a more thorough paper on abieticola and supported Todd's hypothesis that indeed a northern population existed. It also explain explained how the northern populations differed from borealis and calurus. Dickerman and Parkes also stated that many "calurus" identified in eastern US were in fact abieticola. Field guides that list subspecies (Wheeler 2003, Pyle 2008, Stokes 2010) in the past have also failed to acknowledged a distinct population in Canada. At one point, abieticola was even considered an intergrade between borealis and calurus (Clark and Wheeler 1997, Wheeler 2004). For the space of sixty-three years, abieticola was just considered a more heavily-marked borealis and just that. In 2010, ebird finally recognized abieticola and added it as a taxon. Starting 2013 and still is today, Avibase has considered abieticola as a form of Western Red-tailed Hawk (B. j. calurus).

Light was finally shed on the abieticola case when Ligouri and Sullivan (2014) explored the topic and give a thorough discussion on the population. After spending some time explaining how abieticola differs from other subspecies. The reason the subspecies has gotten so much bad publicity in the past is due to the fact we know nothing about their nesting and to the extents of their breeding range so to assume that more heavily-marked individuals are from Canada is a narrow-minded hypothesis.

Wheeler (2018) goes in depth with the discussion claiming that abieticola was nothing more than a type of borealis due to lack of breeding data, borealis in the US showing just as heavily marked individuals in breeding season and Canadian intergradation between calurus and harlani has made heavily marked hawks more common in boreal forests.

Identification

Despite the information presented above, I will proceed to educate you in the identification of abieticola. The description I have provided is a direct quote from my other journal post "Identifying US and Canada Red-tailed Hawks" as it goes in depth what's expected in the subspecies or not.

Head: Dark head. Throat streaked, collared or dark. Darker cheek normal.

Upperparts: Light to moderate white mottling on the scapulars.

Underparts: Bellyband moderately to heavily-marked and always black or very brown black, with each streak resembling an arrow shape. Barring often occurs if the bellyband is moderate. Legs are often unbarred. Breast white but can often be tawny or rufous and these individuals often appear incredibly similar to heavily-marked rufous morph Westerns (calurus). Sides of the breast often have black "dribbling" marks.

Wings: Little to no rufous on lighter morphs, but often heavily rufous on rufous-breasted individuals. Patagials thin but darker than normal borealis. Well defined trailing edge. Underwing coverts are almost always whiter than breast with the exception being intergradation with calurus.

Tail: Similar to borealis except with a broader subterminal band and they are more likely to show partial or complete tail banding.

Morphs: Mostly light but rufous have occurred. Dark morphs are hypothesized.

Juvenile: Nearly identical to borealis but with more variance, including more heavily marked underparts.

Distribution

It is believed that abieticola breeds across the boreal forest across Canada from Yukon to northeastern US. There is one confirmed sighting in California from raptor biologist and eBird admin Brian Sullivan who noted in his observation, "In all likelihood abieticola winters sparingly throughout the West, probably similar to harlani in this regard." Another abieticola was spotted by raptor biologist and colleague of Sullivan, Jerry Ligouri, in Utah.

Pit Falls in Wheeler's Work

I've had many hours of discussion with many raptor experts on the status of abieticola and I get very complex and differing statements. Several believe it's borealis due to inconsistency in diagnostic features, lack of breeding data and southern birds showing heavier bellybands. And it appears these experts are agreeing with Wheeler's statement "The 'Eastern' subspecies exhibits considerably more plumage variation than previously described or depicted in any publication." He goes on to further explain he figured this out by looking at museum specimens.

I believe this is the first pitfall in Wheeler's work is providing a modern example showing that borealis can indeed be more heavily-marked. He failed to provide photographic evidence pertaining to southern Red-tails exhibiting the heavy bellyband. In his final remarks on abieticola he does provide four photos from Canada that are Eastern-type hawks. I believe his purpose was to show that light-marked individuals can be found in northern Canada but it still doesn't answer my question, what about heavily-marked borealis?

I did find one iNaturalist sighting for a Tennessee Red-tailed Hawk in May. I have posted the observation link below. I can see how one might argue and claim this is a abieticola because of the black bellyband, dark throat and thick patagials. Not to mention it's breeding season and it's way out of its "breeding range". Despite the similarities this individual shares with northern populations, there's two solid features here that's telling me it's an abieticola. One, is that there is nearly no streaking on the sides of the breast and what there is, is not black as it should. Secondly, the subspecies is known to have broad subterminal bands despite the very thin one this individual is showing. So in a nutshell, I agree with Wheeler that borealis are indeed much more variable than previously believed but the features a heavily-marked individual has is still differing from northern populations. I will even mention, if this was an abieticola it doesn't mean it's not a nod to the subspecies being invalid. Let's remember in 2010, a Harlan's Hawk was found breeding with a Red-tailed in North Dakota when it's "breeding" range only a decade ago was only Alaska.

https://www.inaturalist.org/observations/25472293

I think the second mistake is claiming that northern Red-tails are exhibiting heavier bellyband due to intergradation with calurus. However, if that were true, why are we not seeing abieticola-like individuals in eastern Colorado. The Colorado Rocky Mountain front has been known for years as a heavy intergradation zone for calurus and borealis, yet we are not seeing these blobby bellyband individuals like in northern Canada.

Thirdly, if abieticola is not a subspecies, why are alascensis and fuertesi still recognized? A group of birders called "Red-tailed Hawks of Western Canada" has admitted to the fact that alascensis is indistinguishable from calurus in the field because of the variance of the latter subspecies. As for fuertesi, I recently had a heated debate with another birder because I identified a Red-tailed as such in Oklahoma and the point of his argument was, how can we call it a possible fuertesi by a nearly nonexistent bellyband when some borealis in Ohio also exhibit no bellybands. Are we going to call them fuertesi too? As much as I hate to admit that (though the named subspecies has other differences from borealis), we can't ignore the fact that other subspecies are much more similar in appearance and yet none are reviewed for its validity.

Lastly, what about dark morphs? One of the reasons why calurus gets confirmed across eastern US is because they are the "only" subspecies with rufous or dark morphs. And it's easy to understand how one might show up in eastern US. The distribution of calurus is very similar to a Golden Eagle; summers/resident to western Canada, year-rounded resident to western US, winter visitor to Great Plains and annual or vagrant to eastern US. If you may see a Golden Eagle in Kentucky every winter, why not a calurus Red-tailed, a population with a very similar distribution.

However, there is a rising hypothesis that abieticola has dark morphs. This hypothesis started with Jean Iron (2012) who stated...

"When dark morph Red-tailed Hawks are seen in southern Ontario they are assumed to be from the western subspecies calurus. This is based on the belief that dark morphs do not occur in the Eastern Red-tailed Hawk borealis breeding population, whereas dark morphs occur in Western calurus. I wonder whether this assumption is always correct or if we should consider an eastern source for some of our dark morph Red-tailed Hawks.

The answer may lie in the northern Red-tailed Hawk population breeding in Canada’s boreal forest...I propose that a few dark morph Red-tailed Hawks probably occur in the abieticola population but have gone undetected in the vast boreal forest where few birders and ornithologists visit. This winter, 2011-2012, at least three and possibly four dark morph Red-tailed Hawks are overwintering near Toronto in Oakville, Oshawa, Guelph and Brantford. Some dark morphs may be breeding among the heavily pigmented abieticola population across the boreal forest. This makes more sense to me than thinking that all are western calurus."

Two years ago, eBird followed suite with the possibility that there are dark morph abieticola out there and proceeded in adding the slash calurus/abieticola. If you happen to be a user of eBird as well, if you see a dark morph Red-tailed Hawk east of the Rockies, it is best to use this slash instead of calurus/alascensis. I actually in fact used this slash a couple of days ago for a light morph Red-tailed (hard to believe) because it exhibited strong abieticola traits but the expected subspecies still couldn't be eliminated.

Conclusion

Though the subspecies may be thrown under the bus as a heavily-marked Eastern Red-tailed, abieticola still shows features that are inconsistent with even heavily marked southern Red-tailed populations. However, intergradation has probably interfered with them becoming such a clear-cut subspecies, especially if the intergradation zone between calurus and harlani extends from Gunsight Mountain, Alaska to North Dakota. There is also apparently problems identifying Red-tails in New England states as well as some Red-tails show very heavy brown bellybands and rich rufous breasts, suggesting a intergradation zone between borealis in that region.

As for it's validity as subspecies, I'm on the vote for yes it is. If it is true that abieticola can indeed have rufous or dark morphs, then it truly is a different subspecies from borealis. But we don't have that information yet. I see this decision of it's validity is very similar to the Harlan's Hawk being elevated to species status. Though it is behavioral and morphically different, we don't know how often it intergrades with other Red-tails and if they will willingly and consistent intergrade. It's just information we don't know yet and to make a decision on abieticola's status now appears premature and narrow-minded, especially in Wheeler's case as he failed to back up his statements with photographic evidence and/or data charts supporting his statements. As Jerry Ligouri stated...

"Although Northern Red-tailed Hawk is slowly becoming more familiar to raptor enthusiasts, much remains to be learned. With today’s advanced technologies for communication, documentation, and data archiving, birders can make solid contributions toward understanding this enigmatic bird’s identification, taxonomy, and natural history."

Acknowledgements

I would like to send some shout-outs to those who have helped me in my progression in understanding and identifying Red-tailed Hawks correctly. I would like to thank Jerry Ligouri and Brian Sullivan for spending some time with me, teaching me how to identify Red-tailed Hawks to subspecies level and how to identify abieticola. I thank Mike Borlé for taking his time in identifying several Red-tails I was skeptical about and trying to guess where the bird originated from. I also thank him for identifying my calurus/abieticola hawk. Shane Brown for sharing opinions on how "well-recognized" subspecies such as fuertesi or alascensis is not a valid subspecies. INaturalist psweet for recommending Wheeler's guide and giving me a new perspective on abieticola besides Ligouri and Sullivan's opinions on the matter. INaturalist Greg Lasley for tagging me in odd Red-tailed/Buteo observations and giving me a further appreciation for Red-tailed variation. INaturalist Bill Chambers for his comment, "when they come through you can really see the difference" when I identified one of his fall sightings an abieticola furthering my hunch that there's a distinct population up north.

Literature Source

Publicado el diciembre 3, 2019 05:56 TARDE por birdwhisperer birdwhisperer | 2 comentarios | Deja un comentario

31 de diciembre de 2019

My 2019 Birding Year

Year Total: 255 species
Life List: 330 species

Best Month: August 146 species
Worst Month: February 74 species

State Stats (Year and Life)

Oregon: 218 245
Washington: 135 271
Idaho: 116 167
Utah: 83 105
Colorado: 67 94

New Counties Visited

Oregon -- Harney, Grant and Gilliam
Washington -- Klickitat
Idaho -- Adams, Gooding, Boise, Jerome, Lewis, Elmore, Cassia, Oneida, Benewah and Minidoka
Utah -- Duchesne and Summit

Year Lifers: Harris’s Sparrow, Mute Swan, White-headed Woodpecker, Juniper Titmouse, Summer Tanager, Black Phoebe, Indigo Bunting, Snowy Egret, White-winged Crossbill, Broad-billed Hummingbird and Red-shouldered Hawk

Big Sightings and Memorable Moments of the Year:

House Finch -- January 4, Union County, Oregon -- I was able to hand catch a House Finch with Finch Eye Disease (Mycoplasmal conjunctivitis) and take it to a rehab for treatment. Unfortunately after a successful treatment, the infection came back and the bird didn’t make it.

Osprey and Bald Eagle -- April 3, Ada County, Idaho -- Watched a spectacular show of an Osprey trying to keep his fish away from the eagle.

Prairie Falcon -- April 3, Ada County, Idaho -- Saw a pair building a nest in an isolated location.

Great Gray Owl -- May 18 and 23, Washington and Oregon -- After three years of searching, I finally got to see not one but two nests with young it. Thanks to those who helped me find the nest.

Summer Tanager -- June 20, Mesa County, Colorado -- Rarity for location and lifer!

Indigo X Lazuli Bunting -- June 23, Mesa County, Colorado -- Found while trying to find an Indigo Bunting.

White-faced Ibis -- June 25, Box Elder County, Utah -- Exact count of 716 ibises that day.

Swainson’s Hawk -- August 1, Union County, Oregon -- Fledgling day for the pair that nested in my yard.

Red-tailed Hawk -- August 6, Benton County, Washington -- Leucistic

Great Egret -- September 5, Union County, Oregon -- Found a county high count of 52 birds!

Indian Peafowl -- September 13, Union County, Oregon -- Male and three females crossed the highway at Catherine Creek SP. Still wondering what they were doing in a National Forest.

Broad-billed Hummingbird -- September 19, Harney County, Oregon -- 3rd Oregon record and gorgeous bird.

Lesser Black-backed Gull -- December 7, Asotin County, Washington -- 2nd Life sighting.

Red-shouldered Hawk -- December 7 and 22, Wallowa County, Oregon -- 1st ever record of the species in the county!

Barred Owl -- December 13, Ada County, Idaho -- First photos and my first daylight sighting.

Publicado el diciembre 31, 2019 10:34 TARDE por birdwhisperer birdwhisperer | 1 comentario | Deja un comentario