Archivos de diario de enero 2020

01 de enero de 2020

Final Summary

This is the December and final summary for the 2019 Inland Pacific Northwest Raptor Migration. I would like to personally thank all of those who have participated and I hope with this information compiled onto this page will help figure out population densities of certain species and if we could find all 35 species of possible raptors. So here we go!

Top Five For December

  1. Red-tailed Hawk: 51
  2. Rough-legged Hawk: 30
  3. Bald Eagle: 14 (+1 spot)
  4. American Kestrel: 13 (-1 spot)
  5. Golden Eagle: 9 (First Time in Monthly Top 5)

Raptor Stats Overall

  1. Red-tailed Hawk: 378
  2. American Kestrel: 73
  3. Rough-legged Hawk: 63 (+6 spots)
  4. Great Horned Owl: 52
  5. Cooper's Hawk: 50
  6. Swainson's Hawk: 49 (-3 spots)
  7. Bald Eagle: 47 (+3 spots)
  8. Northern Harrier: 41
  9. Sharp-shinned Hawk: 36 (-2 spots)
  10. Turkey Vulture: 34 (-4 spots)
  11. Osprey: 32
  12. Golden Eagle: 31
  13. Ferruginous Hawk: 27
  14. Prairie Falcon: 22
  15. Merlin: 12
  16. Peregrine Falcon: 8 (+1 spot)
  17. Northern Pygmy-Owl: 8 (-1 spot)
  18. Northern Saw-whet Owl: 7
  19. Red-shouldered Hawk: 5 (+1 spot)
  20. Northern Goshawk: 3
  21. Western Screech-Owl: 3 (+3 spots)
  22. Barred Owl: 3 (+4 spots)
  23. Gyrfalcon: 2
  24. Long-eared Owl: 2 (-3 spots)
  25. Northern Hawk Owl: 2 (-3 spots)
  26. Great Gray Owl: 1 (-1 spot)
  27. Burrowing Owl: 1
  28. Short-eared Owl: 1
  29. Boreal Owl: 1
  30. Barn Owl: 1 (First Sighting in December)

Project Misses and Comments

There are 35 "expected" species of raptors in our search zone and I would've been extremely surprised if we actually got them all. Here's the five species we missed and some comments regarding to it.

White-tailed Kite: To be honest, finding this species in general was going to be a long shot. Kites are typically not nomadic but I kept crossing my fingers hoping that one might just come over the Cascades.

Broad-winged Hawk: I was actually shocked no one actually saw a Broad-winged Hawk. If I had observers paying attention to the skies, surely one would've been spotted in September. Especially when an average of 3 individuals fly over the Intermountain Bird Observatory in Boise every September day. Perhaps next year.

Flammulated Owl: Technically this bird was found because I did hear one owling one night in the Elkhorn Mountains, Oregon but the owl was too far away to get a decent audio. The fact that this species is incredibly secretive might explain its absence from the project.

Snowy Owl: I was not expecting anyone to have luck with a Snowy since the lemming year was 2017, and additionally, I do not believe any place north of our search zone had harsh enough winter to drive the owls south.

Spotted Owl: Once again, another long shot as this is probably the hardest "expected" species to find.

Subspecies

There are several species that have subspecies. Some of these include the Harlan's Hawk (Buteo jamaicensis harlani) which are really distinct or Northern Sharp-shinned Hawk (Accipiter striatus velox) where the differences between others are subtle. Here's what I got.

Western Turkey Vulture (Cathartes aura meridionalis) -- 34

North American Osprey (Pandion hailaetus carolinensis) -- 32

Northern Bald Eagle (Haliaeetus leucocephalus washingtonensis) -- 47

American Golden Eagle (Aquila chrysaetos canadensis) -- 31

American Goshawk (Accipiter gentilis atricapillus) -- 3

Northern Sharp-shinned Hawk (Accipiter striatus velox) -- 36
Queen Charlotte Sharp-shinned Hawk (Accipiter striatus perobscurus) -- 0

Western Red-tailed Hawk (Buteo jamaicensis calurus) -- 368
Harlan's Hawk (Buteo jamaicensis harlani) -- 7
Western/Northern Red-tailed Hawk (Buteo jamaicensis calurus/abieticola) -- 3
Eastern Red-tailed Hawk (Buteo jamaicensis borealis) -- 0
Northern Red-tailed Hawk (Buteo jamaicensis abieticola) -- 0

American Rough-legged Hawk (Buteo lagophus sanctijohannis) -- 63

California Red-shouldered Hawk (Buteo lineatus elegans) -- 5

Northern American Kestrel (Falco sparverius sparverius) -- 75

Taiga Merlin (Falco columbarius columbarius) -- 11
Prairie Merlin (Falco columbarius richardsonii) -- 1
Black Merlin (Falco columbarius suckleyii) -- 0

North American Peregrine Falcon (Falco peregrinus anatum) -- 8
Peale's Peregrine Falcon (Falco peregrinus pealei) -- 0
Arctic Peregrine Falcon (Falco peregrinus tundrius) -- 0

American Barn Owl (Tyto alba pratincole) -- 1

Interior Screech-Owl (Megascops kennicotti bendirei) -- 3

Western Burrowing Owl (Athene cunicularia hypugena) -- 1

Interior Great Horned Owl (Bubo virginianus lagophus) -- 52
Pale Great Horned Owl (Bubo virginianus subarcticus) -- 0

American Great Gray Owl (Strix nebulosa nebulosa) -- 1

Northern Barred Owl (Strix varia varia) -- 3

Western Long-eared Owl (Asio otus tuftsi) -- 2

Northern Short-eared Owl (Asio flammeus flammeus) -- 1

Pacific Northern Pygmy-Owl (Glaucidium gnoma californicum) -- 0
Rocky Mountains Pygmy-Owl (Glaucidium gnoma pinicola) -- 0
Pacific/Rocky Mountains Pygmy-Owl (Glaucidium gnoma californicum/pinicola) -- 8

American Boreal Owl (Aegolius funereus richardsoni)

Northern Saw-whet Owl (Aegolius acadicus acadicus) -- 7

Counties Missed

There were 38 counties including in our search zone and sadly three counties did not acquire any observations during the course of the project. These counties were:

Gilliam, Oregon
Morrow, Oregon
Wheeler, Oregon

Top Observers By Species

  1. @cgates326 with 19 species
  2. birdwhisperer (myself) also with 19 species
  3. @peterolsoy with 18 species
  4. @nightjar09 with 10 species
  5. @masonmaron with 10 species

Top Observers By Observations

  1. birdwhisperer with 347
  2. peterolsoy with 199
  3. cgates326 with 127
  4. masonmaron with 84
  5. @jnelson with 56

Final Comments

To those that participated both purposefully and unknowingly, we were able to compile 1007 raptor sightings in a very short 6 months. We saw species migrate, come and go. Saw amazing things that made others envy them. Here's a few thoughts I've had about the project.

The amount of Red-tailed Hawks compared to all the other species is quite sobering. Seriously, Red-tailed Hawks covered over 38% of ALL sightings! I'm sure we all know that Red-tails are more common than any other raptor species but to truly see how much they do outnumber everyone else is outstanding.

I never realized how many Rough-legged Hawks winter in eastern Washington or Oregon. In November and December, for every 3 Red-tails there were 2 Rough-legged Hawks. I'm sure if they stayed year-round, I think they might give Red-tails a run for their money.

Prairie species like the Ferruginous Hawk and Prairie Falcon numbers surprised me. The sightings told me two things, Ferruginous are truly the king of raptors in sagebrush Oregon and Prairie Falcons dominate the skies in eastern Washington.

The last time I've personally seen so many Golden Eagles was when I lived in Montana before 2017. I even found not one but two Golden Eagles in Walla Walla County during the project, I placed I've lived in for two years and have NEVER seen a Golden.

I was shocked to even have one Red-shouldered Hawk sighted during the project but to have 5, two of which being my own sighting of Wallowa County's first ever RSHA.

I am shocked by the lack of Barn Owls spotted. Me myself have had my struggles tracking down these owls, despite my good luck in the past.

Well, Happy New Year everyone and thanks for joining the Inland Pacific Northwest Raptor Migration Count!

-- Sean Cozart -- birdwhisperer

Publicado el enero 1, 2020 08:03 MAÑANA por birdwhisperer birdwhisperer | 1 comentario | Deja un comentario

17 de enero de 2020

Preparation for the 2020 Orthoptera Season

@umpquamatt @geographerdave @leppinm @russnamitz @ldibiccari

You have been tagged because you are the top observers for Oregon Orthoptera (Grasshoppers, Crickets and Katydids) sightings. The purpose of this post to grab a few volunteers to help me in this project.

The Purpose of the Project

To collect data from all suitable habitats in Oregon to comprise a complete and thorough identification field guide to Oregon Orthoptera. As of January 17, 2020, there are 136 species of grasshopper and crickets recorded in Oregon but this number can and probably will increase with the help of devoted volunteers.

What data am I collecting?

When you collect data on an Orthoptera species, here's the information I would like those volunteering will collect.

  1. Date
  2. Species (I'll identify it if you can't)
  3. Body Length and Wing Length measured in millimeters.
  4. Sex
  5. Age
  6. Habitat
  7. Accurate location
  8. Any addition notes if any not mentioned above.

These eight aspects cover any data needed to help me develop the outline to creating the Orthoptera field guide.

How can you prepare?

There are several ways for you prepare for the 2020 Orthoptera season. So here's what you can do.

  • I've created a current list of Orthoptera species in Oregon in the following link. It also includes a list of genera that are influx so the genus itself counts as "one" species until new information comes forth.
    https://www.inaturalist.org/lists/2318515-Orthoptera-of-Oregon

  • Start plotting out places prior to grasshopper season that you should go to. If you want to find a particular species, you can look up the species on iNat and see what times of the year they are spotted.
  • Get your gear ready early. When I go out and catch grasshoppers, I always make sure I have my ruler, phone (for photos) and my bamboo butterfly net on me.
  • If you decide to join the group and help me collect data, I'm trying to think of efficient methods of collecting your data. You can add your data to the notes of your iNat observation. However that information might be lost so I created a Google Form that you can fill out if you prefer that, I'll just need to send it to you. If you just want to e-mail me in general, I'll do it.
  • Try to learn beforehand the main groups of Orthoptera and how to best photograph them for identification. For example, Oedipodinae (Band-winged Grasshoppers) best need a wing shot for identification along with a lateral shot while Melanoplinae (Spur-throated Grasshoppers) needs a shot of male genitals for accurate identification.

Thanks for taking the time to read this, I hope you have just as much interest as I am to document Orthoptera in Oregon. If you have any questions, feel free to comment and I'll get back with you as soon as possible.

Publicado el enero 17, 2020 06:08 TARDE por birdwhisperer birdwhisperer | 3 comentarios | Deja un comentario

23 de enero de 2020

Identifying Mexican and Central American Red-tailed Hawks

Recently, I've made several posts in regards to Red-tailed Hawks and it's subspecies. In my first journal post, "Identifying US and Canada Red-tailed Hawks", I explained in thorough detail the differences between Red-tailed Hawk subspecies in that area. I've had thoughts to do a similar post for countries not mentioned above as well and now I'm doing it. But also note that Mexican, Caribbean and Central American Red-tails are very ill-studied and future research may prove invalidity of subspecies or more depending on what researchers find. INaturalist is a great platform to find out the variety of the species so perhaps a little description of each subspecies may help users. All information used here is gathered from photos on iNat/ebird and research papers (usually the describing paper) in regards to the subspecies. Here we go!

Non-Migratory Caribbean Subspecies

The Red-tailed Hawk lives on nearly every island in the Greater Antillean and are vagrant to the Lesser Antillean (probably US migrants though). There are 2 subspecies.

Jamaican Red-tailed Hawk (Buteo jamaicensis jamaicensis)

Range: Jamaica, Hispaniola, Puerto Rico and norther Lesser Antillean Islands

Head: Normally rich brown with no markings. Throat is dark.

Upperparts: Same brown as head with blackish-brown mottling. White scapular mottling light.

Underparts: Bellyband variable from lightly to heavily-marked. Bellyband is normally blackish and often has barring. Rufous wash often occurs on the sides of the breast. Legs are typically unmarked. Breast and legs are white but can have a buff wash.

Wings: Patagials very thin and often has white markings encroaching on it.

Tail: Tail lacks tail banding and subterminal band is very thin. White uppertail coverts.

Morphs: Only light

Juvenile: Heavily marked below, white breast and considerable amount of white in the face.

Notes: Nominate subspecies, described in 1788. Comparing photos on iNat and eBird, I believe there's a good chance there might be geographic variation in the subspecies. I noticed individuals in Jamaica had very thin patagials and lightly to moderately marked bellybands. However, Hispaniola and Puerto Rico hawks, nearly every individual had incredible heavy bellybands, some where the entire belly was black. Patagials were also thicker and breast had rufous, not buff, tones. Subterminal band also appears broader in Puerto Rican individuals. I suspect some research needs to be done.

Photos: (1) Lightly-marked Jamaican Red-tailed Hawk -- Jamaican form (2) Moderately-marked, thick patagial Jamaican Red-tailed Hawk -- Hispaniola form (3) Heavily-marked, thick patagial Jamaican Red-tailed Hawk -- Puerto Rican form (4) Juvenile Jamaican Red-tailed Hawk -- Hispaniolan form

https://macaulaylibrary.org/asset/162664901#_ga=2.227092125.1609460285.1574228334-1175263981.1555651889
https://macaulaylibrary.org/asset/38523631#_ga=2.203165585.1609460285.1574228334-1175263981.1555651889
https://macaulaylibrary.org/asset/55235571#_ga=2.25765437.1609460285.1574228334-1175263981.1555651889
https://macaulaylibrary.org/asset/107772881#_ga=2.198387631.1609460285.1574228334-1175263981.1555651889

Cuban Red-tailed Hawk (B. j. solitudinis))

Range: Cuba, Bahamas and Isle of Pines.

Head: Quite variable. Most common head pattern is a rich brown unmarked head with dark throat but can have a darker malar or white throat. Some Bahama individuals have very pale, "washed out" heads.

Upperparts: Variable but is usually a shade darker than the head. White scapular mottling light to heavy depending on the darkness of the upperparts/head.

Underparts: Light to moderately-marked bellyband with rufous (Cuba) or white (Bahamas) breast. Rufous wash can occur on the sides of the breast. Rufous wash is usually present in the bellyband. Barring uncommon and does not occur on flanks.

Wings: Moderately prominent patagials, white unmarked underwing coverts.

Tail: Subterminal band moderately thick and red tail is usually lacks banding.

Morphs: Only light

Juvenile: Moderately to heavy bellybands with black markings on the sides of the breast making an incomplete breast band.

Notes: Appears to differ from jamaicensis by having thicker patagials, broader subterminal band and lighter bellybands. They are also darker dorsally and head coloring is more variable. Also keep in mind that Bahama individuals appear to be more variable than Cuban individuals and it may suggest geographical variantion but the variations are not nearly to the extent of jamaicensis on their islands.

Photos: (1) Heavily-marked, rufous-breasted Cuban Red-tailed Hawk -- Cuba form (2) Moderately-marked, rufous-breasted Cuban Red-tailed Hawk -- Cuba form (3) Pale-headed Cuban Red-tailed Hawk -- Bahamas form (4) Moderately-marked, bellyband washed Cuban Red-tailed Hawk -- Bahamas form (5) Heavily-marked, incomplete breast-banded juvenile Cuban Red-tailed Hawk -- Bahamas form

https://macaulaylibrary.org/asset/88368911#_ga=2.160507837.1609460285.1574228334-1175263981.1555651889
https://macaulaylibrary.org/asset/129586231#_ga=2.230238876.1609460285.1574228334-1175263981.1555651889
https://macaulaylibrary.org/asset/31512851#_ga=2.127675277.1609460285.1574228334-1175263981.1555651889
https://macaulaylibrary.org/asset/106931881#_ga=2.127675277.1609460285.1574228334-1175263981.1555651889
https://macaulaylibrary.org/asset/106447751#_ga=2.193553197.1609460285.1574228334-1175263981.1555651889

Non-Migratory Central American Subspecies

Central American hosts 7-8 different subspecies of Red-tailed Hawk and the variation between them is amazing. Also note that most non-migratory Central American subspecies are residents of the mountains and highlands. If you happen to see a Red-tailed in the lowlands, it's probably a migrant from the US.

Western Red-tailed Hawk (B. j. calurus)

Range: Resident and breeder to Baja California. Winter visitor throughout Mexico but recent evidence suggests that they migrate and winter all the way to Panama.

Head: Throat mostly dark, some have streaked, collared or white throats and these variations seem to occur more often in northern Canadian breeding areas or southwestern US deserts.

Upperparts: Very dark brown, white scapular mottling is light and barely visible comparative to other subspecies, however it is visible enough to use as an id feature to distinguish from other Buteo species.

Underparts: Perhaps the most variable subspecies in terms of underpart markings. Bellyband can vary from a few streaks and barring on the flanks to a thick black band across the belly with barring extending into the breast. Though typical bellybands have barring on the flanks and belly.

Wings: Almost all individuals have tawny or rufous underwings that contrast with the whit remiges. Patagials are dark and noticeably thick, making a huge "U" shape cut on the humerus region. If the bird is in wing, these two features are key to whether your Red-tailed is Western or not.

Tail: Incredibly variable from the "classic" all red-tail with thin subterminal band to a thickly banded tail with no distinct subterminal band. Also note where the wingtips end on the tail. Eastern/Northern Red-tails have wingtips barely extending past the uppertail coverts while calurus can extend from midway across the tail to the tail tips.

Morphs: Light, Rufous, Intermediate (only juveniles) and Dark. However light morphs dominate other morphs and from a compilation of photos I did for research about 96% of all calurus Red-tails are light morphs and 3% are rufous morphs.

Juvenile: Throat usually dark but younger individuals may have white throats that resemble borealis or abieticola. To distinguish light morphs from other subspecies, look for heavily marked bellyband and underwings. Only subspecies that have intermediate and dark morphs which is heavy markings on the breast (intermediate) or black underparts with white streaking, similar to Harlan's juveniles (dark).

Photos: (1) Dark-throated moderately-marked light morph calurus. (2) Tawny-breasted heavily-marked light morph calurus. (3) Lightly-marked calurus. (4) Dark morph juvenile calurus. (5) Heavily-marked rufous morph calurus. (6) Lightly-marked rufous morph calurus. (7) Flying molting very lightly-marked light morph calurus -- note thick patagials. (8) Flying typical light-morph calurus. (9) Flying dark morph calurus -- note that this was a breeder I observed all season and if you see something like this in the field and this is your only shot, best identify it as rufous/dark morph. (10) Dark morph calurus with very thick subterminal band.

Fuertes or Southwestern Red-tailed Hawk (B. j. fuertesi)

Range: Throughout northern Mexico with the range limits believing to be Durango and Tamaulipas.

Upperparts: Light to moderate whitish or buff scapular mottling.

Underparts: Very little to no bellyband and if markings do show, it's only two or three streaking marks. Western Mexican (aka Arizona) individuals appear to have more streaking (more being visually similar to a very lightly marked borealis) and even barring on rufous washed flanks.

Wings: Underwings completely white with the exception of thin but dark patagials and "chevrons" where the primary coverts end.

Tail: Tail is pale red with a thin subterminal band.

Morphs: Only light morphs.

Juvenile: Similar to borealis but with longer wings and bellyband has a distinct "V" shaped patterning where borealis is just streaking.

Notes: It is disputed if this is even a subspecies or just another form of borealis.

Photos: (1) Arizona fuertesi -- note slight rufous wash. (2) Arizona fuertesi on the far end of markings. (3) Flying Texas fuertesi on the far end of markings. (4) Flying Arizona fuertesi.

https://macaulaylibrary.org/asset/114896381#_ga=2.196605423.2114655241.1571538712-1175263981.1555651889
https://macaulaylibrary.org/asset/22509541#_ga=2.226865246.2114655241.1571538712-1175263981.1555651889
https://macaulaylibrary.org/asset/40878611#_ga=2.28777087.2114655241.1571538712-1175263981.1555651889
https://macaulaylibrary.org/asset/20812731#_ga=2.250607045.2114655241.1571538712-1175263981.1555651889

Sutton's Red-tailed Hawk (B. j. suttoni)

Range: Sierra de San Lazaro of Baja California

Head: Rich brown with dark throat or white throat.

Upperparts: Richly mottled upperparts with white scapular mottling light to moderate.

Underparts: Very little markings to the bellyband or can be absent overall. Typically has a rufous wash to the breast.

Wings: Dark, thick patagials with slight rufous wash to underwings.

Tail: Appears to be variable from brick red with very thin subterminal band to maroon with dense tail banding.

Morphs: Light and possibly dark.

Juvenile: Probably similar to calurus.

Notes: This is an incredibly understudied subspecies and perhaps not a subspecies. Neither iNaturalist nor eBird recognize the taxon but Avibase and Handbook of Birds of the World (HBW) however too. It is possible the subspecies is not well recognized because it was described by Dickerman (1993), quite some time after the American Ornithological Society (AOS) stopped doing assessments in their taxonomic updates. In a nutshell, the description of the subspecies was morphically intermediate between calurus and fuertesi, and measurably smaller. You can read what Dickerman said here -- https://www.jstor.org/stable/30054375?seq=1

Photos: (1) Possible Sutton's Red-tailed Hawk, note almost no bellyband. (2) Possible Sutton's Red-tailed Hawk, note rufous-washed breast. (3) Flying possible Sutton's Red-tailed Hawk.

https://macaulaylibrary.org/asset/66238481#_ga=2.131334927.1609460285.1574228334-1175263981.1555651889
https://macaulaylibrary.org/asset/180248911#_ga=2.24674746.1609460285.1574228334-1175263981.1555651889
https://macaulaylibrary.org/asset/141637341#_ga=2.231892639.1609460285.1574228334-1175263981.1555651889

Mexican Highlands Red-tailed Hawk (B. j. hadropus

Range: Varies by source. Presumed to be Mexican Highlands from Jalisco and Veracruz to Oaxaca. See notes.

Head: Rich rufous-brown with darker malar. White throat normally with collar.

Upperparts: Moderate to heavy white scapular mottling. Upperparts are a strong gray-brown.

Underparts: Light bellyband with dark teardrop-shaped streaking, though an absent bellyband (see notes) is not unusual. Flanks are very contrasting rufous compared to buff or white underparts.

Wings: Dark but thin patagials with rich buff underwings coverts. Banded remiges are well visible both dorsally and ventrally.

Tail: Variable in tail banding and color but it appears the main feature is, is that the 'subterminal band' is actually the tail tips with no visible red or white below the band.

Morphs: Light, rufous and dark. Differs from calurus rufous/dark morphs with white scapular mottling and black terminal band. See notes.

Juvenile: Unknown. See notes.

Notes: Incredibly understudied subspecies. The only published paper on the subspecies is the description paper (Storer 1962). He describes the range as being Jalisco to Oaxaca. Avibase and HBW claim the range goes to east coast of Veracurz. However no ebird photos of breeding Red-tails in hadropus purpose range show any of the features Storer claimed to be diagnostic. The individuals photographed in Jalisco, Guerrero and Socorro looked very much like kemsiesi or perhaps fuertesi. However a photo in Veracruz shows a Red-tailed that shows every feature Storer described in his paper and the features appeared to be consistent with all Veracruz and Puebla individuals. It is possible that hardropus is an eastern Mexican subspecies not western. However, a breeding dark morph individual was photographed in Guerrero and a rufous morph in Veracruz. Storer reported both hadropus and kemsiesi having dark morphs and we know fuertesi only occurs in light morph. So assuming that western Mexican Red-tails are not hadropus, it can be hypothesized that kemsiesi is not geographically separated by the Isthmus of Tehuantepec as originally believed and is the subspecies breeding from Jalisco to Nicaragua. Also in support of this hypothesis is the fact no hadropus individuals were photographed in western Mexico and vice versa for eastern Mexico. In southern Mexico, only one juvenile has been photographed in Puebla, subspecies undetermined but it may possibly be hadropus. The individual showed a heavy bellyband, dark throat, broader patagials and barred flanks. You can read Storer's paper here: https://sora.unm.edu/sites/default/files/journals/condor/v064n01/p0077-p0078.pdf

Photos: (1) Adult Veracruz Mexican Highlands Red-tailed Hawk that appears almost identical to Red-tailed Storer described. (2) Adult Veracruz rufous morph probably Mexican Highlands Red-tailed Hawk. (3) Adult Michoacán kemsiesi/hadropus Red-tailed Hawk. By range it should hadropus but it appears eerily similar to kemsiesi. Look up proceeding subspecies to compare photos. (4) Adult Michoacán dark morph kemsiesi/hadropus Red-tailed Hawk. Note tail tips is the subterminal band. (5) Colima kemsiesi/hadropus Red-tailed Hawk, note again the subterminal band. (6) Puebla juveniles kemsiesi/hadropus Red-tailed Hawk.

https://macaulaylibrary.org/asset/109677071#_ga=2.111764932.1963945058.1577381479-1175263981.1555651889
https://macaulaylibrary.org/asset/169673331#_ga=2.224944346.1963945058.1577381479-1175263981.1555651889
https://macaulaylibrary.org/asset/61597241#_ga=2.124291402.1963945058.1577381479-1175263981.1555651889
https://macaulaylibrary.org/asset/106854071#_ga=2.188246760.1963945058.1577381479-1175263981.1555651889
https://macaulaylibrary.org/asset/167437601#_ga=2.152134265.1963945058.1577381479-1175263981.1555651889
https://macaulaylibrary.org/asset/31544241#_ga=2.213606740.1963945058.1577381479-1175263981.1555651889

Kemsies Red-tailed Hawk (B. j. kemsiesi)

Warning! Theoretically, there is no "common name" for this subspecies but every other subspecies besides this one does and Kemsies is the Latin translation of the scientific name (Kemsies was a Yellowstone park ranger). I'm wondering if a better name can be applied such as the Sierra Madre Red-tailed Hawk to describe it's range.

Range: Chiapas, Mexico to northern Nicaragua. Though photographic evidence suggests that the Isthmus of Tehuantepec is a geographic "break" in their breeding range and they may live all the way up into Jalisco. See notes.

Head: Dark brown. Differs from other subspecies with dark auricular and cheek, not malar.

Upperparts: Light to moderate white scapular markings. Very dark charcoal-brown upperparts.

Underparts: Buff or white underparts with little or no bellyband. Whatever streaking they may have will be more prominent on the flanks. Belly can have a rufous wash that forms a "bellyband".

Wings: Patagials dark and moderately thick. Buff unmarked underwing coverts. Remiges are prominently banded both ventrally and dorsally.

Tail: Variable from brick red to pale chestnut-red. Subterminal band broad and prominent. Tail banding not uncommon. Uppertail coverts are whitish including bases to interior rectrices.

Morphs: Light, rufous and dark. See notes.

Juvenile: Variable, not studied hard so differences from other subspecies is uncertain.

Notes: Photograph evidence suggests that the subspecies range is not restricted the Nicaragua lowlands and the Isthmus of Tehuantepec and it may very well breed in western Mexico. Second issue about range is that most authorities claim kemsiesi range ends in Nicaragua but ebird reports that subspecies costaricensis is the expected subspecies for Honduras, El Salvador and Nicaragua and kemiesi being rare. However I cannot find any individuals photographed and identified as costaricensis appearing similar to "real" costaricensis in their breeding range in Costa Rica and Panama. Most of the reporting are probably misidentifications. They are variable in morphs and there appears to be quite a few rufous and dark morph breeders in their range. However it has been undetermined how dark morphs differ from hadropus. Dark morphs do differ from calurus with white scapular markings not buff or solid brown. Rufous morph differences are unknown as well. Juveniles are hard to place on subspecies especially when most juveniles photographed in the subspecies range are in spring, suggestable that some may not be resident birds. Further study is needed to determine differences.

Photos: (1) Adult Chiapas Kemsies Red-tailed Hawk -- textbook example. (2) Adult Guatemala Kemsies Red-tailed Hawk. (3) Adult Guatemala Kemsies Red-tailed Hawk. (4) Adult Honduras kemsiesi/costaricensis Red-tailed Hawk -- this bird was identified as costaricensis on ebird however I see no features supporting it. (5) Juvenile El Salvador kemsiesi/costaricensis Red-tailed Hawk

https://macaulaylibrary.org/asset/138491501#_ga=2.174818018.1963945058.1577381479-1175263981.1555651889
https://macaulaylibrary.org/asset/158952051#_ga=2.212412884.1963945058.1577381479-1175263981.1555651889
https://macaulaylibrary.org/asset/106475491#_ga=2.191522538.1963945058.1577381479-1175263981.1555651889
https://macaulaylibrary.org/asset/22208401#_ga=2.224013915.1963945058.1577381479-1175263981.1555651889
https://macaulaylibrary.org/asset/109084891#_ga=2.178817764.1963945058.1577381479-1175263981.1555651889

Costa Rican Red-tailed Hawk (B. j. costaricensis)

Range: Though all authorities (including the Clements Checklists) claim this subspecies range to be Costa Rica and western Panama, ebird reports having this subspecies being the expected subspecies throughout central America from Honduras and El Salvador to Panama, though it is expected that most if not all the sightings north of Costa Rica are actually kemsiesi.

Head: Solid rich brown-rufous. Collared throat, often with brown streaking on the white throat. Throat can be almost solid brown.

Upperparts: Light to almost no white scapular mottling. Very dark charcoal-brown upperparts with dark feather tips, giving a mottled appearance.

Underparts: Unique to the subspecies. White breast and very rufous-pink (like rotisserie chicken color, there I said it) belly. If a bellyband is present, it is lightly marked and the markings on the contrast line of the white breast and rufous belly.

Wings: Dark, thick patagials with rich rufous underwing coverts, identical in color with belly and in flight, makes the white breast more distinctive. Remiges are prominently banded.

Tail: Not quite as variable as other subspecies, seems to be relatively consistent for the tail to be between rotisserie chicken rufous to slightly redder but not quite the classic brick red. Tail normally has no subterminal band but a broken or thin subterminal band can be present in some individuals.

Morphs: Light

Juvenile: Like adults except throat is whiter. Bellyband can be heavy but the markings are pale. There is prominent streaking dribbling into the sides of the breast.

Notes: This is perhaps the most unique-looking subspecies in the entire Red-tailed spectrum.

Photos: (1) Adult Costa Rican Red-tailed Hawk. (2) Adult Costa Rican Red-tailed Hawk flying. (3) Rotisserie-colored Costa Rican Red-tailed Hawk. (4) Juvenile Costa Rican Red-tailed Hawk

https://macaulaylibrary.org/asset/30417271#_ga=2.125471050.1963945058.1577381479-1175263981.1555651889
https://macaulaylibrary.org/asset/58612971#_ga=2.118759753.1963945058.1577381479-1175263981.1555651889
https://macaulaylibrary.org/asset/34359881#_ga=2.211914324.1963945058.1577381479-1175263981.1555651889
https://macaulaylibrary.org/asset/153568961#_ga=2.117137862.1963945058.1577381479-1175263981.1555651889

Mexican Island Endemic Subspecies

There are two subspecies of Red-tailed Hawks that are endemic, meaning they live nowhere else, to offshore Pacific Islands in Mexico.

Tres Marias or Smoky-colored Red-tailed Hawk (B. j. fumosus)

Range: Tres Marias Island chain off the coast of Nayarit.

Head: Dark brown overall, including throat.

Upperparts: No scapular mottling. Dark brown upperparts the same color as the head.

Underparts: Dark brown-rufous mottled breast with rufous barring belly and flanks.

Wings: Dark, thick patagials with heavily marked underwing coverts.

Tail: Fairly consistent, rufous tail with thin or no subterminal band.

Morph: Rufous

Juvenile: Like adults except throat is white and collared and tail is finely banded.

Notes: Understudied subspecies as very few photos have been obtained (ebird has none). It may be possible that light or dark morphs exist but because of it's range isolation it is hard to obtain photos. To our current knowledge, only "rufous" morphs exist and is explanatory to the secondary name Smoky-colored Red-tailed Hawk.

Photos: (1) Adult Tres Marias Red-tailed Hawk. (2) Flying adult Tres Marias Red-tailed Hawk. (3) Juvenile Tres Marias Red-tailed Hawk.

https://www.inaturalist.org/observations/5274184
https://www.inaturalist.org/observations/350811
https://www.inaturalist.org/observations/30759604

Socorro Red-tailed Hawk (B. j. socorroensis)

Range: Socorro Island off the coast of Colima

Head: Solid brown, best described in my words as the discoloration in old milk chocolate.

Upperparts: Solid brown like the head with no scapular mottling.

Underparts: Bellyband lightly-marked with smoky-tawny underparts.

Wings: Unknown in rufous morphs. Dark morphs have solid dark underwing coverts.

Tail: Unmarked brick red tail with very broad subterminal band. Uppertail covert color unknown.

Morph: Light morphs (only juveniles), rufous and dark, though dark appears much more common.

Juvenile: Much more variation than adults. Intermediate morphs appear most common and have a arid dirt color with pale spotting on the marginal coverts. Light morphs are very heavily-marked with only a small patch of the breast white. Some appear to have very heavy upperpart spotting while others show scalloped marginal coverts.

Notes: Understudied subspecies and only photos of the subspecies occur on iNat. It's possible that light morph adults exist but range isolation and sensitivity limit a person's ability to study them.

Photos: (1) Adult dark morph Socorro Red-tailed Hawk. (2) Adult lightly-marked rufous morph Socorro Red-tailed Hawk. (3) Flying adult dark morph Socorro Red-tailed Hawk. (4) Juvenile intermediate morph Socorro Red-tailed Hawk. (5) Juvenile spotted Socorro Red-tailed Hawk

https://www.inaturalist.org/observations/7454181
https://www.inaturalist.org/observations/13893705
https://www.inaturalist.org/observations/13893690
https://www.inaturalist.org/observations/25413752
https://www.inaturalist.org/observations/30520000

Migratory Subspecies

There are several subspecies that migrate into Mexico and Central America but do not breed in area. There are three migratory or wintering subspecies.

Eastern Red-tailed Hawk -- Buteo jamaicensis borealis

Range: Confirmed sightings includes several in Costa Rica, Tamaulipas, Quintana Roo and Cayman Islands, but probably migrates throughout Central America, eastern Mexico and Greater Antillean.

Head: White supercilium is common. Throat is usually white, streaked or collared; dark throat is rare. Malar/cheek region usually dark.

Upperparts: Scapulars are moderately to heavily mottled white.

Underparts: Lightly to moderately marked bellyband. Barring occurs often on the flanks, rarely anywhere else. Breast almost always white but tawny does occur.

Wings: No rufous on the underwings. Patagials are thin or dull. Limited underwing markings.

Tail: Nearly all individuals have white uppertail coverts. Subterminal band thin to moderate. Partial or incompletely tail banding is uncommon. Nearly all individuals have white tips to the tail.

Morphs: Only light.

Juvenile: Throat almost always white, supercilium often white, bellyband light to moderately-marked.

Photos -- (1) Clear-cut example of borealis. (2) Lightly-marked streak-throated borealis. (3) Clear-cut flying example of borealis. (4) Flying moderately-marked streak-throated borealis.

https://macaulaylibrary.org/asset/35716511#_ga=2.25563518.2114655241.1571538712-1175263981.1555651889
https://macaulaylibrary.org/asset/51359071#_ga=2.267893197.2114655241.1571538712-1175263981.1555651889
https://macaulaylibrary.org/asset/49386431#_ga=2.230545887.2114655241.1571538712-1175263981.1555651889
https://macaulaylibrary.org/asset/96071241#_ga=2.65992173.2114655241.1571538712-1175263981.1555651889

Krider's Hawk -- B. j. kriderii

Range: No confirmed reports in Mexico or Central America but there are many sightings along the Rio Grande in Texas, and water isn't hard to cross for hawks.

Head: Varies but is normally very whitish. Palest form has nearly completely white head. Darkest form has dark cheek and crown.

Upperparts: Heavy white scapular mottling and scalloping pattern is well defined on the rest of the upperparts.

Underparts: Little to no markings on the underparts and whatever markings an individual may have will be a few streaking. Underparts may have a buffy look, especially when compared side-by-side with the incredibly similar light morph Harlan's.

Wings: Patagials nearly none existent and thin with completely white underwing coverts. When compared to Harlan's look for buffy underparts, banded remiges and reddish-white tail with no other markings.

Tail: Variable with half of the tail being red to completely white. If the rectrices have a white base and reddish tail extends past half the tail, that's a solid candidate for Eastern X Krider's intergrade.

Morphs: Light only.

Juvenile: Heads are typically whiter than adults and white upperparts mottling is even more noticeable. Tail with whitish with banding.

Photos -- (1) Dark Krider's Hawk. (2) Lightest form Krider's. (3) Flying intermediately dark Krider's -- note buffy underwings. (4) Juvenile Krider's. (5) Flying juvenile Krider's.

https://macaulaylibrary.org/asset/109267071#_ga=2.59160046.2114655241.1571538712-1175263981.1555651889
https://macaulaylibrary.org/asset/30529471#_ga=2.221634011.2114655241.1571538712-1175263981.1555651889
https://macaulaylibrary.org/asset/109377501#_ga=2.24056441.2114655241.1571538712-1175263981.1555651889
https://macaulaylibrary.org/asset/37820921#_ga=2.223885528.2114655241.1571538712-1175263981.1555651889
https://macaulaylibrary.org/asset/76574721#_ga=2.223885528.2114655241.1571538712-1175263981.1555651889

Harlan's Hawk -- B. j. harlani

Range: Only two confirmed sightings in Mexico (Baja California Sur and Durango) but there are many sighting along the Rio Grande so it's easy to assume they winter in Tamaulipas.

Overall body difference: Besides I find Harlan's such a unique bird, I'm not going to go through all the body part features. All you need to know is; they are either black and white or cool brown and white, tail is incredibly variable from reddish mottled to brown mottling to white with reddish tip. Light morph adults can appear incredibly similar Krider's and are often misidentified in Western US but they differ with colder brown tones, white tail with mottled tail (usually in light morphs) and lack of buffy underwings. Harlan's also frequently show unbanded remiges and thicker patagials. Some Harlan's have Some juveniles can appear very calurus-looking but they differ with having "V" shaped tail banding.

Morphs: Around 84% are dark morph or intermediate morphs and the rest are light.

Photos -- (1) Light morph Harlan's. (2) White-spotted dark morph Harlan's. (3) Same dark morph Harlan's but shows awesome tail pattern. (4) Intermediate morph Harlan's. (5) Flying juvenile intermediate morph Harlan's. (6) Dark morph Harlan's.

https://macaulaylibrary.org/asset/73157161#_ga=2.28774783.2114655241.1571538712-1175263981.1555651889
https://macaulaylibrary.org/asset/126158571#_ga=2.58512745.2114655241.1571538712-1175263981.1555651889
https://macaulaylibrary.org/asset/126158351
https://macaulaylibrary.org/asset/114075691#_ga=2.267317709.2114655241.1571538712-1175263981.1555651889
https://macaulaylibrary.org/asset/84836181#_ga=2.65919597.2114655241.1571538712-1175263981.1555651889
https://macaulaylibrary.org/asset/119476081#_ga=2.65919597.2114655241.1571538712-1175263981.1555651889

Final Words and Overview

So there you go, all 15 Mexican, Central American or Caribbean Red-tailed Hawk subspecies. Most of endemic, non-migratory subspecies are poorly studied and as new information comes forth, we can better understand them. I believe iNaturalist is a great platform to find out this research and it appears we have a very strong Mexican community compared to ebird.

I believe that southwestern Mexico should be a place closely observed to see if it's true that Kemises' Red-tails really do reside there, along with Baja California Sur and see if the Sutton's Red-tailed really deserves subspecies status.

Also, another shoutout to all of those contributing their sightings and sharing their thoughts on subspecific ids. I hope this post will help you feel just a little more confident in identifying Red-tails.

Literature Sourced:

  • Clark, William S. (2014) -- Harlan's Hawk differs from Red-tailed Hawk, especially in plumages
  • Dickerman, Robert W. (1994) -- Undescribed Subspecies of Red-tailed Hawk from Baja California
  • Ligouri, Jerry (2004) -- Dark Red-tailed Hawks
  • Ligouri, Jerry and Brian L. Sullivan (2010) -- A Study of Krider's Red-tailed Hawk
  • Ligouri, Jerry and Brian L. Sullivan (2014) -- Comparison of Harlan's with Western and Eastern Red-tailed Hawks
  • Storer, Robert W. (1962) -- Variation in the Red-tailed Hawks of Southern Mexico and Central America
  • Wheeler, Brian K. (2018) -- Birds of Prey of the East
  • Wheeler, Brian K. (2018) -- Birds of Prey of the West

Publicado el enero 23, 2020 05:46 TARDE por birdwhisperer birdwhisperer | 1 comentario | Deja un comentario