Wednesday, November 18, 2009

Merlin or Hawk and migration

BirdWeb's classification system for abundance when left BLANK - "Has occurred less than annually (if at all) in very small numbers or at great intervals."  Determinations of abundance or frequency are not solely reflected by a singular birding guide and, in fact, abundance and frequency in general may not be addressed for each of the subspecies of Merlin excepting migration and breeding.




Merlins are commonly found throughout western Washington, including urban areas, in winter and during migration. -BirdWeb

Upon searching the Archives,  a post from December 13, 2007, [URL ref: FRG] indicated that Richardson's Merlin in Western Washington is "pretty rare".  The Richardson's Merlin was also referenced as the "Prairie Parkland" in this post. [ Boreal ref. Tiaga URL.]

Most posts searched in the Archives reference the Taiga Merlin, a brown colored Merlin, which is decidedly the most common, as is the black in Western Washington. A post from British Columbia ref. "Merlin Prairie Falcon"?  I believed the Prairie Falcon to be different from that of a Merlin of three varieties: [ typonymic, subspecific, color description] Prairie - richardsonii, a very light grey; Pacific or Black- suckleyii, and  Taiga - columbaris, brown. The Archives and have found 27 references to the Richardson's variety, 76 references to the Taiga variety.  The only Archive post for term Merlin suckleyii URL. Merlin Pacific 517 or Merlin Black 1242.

At 12 feet from the bird, my visualization of its wing shape and flight pattern indicated strongly that this bird was not a hawk. But, I could be wrong. I did not get to see his head, eyes or full breast, as his head was tucked and facing away from me and he was quick! He swooped in from either the top of a nearby tree or from  above the tree.  I did not see him until he was 1/2 of the way down the side of the trunk, 10 feet above the ground. He flew nearly parallel and vertically to the tree trunk where he flew forward 6ft and likely scooped up a Junco 2 ft off of the ground. A small group of 15-20 Junco's were feeding in this lightly treed area. Another group of 10 or so Juncos were feeding 30ft away in another lightly treed, brushy spot. An alert was called that sounded like a Steller's Jay.  I thought the alert was due to the squirrel that had wandered inside the group's feeding area.  I saw a flash of his underside after he gained my attention, which was fluffy and white on his undertail as he picked up a Junco or ? tip toed and stretched out his legs mid-air for nothing? He then flew sharply to his right 6ft. which was directly in front of me by much less than 12 feet and was 3ft off of the ground.  He had smooth feathers on his backside which were a very very light shade of grey.  He sharply turned left again for 8ft or so where he finally turned again right picking up altitude all the while from 3ft off of the ground to 5'  to 8ft where he flew outside of my vision.  I will have to study Sharp-shinned hawks much further, obviously.

 "To get a positive ID, you'd need to see all five tails bands (all five bordered by dark), the presence of anterior barring on the outermost primary and complete barring on the second most distal spot on the posterior vane of the outermost primary."

     "Wheeler and Clark's Photographic Guide lists male sharp-shinned's as being 9-11 inches long, and weighing 3-4 ounces.  They show a nice picture of the back view on page 34, photo SS05."

    "Kate Davis, Falcons of North America (2008) lists a male Merlin as 9 to 11 inches long as well, and weighs 5.6 to 6 ounces.  So if one were looking for the smaller of the two, the sharp-shinned actually weighs a good bit less."

There was this recent post from the Archives which held a link for photographs of Merlin's. There are others that were sent to me in emails that I will have to dig out and place links to here, as well as book references for hawks and raptors.

  • "Hawks in Flight" URL
  • Raptors of western North America by Brian K Wheeler, Princeton University Press
  • Kate Davis, Falcons of North America (2008) 

The mapped area presented as a guide on BirdWeb suggest that the migration of (Tiaga) Merlin more closely matches the central area of Washington along the western most portion of the mountain range and does not include a migratory range of Thurston County for the Richardson's variety, but the brown Tiaga migration into "the US, Central America, and northern South America." [Prairie Merlins occur in the state, passing through in migration. -BirdWeb] The Patuxent Center indicates that the Prairie Merlin, "Breeder and resident in prairies of south-central Canada and the upper Midwest of the United States with some moving south to New Mexico." What is 50 miles to a bird that travels from Canada to Central America or Mexico during migration?

Given the little guide information that I have absorbed through 5 birding guides and BirdWeb I can say that the migratory pattern's of the Tiaga Merlin have been studied, somewhat?, whereas the Prairie Richardson's variety has not much information on migration in the birding guides. I will have to keep studying to determine. It it also good to note that the varieties interbreed in Canada. [ref. Canada, Merlin, TWET].


[*Contrary to BirdWeb, the Merlin is not Uncommon West of the Cascades per Tweeters Alerts Admin. Nov. 14, 2009 http://www.birdweb.org/birdweb/bird_details.aspx?value=search&id=112 
UNCOMMON meaning=" Found in small numbers, and usually—but not always—found with some effort in appropriate habitat at the right time of year".]

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