geographical ecology of Western Scrub Jays. The technical analysis is
quite frustrating to interpret given the amount of reference to
numerical analysis of which I am so unfamiliar! In general, it was
said that acorn production benefitted scrub jay population by
increasing reproductive success.
Does this also mean in a year that provides for poor acorn production
that the population of Western Scrub Jay may decline in the year that
follows?
https://docs.google.com/leaf?id=0B5dWTSbMv7AYY2MyMjAyMDMtOGM5Ny00NTg1LWE1MjAtMWM0MWVkZDVkYWE0&hl=en
Another title by Mary K. Coldren (ca. 1997)
http://txtbba.tamu.edu/accounts/scja/scjaacc.html puzzled me in that
it appeared to be questionable if Western Scrub Jays had the habit of
assisting with feeding at the nest. No one knows this? That seemed
odd to me especially since the mapping of the Western Scrub Jay
appears south in Mexico to the North in Western Washington.
Evidently, Western Scrub Jay species differ given recent genetic
findings (2003?). (Surprise to me again, there...) It was said that
the only species known to help at the nest were the Mexican species,
A. c. sumichrasti.
Now I have to find pictures of a Mexican Western scrub jay - A. c.
sumichrasti - and find pics of the other variety of sub-species of
Western Scrub jay. I don't think my Peterson's makes the difference on
p. 284, c. 2008.
The wiki was helpful.
http://en.wikipedia.org/wiki/Western_Scrub_Jay ___and this
description___ http://www.avianweb.com/westernscrubjays.html __of
differences in sub-species was good reading.
Genetics is so confusing!
"Judging from mtDNA NADH dehydrogenase subunit 2 sequence data, it
appears there are two clades, namely a Pacific one west and one east
of the Rocky Mountains; the relationships of populations in the latter
are not resolvable to satisfaction. Thus, it is fairly likely the
Western Scrub-Jay is actually another two distinct species, one
belonging to the Pacific and another one to the eastern lineage(s);
the latter's ancestors apparently gave rise to the Florida Scrub-Jay
as well. Paleogeography of the Rocky Mountains range supports this
scenario.
Inland birds (Woodhouse's Scrub-Jay, woodhouseii group and
Sumichrast's Scrub-Jay, sumichrasti group) differ in plumage (paler
blue above, with an indistinct and usually incomplete breast band)
from the coastal birds (California Scrub-Jay, californica group) which
are darker blue above with a strongly defined - but not necessarily
complete - blue breast band. The three groups also differ in ecology
and behavior. The beaks of the California and Sumichrast's groups are
strong and hooked at the tip, as they feed on acorns, whereas the
pinyon-nut feeding Woodhouse's group has a longer, slimmer and
straighter bill with little or no hook.
Each group contains a number of subspecies..."
--http://www.avianweb.com/westernscrubjays.html
It is so much fun to learn something new.
(Notes: "Helping at the nest has been well documented for a closely related species, the Florida Scrub-Jay (A. coerulescens). However, among Western Scrub-Jays, this behavior has only been documented for a population in southern Mexico (A. c. sumichrasti) (Peterson & Burt 1992)."
"Pitelka (1951) and Oberholser (1974) classified the earlier nonbreeding wanderers found in the Panhandle as A. c. woodhouseii, which breed as close as northeast New Mexico and southeast Colorado. However, vocal analysis suggests that the Scrub-Jays that breed in the Panhandle may be more closely allied with A. c. texana of the Edwards Plateau (Coldren 1996). One possible explanation is that birds from the Edwards Plateau traveled north along the Caprock Escarpment to become the breeding year-round residents, while young birds from New Mexico and Colorado sporadically wander altitudinally to become the winter birds reported by Pitelka (1951), Oberholser (1974), and various checklists. Until more research is done, this question remains unanswered."
Text by Mary K. Coldren (ca. 1997)
http://txtbba.tamu.edu/accounts/scja/scjaacc.html November 10, 2010 Accessed, Western Scrub-Jay
* Peterson, A. T. and D. B. Burt. 1992. Pylogenetic history of social evolution and habitat use in the Aphelocoma jays. Anim. Behav. 44:859-866.
"Judging from mtDNA NADH dehydrogenase subunit 2 sequence data, it appears there are two clades, namely a Pacific one west and one east of the Rocky Mountains; the relationships of populations in the latter are not resolvable to satisfaction. Thus, it is fairly likely the Western Scrub-Jay is actually another two distinct species, one belonging to the Pacific and another one to the eastern lineage(s); the latter's ancestors apparently gave rise to the Florida Scrub-Jay as well. Paleogeography of the Rocky Mountains range supports this scenario."
"Inland birds (Woodhouse's Scrub-Jay, woodhouseii group and Sumichrast's Scrub-Jay, sumichrasti group) differ in plumage (paler blue above, with an indistinct and usually incomplete breast band) from the coastal birds (California Scrub-Jay, californica group) which are darker blue above with a strongly defined - but not necessarily complete - blue breast band. The three groups also differ in ecology and behavior. The beaks of the California and Sumichrast's groups are strong and hooked at the tip, as they feed on acorns, whereas the pinyon-nut feeding Woodhouse's group has a longer, slimmer and straighter bill with little or no hook.
Each group contains a number of subspecies. "Sumichrast's Scrub-Jay" stands apart from the others in its altruistic breeding behavior, unlike the others) stand apart; its remaining races are generally not quite as pale but have washed-out colors with indistincly marked borders. Certainly, some gene flow among these populations occurs, but while the hybrid zone between the californica and woodhouseii groups is very limited." --http://www.avianweb.com/westernscrubjays.html Accessed November 10, 2010.
"Birds along the Pacific Coast are sharply marked, with a bold blue necklace against white underparts and a distinct brown back. Great Basin birds (called "Woodhouse’s" scrub-jay and sometimes considered to be a different species) are grayer overall, the necklace is less contrasting, and the back patch is grayish blue." --http://www.allaboutbirds.org/guide/Western_Scrub-Jay/id
Hooked bill study in Pac NW includes a flyer from USGS from Andrew C. Revkin November 9, 2010.
More Crow beak deformities Pacific Northwest and Alaskan beak deformities
How USGS can determine that there is an issue with Crow beaks is my question as various authors have indicated that there are slight curves in crow beaks anyway. I suppose they may be attributing this to other species current issues. However, "On the basis of 186 Northwestern Crows captured at six sites in
Alaska during 2007 and 2008, we estimated the prevalence of beak deformities in adults to be 16.9 ± 5.3%, the highest rate of gross deformities ever recorded in a wild bird population." - October 2010, The Auk 127(4):882−898, 2010.
Yearly totals in Washington from Matt Bartels:
At this point last year, Acorn Woodpecker had been reported only in Klickitat County. This year it has been reported in 9 counties [10 if you include this week's report from Pacific Co.] As for Lewis's Woodpecker & Western Scrub-Jays -- the county level year list perspective doesn't seem to reveal anything unusual -- only one more county reporting each compared with last year (with a couple more counties like to be added in the final update at the end of the year).
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