Subject: Cascadia Hummingbird Report - 4/19/2001
Date: Apr 20 08:04:05 2001
From: WAYNE WEBER - contopus at home.com


Mike, Tweeters, and OBOLinks,

I believe your characterization of the spring migration of Rufous
Hummingbirds as being bimodal (i.e., having two peaks) is inaccurate
when applied to south coastal B.C., although it may accurately
describe the situation in coastal Oregon. This is based on my personal
experience of more than 30 years birding around Vancouver, BC.

Yes, males do tend to arrive at least 2-3 weeks earlier than females.
However, in most years there is one extended "migration peak" lasting
from April 10 or 15 to early May, which consists of mostly males in
the early weeks and mostly females in the later weeks.

One of your correspondents on Thetis Island, BC referred to a "peak"
on March 25. In the Vancouver area, in most years, I would say that no
more than 10% of the Rufous population has arrived by March 31. By no
means is there ever a "peak" at Vancouver before about mid-April.

Please keep in mind that there is a great latitudinal distance between
southern Oregon and south coastal BC. The first arrival Rufous
Hummers, and the migration peak, are both about a month later at
Vancouver than they are at, say, Coos Bay. The vanguard of male Rufous
Hummers is usually present by mid-to-late March in south coastal BC,
but the vanguard is several weeks in advance of the bulk of migrants.

Rufous Hummers may arrive somewhat earlier in the Victoria area and
the southern Gulf Islands, which are farther south than Vancouver and
a bit milder, but your picture of a bimodal migration peak, with a
peak of males in late March, is quite inaccurate when applied to the
Vancouver area.

For partial documentation, I will quote some data from Volume 3 of
"The Birds of British Columbia" by Campbell et al. The earliest large
count of Rufous Hummers for BC is 50 birds at Royal Oak (Victoria) on
April 11, 1954. Another large count is 30 birds on Galiano Island on
April 12, 1981. These dates would be considered early by Vancouver
standards; the peak counts are usually in the last 2 weeks of April.
Many of the "first arrival" dates cited in Campbell et al. are in
April.

The book also states unequivocally that "the main movement occurs in
April on the coast and in May in the interior", with which I would
agree. There is no March peak, just a smattering of "early birds".

Sorry to differ with you, Mike, but I am just trying to assist you in
drawing a more accurate picture of Rufous Hummingbird migration. We
would have a much better picture in B.C. if someone had done daily
hummer counts from March through late May at a favoured location, but
I don't know of anyone who has done so.

Wayne C. Weber
Kamloops and Delta, BC
contopus at home.com



----- Original Message -----
From: Mike Patterson <celata at pacifier.com>
To: Multiple recipients of list OBOL <OBOL at BOBO.NWS.ORST.EDU>;
tweeters <tweeters at u.washington.edu>; hummnet
<HUMNET-L at LISTSERV.LSU.EDU>; Maine, Neal <nmaine at pacifier.com>; Cain,
Lee <lcain at astoria.k12.or.us>
Sent: Thursday, April 19, 2001 10:31 AM
Subject: Cascadia Hummingbird Report - 4/19/2001


> Cascadia Hummingbird Report - 4/19/2001
>
> Rufous Hummingbirds continue their spread into Alaska and the
> interior of British Columbia. A second pulse of birds was recorded
> from feeder counters in Waldport OR, Astoria OR and coastal British
> Columbia. There are usually two peaks to the migration, the first
> with more males the second with more females.
>
> Auke Bay, AK 04-14-2001 104 58.3833 134.6597
> Cheam Lk, BC 04-16-2001 106 49.1931 121.7556
> Terrace, BC 04-17-2001 107 54.5167 128.6058
>
> CALLIOPE HUMMINGBIRDS were reported from Spokane, WA on 4-10 and
> Eugene, OR on 4-15. BLACK-CHINNED HUMMINGBIRDS were reported from
> the Grand Valley, CO on 4-17 and 4-18 and from Grand Coulee, WA on
> 4-19. BROAD-TAILED HUMMINGBIRDS were also reported from Grand
> Valley, but date and location details were not provided.
>
> The Salmonberry (Rubus spectabilis) bloom on the Oregon/Washington
> coast has passed its peak. Rufous Hummingbirds were actively
> nectaring on on Twinberry (Lonicera involucrata) at the Neawanna
> Observatory. I have also received many reports of insect gleaning
> and hawking (most probably Chironomid midges).
>
> --
> Mike Patterson Alas, to wear the mantle of Galileo,
> Astoria, OR it is not enough to be persecuted
> celata at pacifier.com by an unkind establishment,
> you must also be right.
> ---Robert Park
> http://www.pacifier.com/~neawanna/humm/count.html