11/30/04
Respectable. That was the assessment Kent and I came up with
at the end of the walk. Glenn had peeled off a little
short of the finish line to go into Human Resources.
So it was left to Kent and me to finish out
the walk and make our proclamation. We could also have
added that it was a beautiful day for a walk, just a little
chilly at 56 F, but very comfortable.
We recorded 18 species, which is not a record, but
as we said, respectable. The record is 22 for week 48,
attained in 1999 and 2002. See the birds_epoch plot at
http://birdwalks.caltech.edu/bird_data/two_plots.htm.
Nothing really extraordinary this week. We did see
both a Cooper's and a Red-tailed Hawk, if you demand
that I come up with a highlight. We did hear
a Mockingbird, but I refuse to list a Mockingbird
as a highlight, although they have been absent
recently. Likewise for the Crow we saw.
I just can't bring myself to tell you that one
of our highlights was a Crow, although it seems very
likely that they got decimated by the West Nile virus.
No Scrub Jay or House Finch was the lowlight.
The stats:
The date: 11/30/04
The week number: 48
The walk number: 760
The weather: 56 F, sunny
The walkers: Alan Cummings, Glenn Hamell, Kent Potter
The birds (18):
Rock Pigeon
Mockingbird
House Sparrow
Mourning Dove
Anna's Hummingbird
Acorn Woodpecker
Crow
Starling
Yellow-rumped Warbler
Black Phoebe
Ruby-crowned Kinglet
Orange-crowned Warbler
Cedar Waxwing
Band-tailed Pigeon
Red-tailed Hawk
American Goldfinch
Yellow-chevroned Parakeet
Cooper's Hawk
Respectfully submitted,
Alan
11/30/04
http://birdwalks.caltech.edu
11/23/04
It was beautiful day for a bird walk and we
redeemed ourselves from last week's fiasco big time.
Not only did we get the 3rd highest total for a week 47 of the year,
19 species, but we also saw three rarities: Hermit
Thrush, White Pelican, and Northern Flicker.
Kent and I got the ball rolling when the Hermit
Thrush jumped up on a fence (briefly) down in the
maintenance yard. It later jumped up in a
tree and I got enough of a view of the tail to identify it.
Over the last 4 years we've averaged about one Hermit Thrush
sighting per year, so we are right on schedule, as I'm
pretty sure that's the first one of 2004.
Then on to the pelicans. We had just exited Tournament Park and
had been briefly joined by Kent's two eldest children,
Benjamin and Emily, who were participating
in a picnic in the park (along with Kent's wife Sue and
their other children, Timothy, Jonathan, Hannah,
and Daniel). I don't know which of the three possible
Potters saw the Pelicans first but they were a magnificent sight.
Six of them were lazily circling high overhead, overseeing the
construction of the new underground parking lot, I assume.
We've seen White Pelicans twice before on campus,
in 1988 and 1990.
Towards the end of the walk, Glenn and I saw the Northern Flicker.
(Kent had to break off early to go help a student with a
homework question.) This woodpecker is not nearly as rare as the pelicans
but is on a par with the Hermit Thrush for rareness.
So, to have 3 rare birds on the same walk is very unusual, to say the
least. What a day!
For a picture of how 19 species fits in for week 47
see the birds_epoch plot at
http://birdwalks.caltech.edu/bird_data/two_plots.htm.
If we could have spotted a House Finch, Mockingbird, and Crow,
we would have broken the record of 21 seen in 1990 and 1999.
The stats:
The date: 11/23/04
The week number: 47
The walk number: 759
The weather: 60 F, partly cloudy
The walkers: Alan Cummings, Glenn Hamell, Kent Potter
The birds (19):
Rock Pigeon
Scrub Jay
House Sparrow
Mourning Dove
Anna's Hummingbird
Acorn Woodpecker
Yellow-rumped Warbler
Black Phoebe
Hermit Thrush
Red-tailed Hawk
White-crowned Sparrow
White Pelican
Allen's Hummingbird
Ruby-crowned Kinglet
Bushtit
Band-tailed Pigeon
American Goldfinch
Northern Flicker
Gull, sp.
Respectfully submitted,
Alan
11/23/04
http://birdwalks.caltech.edu
11/16/04
The 43rd walk of 2004 and the 758th in the series
was noteworthy, for the wrong reason.
If you throw out 1986, when we were
just getting our bearings, the number of species seen
was the lowest ever for week 46 of a year.
We saw just 11 species and missed the Scrub Jay, Mockingbird,
Morning Dove, and Crow, among others.
See the birds_epoch plot at
http://birdwalks.caltech.edu/bird_data/two_plots.htm.
On the good side, it was a beautiful day in Pasadena,
sunny and about 73 F. Otherwise, maybe the less said
about this walk the better.
The stats:
The date: 11/16/04
The week number: 46
The walk number: 758
The weather: 73 F, sunny
The walkers: Alan Cummings, Kent Potter
The birds (11):
Rock Pigeon
House Sparrow
House Finch
Anna's Hummingbird
Acorn Woodpecker
Yellow-rumped Warbler
Ruby-crowned Kinglet
Bushtit
Orange-crowned Warbler
Raven
Band-tailed Pigeon
Respectfully submitted,
Alan
11/16/04
http://birdwalks.caltech.edu
11/9/04
It was a record-tying bird walk! We recorded
23 species, which tied the record for week 45 set
in 1999. It didn't exactly feel like we
were on a record pace as when we were walking
up Wilson toward the Broad building we still
were missing 5 of the common ones. And we
never did get a Scrub Jay. But little by little
we kept adding birds until - voila - a record.
See the birds_epoch plot at
http://birdwalks.caltech.edu/bird_data/two_plots.htm.
The weather was a cool, comfortable 61 F and very
cloudy. We all wished we had binoculars with larger objective
lenses because it was a dark day and seeing
the colors of the birds was a challenge with our minis.
I guess the highlight was seeing two species of hawk,
a Sharp-shinned and a Red-tailed. The Red-tailed was stirring
up a major convention of Band-tailed Pigeons.
We didn't see him bag one but we saw him try a couple
of times.
The stats:
The date: 11/9/04
The week number: 45
The walk number: 757
The weather: 61 F, cloudy
The walkers: Alan Cummings, Glenn Hamell, Kent Potter
The birds (23):
Rock Pigeon
Mockingbird
House Sparrow
Mourning Dove
House Finch
Anna's Hummingbird
Acorn Woodpecker
Crow
Yellow-rumped Warbler
White-throated Swift
Ruby-crowned Kinglet
Black Phoebe
Sharp-shinned Hawk
White-crowned Sparrow
American Goldfinch
Yellow-chevroned Parakeet
Orange-crowned Warbler
Cedar Waxwing
Raven
Band-tailed Pigeon
Lesser Goldfinch
Starling
Red-tailed Hawk
Respectfully submitted,
Alan
11/9/04
colors of the
http://birdwalks.caltech.edu
11/2/04
What a beautiful day for a bird walk!
Temperature was in the low 70s, not a cloud
in the sky, no smog, and in the distance
to the east a snow-covered mountain.
The birds were not overly plentiful, only
15, a far cry from the record 23 during the same week
44 last year. See the birds_epoch plot at
http://birdwalks.caltech.edu/bird_data/two_plots.htm.
But we had one stellar highlight:
Dark-eyed Junco. Yes, read it and weep.
The last time we recorded Dark-eyed Junco on campus
was 1998. So that was quite a find.
We had two stellar lowlights: no Scrub Jay
(again) and no Mockingbird (again). In response to last week's
report, when the same two birds went missing,
Bob Marshak emailed me wondering if I thought
the West Nile virus might have depleted
the Scrub Jays. Since two weeks in a row with
not seeing a Scrub Jay and a Mockingbird
is almost too much to take, I decided to
check the probability plots at
http://birdwalks.caltech.edu/bird_data/probability_plots.htm.
What I found there was interesting. For one
thing the Scrub Jays seem to be on a gradual decline
since the early 90s. They were 100% probable
to be seen during 1987-1992 but since
then the probability has decreased to about 80%
for the last year of data plotted. The Mourning Doves
show a similar trend. The Mockingbirds have
never been a sure thing actually, but
have fluctuated between 80-100% over the years.
Looking into this further at the same website,
I checked the probability by week number for the
last several years. And sure enough, starting around
week 44 or 45, we have a drop off in the
probability of seeing Scrub Jays and Mockingbirds
from near 100% to as low as 60%. And the same
with Mourning Doves, only worse, as the drop
off occurs as early as week 35. So all is likely
well with the Scrub Jays, Mockingbirds, and Mourning
Doves; they are behaving as per usual.
But how about the Crows, which are pretty scarce,
although we did see a few today? They have the
opposite trend over the years, coming on strong since the
early 90s. In 2002 and 2003, they were
100% probable, no matter which week of the year
we are talking about. And there is no expected drop off
by week number either. So, maybe the West Nile virus
did thin their ranks, as they've gone missing a few times this year.
The stats:
The date: 11/2/04
The week number: 44
The walk number: 756
The weather: 73 F, sunny
The walkers: Alan Cummings, Glenn Hamell, Kent Potter
The birds (15):
Rock Pigeon
House Sparrow
Mourning Dove
House Finch
Anna's Hummingbird
Acorn Woodpecker
Crow
Yellow-rumped Warbler
Bandtailed Pigeon
Ruby-crowned Kinglet
American Goldfinch
Black Phoebe
Townsend's Warbler
Red-tailed Hawk
Dark-eyed Junco
Respectfully submitted,
Alan
11/2/04
http://birdwalks.caltech.edu