5/29/12
One of the beauties of a walk, any walk if you
are receptive, is the subtle casting weave of
familiar and unexpected. It is the leavened
truth of a blue ice tracery budding the sky over
Chamonix or the bright reflection of a child's
smile off a little pool of water by the Niger
River. It is in a mockingbird, simultaneously
dancing for joy at the sighting of a Jerusalem
cricket and fretting consternation because you
might decide to keep it for yourself. It may lie
in watching a young black phoebe swooping off a
favored perch and landing on the grass after
snapping at a midge. In a year, he won't touch
the ground. It is in a lesser goldfinch picking
tufts for a nest while her mate looks on or in a
new life bird, a Lawrence's goldfinch, captured
in Vicky's latest trek. In the Caltech bird
walk, we have the relative constant of a
particular path riven from the years into a basic
framework upon which the avian day passes to and
by us. It grazes the edges of the campus and
provides a natural base in this oddly unnatural
area and, yet it has its own cadence firmed by
repetition but changing with the walkers, and the
weather, and the season. It may be in a bird or
a gesture or a conversation but, every time that
I have been on the walk, it finds a way to bloom.
This week we had an excellent late Spring walk.
We accumulated 22 species spread over both halves
of the walk and, were it not for a 24 species
walk in 2010, this would have been the record for
week 22. We were far above both the median (14)
and minimum (9; that must have been a tough
walk).
See the plots at
http://birdwalks.caltech.edu/bird_data/species_time.html
and
http://birdwalks.caltech.edu/bird_data/two_plots.htm
You will notice a complete lack of hawks
or turkey vultures in our list. It's unclear if
this meant that nobody was up there or that our
speck specialist, Viveca, wasn't with us. It
wouldn't have taken much to put us over the top.
I would have to say that the bloom of the walk
lay in Darren's sighting of a flycatcher high in
a eucalyptus inside the Maintenance yard. The
bird was ensconced on a branch but sallied forth
periodically to snap up some flying delectable.
Unfortunately, it was facing away from us, so it
was difficult to get much further than some sort
of wood peewee, leaving Alan with a flycatcher
species. There were a variety of attempts at
getting a good look at the front of the bird,
which is where one can most readily approach
distinguishing among the possible species
(basically, western wood peewee, olive-side
flycatcher, or willow flycatcher in this case,
although the fairly long projection of the wings
(and body size to some extent) argued against a
willow flycatcher). Our bird would pop out and
back to the same dead branch, ending up in the
same orientation, which was not the correct
orientation for us. Finally, he turns and,
briefly, we get a good view of the front. One
glance is enough. The bird is whitish from chin
down with sharply distinguished dark ellipsoidal
bands extending out from under the wings toward
the center line of the breast. It has the look
of an "unbuttoned vest" and this is
characteristic of an olive-sided flycatcher (a
western wood pewee doesn't have much going on in
front and a vest effect can be there in a willow
flycatcher but generally in a quite subdued
motif). Alan's flycatcher species had
transformed into the rondel of our first
olive-sided flycatcher since 2009 and only the
eighth sighting ever. Ashish and his camera
joined us just in time for a try at photographing
the bird but I am sorry to say that he never
deigned to give Ashish a good look, much less a
good look in good lighting.
Our sightings of olive-sided flycatchers occur
mostly during the Spring migration in weeks 18-22
but we've also had a couple of Fall sightings
(weeks 34 and 39). There are a number of reasons
why olive-sided flycatchers are such a rare
sighting for us. The first problem you face is
that these are long distance migrants (Panama or
northern South America for winter and boreal
Canada/northern continental U.S. and Alaska, or
some of the more mountainous regions south of
that for breeding. They have the longest
migration among the flycatchers and a tendency to
want to get it out of the way as quickly as
possible, so they fly long distance legs when
they are on migration rather than moseying along
and, since we only see this bird on migration,
this puts us at a disadvantage. Second,
olive-sided flycatchers don't much like lowlands,
so most of the birds flying by our area tend to
be at somewhat higher elevations. Third,
olive-sided flycatchers really like tall trees
and snags (standing dead trees) for perching. In
urban areas, snags are generally taken down at
the first sniff of liability or a neighbor's
aesthetic moans and there are few tall trees, for
the same reasons plus lifespan being limited by
the need for development and general mortality
due to poor care. Finally, there is the dark
side. The world population of this species has
been dropping steadily over time, by 76% over the
last 40 years according to breeding bird surveys,
so that olive-sided flycatchers are now
officially viewed as "near-threatened". If you
love large trees and loggers love large trees,
you are going to be in trouble. If your
wintering area is being systematically
deforested, you are going to be in trouble. If
global warming and forestry practices in your
breeding areas lead to wildfires, you are going
to be in trouble. Actually, a few years ago,
there was a series of papers noting that
olive-sided flycatchers seemed to be
beneficiaries of burn areas. Abundances increased
in these regions following fires but the authors
apparently mistakenly connected increased ease of
identification and increased activity to
increased reproductive success. The former did
not translate into the latter and overall
populations continued to decline, even within
these ecological traps. The olive-sided
flycatcher is one of those enjoy it while you
can species and, unfortunately, he has a lot of
company.
The date: 5/29/2012
The week number: 22
The walk number: 1145
The weather: 80°F, sunny
The walkers: Alan Cummings, Vicky Brennan, John
Beckett, Darren Dowell, Ashish Mahabal
The birds (22):
Northern Mockingbird
House Sparrow
Mourning Dove
House Finch
Anna's Hummingbird
American Crow
Common Raven
Bushtit
White-throated Swift
Black Phoebe
Orange-crowned Warbler
House Wren
Red-masked Parakeet
Olive-sided Flycatcher
Spotted Towhee
Lesser Goldfinch
Bewick's Wren
Band-tailed Pigeon
Red-whiskered Bulbul
Common Yellowthroat
Hummingbird, Selaphorus
European Starling
--- John Beckett
Respectfully submitted,
Alan Cummings
6/1/12
http://birdwalks.caltech.edu/index.html
5/21/12
Where can I to carry a lighted dream? If I steal a whelping passage from the deep cavern of my
ancestors, the spirit who lifts a rubbing hand shades in lions, and bison, and bears. I see no birds
in these glacial patterns but here, in our lighted world, they are everywhere though not in every
when. They are in the clans and in the myths. They are in the words passed from father to son
and you can see them in the strength of time rooted in faunal linguistics. There are more birds
than mammals or reptiles in the proto-Austronesian languages. The Maya recognized almost as
many owls as I would. Wren killed coyote. According to the Egyptians, Benu, the heron made
the universe, the gods, the goddesses, and, perhaps to give the gods and goddesses something to
do, the people. It is a fundamental tronche of humanity to recognize the deep connection
between nature and its reflection in birds and their personalities but we live is an odd world that
has at least partly lost its grasp of these spiritual realities. Perhaps, we feel some nascent stirrings
of a trillion birds, now shades, in our walks. Perhaps, we find something else.
From a secular perspective, this was a strong late Spring walk. We picked up three major
migrants, black-chinned hummingbird, ash-throated flycatcher (only our fifteenth sighting
overall, so a relatively rare bird for us), and a yellow warbler. The Throop pond ending for the
walk wasn't "surreal", to quote Alan, like last week, but it was still very productive, giving us
four additional species and guaranteeing a 20+ species walk. We ended up with 23 species, three
below the record 26 for the week, which was set back in 2009, but far above the minimum (11)
and median (15).
See the plots at
http://birdwalks.caltech.edu/bird_data/species_time.html
and
http://birdwalks.caltech.edu/bird_data/two_plots.htm
The walk had a curious variety of highlights. In the Maintenance yard, we encountered a pair of
ash-throated flycatchers. One of them paused near a fence long enough for several of us to pick
up a good look at the pale yellow breast, lightly ashed throat, and bounding russet of this species.
They stuck around just long enough to be tantalizingly close to becoming a new life-bird for
Melanie but, unfortunately, she joined us about a minute too late. Darren, couldn't join us this
week, mentioned seeing a band-tailed pigeon nesting near the restrooms in Tournament Park. We
didn't locate Darren's nest, which is too bad because we never managed to pick up a band-tail.
However, as we walk up Wilson, Alan spots a brown spotted sack resting 3 meters up in an oak.
We had a bushtit nest! A few bushtits, likely including the parents, were foraging in the tree but
the nest was arresting. These are built from spider webs and other convenient materials, insulated
with feathers, at least in the ones I've seen, and decorated on the outside with material from the
tree the nest is placed in, in this case with oak blooms. Bushtits are a very collaborative species.
Both sexes pitch in to help make the nest. Three weeks ago, I found a nest on my driveway. It
looked a little worse for wear, so I assume this to be a nest from a previous season and not a
failed nest from this year. I tossed it onto a table in my patio so that I could show it to my wife
and it stayed there for a several days but that weekend, I noticed a pair of bushtits (no helper for
this pair) pulling material, both oak druss and spider silk, from the nest and flying off with the
bits. Feathers from the interior were ignored or tossed aside. The male, in particular, was pulling
so hard that he was slowly dragging the nest across the table. So, I brought out a shelving brace
and placed the nest in the crook. The male bushtit comes over as soon as I leave, gets a good
perch on the brace and pulls for all he's worth; this became his preferred attack position and,
sometimes he would be leaning back as far as 30 degrees or so off vertical in the process. The
female ignored the brace, preferring to land on the "sock" itself. This process went on for about
two weeks. I suppose it's possible that two, or even more, pairs were involved but, if so, there
was no overlap. Given the recycling behavior on this high grade spider ore, I now suspect that
the nest fell onto the driveway through an overenthusiastic attempt to remove material. To give
you a behavioral point of contrast, we also had a pair of lesser goldfinches came over to the table.
Lesser goldfinches, or perhaps I should say female lesser goldfinches, make small open cup
nests. Our female alights on the old bushtit nest and proceeds to pull on it to remove material.
The male perches on a nearby chair. At first, he watches what his mate is doing but, then,
apparently assured that she isn't about to run off and mate with some other lesser goldfinch, he
preens while she pulls. He takes off with her, no doubt to watch her place her prize in or on her
nest.
The end of the walk yielded a yellow warbler. This week 21 sighting ties the record for the latest
Spring sighting for this species and it is the third yellow warbler sighting of the year, which is a
new record, and particularly interesting given that, prior to this year, we hadn't seen a yellow
warbler since 2007. We mostly see yellow warblers during Spring migration, passing through
Caltech during weeks 17-21. Historically, we have had only a few sporadic sightings during the
Fall, early August through mid-October (weeks 32-41), but, if one shows up, we would have four
sightings for the year, double any previous year and I would be pondering a declaration of 2012
as the year of the yellow warbler (last year was the year of the chickadee).
There is passion in the water. It guides our lives. Civilizations rise and fall on water. It also
guides the lives of birds. Ash-throated flycatchers, are resident in Mexico and some winter as far
south as Costa Rica. I note as an aside that they are willing to eat fruit if insects are scarce, so
they don't "just" hawk for flying insects. We see them because some of them migrate to the U.S.
to breed, passing by Caltech as they head north in the Spring during weeks 15 - 22. They will
come back to us in early August through September, weeks 30 - 38 (adults first, juveniles later),
in order to take advantage of the plant and insect blooms during and following the Mexican
monsoon season. The monsoons hit southwestern Mexico in June and northwestern Mexico, and
parts of Arizona and New Mexico in July and the season lasts into September. If you are an
insectivore, you want your prey to have a nice juice-filling life before you gobble them up, so you
want to give them a good head start. The monsoon is important to ash-throated flycatchers
because molting is a high energy affair and the migratory birds all migrate before they molt.
The date: 5/21/2012
The week number: 21
The walk number: 1143
The weather: 84 F, sunny
The walkers: Alan Cummings, Viveca Sapin-Areeda, Vicky Brennan, John Beckett, Ashish
Mahabal, Melanie Channon
The birds (23):
Northern Mockingbird
House Sparrow
Mourning Dove
House Finch
Anna's Hummingbird
American Crow
White-throated Swift
European Starling
Spotted Towhee
Ash-throated Flycatcher
Black-chinned Hummingbird
Lesser Goldfinch
Red-whiskered Bulbul
House Wren
Nuttall's Woodpecker
Bushtit
Common Raven
Yellow-chevroned Parakeet
Common Yellowthroat
Black Phoebe
Hummingbird, Selasphorus
Yellow Warbler
Mallard
--- John Beckett
Respectfully submitted,
Alan Cummings
5/25/12
http://birdwalks.caltech.edu/index.html
5/14/12
We are neither loom nor weaver but each walk blends with a patterned weave we can see, if we
are sensitive enough, but never define. Sometimes, it is a pastoral motif that seeps through every
setting step as we watch the gathering seasons pass through ourselves and the birds. We see it as
a parting glimpse of hoped for riches or the beginning of what others see in us. Even our
distorted obsidian view can fulfill a harping need to bring ourselves a little closer to what we
were. A walk is a gift.
This week the walk seemed a little warm to start as we were at the tail end of a warming trend
but we have a pleasant gathering throng and we amble into the Maintenance yard where Darren
picks up the song of an orange crowned warbler. This is promising. We may have a summering
warbler with us. In Tournament Park, we get a visual on a couple of first year birds, gleaning
actively in the trees. We appear to have become a mecca for orange-crowned warblers and at
that point, I would probably have chosen the orange-crowned warbler as a bird of the day,
especially since our Nuttall's decided not to show up.
By the time we round onto Wilson Avenue, we are flirting with a total of 20 species and have the
makings of a solid walk. Without Viveca's sky scanning and uncanny ability to see specks, we
are, however, hampered for raptors. Alan finally notes a couple of turkey vultures skimming up a
thermal north of campus but there are to be no hawks of any description for us.
Currently, the walk ends with the Throop ponds and the Millikan reflecting pool above (or vice
versa depending on the approach). We are looking for ravens near Parsons Gates, if we have not
already encountered some, and then, at least over the last year, we try to get a view of a common
yellowthroat near the Throop ponds and of mallards if they were not encountered earlier. The
first part of this axis goes well as we see an adult raven in a tree as we approach Parsons Gates
and then see at least three not quite ready for the big leap juveniles in the nest at north end of the
building.
Now, for our common yellowthroats and ducks. There are no ducks but Alan does a
playback and gets buzzed by the male common yellowthroat. His highness is clearly not overly
perturbed. He flies over to the pond, works his way over to the stream and proceeds to take a
bath in a sunny pool in an easy view. A red eared slider (turtle) watches moodily from the pool
above, no doubt thinking about a lunch that isn't going to happen. He can only provide a lurking
color counterpoint. So, we have our common yellowthroat but we aren't done. There are three
yellow-rich warblers in the jacaranda canopy, east of the ponds. Darren notes that it is often
difficult to distinguish warblers from the bottom but then proceeds to point out that the gray tail
of a Wilson's warbler from below is definitive against a female yellow warbler, whose tail will be
yellow from below. We were looking at a trio of Wilson's warblers. Our identification of a
yellow warbler a couple of weeks ago was sound but we were definitely doing it the hard way.
This was easy. Darren also picks up on a warbling vireo in the same area, a relatively rare bird for
us and a generally declining species in coastal California (nest depredation by Stellar and scrub
jays, nest parisitism by cowbirds, and commercial thinning and clear cutting of forests by loggers
is not a good combination if you are a warbling vireo). We walk up along the path winding
between the ponds and Darren sees a male yellow warbler (red streaks on the breast were quite
obvious, so this was a male) and, then, an extraordinarily late yellow-rumped warbler. I admit to
being quite dubious when Darren made a call for this bird but I eventually got a good view and it
wasn't subtle. It was a yellow-rumped warbler. We set the record for latest Spring sighting of a
yellow-rumped warbler a couple of weeks ago. That record has just been crushed. This guy
apparently knows that she(?) is supposed to be moving north but there are no yellow-rumped
warblers left to go with, so the only choice is joining a mixed species flock moving in roughly the
right direction. Darren had accompanied us to the ponds because Ernie's, the campus lunch
wagon had a long devoted line. Clearly, being hungry brings out some devastatingly effective
bird hunting ancestor in Darren. I'm sure we would have gotten half or more of these special
birds without Darren but surely not all of them and certainly not with such ease. So, the end of
the walk, which usually adds no more than a bit of frosting to the species total, brought us a main
course of five new species, all of which were spectacular in one or more ways. I added a much
more mundane starling that flew over my head as I walked back to Arms following the walk and
this brought us to a final total of 28 species, breaking the old record for week 20 of 27.
See the plots at
http://birdwalks.caltech.edu/bird_data/species_time.html
and
http://birdwalks.caltech.edu/bird_data/two_plots.htm
You may have noticed that we had a lot of warblers on this walk. We had an orange-crowned
warbler, a Wilson's warbler, a yellow warbler, a yellow-rumped warbler, and a common
yellowthroat (yes, common yellowthroats are wood warblers). That's a five warbler day. Four
warbler days are relatively rare, only 18 in 25 years although five of these were last year, but
there have been only three previous five warbler walks, all in the Fall (weeks 38-41) and none
since 2002. So, this is the first ever five warbler Spring day on the Caltech bird walk and the
first five warbler day of any description in nearly a decade. Wilson's and orange-crowned
warblers appear to be the key species as they appear in all four of our five warbler days.
Wilson's males generally move north (to northern California and points north of there) a little
earlier than the females in Spring but, in the Fall, it's juveniles first followed by the adults. You
can see this in our capture rates at Caltech. In the Spring, we get a smattering of sightings in
weeks 13-16 but the big pulse is in weeks 17-20 (18 of 22 Spring sightings) and nothing after
week 20. So, our sighting of a Wilson's warbler in week 20 of this year is consistent with typical
timing. In the Fall migration, we get a crudely normal looking distribution of sightings starting
with the earliest in week 34, the bulk of the sightings in weeks 37-40 and a last Fall sighting in
week 42 (mid-October; there is also a smattering of winter sightings). These birds are heading
back to the west coastal regions of Mexico and Central America (i.e., Wilson's warblers are
Neotropical migrants), although a few do winter as far north as San Diego County. So, basically,
an expectation based on past performance is that we have seen our last and only Wilson's warbler
for the Spring and that we are unlikely to encounter another before early September. Of course, I
would have said the same for the yellow-rumped warblers of a couple of weeks ago, when we set a
new record for the latest Spring sighting, now eclipsed by this week's encounter.
As a little factoid for Wilson's warblers, I offer the following. Wilson's warblers are leapfrog
migrants (also true of yellow warblers, incidentally). The birds breeding the furthest north also
winter the furthest south.
Finally, I feel compelled to mention the warbling vireo as a highlight. On a more normal walk, he
would have been THE highlight. Caltech sightings of warbling vireos are similar to those for
Wilson's warblers. Most of the Spring sightings are in weeks 17 - 20 (total spread is 15 - 22) and
Fall migration sightings occur in weeks 37-41. I don't know if our bird was taking advantage of
a mixed species flock for moving north or he happened to stop in the same place as the warblers
because we have some big larval carnival going on in the jacarandas near the Throop ponds but I
think it is fair to say that if you see one of a warbling vireo, yellow warbler, or Wilson's warbler,
you should be looking very hard for the other two.
The date: 5/14/2012
The week number: 20
The walk number: 1142
The weather: 76 F, sunny
The walkers: Alan Cummings, John Beckett, Vicky Brennan, Darren Dowell, Kent Potter
The birds (28):
Scrub Jay
Northern Mockingbird
House Sparrow
Mourning Dove
House Finch
Anna's Hummingbird
American Crow
White-throated Swift
Band-tailed Pigeon
Black Phoebe
Northern Rough-winged Swallow
House Wren
Orange-crowned Warbler
Hummingbird, Selaphorus
Spotted Towhee
Red-crowned Parrot
Bushtit
Lesser Goldfinch
Western Bluebird
Turkey Vulture
Common Raven
Yellow-chevroned Parakeet
Warbling Vireo
Common Yellowthroat
Yellow-rumped Warbler
Wilson's Warbler
Yellow Warbler
European Starling
--- John Beckett
Respectfully submitted,
Alan Cummings
5/18/12
http://birdwalks.caltech.edu/index.html
5/7/12
John couldn't make the walk so reporting duties
fell back in my lap.
We had a good walk. We observed 21 species,
in between the max of 28 and median of 17 for a
week 19. Not half bad.
See the plots at
http://birdwalks.caltech.edu/bird_data/species_time.html
and
http://birdwalks.caltech.edu/bird_data/two_plots.htm
Unfortunately, I am so overwhelmed with finding
out what the Voyager data mean, that I'm going to have to keep
this short, even by my standards.
The only unusual bird was a flycatcher and it was so
far away we had to go with flycatcher, sp. OK, that's about it;
Voyager data are calling.
The date: 5/7/2012
The week number: 19
The walk number: 1142
The weather: 75°F, sunny
The walkers: Alan Cummings, Viveca Sapin-Areeda,
Carole Worra, Vicky Brennan, Melanie Channon
The birds (21):
Northern Mockingbird
House Sparrow
Mourning Dove
House Finch
Anna's Hummingbird
American Crow
White-throated Swift
Spotted Towhee
Swallow, sp.
Flycatcher, sp.
Bewick's Wren
Hummingbird, Selasphorus
House Wren
Nuttall's Woodpecker
Lesser Goldfinch
Cooper's Hawk
Bushtit
Black Phoebe
Band-tailed Pigeon
Yellow-chevroned Parakeet
Common Raven
Respectfully submitted,
Alan Cummings
5/11/12
http://birdwalks.caltech.edu/index.html