Dennis Manzer posted the following messages concerning Bald Eagles nesting at Jackson Bottom Wetlands, Hillsboro, to the on-line discussion group, Oregon Birder's On-Line (OBOL).
Monday, January 21, 2002
Hi all,
Jackson Bottom had 5 TREE SWALLOW on 01/19/02, 3 TRSW & 2 BARN SWALLOW on 01/20. Other notables were 5 subadult BALD EAGLE (mixed age classes, 2yr thru 4yr) on 1/19 in addition to the resident pair of adults. 1 NORTHERN HARRIER, 2 AMERICAN KESTREL, 5 RED-TAILED HAWK, 1 PEREGRINE FALCON. 1/20 the RED-SHOULDERED HAWK made itself
visible much of the afternoon.
Yours for better birding,
Dennis (:>}
Friday, February 1, 2002
Greetings!
The RED-SHOULDERED HAWK is still being seen today, 02/01/02, as
the latest high water event recedes. At any given time from 2 to 7
RED-TAILED HAWKS may be seen. On 01/26 there were 1 imm BALD EAGLE, 2
adults, 1 PEREGRINE FALCON, 1 NORTHERN HARRIER, 1 AMERICAN KESTREL,
BUSHTITS, BLACK-CAPPED CHICKADEE, & RUBY-CROWNED KINGLET in & out
during the course of the day.
On 01/19 there were 5 subadult BALD EAGLES representing all age
classes in addition to the resident pair of adults. On 01/31 there was
a 3rd adult perched a short distance from the residents. They eyed
each other more than 40 min. before finally engaging in an airshow &
disappearing behind the treeline bordering the retention pond just as
dusk turned to dark.
For those of you who haven't visited in a while, the eagles have
begun a new nest much more visible than the old one. The original blew
out on the night of 11/30/01 during an all night gale of 40 mph
sustained wind with gusts to 50 mph. I laid awake all night listening
to it howl & all the while fearing the worst.
Well, I think it turned out to be a lucky break after all, as this
new nest has been placed within the existing nest grove, but at its
Southwest margin. The nest is being built upon a very horizontal limb
of an oak right at its juncture with the trunk. The eagles had
returned in early Oct. & had been adding sticks to the original nest on
a daily basis. It was located in a young, limber Oregon Ash. After
the blowout they ceased gathering sticks & I feared they may build in a
different neighborhood altogether. But on 12/10 they each brought
sticks to their nest grove.
Each brought a stick to a different spot & placed it. Then the
other examined the placement of the stick by its mate. Next, one of
them brought a stick to the present spot & the building commenced.
They've been adding to it steadily since then & it's about 3'~4' tall X
about 6'~7' wide. Some of the sticks they've used are about 7' long &
several have multiple forks. At no time have I witnessed plundering of
the remains of the old nest, and in fact have only once seen one of the
eagles atop it. They've also added reed canary grass, mud, & sod.
Tonight for the first time I observed them each taking multiple turns
lowering themselves into the nest as if "trying it on" and making
desired adjustments to its interior. They were still perched above it
when I left @ 5:52 p.m.
Other passerines seen this past week include SPOTTED TOWHEE,
DARK-EYED JUNCO (OR), FOX SPARROW, LINCOLN'S SPARROW, GOLDEN-CROWNED
SPARROW, SONG SPARROW, HOUSE SPARROW, HOUSE FINCH, AMERICAN ROBIN,
RED-WINGED BLACKBIRD, STARLING, WESTERN SCRUB JAY, YELLOW-RUMPED
WARBLER, 10 TREE SWALLOW, 3 BARN SWALLOW, BELTED KINGFISHER,
BAND-TAILED PIGEON, ROCK DOVE, MOURNING DOVE & 1 BEWICK'S WREN.
The dramatically fluctuating water levels really affect the
presence &/or absence of waterfowl. The most common remain RING-NECKED
DUCK, NORTHERN PINTAIL, MALLARD & DOUBLE-CRESTED CORMORANT. AMERICAN
WIGEON, PIED-BILLED GREBE, AMERICAN COOT, LESSER CANADA GOOSE, GREATER
CANADA GOOSE & COMMON MERGANSER are usually present. Only occasionally
GREEN-WINGED TEAL & CINNAMON TEAL. The TUNDRA SWAN are in & out but
down from their peak of 600 during the prior high water events.
Jackson Bottom Wetlands Preserve can be found in DeLorme Oregon
Atlas p66, D1. The N view stand is located approx 1/2 mi S of
downtown Hillsboro, OR, on OR Hwy 219 (S 1st St.).
Yours for better birding!
Dennis (:>}
Sunday, March 3, 2002
Obol,
Happy 9th anniversary! Today @ about 1630 a strange goose came in
for a landing with a sizable flock of CANADA GEESE, mixed greaters &
lessers. As it descended at first glance I thought it was a Greater
White Fronted but something just wasn't quite right. I quickly laid
the scope on it to discover no white front. Uh-oh...study this bird
for marks, colors, & shadings.
A lady got out her NGII & I my NGIII. We took turns calling out
descriptors & were able to eliminate several possibilities. Finally I
got out my Sibley & bingo, there it was as if the live bird in front of
us had been painted by the very artist himself! Neat treat!!
The BALD EAGLE pair hasn't begun incubation yet. There was a 3rd
adult in the vicinity on Sat and a 2 yr most of Sun. Possibly the
fledgling of 2000. The adults tolerated its presence at a measured
distance as they allowed it to fish & feed unmolested.
Jackson Bottom Wetlands Preserve is located approx 1/2 mi S of
downtown Hillsboro on S 1st St, (OR Hwy 219).
Yours for better birding!
Dennis (:>}
Monday, April 8, 2002
Greetings!
Among the more interesting things this evening were 17 TUNDRA
SWAN, 12 of which had clear white necks. 5 had only a slight hint of
gray. All bobbed their heads rhythmically as they leisurely swam about
before departing at 1955 hrs. They circled the N end 7 times to slowly
gain altitude before heading E above TV Hwy for some distance before
veering N toward the Sauvie Island direction.
Other notables were a pair of CINNAMON TEAL in spring finery, very
vocal GREATER YELLOWLEGS, & yet 2 GREAT EGRET.
This is incubation day 32 for the BALD EAGLES. The hatch is
imminent. My betting cash goes for Fri, 04/12/02.
Jackson Bottom Wetlands Preserve is located approx 1/2 mi. S of
downtown Hillsboro, OR, adjacent to OR Hwy 219 (S 1st St.). Consult
DeLorme Atlas p 66, D1.
Yours for better birding!
Dennis (:>}
Sunday, April 14, 2002
Greetings!
At least one eaglet hatched on Fri, 04/12/02. I observed 4
feeding sessions between 1620-1940 hrs. Duration varied from 7 to 12
min. The prey item was large but unidentifiable and was already in the
nest prior to my arrival.
Saturday's feeding sessions averaged 3-7 min duration
approximately every 50 minutes. Sunday's sessions were lenghtier &
more frequent. This may suggest more than one chick. With any luck
the eaglets should be scope-visible from the N viewing stand within a
week since the nest location gives such a clean sightline.
A Sunday highlight was when the M BAEA captured a large carp from
shallow water. The eagle struggled crazily to gain altitude with his
unweildy cargo. The apparent ineptness prompted a lot of questions
from onlookers & puzzlement on my own behalf, when a blur of a
PEREGRINE FALCON blitzed the eagle from out of nowhere. It tried twice
to seize the eagle's prize but was met with adroit maneuvers & flips by
the eagle which then replenished the nest pantry.
Yours for better birding!
Dennis (:>}
Sunday, April 21, 2002
Greetings!
There was a lot of action @ the ol' bottom today. The eaglets
hatched on 04/12 & 04/14 as expected. There are 2 & that seems to be
all. This should be a very interesting experience. Both adults are
great providers. At no time during the past 8 days (49 hrs
observation) were the adults forced to hunt to fulfill an immediate
feeding demand from the eaglets. Feedings are every 40 - 60 min for as
little as 3 min all the way to 25 min. Both eaglets are scope-visible
from the sidewalk at the N parking lot during most feedings.
Up until later this afternoon both adults seemed to be great
defenders of their territory as well. There were visits from an adult
F, adult M (twice), 4 1/2 yr F (wearing a beautiful sub-terminal band
on her tail), 1 nearly 5 yr M (smudgy gray in the head & rectrices) and
a PEREGRINE FALCON all before 1400 hrs. Each was vigorously escorted
out of the area, sometimes by both adults or sometimes by only one.
At 1500 hrs the nearly 5 yr M returned bent on destruction &
amour. The pair chased him quickly to the distant S & out of view.
The F returned to her nestlings. About 30 min later the rascal
returned & raided last year's nest. The resident M was lurking on the
E side of the nest grove & rose to chase when the F joined in. She
went only a short distance before returning. The M continued pursuit
out toward Meriwether Golf Course & out of view.
Another hour passed & the interloper returned making a stoop on
the nest which he averted at the very last moment. The resident M
again appeared from nowhere to give chase to the S while engaging the
intruder 3 times midair. A fine aerobatic display! They both went out
of view.
At 1900 hrs the dirty bugger came back & perched ~8m directly
above the nested F. She began screaming & crying her loudest &
longest. She was clearly audible across the 400m. Her mate was not to
be seen. After about 15 min of this the interloper aggressively
dropped straight down ~2m. The F became even more hysterical & still
no sign of her mate as the terrorist gazed down upon her nest of young.
Periodically my wife, Diane, our daughter, Michelle, & I thought we
heard a weak distress answer. None of us could quite pinpoint the
location of the suspected call. Locations seemed to vary & responses
were very irregular. I began to fear the worst, perhaps that there had
been a fight & our dad bird got whupped.
I grabbed 1 of the scopes & drove to the Water Quality Lab
parking lot 0.7 mi S for a different perspective. Nothing. Scoped
everything I could think of as a possible retreat.
Her screaming continued until 2040 hrs when her mate finally
appeared from the near darkness. He came in with a contact call, she
continued with a distress call. We quickly lost track of him as we
were keeping all eyes on the nest. The terrorist began to fidget as
both he & our mom eagle cast their gazes toward the general direction
of the M.
Suddenly the unwanted company made a break for it to the east &
the F just as suddenly gave chase but wisely made a U-turn to her nest.
I could see flashes of white of 2 bald eagles thru the trees as the 2
M's clashed. By then it was too dark to follow any further events, but
as I left the F was in her nest.
I've never thought I could harbor the thought of never wanting to
see an eagle again - but this aggressive youngster is more welcome as a
memory than as another day-guest. This was one terrifying day.
Yours for better birding!
Dennis (:>}
Monday, April 22, 2002
Greetings!
After Saturday's terror at Jackson Bottom, I thought it prudent to
begin there today, Sun. Both adults were present upon my arrival @
0620 & seemingly healthy. Both eaglets fed heartily @ 0700. Feedings
continued about hourly as usual the preceding week. All seemed to be
normal. Best bird of the visit had to be HAIRY WOODPECKER up close.
Fernhill was next on the route. Both of the nearly 5 week old
eaglets were exercising & lazing atop their aerie as mom stood by.
Both looked healthy. No other eagles were seen. Prettiest sight was a
mixed group of single sparrows side by side upon a single branch:
LINCOLN'S, SONG, GOLDEN CROWNED, WHITE CROWNED. Other interesting
birds were a single CANVASBACK on Eagle Perch Pond, ~60 DUNLIN, 4
WESTERN SANDPIPERS, 8 LEAST SANDPIPERS, 3 DOWITCHERS, & 2 GREATER
YELLOWLEGS in standing water across Fern Hill Rd on its W side.
My 2 hour visit to the Hagg Lake BALD EAGLE nest site proved
inconclusive beyond the fact that the nest is occupied. The M was
perched ~150m E of their aerie. The F was in the nest but all I could
see was <1/2 of her beak & ~3/4" of 3 rectrices. A very tough sight
line. She did make some movement which could be broadly interpreted to
suggest a possible nestling. (Lotsa wiggle words in that sentence!)
Their hatch date was forecast for 04/20, so I'll be keeping an eye out
for prey deliveries &/or stand-up tending. It's a really tough
sightline in, around, & through dense foliage with only a couple of
peepholes & exactly 0.5 mi distant. What a joy (;>)! Best birds today
were 3 squabbling RED-BREASTED SAPSUCKERS up close in a brief moment of
bright light.
I spent the last 6 hours of daylight @ Jackson Bottom where all
was peaceful, the eagles strong, & the feedings were above average.
Still pretty well convinced of only 2 eaglets.
Yours for better birding!
Dennis
Saturday, May 11, 2002
Greetings!
Today, Sat, 05/11/02, was NAMC. I posted to Jackson Bottom
Wetlands Preserve's N viewing stand @ 0519 thru 2055 hrs. All
observations were made from this location. I travelled 17 mi round
trip from home & no birding was done while driving. I took a 30 min
break after 5 hours & a 20 min break after 10 hrs but continued
vigilance throughout. Visitor distraction was minimal.
I normally monitor the nesting Bald Eagles at this site. The
chicks are 4 weeks old now & getting 2nd down. Today I witnessed for
the first time this season the adults being forced to hunt to satisfy
a feeding demand. They failed 2 demands. Apparently their pantry
has gone bare & I hope only a temporary condition. The F did make a
small prey capture @ 2045 so the eaglets entered darkness with at
least a little something in their stomachs.
The N view stand is located approx 0.5 mi S of downtown
Hillsboro, OR, on Hwy 219 (S 1st St). See birdnotes.net "Site Guide"
section for additional info.
Yours for better birding!
Dennis (:>}
Saturday, May 25, 2002
Greetings!
A single BLACK TERN was working the distant water in front of the
N viewing stand on Fri from 1600 - 1900 hrs. This is my first sighting
of this specie this year. In '00 &'01 they visited in mid April, mid
May & late May. I was beginning to wonder if maybe we'd been dropped
from their itinerary.
Other fun birds being seen regularly include CEDAR WAXWING, BELTED
KINGFISHER, GREEN HERON, & SPOTTED SANDPIPER. The SPSA act as if
they're interested in nesting again. Many of the KILLDEER are on
second clutches. CANADA GOOSE families are paddling about & broods
range from 6 wks to 1 wk. There has been very little eagle depredation
on the waterfowl this spring. Several of the earliest broods are still
intact.
The BALD EAGLE family is thriving. Their diet is >95% carp. The
eaglet twins are 6 weeks old now & exercising vigorously, sometimes
even getting daylight beneath their talons as they beat their wings
furiously. They have exhibited almost no sibling rivalry from the
hatch & each continues to be fed more or less equally.
Jackson Bottom Wetlands Preserve is located approx 0.5 mi S of TV
Hwy (OR Hwy 8) from downtown Hillsboro, Or, on OR Hwy 219 (S 1st St).
See birdnotes.net for additional details in their "Site Guide" option.
Yours for better birding!
Dennis (:>}
Saturday, May 25, 2002
Greetings!
One eaglet 6 weeks old shredded prey in the nest & offered same to
its sibling. The sibling accepted about 10 offerings in this fashion.
Neither parent was in the nest at the time but each was nearby. I've
never witnessed this behavior before & wonder if anyone else has? Any
responses kindly appreciated. Thanks in advance.
Yours for better birding!
Dennis (:>}
Tuesday, July 2, 2002
OBOL,
Loud firecrackers were being exploded today some several blocks
away from the BALD EAGLE family of Jackson Bottom Wetlands Preserve.
The adults about got whiplash with each report. The juv's didn't seem
to notice. These crackers weren't M-80's or anything near their size
but the pops got my attention over the normally high ambient noise.
What's really peculiar to me is that during the waterfowl hunting
season, the skybusting sportsmen across the highway pop off with their
10 & 12 gauge shotguns & the eagles don't even twitch. I think the
birds' reactions are related to the sharpness of the "boom". Even
small firecrackers have a sharper report than the shotguns. Another
influencing factor could be that during the winter the eagles are only
occupying territory & aren't brooding young or overseeing fledglings on
the wing.
Yours for better birding!
Dennis (:>}
Tuesday, July 2, 2002
Greetings!
The BALD EAGLE fledglings (suspect both M) are successfully in the
air. They took wing on 06/28 & 06/30, each at exactly 11 weeks
uncannily almost to the hour. They are quite a sight in flight! A
little shaky here & there but they have their share of graceful
successes as well. The landings can sometimes be real heart stoppers.
This (07/02) evening's 1730 breezes with gusts to 15 mph brought
them off of their hidden perches & into the sky for some real airshow
demo's of their abilities. They played in the air together & sometimes
flew formation as they continued to discover their newly acquired
powers.
They return to their eyrie to feed at will & so far the parents
have had a full pantry waiting. This evening I saw the adult F take a
5~6 lb carp but rather than delivering it she simply put it aside,
presumably for consumption at a later time.
One of the young was perched on a fairly visible branch in the N
of the nest grove for quite some time which I hadn't previously noted
as ever being used. Its mother was perched about 10m higher & a little
further N. Then the adult M came from seemingly nowhere & moved it off
the perch. The juv hastily departed to the S end of the grove & had 2
missed attempts to perch atop the last tree on the right which is a
clear shot. Oddly he continued on into the thicker trees just meters
from last year's nest & landed after a fashion with a lot of imbalance
& counterbalancing wing-flapping. At least the indignity of it all was
somewhat obscured by the heavier foliage.
They seem to be most active at the first hour of daylight & then
tapering off by 0800 or so. They again become active between 0930 &
1000 when the thermals begin to develop. Hot afternoons are for shady
siestas. They get active again as the temp cools & the late
afternoon/early evening breezes pick up. Best photo light is after
1600 hours. Bring a gallon of patience.
Yours for better birding!
Dennis (:>}
Tuesday, Octctober 1, 2002
Greetings,
This p.m. @1655 PDT a MERLIN sliced through the N end. I had
already thoroughly glassed and found nothing different but glassed
again & there was an adult male BALD EAGLE perched atop the
southernmost snag in the nest grove.
It made 2 position changes in 40 min. Once to the NE corner of
dead cottonwood & then to the favored perch in the N end of the nest
grove. It investigated the available waterfowl which went berserk on
each position change, but made no strikes.
Other birds present & not seen previously this week included 2
BARN SWALLOW, 30 BUSHTIT, 1 AMERICAN KESTREL, 40 VAUX'S SWIFT & 3
NORTHERN FLICKER.
Jackson Bottom is located approximately 0.5 mi S of downtown
Hillsboro, OR on the E side of OR Hwy 219 (S 1st St).
Yours for better birding!
Dennis (:>}
Friday, October 18, 2002
Greetings,
The female of the pair joined the male in residence on the p.m. of
TUE, 10/15. They act like the same pair of the most recent nesting
season. I've not seen any activity on or near the nest however it's
way early for any stick gathering just yet.
This evening's highlights included an adult PEREGRINE FALCON on
premises as well. 2 LINCOLN'S SPARROW were just off the N view stand.
1 WILSON'S SNIPE was on the long island in front of the eagles' nest
grove. Aprox 5K CANADA GEESE, mostly Cacklers, settled in just after
dark. Yesterday I saw two with yellow plastic collars but too distant
to glean markings. BELTED KINGFISHER is still regular as are 3 - 5
GREAT EGRET. GADWALL are coming into beautiful plumage.
Jackson Bottom Wetlands Preserve is located approx 0.5 mi S of
downtown Hillsboro, OR, on OR Hwy 219 ( S 1st St).
Yours for better birding!
Dennis (:>}
Monday, October 21, 2002
Greetings!
Last week upon the arrival of the F BAEA I mentioned in my post
that I thought it was way too early for stick-gathering & presentation
at the nest. Well, that may have been true last week but it's under
way now. The M broke off a fairly green stick approx 4.5' length &
multi-forked of unidentified tree sp & delivered it to his mate upon
their nest.
If any of you observers out there see similar BAEA behavior, I'd
certainly appreciate an e-mail noting the circumstances & approximate
location to "Dennis Manzer". Thanks in advance!
Yours for better birding!
Dennis (:>}