Date: 7/30/19 9:14 pm From: Range Bayer <range.bayer...> Subject: [obol] OSU Seabird Oceanography Lab: 2019 Yaquina Head Murre Monitoring Update #2
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From: Porquez, Jessica <porquezj...>
Date: Tue, Jul 30, 2019 at 8:57 PM
Subject: 2019 Yaquina Head Murre Monitoring Update #2
To: Orben, Rachael <Rachael.Orben...>
Hello again everyone!
Monitoring is still underway at Yaquina Head Outstanding Natural Area and
we are excited to report that many common murre chicks are now roaming
around the rock. As of July 25th, 135 nests (of 229 throughout the season)
still had chicks. Within the first week of July, a total of 76 chicks were
observed from the monitored colonies. The first chick was recorded on the 1
st, while the youngest of our sample was observed during the 4th week of
July. Fledglings are now calling -- audible even through the cacophony of
adult calls -- and are coming close to getting ready to jump off the rocks
and into the water. We look forward to summarizing and reporting fledging
success in our next update.
Our first chick provisioning watch was on July 11. During this watch 12
nests with chicks were monitored from sunrise to sunset to record the
frequency and composition of chick feeds. Various types of prey were
brought back to the chicks including smelt, large juvenile herring,
flatfish, and squid. The average temperate of 64 oF and average winds of
0.6 N seemed like optimal conditions for the murres to grab some breakfast,
lunch, and dinner for their young; activity and provisioning frequency far
surpassed watches over the last handful of years, with a total of 51
feedings (about 3.18 feeds/hour) over the course of the day.
The second chick provisioning watch (July 18) seemed slower compared to the
first (22 total feeds, about 1.38/hour). The average temperature was 62.05 o
F with average wind speeds of 4.7 N compared to the first watch. Notably,
there was little to no wind most of the morning and early afternoon.
Observers noted that there was more territorial behavior and prey being
taken by surrounding murres when adults returned with fish. Anecdotally,
there were more scuffles whenever food was brought back as well when chicks
would wander too close to other nearby nests. Despite lower feeding rates
than the first watch, both watches in 2019 had higher provisioning
frequency than the preceding five years (2014-2017 = near or total breeding
In keeping with seasonal observed activity over previous years, predatory
disturbances (mainly from bald eagles) seemed to have slowed down during
the regular monitoring sessions as well as the sunrise to sunset chick
monitoring sessions. There have been several instances during the month of
July where monitors have noted the absence of either eggs, chicks, or
entire nests upon arrival at the colony, but the event(s) and primary
predator(s) were not observed. A few, mainly unsuccessful, disturbance
events were observed during the second chick provisioning watch, as well as
the regularly scheduled monitored days that followed it. Unsuccessful
disturbances are classified by a predator (gulls or eagles) landing on the
colony, or an attempt to grab a bird from the rock that results in an
unsuccessful take of an adult, egg, or chick.
The Brandt’s cormorants (BRAC) nests have all hatched. Chick ages vary, but
most are now several weeks old; some are showing the emergence of pin
feathers in their wings, while others are close to fledging! The total
number of Brandt’s cormorants with active nests are 35 while the pelagic
cormorants (PECO) have a total of 29 nests active.
We at the Seabird Oceanography Lab are delighted to share with you the
status of the common murres here at Yaquina Head Outstanding Natural Area.
We’ll keep you all informed on developments for the remainder of the season
with another update as we wrap up our monitoring effort. Thanks for your