Subject: [Tweeters] Fwd: Heron Colony Abandonment Dynamics (fwd)
Date: Mar 14 17:23:10 2007
From: C. Anderson - christyrae at hotmail.com


I would be most interested to learn about the Puget Sound Bird Observatory.
Does anyone have any information?

-----Original Message-----
From: tweeters-bounces at mailman1.u.washington.edu
[mailto:tweeters-bounces at mailman1.u.washington.edu] On Behalf Of Christine
Southwick
Sent: Wednesday, March 14, 2007 2:51 PM
To: tweeters at u.washington.edu
Subject: [Tweeters] Fwd: Heron Colony Abandonment Dynamics (fwd)

Posting for Don Norman, who is not currently a member

Christine Southwick
N Seattle/ Shoreline

clsouthwick at comcast.net
From: "Puget Sound Birds" <pugetsoundbird at gmail.com>
To: szkrom at drizzle.com, tweeters at u.washington.edu,
science at seattleaudubon.org
Date: Wed, 14 Mar 2007 16:36:08 -0500
Subject: Heron Colony Abandonment Dynamics
Suzanne-
It is great that you have continued to monitor the Black River colony to
note the change in its numbers. Data from annual monitoring by the Province
and Canadian Wildlife Service in BC has shown that heron colonies do change
over time, likely due to changes in food supply in an area, as well as
possibly some age dynamics in colonies. We know that Black River has even
been abandoned and re-occupied over the past 20 years. We still do not have
repository for observations to be sent. Perhaps we can see if ebird has the
capacity to receive such data. Obviously, the details of number of nests
etc.. is more detail than is currently collected by ebird. Check out the
Avian Knowledge Network, also part of Cornell. Getting an online dataentry
system for such observations beyone ebird is a major objective of the newly
formed Puget Sound Bird Observatory.

It is important to note that this year we had three MAJOR storm events that
could have also drastically increased the mortality of herons across the NW
over the winter. The two worst freezes in well over a decade and the worst
wind storm in 40 years are both heron killers.
Can other folks looking at colonies send Russell Link and myself info?
It is likely that specific disturbances coupled with such stressors may be
responsible for fewer birds being at the colony. The colony at Maury
Island, which had 120 nests suddenly abandoned in the middle of the nesting
season in 1994, with the possibility that there was a shooting of a heron
(never confirmed). Those birds have never returned. We have no idea where
they went. Bainbridge?

Having monitored the Kenmore colony closely when the Park and Ride was being
constructed, and also having Adolphson biologists onsite, we never even
noticed at least 13 visits in March and April into the colonty by
GeoCachers, obviously not right when we were doing the monitoring, that went
UNDER the colony to put their name in the can left there. We have no idea
whether that caused the failure of nests, but it is certainly a possibility.
With so much access at Black River, it is certainly possible some is causing
disturbance.

Finally, I have been interested in whether the adult female herons were
using the mouth of the Cedar River as a location to store up calories for
their eggs by feeding on spawning smelt. I have observed birds feeding at
night there in the past and changes in that area could be responsible for
disrupting the females. This has always been a theory of why this colony
starts earlier than the saltwater colonies, which Rob Butler showed were
related to daytime spring tides.

Changes continue to occur in the area where most of the herons appear to be
foraging to the south of the colony in the Kent valley, so we must also
remember that there needs to be foraging areas, as well as alternative
nesting sites protected for the herons.

I wonder if there are volunteers who wish to brave the cold evenings at Lake
Sammamish State Park, the mouth of the Sammamish Slough at Kenmore to look
for the smelt spawning. I have heard reports from Issaquah Creek of herons
foraging at night, but never confirmed them, and looked for birds at Kenmore
but never saw any the one FREEZING night I went out in a canoe... perhaps on
clear nights the smelt can see the herons???

I have excellent protocols as well as datasheets to record arrivals and
departures, and would be glad to email them to anyone interested...

don
Please note that I have a new email on gmail and do not check my AOL account
daily.

Donald Norman
Norman Wildlife Consulting
and Go Natives Nursery (Email: gonatives at gmail.com) www.gonatives.com


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