Subject: FWD: Canadian GBH rookeries vs bald eagles
Date: Sep 12 09:38:30 1999
From: Diann MacRae - tvulture at halcyon.com


Tweeters, For those of you not on eagle-net, I thought you might like to
read this posting since there has been discussion on our list regarding
eagles and great blue herons.

Diann MacRae

>From: owner-eagle-net at interchange.ubc.ca
>Subject: Re: Bald Eagles vs GBH, etc.
>Sender: owner-eagle-net at interchange.ubc.ca
>To: eagle-net-outgoing112-42 at interchange.ubc.ca
>Date: Sun, 12 Sep 1999 06:49:19 -0700
>
>>Date: Wed, 25 Aug 1999 00:02:35 -0700
>>From: RaynaHoltz at aol.com (by way of Joel Kuperberg)
>>Subject: Re: Eagles vs GBH, etc.
>>
>>Rayna Holtz, president of our Vashon Island Audubon Society and
>>founder of the Mileta Creek Wildlife Refuge, until 1994, one of the
>>two or three largest Great Blue Heronries on Puget Sound, ravaged by
>>bald eagle predation and today, abandoned, sent the following to me
>>after I sent your last postings along to her. Use what you see fit
>>from the following.
>>
>>Yours truly,
>>
>>Joel Kuperberg
>>Vashon Island, WA
>>
>><><><><><><><><><><><>
>>
>>
>>Joel, if you have a way to forward this to the eagle-net, I happen to
have an
>> article from Waterbird Watch Collective's August 1999 newsletter that is
>>pertinent. It was sent to me by Nina Raginsky, the WWC coordinator who lives
>>on Saltspring Island and spearheaded the effort there to save a heronry very
>>comparable in size to our Maury Island site when it was in its prime and
held
>>about 120 nests.
>>
>>
>>The Bad News: Major Regional Coastal Great Blue Heron Breeding Failure
>> We have just received the final results from the 1999 Vancouver Island,
>>Gulf Islands, Lower Mainland and Sunshine Coast Heron Breeding records.
Eight
>>heronries out of fourteen surveyed on Vancouver Island and the Gulf Islands
>>have abandoned totally. A total of ohnly 130 chicks were accounted for
out of
>>all 14 colonies. All the colonies on the Sunshine Coast have abandoned this
>>year. Biologist Ann Eisinger reports that 8 sites in Puget Sound, Washington
>>abandoned this year, including the 400 nest colony at Birch Bay. A total of
>>approximately 700 nesting pairs in south and central Puget Sound and 240
>>nesting pairs on Vancouver Island have abandoned this year. The UBC and
>>Boundary Bay sites are both doing very well with 188 nests at UBC and 400 at
>>Boundary Bay. Only one colony did well on Vancouver Island. That was the
>>Drinkwater site at Duncan. Our McFadden Creek herons are still breeding and
>>the total success rate has not yet been calculated. It seems that so far
only
>>25 young have fledged this year, compared to 54 last year. These records are
>>from local W.W.C. field notes.
>> Most of the sites that abandoned on Vancouver Island were due to eagle
>>predation, due mainly to development near to the heron colonies. A loss of
>>forested land around a heron colony makes it easier for eagles to enter and
>>prey ohn the heron's eggs and nestlings.
>> There is a definite increase in the eagle population.
>> There is a definite decrease in fish stocks.
>> Eagles are turning to a variety of animals as prey for their hungry
>>young. Everything from barnyard chickens to cormorants to oystercatchers are
>>being taken by eagles.
>> Ian Moul, the biologist doing the status report on herons and
cormorants,
>>thinks that both species might be red listed this year.
>>
>><><><><>
>>
>>Rayna continues:
>>
>>So there's the story from Saltspring, and I agree with the analysis. I have
>>had one eyewitness report from a person who observed an eagle carrying a
>>young heron to a tree on the Burton Peninsula (on Vashon Island) and
>>devouring it.
>>
>>I also heard a story from Dan Willsie (Vashon birder )of watching a
>>bald eagle dive at a heron at the north end of Vashon. The heron
>>turned his long beak upward and stabbed at the eagle each time the
>>eagle dove. The heron was perched on a round rolling
>>buoy, and on one dive the eagle knocked it into the water. But the heron
>>floated there, maintained its defensive posture, and succeeded in driving
off
>>the eagle. This latter incident occurred in the summer of 1997.
>>At the Mileta Creek heronry, a few herons, six to eight pairs, try nesting
>>every other year. We have no evidence that they have succeeded once in the
>>years since 1994.
>>
>>New colonies at Spring Beach and Raab's Lagoon (Vashon Island
>>locations) have started up and been abandoned, evidently due to eagle
>>predation. Neighbors at both sites have
>>observed eagles harassing the herons.
>>
>>Rayna Holtz.
>>
>
>
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