Date   

Coyote Hills (10/24) - Palm Warbler, Northern Flicker (variations)

Jerry Ting
 

Early this (10/24) afternoon (1:10PM) I found a Palm Warbler (pic http://www.flickr.com/photos/jerryting/8120442644/in/photostream) foraging on the ground on Quail Trail (the trail between the Nectar Garden and Hoot Hollow) around the outhouse area. I observed the bird for a good 10 minutes then the bird flew down to the Garden area and I coundn't re-find it.

There were also Northern Flickers with different variations feeding termites on the ground in Hoot Hollow area. I had a male Yellow-shafted, 2 feamle Red-shafted females, 2 female Red X Yellow-shafted females, and 1 Red X Yellow-shafted male in the picnic area at the same time. Here is the post with all 4 variations (http://www.flickr.com/photos/jerryting/8120442572/in/photostream).

Yesterday (10/23) afternoon there were also quite a lot of Yellow-rumped Warbler and Ruby-crowned Kinglet feeding termites in Hoot Hollow area. Here is a picture of the male kinglet showing off his brilliant buby crown (http://www.flickr.com/photos/jerryting/8117291253/).

Happy Birding.

Jerry Ting
Fremont


Western Tanager & Northern Pygmy-Owl

Jeff Acuff
 

Yesterday, mid-day, a female (perhaps a juvenile male) western tanager visited my backyard birdbath in unincorporated Lafayette.

Today, just after 2pm, I heard a Northern Pygmy-Owl's evenly spaced toots.  The tooting lasted about 10 minutes.  Before it stopped, I tried to track down the location.  It seemed to be coming from a heavily wooded riparian drainage area between the backs of residences on Brookwood Drive on one side and Jordon Place on the other.

Good Birding,
Jeff Acuff



[Non-text portions of this message have been removed]


Western Tanager & Northern Pygmy-Owl

Jeff Acuff
 

Yesterday, mid-day, a female (perhaps a juvenile male) western tanager visited my backyard birdbath in unincorporated Lafayette.

Today, just after 2pm, I heard a Northern Pygmy-Owl's evenly spaced toots.  The tooting lasted about 10 minutes.  Before it stopped, I tried to track down the location.  It seemed to be coming from a heavily wooded riparian drainage area between the backs of residences on Brookwood Drive on one side and Jordon Place on the other.

Good Birding,
Jeff Acuff



[Non-text portions of this message have been removed]


Re: Coyote hills stuff

Alan Howe
 

I was in Hoot Hollow yesterday & saw @ least 4 or 5 flickers, all in or near the tallest tree(s)--mostly red-shafted, but at least 1 yellow. (Lots of winged ants in the air & shed wings on the ground in the hollow, too.)
Saw or heard about 32 species. It was nice to see FOS of some of my favorite waterfowl, including northern pintail, northern shoveler & green-winged teal. There were just a few of each--no flocks yet.
Alan Howe
North Oakland
On Oct 23, 2012, at 1:59 PM, Dave Weber <dwbirdster@sbcglobal.net> wrote:

Quick stop at Coyote Hills before work today got one Golden-crowned Kinglet in front of visitors center in the big oak and a flying-away Northern Flicker with yellow shafts in Hoot Hollow.
Dave Weber,
Milpitas
by phone


[Non-text portions of this message have been removed]


Re: 10/22 -- Pine Siskins and a tragedy

Todd Easterla
 

I can do the math off the top of my head (millions of people have millions
of outdoor cats not to mention the more feral population) and know that cats
are one of the many combined detrimental things to song birds in North
America. They are not even a natural predator here, so yes they must be
having a noticeable impact on the many bird populations, not to mention wind
turbines, towers, windows, fast moving vehicles, airplanes, chemicals, Large
oil spills, pesticides and probably many other man-made influences and
disasters against birds. That is just in our Country.... I can only imagine
what goes on in a third world country.

I hate to even tell this story, but I was at a friend's house that used to
have an outdoor cat while having a BBQ at his residence his cat brought up
three different birds (Scrub Jay, American Goldfinch(2)) that it had caught
in only about two hours. He no longer has that cat outdoors after I showed
him the birds the cat had laid at my feet during that two hours. There is a
place in Sacramento County at the end of Sherman Island Road where there are
about 15 feral cats at a bird sanctuary and people come and feed the cats
daily. A very sad sight to say the least when there are bird feathers strewn
about the cat city. There used to be quail there NOT ANY MORE!

Once at Point Reyes, Nunez Ranch to be exact, I saw one of the outdoor cats
here carrying off a Prothonotary Warbler and it made my heart skip a beat.
I'm sure Mr. Stallcup has seen his share of this kind of thing out there
over the years.

And we worry about playing tapes and recordings which is a lot like pishing
and spushing. Give me a break!

Oh, by the way I like neutered indoor cats and no need for anyone to reply
to this self-venting e-mail.

Todd Easterla
Rancho Catdova, Ca

-----Original Message-----
From: EBB_Sightings@yahoogroups.com [mailto:EBB_Sightings@yahoogroups.com]
On Behalf Of Jaan Lepson
Sent: Tuesday, October 23, 2012 10:51 AM
To: bird sightings East Bay
Subject: Re: [EBB_Sightings] 10/22 -- Pine Siskins and a tragedy

Technically, the Stephen's Island Wren was not wiped out by feral cats. It
was wiped out by Tiddles, a single pet cat belonging to the lighthouse
keeper. At least that is the story. And that was the final extinction; I
believe there is fossil evidence for it on the new Zealand mainland, where
it had earlier been extirpated by various alien predators.

I believe there was a recent study using cat cams that suggested that
domestic cats are responsible for killing upwards of 100 million birds a
year in the U.S. Anyone else familiar with this and do I have the numbers
correct?



Jaan Lepson
Livermore

On Oct 23, 2012, at 10:40, Joseph Morlan wrote:

On Tue, 23 Oct 2012 09:56:14 -0700, "Alvaro Jaramillo"
<chucao@coastside.net> wrote:

There may be some local declines here and there exacerbated by cats
(usually there are other factors involved like habitat degradation),
but cats have not caused any species to decline that we know of.
The Stephens Island Wren went extinct largely because of Feral Cats.
Feral cats have been implicated in the decline and/or extinction of
several other species of birds and animals, particularly on island
ecosystems.

The rise of cat colonies in the SF Bay Area have caused some
significant local declines, such as the well-known example of
California Quail in San Francisco. The late Louis Baptista had to
abandon a project on nesting White-crowned Sparrows in Golden Gate
Park after feral cats wiped out his study population.

Additional information:

http://www.abcbirds.org/abcprograms/policy/cats/index.html

Some additional references:

http://en.wikipedia.org/wiki/Feral_cat
--
Joseph Morlan, Pacifica, CA
"It turns out we're very good at not seeing things" - Jack Hitt


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=============================
Jaan Lepson

University of California
Space Sciences Laboratory
7 Gauss Way
Berkeley, CA 94720-7451



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thrushberries

Mark Rauzon
 

What Alan Kaplan described in Tilden, I saw in Dimond Park, Oakland today; thrushes going after Madrone berries. Sometimes the simple commonplace magic of nature is overwhelming, as seen here in a robin plucking a madrone berry from the Friends of Sausal Creek's demonstration garden. Also heard an Orange-crowned Warbler singing a different fragment of song than it's buzzy trill of spring.


http://rauzon.zenfolio.com/p859914566/h488445ec#h488445ec


enjoy!





Mark Rauzon


Tilden Nature Area, Tuesday AM, 10.23.12

Alan Kaplan <lnkpln@...>
 

Friends!

Naturalist James Wilson and I took a quick look at the Upper Pack Rat trail (just before its junction with the Lower Pack Rat trail, near the lake) after the rains of the last two days to look for Rain Beetles (Pleocoma behrensi) and found a few emergence holes, and a big flock of Cedar Waxwings feeding on Madrone berries, along with American Robins. Also included were Ruby-crowned Kinglet and Myrtle-type Yellow-rumped Warbler.

Further along the trail we saw Fox Sparrows and they were singing! Not just calls but a beautiful, full-throated song (literally, I saw the throat in motion). James suggested they were singing out of happiness for the rain!.

Best of Birds to you!

Alan Kaplan


Rock Wren in Pt. Richmond

tonybrake@sbcglobal.net
 

Today at about 6 PM I observed a ROCK WREN working along the rip-rap in the cove between the Ferry Point Fishing pier and the derelict dock and building to the east. I also saw a tan-striped WHITE-THROATED SPARROW along the Old Country Road trail in th ehills of Miller-Knox Regional Park. This appeared to be a different individual than I saw last week, as that one appeared to a first-winter bird.

Tony Brake
Pt. Richmond, CA


Re: 10/22 -- Pine Siskins and a tragedy

Michael Park
 

-------- Original Message --------
Subject: Re: 10/22 -- Pine Siskins and a tragedy
Date: Wed, 24 Oct 2012 01:51:06 -0000
From: moonshadow.sandy <moonshadow.sandy@yahoo.com>
To: EastBayBotanist <dpbot@earthlink.net>



EBB friends, Escaped and feral domestic housecars are not part of the "natural order of things."

Outdoor cats in the United States kill more than one million birds every day, and about twice as many other small creatures. At the same time that cat numbers are on the rise, nearly one-third of the bird species in the U.S. are endangered, threatened, or in decline.

Here is a series of great articles from Wildlife Professionals, for those who are interested:
I'd strongly encourage people to learn more, and PLEASE keep your cats inside, where both the cats and the birds are safe.

http://www.wildrescue.org/cat_package.pdf

Articles include:
- Cats as Carriers of Disease
- The Trickle-down Effect: How Toxoplasmosis from cats kills Sea Otters
- By Land and By Sea: The Wide-spread threat of feral cats on Hawaiian wildlife
- An Issue with All-Too-Human Dimensions - It is people, not science, at the Heart of the cat debate.


Credit for these articles to: WildRescuehttp://wildrescue.blogspot.com/

I should also state that I am a cat lover, and have 2 registered Birmans who NEVER are allowed outside. The average lifespan of a cat allowed out is only a very few years. Kept safely INdoors, many live to 15 or beyond.

Sandy R, RN
Walnut Creek




--- In EBB_Sightings@yahoogroups.com, "EastBayBotanist" <dpbot@...> wrote:

This afternoon, over lunch I noticed a commotion outside my window. To my delight, I saw a flock of PINE SISKIN at my neighbor's feeder and in a nearby tree. They were busy chattering and feeding. And after some time, perhaps an hour, they fell silent perhaps sated and were mostly perched in the tree. Other resident or common birds at this spot were mostly finches -- HOUSE FINCH, LESSER GOLDFINCH -- but also CHESTNUT-BACKED CHICKADEE and RED-BREASTED NUTHATCH.

Just a few minutes, I looked out again from my back porch and discovered a roving house cat or feral cat -- it's hard to tell the difference in some neighborhoods in Berkeley. It was walking down the step from the area where the feeders are located and it had a bird in its mouth.

The fallen bird had a streaky breast. I certainly hoped it was not a siskin. It has been over 5 years since there last were any in this yard.

The flock almost immediately departed the yard. I don't doubt the connection with the strike at the feeder by the loose cat.

Michael Park
Berkeley


Re: 10/22 -- Pine Siskins and a tragedy

shuckabone@...
 

I personal believe cats do cause an unnatural stress on birds which frequent feeders. So is it the feeders that are the root cause? I have a feral / roaming cat that stalks my feeders and I believe it kills one bird a day during the winter months. I’ve installed barricades in the places it likes to sit and wait on unsuspecting birds but it always seems to find an new spot. There are times when I’ve contemplated removing my feeders to eliminate the artificial concentration of birds.

Steve Huckabone
Livermore, CA
Alameda County

From: Bruce Mast
Sent: Tuesday, October 23, 2012 5:55 AM
To: mikeshannon@comcast.net ; 'EastBayBotanist'
Cc: 'EBB Sightings'
Subject: RE: [EBB_Sightings] 10/22 -- Pine Siskins and a tragedy


House cats preying on birds is not "the natural order of things". House cats are human-introduced disruptions to the natural order of things as surely as pollution and habitat loss.

Bruce Mast
Oakland

-----Original Message-----
From: mailto:EBB_Sightings%40yahoogroups.com [mailto:mailto:EBB_Sightings%40yahoogroups.com] On Behalf Of mailto:mikeshannon%40comcast.net
Sent: Monday, October 22, 2012 3:12 PM
To: EastBayBotanist
Cc: EBB Sightings
Subject: Re: [EBB_Sightings] 10/22 -- Pine Siskins and a tragedy

Hi Michael,

It is sad to see one of our birds fall prey, but that is the natural order of things.

Mike S.

----- Original Message -----

From: "EastBayBotanist" <mailto:dpbot%40earthlink.net>
To: "EBB Sightings" <mailto:EBB_Sightings%40yahoogroups.com>
Sent: Monday, October 22, 2012 12:42:21 PM
Subject: [EBB_Sightings] 10/22 -- Pine Siskins and a tragedy

This afternoon, over lunch I noticed a commotion outside my window. To my delight, I saw a flock of PINE SISKIN at my neighbor's feeder and in a nearby tree. They were busy chattering and feeding. And after some time, perhaps an hour, they fell silent perhaps sated and were mostly perched in the tree. Other resident or common birds at this spot were mostly finches -- HOUSE FINCH, LESSER GOLDFINCH -- but also CHESTNUT-BACKED CHICKADEE and RED-BREASTED NUTHATCH.

Just a few minutes, I looked out again from my back porch and discovered a roving house cat or feral cat -- it's hard to tell the difference in some neighborhoods in Berkeley. It was walking down the step from the area where the feeders are located and it had a bird in its mouth.

The fallen bird had a streaky breast. I certainly hoped it was not a siskin. It has been over 5 years since there last were any in this yard.

The flock almost immediately departed the yard. I don't doubt the connection with the strike at the feeder by the loose cat.

Michael Park
Berkeley

[Non-text portions of this message have been removed]

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[Non-text portions of this message have been removed]


Brant and Whimbrel in Emeryville

Patricia Bacchetti
 

After Jim C posted about the 2 Brant near Powell St in Emeryville this afternoon, I was able to drive down and get my first look at these geese in Alameda County. Both Brant were near the shore just east of the Emeryville fire station on Powell ST, west of I80. Cal Waters and I were able to watch them feeding on the algae on the rocks before they drifted off to the east. This was around 2 PM, several hours after the high tide.

The mudflats near the freeway were teeming with shorebirds, so I took my scope down for a look. In addition to Willets, Marbled Godwits, Dunlin, Sanderlings, Western and Least Sandpipers, there were 3 Whimbrels in the general area. Northern Shovelors, American Wigeons, and grebes were also floating in the shallows.

Good birding,

Pat Bacchetti
Oakland, CA


American Bittern at Aquatic Park

John H. Maurer
 

Berkeley' Aquatic Park: in the reeds at the north end of the big lagoon, a little west of center.

This means we saw 5 herons at Aquatic Park today:

Snowy Egret
Great Egret
Great Blue Heron
Green Heron

a n d ...................................

American Bittern

John


Coyote hills stuff

Dave Weber
 

Quick stop at Coyote Hills before work today got one Golden-crowned Kinglet in front of visitors center in the big oak and a flying-away Northern Flicker with yellow shafts in Hoot Hollow.
Dave Weber,
Milpitas
by phone


Re: 10/22 -- Pine Siskins and a tragedy

Kay Loughman
 

Phila and all,

Check out the American Bird Conservancy's long-running campaign "Cats Indoors" at

http://www.abcbirds.org/abcprograms/policy/cats/index.html

Kay Loughman



phila rogers wrote:


Though cat predation is not a subject for our Sighting site, I urge
everyone to encourage Golden Gate Audubon to take a stand against roving
house cats as they are partly responsible for declining species.

-- Phila Rogers


It's a jungle out there

Phila Rogers
 

Dear Friends:

A biologist member of our sightings group, pointed out to me that though
cats kill large amounts of birds, they alone (except in rare cases) are not
responsible for species decline which is a complex matter with a number of
factors. Still, I strongly support the idea of controlling house cat
predation.

I witnessed a more "natural" predation this morning when I saw a Shrub Jay
delivering a series of jabs to a twitching form on my roof. When the jay
saw me, he lifted a small songbird by the neck and flew off. I have seen
jays kill feeding Lesser Goldfinches in the spring and attempted to
rationalize the act as the jay's need to feed its young. This, I suppose,
was the act of a jay defending its feeding territory (I have nearby
feeders). Still, I would guess that jay and crow predation amounts to
considerably less than cat kills.

-- Phila Rogers


Brant Emeryville

jchiropolos <jchiropolos@...>
 

Two brant are present in Emeryville about 50 yards south of the Emeryville Fire department building on Powell Street. I can see them from my office window, so I guess they count as an office bird!

Their camouflauge is amazing, I know exactly where they are looking down and they are very difficult to pick up from the "air", compared to from the ground.
Cool!


Jim


Re: 10/22 -- Pine Siskins and a tragedy

Jaan Lepson <lepson@...>
 

Technically, the Stephen's Island Wren was not wiped out by feral cats. It was wiped out by Tiddles, a single pet cat belonging to the lighthouse keeper. At least that is the story. And that was the final extinction; I believe there is fossil evidence for it on the new Zealand mainland, where it had earlier been extirpated by various alien predators.

I believe there was a recent study using cat cams that suggested that domestic cats are responsible for killing upwards of 100 million birds a year in the U.S. Anyone else familiar with this and do I have the numbers correct?



Jaan Lepson
Livermore

On Oct 23, 2012, at 10:40, Joseph Morlan wrote:

On Tue, 23 Oct 2012 09:56:14 -0700, "Alvaro Jaramillo"
<chucao@coastside.net> wrote:

There may be some local declines here and there exacerbated
by cats (usually there are other factors involved like habitat degradation),
but cats have not caused any species to decline that we know of.
The Stephens Island Wren went extinct largely because of Feral Cats. Feral
cats have been implicated in the decline and/or extinction of several other
species of birds and animals, particularly on island ecosystems.

The rise of cat colonies in the SF Bay Area have caused some significant
local declines, such as the well-known example of California Quail in San
Francisco. The late Louis Baptista had to abandon a project on nesting
White-crowned Sparrows in Golden Gate Park after feral cats wiped out his
study population.

Additional information:

http://www.abcbirds.org/abcprograms/policy/cats/index.html

Some additional references:

http://en.wikipedia.org/wiki/Feral_cat
--
Joseph Morlan, Pacifica, CA
"It turns out we're very good at not seeing things" - Jack Hitt


------------------------------------

To unsubscribe go to: EBB_Sightings-unsubscribe@yahoogroups.com
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Yahoo! Groups Links


=============================
Jaan Lepson

University of California
Space Sciences Laboratory
7 Gauss Way
Berkeley, CA 94720-7451


Re: 10/22 -- Pine Siskins and a tragedy

Alvaro Jaramillo
 

Rusty and others



Mark Rauzon reminded me that in island environments, cats and other
predators have definitely caused declines in nesting seabirds.



With regard to the Tilden observation, my point is that cats are there and
cats are killing birds, but do we know 100% that they are causing the
decline of the quail? Were there no cats before 1987? Are there many more
now? Is this documented? The issue is that it that one can correlate all
sorts of stuff with a declining population, and if there is a logical thread
we can hook on to then we assume the correlation explains the pattern
(causation). You could easily have said that in 1987 there were very few
birders at Tilden, and now there are a lot more, but none of us are going to
suggest that increases in birders have caused declines in quail. That would
be silly! It is possible that the argument that cats caused the decline in
quails is equally silly, but since we know that cats kill quail, we reject
that notion even if it is possible. It could be that disease, habitat
degradation, sudden oak death, pollution, increase in turkeys.or who knows
what else has a greater effect in the declines of these quail - we don't
know. I do know that we need people to study this stuff, the science that
has real benefits to urban birds and wildlife, and we as birders should be
out there not only protecting science funding but asking for the answers we
need to adequately manage our local wildlife. People don't want to fund
these types of studies because they are not "sexy" but in the end they may
be a great investment in research money.



In the meantime, keep them cats from causing trouble!



Alvaro



Alvaro Jaramillo

alvaro@alvarosadventures.com

www.alvarosadventures.com



_____

From: EBB_Sightings@yahoogroups.com [mailto:EBB_Sightings@yahoogroups.com]
On Behalf Of Rusty Scalf
Sent: Tuesday, October 23, 2012 10:14 AM
To: EBB_Sightings@yahoogroups.com
Subject: Re: [EBB_Sightings] 10/22 -- Pine Siskins and a tragedy






There is one ecological consideration here though.

Wild predators such as Weasels must make a living entirely by successful
predation within their territory. A lactating female is under great
pressure and her territory must be large enough to sustain her family.
Hence Weasel population density has a certain natural limit, beyond
which the creatures simply cannot sustain themselves.

Among free roaming cats, pets enjoy complete food supplementation and
even feral cats are fed way more often than is appreciated. With cats,
predator densities can be over the top; far higher than could be
sustained in a natural predator/prey balanced ecosystem. I think that's
why California Quail can continue in balance with Weasels and Coyotes
but not with cats in the mix.

When I first moved to the East Bay in 1987 I used to encounter
California Quail all the time at Tilden Park. I haven't seen or heard
one there on in years.

Without a doubt a new equilibrium has been established at Tilden, one
forced to accommodate this increased predation. But sadly, it's an
equilibrium without quail.

Rusty Scalf

Phila

I know what you mean, but as a biologist I need to point something out.
Cats are responsible for the deaths of many birds, and other creatures.
However, there is no evidence that cats are responsible for any declining
species. Mortality and population declines are not related in a simple way
in nature. You can have masses of a creature die, but still have a
steady or
even increasing population! It depends on lots of factors including
reproductive output etc. So cats cause the death of individual birds (many
deaths!), but they do not cause declines of populations of birds at
least at
a large scale. There may be some local declines here and there exacerbated
by cats (usually there are other factors involved like habitat
degradation),
but cats have not caused any species to decline that we know of.

Alvaro

Alvaro Jaramillo

alvaro@alvarosadventures.com <mailto:alvaro%40alvarosadventures.com>
<mailto:alvaro%40alvarosadventures.com>

www.alvarosadventures.com

_____

From: EBB_Sightings@yahoogroups.com
<mailto:EBB_Sightings%40yahoogroups.com>
<mailto:EBB_Sightings%40yahoogroups.com>
[mailto:EBB_Sightings@yahoogroups.com
<mailto:EBB_Sightings%40yahoogroups.com>
<mailto:EBB_Sightings%40yahoogroups.com>]
On Behalf Of phila rogers
Sent: Tuesday, October 23, 2012 9:39 AM
To: EBB_Sightings@yahoogroups.com <mailto:EBB_Sightings%40yahoogroups.com>
<mailto:EBB_Sightings%40yahoogroups.com>
Subject: RE: [EBB_Sightings] 10/22 -- Pine Siskins and a tragedy

Though cat predation is not a subject for our Sighting site, I urge
everyone to encourage Golden Gate Audubon to take a stand against roving
house cats as they are partly responsible for declining species.

-- Phila Rogers






Re: 10/22 -- Pine Siskins and a tragedy

Joe Morlan
 

On Tue, 23 Oct 2012 09:56:14 -0700, "Alvaro Jaramillo"
<chucao@coastside.net> wrote:

There may be some local declines here and there exacerbated
by cats (usually there are other factors involved like habitat degradation),
but cats have not caused any species to decline that we know of.
The Stephens Island Wren went extinct largely because of Feral Cats. Feral
cats have been implicated in the decline and/or extinction of several other
species of birds and animals, particularly on island ecosystems.

The rise of cat colonies in the SF Bay Area have caused some significant
local declines, such as the well-known example of California Quail in San
Francisco. The late Louis Baptista had to abandon a project on nesting
White-crowned Sparrows in Golden Gate Park after feral cats wiped out his
study population.

Additional information:

http://www.abcbirds.org/abcprograms/policy/cats/index.html

Some additional references:

http://en.wikipedia.org/wiki/Feral_cat
--
Joseph Morlan, Pacifica, CA
"It turns out we're very good at not seeing things" - Jack Hitt


Re: 10/22 -- Pine Siskins and a tragedy

rfs_berkeley
 

There is one ecological consideration here though.

Wild predators such as Weasels must make a living entirely by successful
predation within their territory. A lactating female is under great
pressure and her territory must be large enough to sustain her family.
Hence Weasel population density has a certain natural limit, beyond
which the creatures simply cannot sustain themselves.

Among free roaming cats, pets enjoy complete food supplementation and
even feral cats are fed way more often than is appreciated. With cats,
predator densities can be over the top; far higher than could be
sustained in a natural predator/prey balanced ecosystem. I think that's
why California Quail can continue in balance with Weasels and Coyotes
but not with cats in the mix.

When I first moved to the East Bay in 1987 I used to encounter
California Quail all the time at Tilden Park. I haven't seen or heard
one there on in years.

Without a doubt a new equilibrium has been established at Tilden, one
forced to accommodate this increased predation. But sadly, it's an
equilibrium without quail.

Rusty Scalf

Phila

I know what you mean, but as a biologist I need to point something out.
Cats are responsible for the deaths of many birds, and other creatures.
However, there is no evidence that cats are responsible for any declining
species. Mortality and population declines are not related in a simple way
in nature. You can have masses of a creature die, but still have a
steady or
even increasing population! It depends on lots of factors including
reproductive output etc. So cats cause the death of individual birds (many
deaths!), but they do not cause declines of populations of birds at
least at
a large scale. There may be some local declines here and there exacerbated
by cats (usually there are other factors involved like habitat
degradation),
but cats have not caused any species to decline that we know of.

Alvaro

Alvaro Jaramillo

alvaro@alvarosadventures.com <mailto:alvaro%40alvarosadventures.com>

www.alvarosadventures.com

_____

From: EBB_Sightings@yahoogroups.com
<mailto:EBB_Sightings%40yahoogroups.com>
[mailto:EBB_Sightings@yahoogroups.com
<mailto:EBB_Sightings%40yahoogroups.com>]
On Behalf Of phila rogers
Sent: Tuesday, October 23, 2012 9:39 AM
To: EBB_Sightings@yahoogroups.com <mailto:EBB_Sightings%40yahoogroups.com>
Subject: RE: [EBB_Sightings] 10/22 -- Pine Siskins and a tragedy

Though cat predation is not a subject for our Sighting site, I urge
everyone to encourage Golden Gate Audubon to take a stand against roving
house cats as they are partly responsible for declining species.

-- Phila Rogers





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