Wildlife experts: Cats are killing Baylands wildlife | September 13, 2013 | Palo Alto Weekly | Palo Alto Online |

Palo Alto Weekly

News - September 13, 2013

Wildlife experts: Cats are killing Baylands wildlife

Proposed ban on feeding feral cats in Palo Alto open space could help save endangered species, officials say

by Sue Dremann

Feral cats are being accused of eating the Palo Alto Baylands' endangered species, and a proposed city ban on the public feeding of the cats could give the endangered wildlife a fighting chance, land managers and biologists said.

"From my personal experience as Palo Alto park ranger for over a decade, I have personally seen feral cats hunt and catch birds in the Baylands Nature Preserve," said Daren Anderson, the city's division manager of open space, parks and golf.

Not only do feral cats kill mammals, reptiles, insects and birds, they also eat their eggs and can spread diseases. They also compete for prey with other predators, who shift to hunting endangered species, he said.

It's unknown how many feral cats live in the Baylands, but 14 endangered, threatened and sensitive wildlife species, including the California clapper rail and salt marsh harvest mouse, are affected by the cats, wildlife officials said.

The populations of the Baylands' endangered species are shrinking. In 2011, about 14 clapper rails were found there; as many as 19 are known to exist at Palo Alto Harbor and Hooks Island, according to a 2011 Point Reyes Bird Observatory Conservation Science report. Those numbers are down from 2010, when the Baylands had as many as 22 of the birds.

No one knows how many salt-marsh harvest mice live in the Baylands, but they too are being devoured by cats and other predators, Anderson said.

Ann Nussbaum, a volunteer with the Palo Alto Humane Society, disagreed with wildlife experts' view that feral cats are killing the wildlife at any significant rate.

"Many people blame feral cats for being predators and accuse them of hurting the bird population. The real problem is habitat loss, pollution and pesticide use. Humans are the top predators. Studies show that feral cats do their hunting at night and much prefer rodents to birds," she said.

She defended the program that feeds the feral cats, known as "trap, neuter, release."

"When they are fed in neutered, managed colonies, they are not starving and have less impulse to hunt at all. Compared to people, the damage feral cats do is minor," she said.

Because the feral cats are spayed and neutered, the program actually reduces the number of cats over time, she added. The Stanford Cat Network reduced the university's population of feral cats from 1,500 to an estimated 25 or 35, feeding-program proponents have said.

But Anderson said he has seen an increase in the cat population in Palo Alto's open space.

"Feral-cat feeding stations, which leave large quantities of cat food in park and open space areas, lure in other stray cats, and encourage people who are looking for a place to abandon their cats to choose that site. I've personally caught dozens of people dropping off a variety of animals — dogs, ducks, roosters, turtles, rabbits and cats — at the Baylands Duck Pond because they thought it was a site where people would feed them," he said.

At any rate, wildlife experts say, cats are not native animals, and they have no place in refuges where there are endangered and threatened species.

Doug Cordell, spokesman for the U.S. Fish and Wildlife Service's San Francisco Bay National Wildlife Refuge Complex, said the argument that fed cats don't hunt wildlife doesn't hold up. Remote cameras show feral cats hunting and catching endangered species near the feeding stations. Postmortems have found remains of endangered species in their stomachs, according to research by the Fish and Wildlife Service and U.S. Geological Survey.

A two-year study by the East Bay Regional Parks in two grassland parks found that cats had a significant impact on wildlife. One park had no cats; the other had more than 20 cats, who were fed daily. Scientists saw almost twice as many birds in the park with no cats. California thrasher and California quail were found in the cat-free area; the birds were never seen in the park with cats.

More than 85 percent of the native deer mice and harvest mice that researchers trapped were in the catless park. In contrast, 79 percent of house mice, an exotic pest species that had replaced the native species, were found in the area that had cats.

Anderson said city staff is researching the best ways to handle the feral cats.

Trapping and euthanizing cats that cannot be adopted out is one method. But wildlife experts are exploring cutting into berms. The method would inundate areas with water so predators don't have access into marshes, according to a California Coastal Conservancy clapper-rail habitat plan.

The City Council this fall will consider adopting the ban on feeding wildlife and feral cats in city parks and open-space preserves.

Threatened/sensitive/endangered species found in Palo Alto open space:

Alligator lizard

Black rail

Black-crowned night heron

California clapper rail

California vole

Long-billed dowitcher

Marbled godwit

Northern pintail

Peregrine falcon

Pygmy blue butterfly

Ruddy duck

Salt marsh harvest mouse

Savannah sparrow

Western sandpiper

Threatened/sensitive/endangered species rarely found in Palo Alto open space:

California brown pelican

California least tern

California tiger salamander

Red-legged frog

Western snowy plover

Staff Writer Sue Dremann can be emailed at sdremann@paweekly.com.


Like this comment
Posted by Nature Advocate
a resident of another community
on Sep 13, 2013 at 10:43 am

[Post removed.]

Like this comment
Posted by bru
a resident of Crescent Park
on Sep 13, 2013 at 11:57 am

bru is a registered user.

I go out to the Baylands quite a bit ... I've never seen a feral cat out there, save about 20 years ago way down near the Sunnyvale dump? Where are all these cats? Not saying they do not exist ... I've never seen them and I've pretty much been all over the Baylands?

Why is it necessary to lock this subject down after one post that was deleted anyway?

AND ... when you lock these things down, and I have to log in, why do I also them have to type in a Verification Code? Why isn't it enough to log in. You might get more people to log in if you made it worth their while and they did not have to type in the Verification Code.

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Posted by bru
a resident of Crescent Park
on Sep 13, 2013 at 12:03 pm

bru is a registered user.

>> I've personally caught dozens of people dropping off a variety of animals — dogs, ducks, roosters, turtles, rabbits and cats — at the Baylands Duck Pond because they thought it was a site where people would feed them,"

Ugh .... how can people be so clueless?

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Posted by Vox Felina
a resident of another community
on Sep 15, 2013 at 10:28 am

Vox Felina is a registered user.

To suggest, as Daren Anderson does, that feeding stations lead to an increase in the population of free-roaming cats ignores the obvious: these cats are “out there” already. The feeding is a necessary first step to getting the cats sterilized and, in many cases, adopted.

Regarding the risks to wildlife, there’s actually plenty of evidence that contradicts the claims made in this piece.

In their contribution to “The Domestic Cat: The Biology of Its Behaviour,” for example, researchers Mike Fitzgerald and Dennis Turner thoroughly several dozen predation studies, concluding rather unambiguously: “We consider that we do not have enough information yet to attempt to estimate on average how many birds a cat kills each year. And there are few, if any studies apart from island ones that actually demonstrate that cats have reduced bird populations.” [1]

Something else to keep in mind: predators—cats included—tend to prey on the young, the old, the weak and unhealthy. At least two studies have investigated this in great detail, revealing that birds killed by cats are, on average, significantly less healthy that birds killed through non-predatory events (e.g., collisions with windows or cars). [2, 3]

One final point: the East Bay Parks study referred to here is plagued with methodological problems—beginning with the fact that Cole Hawkins, the PhD student undertaking the work, had no idea what the “cat area” was like before the cats arrived. He therefore had no way of measuring their impact. Interestingly, Hawkins ignores almost entirely the fact that five of the nine ground-feeding species included in his study showed no preference for either area. [4]

Now, if he couldn’t explain why THESE birds were unaffected by the presence of cats nearby, he was simply in no position to blame the cats for the absence of the OTHERS. Indeed, Hawkins’ scat analysis suggests that predation on birds was minimal: just four percent of 120 scats contained feathers.

If we’re really serious about resolving this issue, I think it’s important that we begin by getting the facts straight.

Peter J. Wolf
Web Link

Literature Cited
1. Fitzgerald, B.M. and D.C. Turner, Hunting Behaviour of domestic cats and their impact on prey populations, in The Domestic Cat: The biology of its behaviour, D.C. Turner and P.P.G. Bateson, Editors. 2000, Cambridge University Press: Cambridge, U.K.; New York. p. 151–175.
2. Møller, A.P. and J. Erritzøe, Predation against birds with low immunocompetence. Oecologia, 2000. 122(4): p. 500–504. Web Link
3. Baker, P.J., et al., Cats about town: Is predation by free-ranging pet cats Felis catus likely to affect urban bird populations? Ibis, 2008. 150: p. 86–99. Web Link
4. Hawkins, C.C., Impact of a subsidized exotic predator on native biota: Effect of house cats (Felis catus) on California birds and rodents, 1998, Texas A&M University.

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Posted by jardins
a resident of Midtown
on Sep 16, 2013 at 11:26 am

jardins is a registered user.

If the feeding of feral cats is banned they will naturally have to seek wildlife prey to sustain them.

Then the city will issue a death-warrant for the feral cats.

That is not ethical--the cats didn't choose to be abandoned in the Baylands.

Given that the current situation is working--read the facts in the sources that Vox Felina cites above--why is the city going in the face of such facts and upsetting everything?

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Posted by Patty
a resident of University South
on Sep 16, 2013 at 12:21 pm

Patty is a registered user.

The same approach was used at Mountain view where they trapped and euthanized abandoned cats because they were killing wild life until a Cats protection organization was started by a group of ladies in order to protect the cats and find homes for these creatures.
However years later, the construction to build a new Google camp at the field was approved and started...killing hundreds of animals. Who protects the wild life now? ....I think The number one threat to our animals are us humans. How many animals are killed on wild fires because of human errors? How many because of new construction? new highways? how about hunting? are you really that hungry to go hunting for bears or deers or ducks?

Now you are blaming the cats who were abandoned here and have no where to go. Their nature is to kill in order to survive... yes just like any of other animal. There are domesticated cats and there are also feral cats...there are domesticated horses as well as wild horses...etc.

We are intelligent beings and I am sure together we can find other ways to handle a situation like this than killing them.
NO! Trapping and euthanizing cats that cannot be adopted out is NOT! one method.

I hope those whose have a voice can and authority take their time to think and feel and make a correct and kind decision .


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Posted by bru
a resident of Crescent Park
on Sep 16, 2013 at 1:54 pm

bru is a registered user.

> The number one threat to our animals are us humans.

Right on, Patty!

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Posted by rainbow38
a resident of Mountain View
on Sep 16, 2013 at 2:08 pm

rainbow38 is a registered user.

This issue has been researched for years and well-documented by such organizations as Alley Cat Allies and Best Friends Animal Society. It's all too easy for inexperienced people to overcount animal populations if individual animals aren't identified. Building/overbuilding on habitat, use/overuse of toxic chemicals, polluting land and water, and abandoning pets are all human activities. Humans are the most destructive species on the planet. Were any of the people seen abandoning their pets stopped or arrested? Abandoning animals is illegal under County law. More effort needs to go into neuter/spay and helping people keep their pets. Humans need to use their "superior" intelligence to find better ways to deal with this situation.

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Posted by Observer from the other side
a resident of Menlo Park
on Sep 16, 2013 at 5:15 pm

Observer from the other side is a registered user.

I don't know about research on solutions for getting rid of feral cats. The studies quoted were paid for by entities that see no problem with the ever increasing colonies of such animals.
But I can tell you that some 3 years ago, for the first time in many years of visiting Bayfront Park in Menlo Park, I ran into a cat. Very soon, there were 3, then 6, then 8, and then I lost count.
You can go see foryourself. They congregate to eat at the end of the paved road, straight ahead from the entrance. Most times, there will be a couple of racoons feasting with the cats (and fighting for food). I alerted one member of the Menlo Park's Parks Commission, and as far as i could tell, the cat population continued to increase.
And boy do they reproduce! Last time I visited, there were a bunch of kittens. I hear there is a "crazy lady" that drops off cat food everyday.

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Posted by bru
a resident of Crescent Park
on Sep 16, 2013 at 6:02 pm

bru is a registered user.

> But I can tell you that some 3 years ago, for the first time in many years of visiting Bayfront Park in Menlo Park, I ran into a cat. Very soon, there were 3, then 6, then 8, and then I lost count.

Really .... where. I go out to the Baylands all the time and I've never seen a single cat out there. Including Byxbee Park, the trail over to Mountain View, the Duck Pond, the Sailboard launch, the trail around the Airport and down towards 101. I've seen lots of rabbits, snakes, some skunks, I think 2 foxes as well, but only one small cat way out behind the Sunnyvale dump when it was possible to bike out there around Moffett Field.

If there are a lot of cats out there that would be a concern if they cannot be neutered, I just have not seen them ... but I sure have seen an explosion in birds, so if the cats are eaten them or their eggs they do not seem to be cutting into populations very much.

Cats are not part of the ecology out there, but I imagine at some point in the past mountain lions or bobcats must have been.

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Posted by rick
a resident of Midtown
on Sep 17, 2013 at 4:33 am

rick is a registered user.

I'm out at the Palo Alto Baylands occasionally and haven't seen any cats, but haven't really looked for them. Observer's observations about Bayfront Park over by Marsh Road may be well-founded. Different county. Haven't been there but I should check it out next time I'm on a more northerly errand. I worry about development pressures in the adjacent mudflats and salt ponds. 101 is already a parking lot half the day. Don't know whether that Dumbarton rail corridor will ever be renovated -- or whether it would alleviate any of the auto traffic.

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Posted by marcoeg
a resident of Downtown North
on Sep 18, 2013 at 8:42 am

marcoeg is a registered user.

Cats are not a pest and have been living with humans for 10,000 years. Their presence is of great comfort to many people and in progressive cities around the world feral cats colonies are sanctioned and protected. I am outraged that the community that calls itself the "birthplace of Silicon Valley" is even considering deliberately starving to death feral cats, when there are responsible organizations that have demonstrate their effectiveness in providing for feral cats.

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Posted by Observer from the other side
a resident of Menlo Park
on Sep 19, 2013 at 2:44 pm

Observer from the other side is a registered user.

You quoted me word by word, and still missed the fact that I said "Bayfront Park in Menlo Park".

Try reading it again--BAYFRONT PARK IN MENLO PARK--and then go for a little walk. Afterwards you can tell me if you didn't see any cats. OK?

Sorry, but further commenting on this topic has been closed.