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Hummer, Tufted Duck, Re: cats
- To: carolinabirds@duke.edu
- Subject: Hummer, Tufted Duck, Re: cats
- From: Joshua Stuart Rose <jsr6@duke.edu>
- Date: Tue, 30 Jan 2001 22:17:47 -0500 (EST)
- In-Reply-To: <000501c08a46$5ed90a80$93880b41@grnvle1.sc.home.com>
- Sender: carolinabirds-owner@acpub.duke.edu
Hi Carolinabirders,
Well, it's confirmed: my backyard hummer is a female-type Selasphorus. I
watched it preen in a shrub this afternoon, after which it stretched a
few times and fanned its tail. I also finally heard it call, a series of
evenly spaced, soft, slightly metallic chip notes. No hints yet as to
which species, but Rufous is by far the most likely. Still, I can't wait
for Susan C. to come by and make sure! Other yard sightings included the
Brown Creeper several times (or maybe several Brown Creepers), and the
Red-shouldered Hawk again as well.
Jeff Lewis mentioned the Tufted Duck sighting. I now have it on good
authority that a private waterfowl collection in the Manteo area, very
near the sighting, was vandalized recently, with many birds killed and
others escaped. Tufted Duck was apparently among the escapees. So was a
pair of Mandarin Ducks, in case anybody sees them...
On Mon, 29 Jan 2001, Jerry Pasquarella wrote:
>
> Feral cats (actually any "outside" domestic
> cats) are basically an unnatural predator (i.e. not in their "native"
> habitat) in a natural world.
Actually, their unnatural-ness is not the biggest problem. If the cats
were allowed to be a real part of the natural system, subject to the
predators, disease, and exposure, and most of all starvation that limits
the populations of other predators, their damage to birds and other
wildlife would be far less of a problem.
The problem comes back to human behavior. Normally, when prey becomes
rare, predators starve, allowing prey populations to recover. However,
when the prey of stray and outdoor pet cats becomes rare, the cats just
become more dependent on handouts from misguided, well-meaning humans for
their survival. The predators thus remain abundant, while the prey
becomes scarcer and scarcer instead of recovering. Even those of us who
don't let our pets outside or voluntarily feed and shelter stray cats may
unknowingly do so by throwing away garbage that they can eat and
providing other benefits unconsciously. This allows the cat population,
as well as populations of certain other bird predators like Raccoons and
foxes, to survive at levels tens, hundreds, maybe thousands of times
greater than what could be supported by the natural food supply.
This is one of the reasons why habitat fragmentation is a problem. Forest
interior birds can only successfully breed if their forest habitat is
separated by a wide buffer from the human populations that create
artificially huge populations of bird nest predators. Even a single road
to a single house or even campground can provide a link for suburban
predators like these to infiltrate the forest and wipe out the nests of
Wood Thrushes, Ovenbirds, and the rest. This may also be true for
grassland and wetland nesting species.
> However, after eliminating most of the cats, the last two years I lived
> there saw the return of the Ovenbirds! And I felt ten times more joy from
> the Ovenbirds than any sense of remorse over what may have happened to those
> cats!
I had a similar experience. When I lived with my parents, our first two
cats were allowed to go outdoors (the first one was actually a stray who
adopted us). They coughed up the occasional mole, and sometimes we'd see
them go after birds, but didn't think it made a difference overall. When
the second cat died, I convinced my parents to keep any future cats
strictly indoors; at this point it was just for the cats' health, I had a
friend who was a veterinary technician who informed me that indoor cats
live three times as long as outdoor cats. However, following this change
in our behavior, the ecology of the yard recovered from predation that
must have been far more intense than we ever expected! Not only did bird
species appear that we hadn't seen or had only rarely seen previously,
but we started seeing chipmunks, moles, and even Garter and Milk Snakes
that had been rare or absent when we had outdoor cats! So I shared
Jerry's joy, and am glad that he, John Argentati, and many others (one of
whom has contacted me off the list) have taken action to get cats out of
their yards. Keep up the good work, y'all...
Good birding,
Josh
Joshua S. Rose
Duke University
Department of Biology (Zoology, R.I.P.)
jsr6@acpub.duke.edu
http://www.duke.edu/~jsr6/