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Hummer, Tufted Duck, Re: cats



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/