10Sguy
writes:

I'm in the design stage for my first pond. I intend to have a few fish, the
usual array of plants and whatever else shows up.

Try to insure that good size bio-filter shows up.

I'd also like to have a
resident turtle.

I assume you mean a typical aquatic turtle like a slider or painted turtle.
Those would be the best choices.

If I find a local turtle and bring it to my pond, is it likely to stay
around?

I think if it's a very large at all, it's only going to stay if you've created
a fairly balanced ecosystem with food sources and some places to hide, both on
shore and down in the water.

Would it be more ethical to purchase a turtle from a pet store?

Somewhat, but it would be best if you buy a turtle species that's native to
your area in case it escapes. If you can find a hatching turtle in the wild
there's nothing wrong with taking that to your pond, as about 98% of hatchlings
are eaten in the first few months of life anyway. A hatchling that grows up in
your pond is far more likely to stay. Once it figures out fish food, it will
tame down quickly.

Occasionally I see them along the roads where I ride bike. I'm sure some of
those that wonder onto the road meet an untimely demise.

Cars kill a phenomenal amount of wildlife, often because of worthless imbeciles
who won't just slow down or drive around them. Turtles killed on the road are
almost all females who've left the water to travel to a spot to lay eggs. This
has caused the decline of a number of species like the beautiful little spotted
turtle (all black with yellow spots). If you can see which way a turtle is
headed you can often help it "get to the other side."

As I understand it I'd need to provide an area where it can get easily get
easily get
out of the water. Are there any other special considerations for turtles?

A log or stone that is at the shore level and goes out over the water is ideal,
because turtles love to be able to dive in the water if they are spooked while
sunning. They need to get in the sun each day for several reasons: they get
vitamin D, it kills moss on the shell, and it warms them up. Best of all is a
rock coming up out of the like a small island.

The other consideration is that they need some soft material to dig into on the
pond bottom to hibernate in winter. Since "muck" on the pond bottom (in a
garden pond) is a huge threat to fish health, you've got to come up with
something special along these lines, like a shallow pan filled with thick clay
put on the bottom in the late fall.

Mark Ervin