Seckel sets fruit for me in Norcal and it's my only pear, no pears in my immediate neighborhood that I know of.

Some pears will be self fertile in warm weather climates, especially some of the Asian pears. However, you will still get more fruit if you can cross pollinate. Hood seems to need a pollinator, however. Seckle doesn't.

seckel pear pollinators

Here is a link that might be useful: seckel pear pollinators

Here's the "definitive" answer. From the NCGR Corvallis database, it's self-fertile.

Here is a link that might be useful: NCGR Corvallis Pyrus Catalog Entry - Seckel

I can confirm that a Hood pear needs a pollinator. My 10 year old Hood never had more than one pear each year until I planted a Flordahome next to it. The first year the Flordahome had a few blossoms I hand-pollinated the Hood from it and produced a bunch of fruit. This year I had more blossoms to work with and did a lot of hand pollination...the Hood is loaded with small pears right now, even in areas that I didn't hand pollinate. I've found a list of about 6 pear varieties that pollinate the Hood...the Hood blooms earlier than many pear so it's through blooming before my two other pears even start to open their blossoms (that's beside the Flordahome which seems to start blooming here a few weeks after the Hood starts).

Here's the list of varieties that are supposed to pollinate the Hood pear: Courthouse, Flordahome, Baldwin, GoldenBoy, Le Conte, Pineapple Pear. Here in S. Calif the Flordahome is easy to find, and I've seen Pineapple pear also. The others are uncommon.

You also need to know that bees don't particularly like pears(or the pear nectar) so hand-pollination can make a big difference.