We use multi-wavelength, matched aperture, integrated photometry from
GALEX, SDSS and the RC3 to estimate the physical properties of 166
nearby galaxies hosting 168 well-observed Type Ia supernovae (SNe Ia).
Our data corroborate well-known features that have been seen in other SN
Ia samples. Specifically, hosts with active star formation produce
brighter and slower SNe Ia on average, and hosts with
luminosity-weighted ages older than 1 Gyr produce on average more faint,
fast and fewer bright, slow SNe Ia than younger hosts. New results
include that in our sample, the faintest and fastest SNe Ia occur only
in galaxies exceeding a stellar mass threshhold of ~10^10 M_sun,
indicating that their progenitors must arise in populations that are
older and/or more metal rich than the general SN Ia population. A low
host extinction sub-sample hints at a residual trend in peak luminosity
with host age, after correcting for light-curve shape, giving the
appearance that older hosts produce less-extincted SNe Ia on average.
This has implications for cosmological fitting of SNe Ia and suggests
that host age could be useful as a parameter in the fitting. Converting
host mass to metallicity and computing 56Ni mass from the supernova
light curves, we find that our local sample is consistent with a model
that predicts a shallow trend between stellar metallicity and the 56Ni
mass that powers the explosion, but we cannot rule out the absence of a
trend. We measure a correlation between 56Ni mass and host age in the
local universe that is shallower and not as significant as that seen at
higher redshifts. The details of the age -- 56Ni mass correlations at
low and higher redshift imply a luminosity-weighted age threshhold of ~3
Gyr for SN Ia hosts, above which they are less likely to produce SNe Ia
with 56Ni masses above ~0.5 M_sun. (Abridged)
