Rarity--Where species is abundant in a rare habitat

[Richard Hill]

How would you classify species that are easily found
and abundant where found, but live in uncommon or
"rare" habitat types?  I am thinking of endemic species
that may have restricted ranges, and species that are
specialized for unique habitats often missed in general
surveys, but easily located by the specialist (who may
also be rare and/or endangered  ;-)).

These situations, I think, often cause difficulty
where there is no clear understanding of the difference
between rare (=uncommon) and rare (=endangered).