Use of "although" with a modifier

Is it grammatically correct to use "although" in a modifying clause, but without a conjugated verb? Example:

Although not regarded as nocturnal, the Black Bear of North America is active at night in some areas.

Or is it necessary to spell out the clause fully?

Although it is not regarded as nocturnal, the Black Bear of North America...

Solution 1:

This usage is fine. Just make sure you don't create a dangling modifier.

Example:

Although not regarded as nocturnal, experts believe the black bear of North America is active at night in some areas.

This makes it look as though it is the experts who are not regarded as nocturnal, not the bears. Hence, a dangling modifier. But your example works.

Solution 2:

Yes, this is correct. Adjectives and participles can be used like this with a few conjunctions, such as (al)though and while.

Conventional grammar calls this an elliptical clause, because some form of the verb to be is left out.

[I heard modern grammar calls any participle construction a clause, but I have no idea how they'd analyse the syntax of a sentence like this ring, though small, has the power to topple kings, which is quite similar.]