[GRASSLIST:3999] texture analysis and r.out.tiff output

Hi -

I am running texture analyses on individual Landsat bands using 
r.texture (using the contrast measure).  In order to produce a 
directionally invariant texture image, I am taking the average of the 
four ouput rasters, using r.mapcalc.

When I export the final result to a tiff image using r.out.tiff, I get a 
3 band image, and I'm not sure why.  I have only been using the first 
band for further analyses, but want to be sure of what I am leaving 
out.  Does r.out.tiff always create a multiband output image?   Or is it 
related to the r.texture output?

Thanks for any help on this!

Murray Richardson