Allowing your pictures to be used in a magazine

[MontanaZoo]

I just received a flickr mail from someone. Usually, the zoo just goes fine, use our pictures (that are my pictures) for whatever magazine for free. But I'm starting to wonder, should I as the photographer be asking for compensation? I volunteer for the zoo and let them use the pics for free but this person is contacting me directly and not the zoo. What would you do?

Picture request French Magazine
Dear,

I am french picture editor for the magazine Science et Vie Découvertes. I am going to writte an article about the enrichment in zoo. I would like to us a picture you did: www.flickr.com/photos/juliez_pics/254407056/

Are you ok?
Please, let me know quickly, my requets is really urgent.
Best regards,

French name that I edited out
Picture Editor