Comic book writer and novelist Greg Rucka (Stumptown, Queen and Country) answers a frequently asked question in an incisive essay for io9 titled "Why I Write 'Strong Female Characters'".
The entire piece is well worth a read, but here's the key passage:
Writers don't write Men or Women or Dogs or Salmon. Writers write characters, and at our best, if we do it well and with care and with thought, we invest in those characters a spark of life, a realism and nuance that makes them believable and relatable.
Rucka also questions why journalists don't tend to ask female writers how they write "strong female characters," and why more male writers don't do the research about their female characters, the way they would with any other character whose experience differs from their own.