Hi!
I’m also applying for zoology this year!!
A lot of people in my year have done research projects- ranging from literature reviews to full blown studies published in pretty reputable journals. Most of them are applying to ivies and oxbridge so they’ve done it to make their applications look even better. It can certainly benefit your application, though the degree to which it will will really depend on if you get it published and where (from what I’ve heard)
I had wanted to do one myself though time has suddenly run out! If you still have the time and have something you’re interested in looking into, i’d say it’s a great thing to do as you can talk about it in your personal statement to highlight your interest in the subject.
I’m relying on my volunteering experience and extra projects now but I think they still convey my love for the subject pretty well 😄