Welcome to the Canon Forums and thanks for your post!
Whenever somebody replies in a thread after you, the forum will display the name of the most recent person to post on the main page view. On the 'Wildlife' thread, your pictures are the most recent post which is why you see your name on that thread. However, a few people have posted after you on the 'Fall' thread, which is likely what you are seeing.
We hope this clarifies and look forward to your contributions!