Can early riser used in a similar way as early bird?

Hi I always say early bird but I have heard people use the term early riser. Do they convey same meaning?

Yes, when it comes to waking in the morning, they are just about the same thing.

An early riser is "Someone who rises (gets up) early in the morning."

An early bird is "A person who wakes early or arrives early, typically before most others," and comes from the expression, "the early bird catches the worm," suggesting someone who does something before everyone else and therefore has a competitive advantage.

However, although both can be used to describe someone who wakes early, both cannot be used to describe someone who does something first.

An early riser wakes early. An early bird answers ELU questions first!

I think they are actually a fair bit different.

An "early bird", by implication from the old saying, is someone who is actually going out working on the day's activies (or some particular thing) as early as possible.

An "early riser" on the other hand, is just someone who wakes up relatively early. They may not actually start working on anything productive, but rather use that extra early time for reading, devotion, playing crosswords, etc.

In other words, an "early bird" is almost certianly out of their night clothes early as well, while an "early riser" might not be.