Please note: I looked at previous questions before posting this, the situation described here is dissimilar because I am not the competitive one.
Background to question: I am very new to my team (3 months), and I have a senior team member who has been here for 3 years. I have certain technical skills that my senior team member does not.
The situation: This team member has always been, and continues to be, very competitive with me, to the point that this team member tries to "mimic" any project I am working on. So if I say during standup that I am working on A, team member will report next week that he is now working on A, and has made lots of progress on it.
If I say I am working with Person B from another team, team member will create some project to start working with Person B. This team member acts like he doesn't want me to make friends in the company, to which my response is why?
Another example of competitiveness is not looping me into discussions that are relevant to my projects. He is very secretive about what he himself is doing, which I don't care about in general, but I need to know if he's is working towards the same things as I am so that we can either 1) work together, or 2) have one person do it.
We both report to the same manager, who has less friends and less political clout in the company than this team member, so he is pushed around by this team member's aggressive behavior.
I feel I am too new to complain about the senior team member in explicit terms to our manager because I am very new. But the team member's behavior creates confusion on what steps have been completed towards my project, so essentially I am doing useless or duplicate work.
Note that I do ask this team member what he is doing regarding A, and have requested that he loop me into progress on things that overlap with me, and while he is receptive on this and very professional, his actions remain the same.
Question: how do I navigate co-working with a competitive, senior team member in a professional manner?