I did a google for "écologie égologie" and got 14,500 matches. Translated some and still don't have a clue what it means.
In English, Ego is about the self, the id, the, ummmm, conscious psyche that controls thought and behaviour. It is about an awareness of self, the individuals essential nature, that which distinguishes "self" from all the other "selfs" out there. It has connotations relating to self esteem and self worth.
The word comes from a Latin source.
"Ology" generally means a field of study or an area or branch of knowledge, a scientific discipline, whatever. Like Theology, Geology, etc.
Ecology is the science studying the interactions of organisms with their environment and with each other.
If the two words are used together, and if the French roots are the same as the English roots (likely, I think) then we seem to be discussing the environment of the self (id). Perhaps environment as a parameter in patterning behaviour, where environment is not just physical but also emotional?
Perhaps I am guessing badly and talking crap.
I wonder why I got all caught up in this? Perhaps it was the way (and where) I was brought up.