Jaeger, or moreover Jäger with an "umlaut", is the common
German word for "hunter". It occurs as a family name in German-speaking countries, but is not used as a given name there.
I think it is hard to really prove that the use of Jaeger as a given name in English is taken from the
German word, but on the other hand it would be a strange coincidence if the two are not etymologically related at all, just written in the same way.
Rene www.AboutNames.ch