Ears to the ground 日本語

Doing some googling and I found a few examples. Looks like there are several ways to express this idea.

1. You know it? You've sure got your ear to the ground.
「もう知っているの？耳が早いね」

2. If you want to make a good journalist, always have an ear to the ground.
いいジャーナリストになりたかったら、社会の動向に常に注意を払いなさい。

3. Mary kept her ear to the ground and learned about the promotion opportunity.
メアリーは、昇進のチャンスを見定めていた。

4. I have to keep my ear to the ground to stay on top.
トップにいるために、常に最新の情報を得るようにしている。

5. The producer kept his ear to the ground and signed the young artist to his record label.
そのプロデューサーは才能がある若いアーティストを探し出し、彼のレコード会社と契約をした。

Very nice selection you found. I'm curious about how you went about your search. I also tried to search translations for the phrase, but came up empty handed.