立つ鳥跡を濁さず
(Tatsu tori ato wo nigosazu; “The bird taking flight doesn’t muddy its tracks”)

Definition:

When you leave a place, don’t leave it a mess – leave it at least as pristine as the condition you found it in. Clean up after yourself when you go home. Leave things better than how you found them.

Breakdown:

This saying is a full sentence. The subject (albeit unmarked by any particle) is 鳥 (tori), “bird,” modified by the verb 立つ (tatsu) – often “to stand,” but in this case “to take flight,” in prenominal form. The sentence’s direct object – as marked by the particle を (wo) – is 跡, “trace,” “mark,” “footprint,” etc. And the verb that (isn’t) done to this object is 濁す (nigosu), “to roil,” “to muddy.” This verb appears in imperfective form with the negative suffix ず (zu) in sentence-final form.

Notes:

The specific image is of a wading waterfowl such as a crane, taking off to fly without kicking up mud from the bottom and dirtying the water in its wake.

Some versions replace 立つ with the more prosaic 飛ぶ (tobu), “to fly,” or 濁さず with 汚さず (yogosazu), “(don’t) make dirty.” One version specifies that the bird is a heron, 鷺 (sagi).

This saying is also attributed to the Kefukigusa.

Example sentence:

「立つ鳥跡を濁さずで、花見が終わったらちゃんとゴミを拾うの忘れないようにね」

(“Tatsu tori ato wo nigosazu de, hanami ga owattara chanto gomi wo hirou no wasurenai you ni ne.”)

[“Like the bird that takes flight without muddying the water, let’s not forget to pick up the trash properly once the flower-viewing has ended.”]