Our Gemara on Amud Aleph explains, regarding the commandment to cover the blood of a slaughtered bird or wild animal:

⁦With regard to one who slaughtered a non-domesticated animal or a bird and is obligated to cover the blood, if he covered the blood and it was then uncovered, he is exempt from the obligation to cover it a second time. However, if the wind blew dust and covered the blood and no person was involved, he is obligated to cover it. Rabba bar bar Ḥana said that Rabbi Yoḥanan said: They taught that he is obligated to cover the blood after the wind covered it only if the blood was then exposed. However, if it was not then exposed, he is exempt from the obligation to cover it.

Hamiddos L’Cheker Halacha (II:15:69 “poel, pa-ul, and poel yotzeh”. Rav Moshe Avigdor Amiel 1882-1946) notes the difference between the Mitzvah of covering the blood and Hashavas Ha-Avedah. Why is it that one is continuously obligated to return a lost object, “even 100 times“, that is, each time it gets lost you have to return it to the owner, unlike the commandant of covering the blood, which when covered first by a person, even if the wind uncovers it, you are no longer obligated to cover it again?

He explains as follows: A Mitzvah whose obligation at its core comes from an obligation upon a person, then its obligation remains continuously in effect. On the other hand, an obligation that is stemming from the object, once that objective is met, the obligation is fully discharged. Thus regarding covering the blood, there is a requirement that the blood is covered but not necessarily on the person, while the obligation to return a lost object is upon the person to do it to the object. Sending away the mother bird is also seen as an obligation on the person, and thus the Gemara also ruled one must do it “even 100 times”. 

In actuality it’s ambiguous often if the mitzvah is on the person or the mitzvah is on the object. Rav Amiel explains the various derashos in the Gemara regarding different mitzvos aside from the ones above, such as burial and bris milah in a comprehensive clear manner. 

I will add that there is an ethical idea being expressed as well through these halachos. Any mitzvah that is merely an obligation upon an object, can be dispensed with through a ritualary action. However, when a person is obligated, even if the Obligation is toward the object, it cannot be dispensed with in a one time manner. The upshot is that personal responsibility is broad and eternal.