Yes 1-4 eyelashes falling a day is normal,eyelashes are kinda like hair they fall and then grow back. Hope this answers your question!
Answer:
New predatory animals .
Explanation:
A valid reason on why a "predatory" animal would disappear or decrease in great numbers is new animals being involved such as animals eating those "predatory" animals or them eating the food source of the original animal . Humans are also a factor but i'm pretty sure they are not hunting them ! I hope this helped