If it's not drought, it's some disease...
like TB. EHD, CWD, blue tongue, abcessed brain disease or whatever. (could have fouled up the initials)
If a 16 year old archer doesn't take the trophy in an adjoining property, something else will prevent a number of 3 1/2 or 4 1/2 year olds from surviving.
Saw one owner who spends much time and money on getting an older herd, lost two shootable trophies before the hunting season opened in 2012. I can feel his pain.
Depend on nature, and it will extract some price.