There are potions of animal speaking. Just use that...
+1 - exactly, they last until long rest and they don't over-write anything and they are cheap.
And they are all over the place. I use them all the time and I generally have 2-3 on hand without every having to buy one. Wasting a spell slot or an item slot is a complete waste when a 30gp potion will solve the problem.
I generally have well over 15k in cash before even hitting the underdark, so I wouldn't sweat a few dozen gp. There are also amulets or rings for most of the useful noncombat spells out there, and a little money and/or searching is a much better use of your resources as every spell slot counts when a fight could be right around the corner.
