"You remember the names of these birds."
Translation:Jména těchhle ptáků si pamatuješ.
"pamatovat se" requires the "na" preposition and and an object in accusative. Usually it is for remembering some older events, your youth, etc.
"pamatovat si" takes a direct object in accusative.
just "pamatovat" with a direct object means you are old enough to remember something
"pamatovat" + "na" + an object is to keep something in mind, not forget something "zákon na to pamatuje" "the law counts with this"