"Do you see those animals?"
Translation:Widzisz tamte zwierzęta?
te and tamte are the same. the only difference is that tamte is more specific. "Czy widzisz te ptaki?" "Do you see those birds?" "Nie, nie tych ptaków." "No, not those birds." the guy points to a different set of birds and says: "Czy widzisz tamte ptaki?" "Do you see those birds?" At least that is my understanding... Please let me know if I'm wrong.
In Polish, "tamte" is really "those ones over there", so it has to be translated as "those". It's used a lot more seldom than English "those".
"Nie, nie tych ptaków" doesn't make much sense, I'm afraid. It could work if there was some context that needed Genitive already (Szukasz tych ptaków? = Are you looking for these birds), "Nope, not these ones, the other ones". But... still rather unusual. Here, as you don't actually have a negated verb, you don't have the Accusative->Genitive change.
than what is "te" in English? and it would be in Dopełniać because of negation. I figure you would just assume the verb is thrown in there because of the story. "Nie widzę tych ptaków." but what is the difference in "nie widzę tamtych ptaków." I feel like it just being more specific.
The direct translation of "te" (here: "tych") is "these". But "those" works as well. As "te/te/tamte" = "these/those/those".
Yes, it would be dopełniacz (Genitive) because of negation, but only because the positive sentence took Accusative. Only Accusative changes the case when negated.
"Nie widzę tamtych ptaków" is like "I don't see those birds over there" - correct, but a bit unusual.