In page 37 panel 1, there are 2 rabbits sitting down and talking. What nationality do they represent?
I am proceeding from the assumption that you're referring to panel 1 of page 35.
Truth be told, the answer is probably that they aren't intended to represent any particular nationality. As per the answer to Why were these animals used to represent the different countries in Maus?, Spiegelman is on the record that he only made specific choices for animals and nationalities in a few cases, and for the rest, he just drew other animals.
As the book was coming to a close, I really couldn’t have cared less about my metaphor, but I was stuck with it. People would ask me, “Oh, how would you draw us Italians?” and I as always stumped. I just had to deal with each of these issues as they came up, and it led to the whole sequence in Maus II of talking to Françoise about how to represent her. In a way I started reaching for the absurd to make sure one didn’t take the ruling metaphor at, um, “face” value.