Did you load the game as your mayor or another existing character? If you did, you can't reset now. If you want to avoid getting species you want, as long as you have less than 10 villagers, use a new character to check for plots in your town.
I like the chickens in the game. Maybe your new villager will grow on you, I had a bunch of villagers I didn't like at first but ended up really liking. It can just take some time. If you really do hate them, you can always be patient and move them out as soon as you can.