Hi @JenniferS - it's hard to tell which species of rat this is without seeing the full tail. However, the large ears and that it has climbed up to the bird bath suggest a black rat (Rattus rattus).
Thanks for the extra pictures. Given the length of the tail (it looks long in the second picture), the size of the ears (will reach the eyes if folded forward) and the clear climbing ability (black rats are very good climbers whereas bush rats tend to stick on the ground) I think its a black rat.