At the height of Washington Park's developmental phase, the area's wildlife saw great changes as certain species were pushed out and away from the new neighborhood, while others adapted to the new conditions. During the 1860s Washington Park was still very undeveloped, allowing wildlife to live in peace and thrive. When the neighborhood began to take shape in the mid-20th century, larger animals like deer left for less populated areas.
Even though the neighborhood existed at this point, smaller wildlife was still a very common sight, as the area was still zoned as farmland. As Washington Park grew, smaller scavengers such as coyotes, foxes, raccoons, and opossums moved into the area. These animals typically wandered between developments and the train tracks looking for food.
When the zoo came along in 1892, Washington Park caught a glimpse of exotic animals from all over the world -- animals like elephants, polar bears, monkeys, bighorn sheep, and exotic fish. Additionally, the various lagoons that Olmsted had designed in the park brought new populations of waterfowl to the area. Ducks and geese that otherwise would have avoided the area entirely utilized this newfound access to water.