Some zoologists and wildlife biologists are involved in conservation work, helping to understand and preserve at-risk populations of animals. They may also work to set up and maintain good environments for animals in nature preserves and zoos. Zoologists usually are identified by the animal group they study. For example, ornithologists study birds, mammalogists study mammals, herpetologists study reptiles, and ichthyologists study fish. Zoologists and wildlife biologists, particularly those in academia, may spend a significant amount of time writing.