The MVZ acquires specimens and other material from a variety of sources. Historically, specimens were obtained primarily through general and targeted collecting activities of MVZ biologists. While this continues to be an important source of new material for the specimen and tissue collections, the Museum also routinely receives specimens through donations and salvage activities (see "What do I do if I find a dead animal?"). Sources of salvage include incidental pick-ups by individuals, state and federal agencies, conservation organizations, zoos, and wildlife rehabilitation centers. Other sources of specimens include groups involved in special activities such as wildlife or disease monitoring and oil spill clean-ups. Non-specimen-based materials (e.g., photographs, avian sound recordings) are acquired primarily through research activities of MVZ biologists and through donations (see Donating Specimens).