ESA Improvement Act of 2014 - Amends the Endangered Species Act of 1973 to prohibit the Secretary of the Interior from adding a species to the list of endangered and threatened species: (1) if the Secretary has approved a State Protective Action (SPA) for such species, and (2) before the Secretary has made a final determination regarding approval of an SPA.

Directs the Secretary to: (1) notify each state of the opportunity to submit an SPA prior to proposing to add a species to the federal list of endangered and threatened species, and (2) provide guidance to states regarding the preparation of an SPA.

Establishes a process for approving or disapproving a proposed SPA.

Requires the Secretary to review the implementation and effectiveness of an SPA every five years and, if necessary, provide guidance on improvements or revisions that are required to maintain the Secretary's approval of the SPA.

Authorizes the Secretary to: (1) revoke approval of an SPA and propose adding a species to the federal list if the state has failed to implement the SPA or the SPA failed to make measurable progress toward meeting the recovery criteria for the species, and (2) terminate the effectiveness of an approved SPA if the recovery criteria for the species have been met.