Transferring Translocation Science to Wildlife Conservation on DoD Installations: Demonstration of Environmental Enrichment and Soft Release Technology

Dr. Brett DeGregorio | U.S. Army Engineer Research and Development Center - Construction Engineering Research Laboratory



As wildlife populations decline and their habitat is fragmented or lost, land managers are adopting active management approaches such as wildlife translocation to maintain or augment viable populations. Translocation is the intentional release or movement of animals in the wild for the purpose of establishing a new population, augmenting a critically small population, or moving at-risk animals. Despite substantial investments of time, energy, and resources, these endeavors fail to meet their objectives in upwards of 50% of cases. They often result in higher mortality rates or failure of the translocated animals to establish a population. The practice, however, is becoming more common on private, state, and federal lands including on Department of Defense (DoD) installations. This project will demonstrate and validate two promising translocation techniques (soft release and environmental enrichment) that can potentially and cost-effectively improve the success of translocation projects on DoD installations.

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Technology Description

Most translocation programs move animals from their capture location or captive housing to the release site and then let them go. Released animals often are disoriented and make long, erratic movements increasing their likelihood of injury or death. Soft release entails holding individuals in outdoor enclosures at the release site for some period of time prior to their release. This allows animals to experience local environmental conditions and develop fidelity to the release area. Soft release enclosures may be as simple and inexpensive as fenced areas of the release site or more complex enclosures designed to expose the enclosed animals to important food and shelter items or habitat features. Soft release encourages animals to exhibit natural behaviors such as foraging and refuge seeking and has proven effective for a number of successful translocation projects. Limited time in these soft release enclosures (two to six weeks) enables animals to acclimate to the local environment and form an affinity with the area to prevent immediate dispersal from the release site and into potentially unsuitable surrounding habitats.

Environmental enrichment entails housing pre-release animals within complex captive enclosures that stimulate ecologically relevant brain functions and behaviors. This may include providing animals with natural substrates, climbing structures, companionship, retreat sites, or live, natural prey items. The behavioral benefits of environmental enrichment have been documented for a wide range of taxa and most importantly may increase the survival of wildlife post-release in translocation projects.

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Wildlife translocation is a promising and high profile management approach. Failed translocation efforts are costly and can draw severe negative publicity. If soft release and environmental enrichment techniques can be demonstrated to improve the survival of wildlife post-release to establish or contribute to viable populations, the DoD will benefit by reducing training restrictions, fulfilling federal regulatory mandates (e.g., Endangered Species Act, Sikes Act), and garnering positive public relations. If soft release and captive enrichment increase survival of post-release animals, the duration of translocation projects can be reduced. This could result in substantial cost savings. (Anticipated Project Completion - 2019)

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Points of Contact

Principal Investigator

Dr. Brett DeGregorio


Phone: 217-373-7253

Program Manager

Resource Conservation and Resiliency