Article | 29 Avr, 2021

Scientists Say Policy is Urgently Needed for “Assisted Colonization” to help Wildlife Cope with Climate Change 

NEW YORK, 30 April 2021 – New paper in journal Science provides policy guidance for species assisted colonization, which is critically needed in the face of rapid climate change

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Neurergus microspilotus, Iran.

Photo: M. Sharifi

A team of scientists is calling for the Convention on Biodiversity (CBD), which holds its 15th meeting of the Conference of the Parties (CoP 15) in October in China, to launch a process to establish global standards for “assisted colonization,” the practice of physically moving wildlife into new areas to reduce extinction risk from climate change. 

Writing in the journal Science, authors representing conservation organizations and academic institutions from around the world say that CBD CoP15 should empower a technical committee to establish guidelines and protocols, and to establish a risk-benefit assessment for countries to jointly engage in when considering such action, at the same time that existing conservation strategies do not become impediments through lack of forethought and planning.

The authors include Jedediah F. Brodie of the University of Montana; Susan Lieberman of WCS; Axel Moehrenschlager of IUCN SSC Conservation Translocation Specialist Group and Calgary Zoo; Kent H. Redford of Archipelago Consulting; Jon Paul Rodríguez of IUCN Species Survival Commission; Mark Schwartz of the University of California, Davis; Philip J. Seddon of the University of Otago, and James E. M. Watson of the University of Queensland.

Assisted colonization could include moving species poleward in latitude, upwards in elevation, downwards in water depth, or to refugial areas that might lie outside their current or historical indigenous range.

For many species, these movements are currently stymied by barriers from agriculture, cities, roads, and other human infrastructure and disturbance. Assisted colonization could facilitate species conservation by moving individuals of species that cannot disperse sufficiently around these barriers, allowing them to escape from shrinking climate refugia and to establish populations in new locations that have the conditions needed for population persistence.

While some scientists argue that assisted colonization should never be used due to the risk of introducing invasive species, the authors argue now is the time to initiate a formal evaluation of regulatory approaches for assisted colonization, along with regulatory guidance on its implementation.

“The combination of climate change and habitat destruction will just be too much for many species” said Jedediah Brodie of the University of Montana, lead author of the study. “We need a framework to help species move to where they need to go to escape climate change, while minimizing the threat of introducing species that could become invasive.” 

Said WCS Vice President for International Policy Dr. Susan Lieberman, a co-author of the study: “Many governments have not yet established regulations or policy frameworks around assisted colonization but the need for such efforts is increasingly urgent. The accelerating rates of the climate and biodiversity emergencies necessitate engagement from many stakeholders and sectors of society. International leadership through the CBD that brings together experts can provide a model for national policies.”

Said Axel Moehrenschlager of the IUCN Conservation Translocation Specialist Group and Calgary Zoo and co-author of the study: “Increasingly life and death decisions need to be made to help save species.  Assisted colonization is a powerful conservation translocation tool that can help prevent extinction of plants and animals in all ecosystems on Earth. Like many innovations, it needs to be employed thoughtfully to maximize profound benefits for nature and humanity.”
Said Mark Schwartz of the University of California at Davis, a co-author of the study: “Ideas for action consistently run ahead of policy to guide responsible action. As we embrace managing biodiversity on a radically changing planet, now is the time for global governance on how to responsibly engage in assisted colonization, including when not to deploy such actions.” 

Said Philip J. Seddon of the University of Otago, a co-author of the study: “Rapid environmental change is challenging traditional conservation management approaches, such as ecosystem restoration to some arbitrary past target state. We need to recognize that historically suitable sites for some species have or will become unable to support viable populations in the near future, and the barriers to natural dispersal, many of which humans have created, will trap some species and doom them to extinction unless we intervene. We need to be able to assist such stranded species to access suitable areas of habitat, wherever these lie.”

Said James Watson of the University of Queensland and a co-author of the study: “The status quo in how we do conservation will not work—regardless of the level of ambition outlined in climate change and biodiversity agenda—for many species around the world. Climate change, alongside death and taxes, are the only true certainties we face, and nations around the world now need guidance in how best deal to deal with helping species survive the current climate crisis.”

Said Jon Paul Rodríguez of IUCN Species Survival Commission and co-author of the study: “A desired outcome of all the work that we do is the implementation of evidence-based conservation interventions by policy makers and governments. It requires that scientific research be repackaged for multiple audiences, synthesized and adapted to local contexts. Creating international guidelines that reflect the consensus of academics, practitioners, communicators and local communities, for example, is an important gap that must be addressed.”

The authors note that in many cases, assisted colonization translocations may cross international borders, increasing the need for a global body, including the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) and the International Union for Conservation of Nature (IUCN), to establish guidelines for best practices in decision-making.

Ongoing negotiations in advance of CoP 15 will set the course of international conservation for the next several decades, providing a critical opportunity to harmonize policy and set priorities for species conservation and climate change adaptation. CBD CoP15 also has the opportunity to recognize that solutions to the rapid loss of biodiversity and ecosystem integrity caused by climate change can be mitigated by assisted colonization, but guidelines and best practices are needed now.

Said Elizabeth Maruma Mrema, UN Assistant Secretary General and Executive Secretary, and Secretariat of the Convention on Biological Diversity: “The authors usefully raise a number of issues that the global community will need to address in designing viable approaches to species protection in the face of ongoing climate change and ecosystem fragmentation.”


(WCS) STEPHEN SAUTNER: M: +1 908 247 2585;



WCS (Wildlife Conservation Society)
MISSION: WCS saves wildlife and wild places worldwide through science, conservation action, education, and inspiring people to value nature. To achieve our mission, WCS, based at the Bronx Zoo, harnesses the power of its Global Conservation Program in nearly 60 nations and in all the world’s oceans and its five wildlife parks in New York City, visited by 4 million people annually. WCS combines its expertise in the field, zoos, and aquarium to achieve its conservation mission. Visit:

IUCN SSC Conservation Translocation Specialist Group
The IUCN SSC Conservation Translocation Specialist Group (CTSG) aims to ‘empower responsible conservation translocations that save species, strengthen ecosystems, and benefit humanity’ for a vision of ‘a world where courageous action repairs nature’s past damage and secures against threats of the future’. CTSG collaborates with others to plan, conduct, or evaluate any conservation programs that involve translocations in the wild, or releases arising from breeding, propagation, or headstarting. Through science, policy, guidance, training, action, and outreach, CTSG can help enable effective reintroductions, reinforcements, assisted colonization, or ecological replacements spanning all terrestrial, freshwater, or marine ecosystems.

Calgary Zoo
The Calgary Zoo is a globally recognized conservation organization that guides, innovates, and applies scientific solutions to restore some of the world’s most endangered species.  Locally and globally we take action in the wild every day to yield powerful benefits for nature and for people.  Our over 1,000 employees and volunteers are passionate about inspiring people to take action to sustain wildlife and wild places, welcoming over 1.3 million guests annually. As visitors discover the rare and endangered species that we love and care for at our facilities, they are directly contributing through admission and on-grounds sales to a not-for-profit charitable conservation organization that works to fight extinction of plants and animals worldwide. For more information, go to