Species on the move: things to consider when translocating species

Anchor Island is one of the few predator-free islands off the New Zealand coast were Kakapo are still surviving following translocation (photo by Paul Nevin, http://bit.ly/13vbRaq)

Anchor Island is one of the few predator-free islands off the New Zealand coast were Kakapo are still surviving following translocation (photo by Paul Nevin, http://bit.ly/13vbRaq)

The last QAECO reading group tackled a topic of great interest to all the people in the group, be they Q, A, or ECO. We discussed a new paper in Annals of The New York Academy of Sciences where Mark Schwartz and Tara Martin review the potential use of translocations and managed relocations in the face of climate change, and then explore how these conservation actions lend themselves to a structured decision making approach.

As acknowledged by the authors, the paper was written at the same time as the IUCN guidelines and to a large extent it reflects their content, but the connection with decision theory was what really got us excited. Almost immediately, the most “A” of QAECOlogists (for “applied”) began to think – how can we really start implementing this? What are the key issues that we still need to resolve?

The use of managed relocations to deal with critical impacts of climate change, in which we move species beyond their current or known historical range, has received a lot of attention in recent years. Whilst the most visible parts of the debate naturally focus on bold proposals (perhaps peaking with the idea of “Pleistocene rewilding”), managed relocations have been used as conservation tools for more than 100 years. In New Zealand, for instance, the endangered kakapo and kiwi have been relocated to offshore islands free from introduced predators since the 1890s. We felt this history of managed relocations could have been assessed more openly in the paper and many of us wondered: if we act in the face of climate change, are we simply extending the same concept? What makes this specific application different?

Pleistocene rewilding: a continent too far for a managed relocation?

Pleistocene rewilding: a continent too far for a managed relocation?

In fact, Schwartz and Martin’s advocated approach is largely applicable to most translocation/reintroduction projects: their analysis follows that applied-common-sense approach that underlies structured decision making. They disaggregate the process in three phases,

(1)   conservation needs assessment ,where the current situation is analysed, the vulnerability of the species feasibility and the feasibility of the proposed actions are evaluated, and a comprehensive socio-economic analysis is carried out

(2)   Project planning, where a decision-analytic process is followed, together spatial planning, risk assessment, engagement of stakeholders and the inevitable institutional procedures

(3)   Finally, project implementation, from the collection of specimens to post-release monitoring, but not forgetting to address and resolve potential conflicts in the social environment.

The paper is quite comprehensive and we had a great discussion, with some points in particular emerging.

Invasion ecology and plenty of evidence tell us that we should care about the risks of moving species to new environments, and the full complexity of this issue is acknowledged in the paper, from the actual ecological threat to the social perception of its impacts. In the end, any risk analysis will depend on the objectives of the managed relocation, whether it simply reflects our will to have a species not disappear, or it addresses the need to carry out an important ecological function in the recipient ecosystem. We will need to define measures to judge our ability to achieve these objectives, and then monitor for those measures in the implementation phase: both aspects are a historical weakness of translocation programs, but the growing recognition they receive gives us hope for the future.

We agreed that in many cases, when setting objectives even the simple definition of “managed relocation” may be subject to debate, since the thresholds used to discriminate the historical and geographic ranges may often depend on values. For Australia, we may refer to pre-European-settlement, but what about recent comers such as dingoes? And what about projects where European settlement was much earlier like, for example, Europe? Some might call these criteria “arbitrary”: we’d say they are really value-based, like most conservation decisions. Defining them rigorously and transparently is where structured decision making becomes important.

Finally, it is interesting to note how managed relocations that explicitly aim to counter the effects of climate change are born under the idea of “adaptation” rather than “restoration”. We are not moving a species to an environment that has been restored to some state of choice, but rather to one where we expect things will change in a specific way. This may be a slight but significant deviation from the dominant approach of most conservation biology, and has practical implications, for example, in the capacity of the relocated individuals to evolve.

The complexity of managed relocations makes them ideal testing ground to combine frameworks and tools from a range of disciplines, such as invasion ecology, biocontrol, economics, and our beloved decision-theory. We appreciated the comprehensive way in which Schwartz and Martin advocate for a structured approach to decisions for managed relocations. However, we felt their paper would have been improved by an assessment of the benefits that such a structured approach can provide, for example via a meta-analysis of past projects that have approached at least some of the key decisions in a structured way. This would be an ideal direction for future research.

Managed relocations, and translocations in general, are an exciting, complex topic. Successful programs need good decisions, and these require good science. As you can expect, there are QAECOlogists working on it!

By Stefano, Michaela and team

Stefano is interested in reintroductions and structured decision making. Check out the website for the ACEAS working group he is coordinating, focusing on captive breeding for Australian frogs. He’ll talk about it at INTECOL in London this year – or you may catch him at ICCB in Baltimore in July, talking about making decisions when releasing frogs into the wild.

Michaela focuses on assessing and managing co-threatened species. In one of her PhD chapters she deals with the question of how to translocate interdependent species: you can find out more about it at INTECOL in August.

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Mark W. Schwartz and Tara G. Martin (2013). Translocation of imperiled species under changing climate. Annals of the New York Academy of Sciences, online view. doi: 10.1111/nyas.12050

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