Planning translocations under a changing climate

Just before Christmas I attended the British Ecological Society Annual Meeting at the University of Birmingham and saw a talk by Alienor Chauvenet of ZSL. Her talk, entitled 'Planning translocations under a changing climate' used the example of the hihi, Notiomystis cincta, to explore some ideas she originally proposed in her paper in Animal Conservation last year (reference below).

Chauvenet noted, as I have in my systematic review of plant reintroductions, that climate change is very rarely cited as a motivation for undertaking translocations. However, climate change is not an issue that should be only be tackled when we discuss the pros and cons of assisted colonisation and other types of conservation introduction. Climate change has the potential to irreversibly alter the distribution of suitable habitat and therefore, needs to be accounted for in translocation projects whether it is a reintroduction or an introduction to new sites.

Both her paper and the BES talk propose a combination of methods to ensure that site selection in translocation projects maximises the success of reintroductions and assisted colonization under climate change. The strength of using a variety of methods to attempt to select translocation sites is made clear in

Translocations and genetics - a simple summary of a complex subject

This may be a bit of a cop out but I wanted to blog about some of the issues surrounding genetics and translocations and found this post on the excellent Conservation Bytes blog run by Corey Bradshaw.  The author, Dr Salvador Herrando-Perez, has done a much better job than I could so I encourage you to follow the link below:

http://conservationbytes.com/2013/01/14/translocations-genetic-rescue-paradox/

Interdisciplinarity and definitions of reintroduction

I’m sure many of the readers of this blog will be aware of the importance of interdisciplinarity in finding solutions to environmental challenges.  However, I admit that when I was working on the IUCN Guidelines for Reintroductions and Conservation Translocations, I felt that we were writing for an audience of conservation practitioners and while this involved using plain English, it required little consideration of disciplines beyond ecology.  Just how narrow my perspective was, was made clear to me when I attempted to respond to a paper by an environmental historian, Dolly Jørgensen (2011) on the concept of historic range.  The subtlety of the difference between 'historical range' and 'native range ... in historic times' was quite an eye-opener especially if you followed her arguments to conclusion to look at the impact it might have on translocation practice.

On her recommendation, we have adopted the term ‘indigenous range’ as a replacement for the problematic concept of historic range but I found that writing the first the definition of indigenous range was very challenging.  The process of honing this key definition was made much more rigorous by the thought processes I went through in responding to Jørgensen's paper (Dalrymple & Moehrenschlager 2013). Whilst we didn't agree with all her assertions, the process of being challenged was constructive and insightful.

So my message today is that interdisciplinarity is important because it has the potential to throw in a wildcard - something you can't predict but should still be responding to.  It challenges and ultimately improves our actions and in the potentially emotive arena of conservation translocations it should be something we all incorporate from the outset of any species recovery attempt.

Dalrymple, S. E., & Moehrenschlager, A. (2013). “Words matter.” A Response to Jørgensen’s Treatment of Historic Range and Definitions of Reintroduction. Restoration Ecology. doi:10.1111/j.1526-100X.2012.00932.x

Jørgensen, D. (2011). What’s History Got to Do with It? A Response to Seddon's Definition of Reintroduction. Restoration Ecology, 19(6), 705–708. doi:10.1111/j.1526-100X.2011.00834.x

Translocation digest - January 2013

This post is the first of a new monthly digest which will feature brief descriptions of translocation projects and related news.  As those of you who regularly read my blog will know, most of my posts cover a journal article or news story on a particular species or aspect of translocation practice. However, this doesn't do justice to the number of ongoing projects there are and the monthly digest aims to represent this.  As ever, please let me know if you want any projects featuring in the digest or as a longer post - I'm hoping this addition will prove valuable to the translocation community so feedback always welcome.

Translocation projects:

Bighorn sheep not being reintroduced into Bridger Mountains yet KTVQ Billings News Instead of an immediate reintroduction, FWP plans to work with sheep owners in the Bridgers to help reduce the risk of contact between domestic and Bighorn sheep. The aim will be to create a better opportunity for success with a future reintroduction.

Kihansi Spray Toad Reintroduced into its Native Habitat Student Operated Press The Wildlife Conservation Society`s Bronx Zoo, the Toledo Zoo, Tanzanian government, World Bank and other partners have reintroduced 2,000 Kihansi spray toads into the Kihansi Gorge in Tanzania. Changing locations fail to mitigate man-beast conflict, says ... The Sunday Times Sri Lanka By Kumudini Hettiarachchi Translocation of elephants, undertaken to mitigate the human-elephant conflict and conserve elephants, does not reduce the conflict or save elephants but causes an increase in the conflict and deaths of elephants, is the surprising finding of a study conducted in Sri Lanka.

Publications:

Sarah E. Dalrymple & Axel Moehrenschlager (2013).
"Words matter." A response to Jorgensen's treatment of historic range and definitions of reintroduction.
RESTORATION ECOLOGY vol 20 (6) DOI:101111/j. 1526-100X.2012.00932.x

Turlure, C., Radchuk, V., Baguette, M., Meijrink, M., van den Burg, A., De Vries, M. W. and van Duinen, G.-J. (2012), 
Plant quality and local adaptation undermine relocation in a bog specialist butterfly. 
Ecology and Evolution. doi: 10.1002/ece3.427

Reintroduction or ecological replacement? Or both?

Firstly, happy new year and apologies for the break in posts as a result of my baby girl falling ill (she's now better) and Christmas. Normal weekly service will now resume and I have a backlog of posts to bring you of which this is the first.

The idea for this post was prompted by a widely-reported paper on the genetic legacy of Lonesome George, the last known purebred individual of Chelonoidis abingdoni, or Galapagos giant tortoise native to Pinta Island (Edwards et al. 2013, authors webpage here). The discovery of individuals with very similar genetic ancestry on another island (Isabela Island) provides hope that hybrids with C. abingdoni parents could be taken into captive breeding programmes to produce tortoises that might be translocated to 'back' Pinta Island. The authors suggest an interesting strategy of tiered translocation whereby any individuals with a very high genetic similarity to the extinct Pinta Island tortoises are saved for the captive breeding whilst hybrids that are further removed (offspring of hybrids rather than purebreds) are moved directly to Pinta, the former constituting reintroduction albeit with a little genetic mixing, the latter being an example of ecological replacement (see page on definitions). This would be motivated by the need to restore giant tortoises as ecosystem engineers and would hopefully improve the habitat quality prior to release of the 'purer' individuals.

On reading this, I went back to another paper from three years ago (Hansen et al. 2010) in which the authors discuss the pros and cons of a range of translocations of large and giant tortoises. Back then, Lonesome George had mated unsuccessfully with females of a similar subspecies but there was still hope that

1 million fish reveal translocation and captive-breeding synergies

The translocation described in this post could be an example of assisted migration although not in the sense that this is a climate change-motivated intervention. The movement of the Chinook salmon described by Holsman et al (2012) is assisting migration by transporting fish passed hydroelectric dams from the spawning headwaters to the ocean. As someone who has worked with threatened species and the small numbers of individuals this normally entails, I am envious of their sample size - over 1 million tagged fish made up the dataset and allowed an exceptional number of explanatory variables and interactions to be explored.


Key to their findings are the fact that their million fish represented wild and captively reared individuals, and translocated fish (moved down river) and non-translocated fish (in-river migrants) in all combinations over the period 1998 - 2006. They found that the origin of the fish and whether they were translocated around the hydropower schemes interacted synergistically on fish mortality: captive-reared fish benefited from being transported while wild fish were detrimentally affected by translocation. The latter occurred despite the fact that transportation should minimise deaths associated with migrating through hydropower systems.


The authors go on to explore a range of factors affecting survival in the marine environment before concluding with three important recommendations for management. Firstly, that the effects of management and environment can interact and this must be considered at the outset of any conservation programme. Secondly, that the survival translocated or captive-bred populations cannot be predicted from survival of wild populations because the intervention can alter some of the key phenological, behavioural, genetic and demographic parameters of a cohort. Thirdly, and I feel most importantly, practitioners should adopt an adaptive management approach. Whilst Holsman et al (2012) have the benefit of 1 million fish in their dataset, all translocation projects can improve the ability to identify and respond to unexpected and detrimental outcomes if translocated plants and animals are followed throughout the translocation programme on an individual basis.  As a systematic reviewer of plant reintroductions, I can vouch for this recommendation - survival analysis of an entire cohort is much more diagnostically powerful than samples of an already small population. However, I know it is easier said than done if you are say, trying to reintroduce a plant using seed, but it's not impossible and the rewards for the success of the project are more than worth it.

Holsman, K. K., Scheuerell, M. D., Buhle, E., & Emmett, R. (2012). Interacting Effects of Translocation, Artificial Propagation, and Environmental Conditions on the Marine Survival of Chinook Salmon from the Columbia River, Washington, U.S.A. Conservation biology : the journal of the Society for Conservation Biology, 26(5), 912–922. doi:10.1111/j.1523-1739.2012.01895.x

Definitions of conservation translocation

This post is just to highlight the fact that I've updated the 'definitions' page on this blog (see top tabs to find the different pages).  Definitions are key to a discipline such as this one, where confusion in terminology generates a host of uncertainties about the motivations, appropriate methods and policy implications for species conservation.  For this reason, the IUCN Task Force charged with revising and expanding the Guidelines for Reintroductions and Other Conservation Translocations spent a great deal of time scrutinising the definitions and testing their applicability under a range of scenarios and case-studies.

The new definitions for conservation translocations include a shift from 'historic range' to 'indigenous range' and the following interventions:

• Population Restoration - including reinforcement and reintroduction
• Conservation Introduction - including assisted colonisation and ecological replacement

The full Guidelines are available in an interim version just now (please email me if you would like this version) but will be freely available on the IUCN Re-introductions Specialist Group website in the final format soon.  There are also plans underway for translation of the Guidelines into several languages and hard-copies to be made available.

Sensationalist press coverage - is this always the way the general public will see our work?

This is just a quick post today, and features an article in Engineering & Technology magazine which in turn has quoted me.  I was pretty relieved to see that I'd been quoted appropriately and I come across as a voice of caution.  However, the real reason I'm blogging about it now, is because it raises questions about the 'face' we present to the non-specialist audiences when translocations are covered in the media.

E & T magazine has a print circulation of 180,000, mostly professional engineers, and is published online.  If we assume this is the first time many of these readers have heard about assisted migration, it presents quite a controversial picture.  Importantly, careful reading of this article reveals that it is well-balanced in its portrayal of when out-of-range translocations should be used, but how many people read this sort of article carefully?  Instead, will the take home message to many engineers be that biologists can sort it out - we're not there yet but it won't be long before we can move threatened species with certainty.  Is that the message they will read because that's the message they want to see?

Of course, I don't want to polarise engineers and biologists as 'them and us', we're going to have to work closely to make sure ecosystem functioning is protected whilst we continue to develop the infrastructure to house, educate and employ the 7 billion people on the planet.  But how do we communicate a more nuanced message that can actually achieve results?

Pool, R. (2012). Assisted migration and the ethics of playing  'eco god'. Engineering & Technology Magazine, 7(11). Available at: http://eandt.theiet.org/magazine/2012/11/move-it-or-lose-it.cfm

Have the guidelines really sunk in?

This post features a paper by Irene Perez and co-authors (2012), and is a wake-up call for those of us undertaking translocations as it reports on the lack of compliance with 10 key criteria for evaluating translocation projects. None of the criteria will be new to anyone who has read the IUCN Guidelines on Re-introductions (1998) and so it is pretty shocking to see that the median number of criteria in published studies is three, and in a dataset of Spanish translocations used to avoid publication bias, the median number of criteria used rises only to five. Even if, as the authors acknowledge is possible, the publications and reports neglect to mention criteria that were addressed in any feasibility assessment of translocations, it seems appropriate to expect that a full rationale of every translocation is available for all stakeholders to view.

Perez et al. go on to propose a propose hierarchical decision-making system, represented as a flow chart.  It is sensible and easy to apply to real examples of candidate species for translocation. However, I worry that with all attempts to provide a framework for complex decision processes, some of the important detail is omitted.  Ultimately, the responsibility of properly interpreting the decision-making system is left with the person undertaking a translocation and this framework might be open to misuse whether intentional or not.  For example, the second level of the decision-making system asks if risks are posed to the target species, other species or ecosystems by undertaking a translocation.  As Perez et al. have demonstrated, risk evaluation is not a strong point in the translocation community and the comprehensiveness of risk assessment will vary enormously based on practitioner capacity and data availability. Further, the dichotomous outcome following the question on risk is presented as 'intolerable risk' versus 'tolerable risk' and this is a subjective decision that I know from experience would divide stakeholders in species conservation.

It seems to me that we need to get better at explicitly addressing guideline documents and particularly the area of evaluating risk potential in terms of the target species and other species and the ecosystem at both the donor and recipient sites. We also need to develop robust ways of judging where the balance lies between tolerable and intolerable risks and involve stakeholders in this decision. There is plenty of treatment of risk in the scientific literature but as far as I'm aware (and Perez et al.'s paper would support me on this), few examples of practical assessments of risk prior to a proposed translocation. If someone out there is already doing this please make yourselves known - we need to learn by your example!

Pérez, I., Anadón, J. D., Díaz, M., Nicola, G. G., Tella, J. L., & Giménez, A. (2012). What is wrong with current translocations? A review and a decision-making proposal. Frontiers in Ecology and the Environment, 10(9), 494–501. doi:10.1890/110175

Combining data-led methods with expert opinion - how Bayesian approaches can bridge the gap between academia and practice.

With hindsight, I have mistakenly avoided Bayesian approaches to ecological modelling  because they incorporate prior beliefs. The quantitative scientist in me thought that this sounded a little too vague to be of use in conservation and would surely fall foul of bias towards preconceived ideas. However, after reading the paper featured below and the detailed supplementary materials, I am now a convert to Bayesian techniques and hope to incorporate them into my work in the future.


Laws & Kesler (2012) have developed a model for selecting translocation sites for the Guam Micronesian kingfisher (GMK), Todiramphus cinnamominus cinnamominus and to me, it seems like an excellent way of combining quantitative methods with common sense whilst incorporating the complexity of issues involved in selecting suitable sites for translocation. The best way I can explain their approach is to describe their inference diagram: imagine a tree where the main thing we're interested in, island suitability, is the trunk. The trunk splits into four branches representing ecological requirements, impacts on native species, anthropogenic threats and operational support. The tree continues to branch until the generic factors associated with any translocation (e.g. presence of disease, habitat protection laws, food availabilty) give way to GMK-specific factors (e.g. West Nile virus, protected areas, insect prey). At that point, my tree analogy breaks down because some of the 'twigs' feed into several branches but hopefully, you appreciate that this is a relatively straightforward way of representing the complexity in the GMK's translocation needs.


The next job is to assign conditional probablities to each of the factors that contribute to island suitability. For habitat suitability, the two components of available area of suitable vegetation and the extent of habitat fragmentation were modelled using data from 156 Micronesian islands and the occurence of kingfishers of the same genus as GMK. This was used as training data for the GMK model to select candidate translocation sites from 239 island. The rest of the modelling process relied on qualitative decisions to set categorical outcomes, for example, if predatory non-native species were present, the island would be deemed unsuitable. These were then translated into quanitative combinations for the purposes of the judging each island's suitability (see appendix A of the paper for more details).


Only five islands were considered suitable for GMK translocation and even then, they were thought to require varying levels of management. Site visits to the five islands found two of these to be unsuitable due to degraded habitats and lack of political support. The authors caution that the models are only as good as the input data they are built on.


I can see from Laws & Kesler's paper that Bayesian methods have real potential for bridging the gap between expert knowledge and data-driven correlative methods. However, we still need people with the statistical know-how to reach across the gap. Any volunteers?

Laws, R. J., & Kesler, D. C. (2012). A Bayesian network approach for selecting translocation sites for endangered island birds. Biological Conservation, 155, 178–185. doi:10.1016/j.biocon.2012.05.016