The 3 R’s of Fish and Wildlife Translocations: Rescue, Reinforcement, and Reintroduction

Symposium
ROOM: RSCC, C1
SESSION NUMBER: 8169
 
Translocations are commonly used in the management of fish and wildlife populations, and recent calls have been made for a paradigm shift towards even greater use of translocations. Translocations are typically implemented to promote the persistence of extant populations or re-establish extirpated populations. Translocated into an extant population are implemented to alleviate inbreeding depression, restore individual fitness, and increase abundance. This has been termed demographic rescue, genetic rescue, and reinforcement by various authors. Translocations into previously inhabited but currently vacant habitat are implemented to establish a population for long-term persistence, ecosystem services, or decreased risk of species-level extintion. This has generally been termed reestablishment or reintroduction. Demographic and genetic concerns overlap for both types of translocations. There are numerous, outstanding questions relevant to of both types of translocations that need to be addressed to increase success and confidence in implementation. This symposium will bring together fisheries and wildlife researchers and managers who have conducted translocations with the goal of understanding commonalities and differences in terminology and project goals. Presenters will be asked to place their research in the context of the framework used here to define types of translocations. We hope that much-needed best practices for implementing and monitoring translocations start to emerge from the symposium. The organizers have extensive experience with translocations in both aquatic (headwater trout) and terrestrial (ungulates) systems. We will invite speakers who have conducted translocations across a wide set of species, conditions, and management goals. We will alternate talks between aquatic and terrestrial presenters to attempt to maximize cross-society knowledge transfer.

8:00AM Introductory Remarks
 
8:20AM Focusing on Values: Decision Analysis As a Conceptual Framework for Integration of Genetic and Demographic Considerations in Conservation Translocations
  Sarah Converse, Chris Funk
Conservation translocations – including reintroductions, re-stocking, and conservation introductions – are an increasingly common approach to addressing the biodiversity crisis. The emerging field of reintroduction biology has brought greater attention to the management of conservation translocations. One clear message from this literature is that decisions about conservation translocations – including the whether, the when, and the how – have two near-ubiquitous characteristics: uncertainty and multiple management objectives. These characteristics, plus the large array of candidate strategies for carrying out conservation translocations, make for a cognitively challenging decision landscape in which managers must operate. Decision analysis is a powerful framework for assisting managers tasked with making decisions about conservation translocations, in which the impediments to decision making can be identified, organized, and analyzed. Both demographic and genetic considerations are typically in play in conservation translocations. Understanding, and focusing on, the management objectives to which these considerations are relevant is key to understanding the predictive tasks that are required to support science-based decisions. Using a variety of case studies, we will demonstrate the ways in which genetic and demographic considerations fit within decision-analytic frameworks for conservation translocations and point to the technical developments needed to better integrate these considerations into decision making.
8:40AM Community-Level Consequences of Conservation Translocations
  Sara Bombaci, Laura Gigliotti, Liba Pejchar, David Jachowski
Assessing the interactions of species undergoing assisted colonization, reintroduction, or translocation (i.e. conservation translocations) with recipient ecological communities has been a research priority since the birth of reintroduction biology. Yet, most research and monitoring efforts remain focused on the demographic recovery of the target species subject to translocation. We suggest that insights from community ecology can help managers achieve a broader interpretation of translocation success, both in terms of restoring target populations and by increasing understanding of the intended or unintended cascading ecological consequences of conservation translocations. Here we highlight two themes emerging from our work at the intersection of conservation translocations and community ecology: 1) we find that community ecology may enhance translocation success by increasing understanding of bottom-up and top-down drivers affecting demographic recovery, and 2) we also explore how studies of community ecology can improve our understanding of the role of translocated species in recovering lost ecological processes. We further draw on other community-level studies on conservation translocations to discuss how core concepts in community ecology, i.e. competition, predation, herbivory, parasitism, mutualism, food webs, and community assembly and diversity, can provide a framework for understanding conservation translocations in a broader ecological context.
9:00AM Reintroduction of Wolves and Wild Boar in a Context of Faunal Abundance
  Göran Ericsson, Camilla Sandström, Shawn Riley
A key concern in translocations is how society will accommodate large species that require vast areas of habitat and potentially create conflicts with humans, especially when prominent faunal changes have occurred since extirpation of species in question. Our objective was to explore human risk perceptions related to wolves and wild boar in Sweden, which were historically native, extirpated, and then were translocated to or re-inhabited the landscape and subsequently increased in abundance. Since the historical extirpation of wolves and wild boar, however, the landscape was re-populated with other species such as native moose, red deer, roe deer, brown bear, as well as non-native fallow deer. To explore how tolerance for wolves and wild boar has changed since reintroduction into faunally-rich landscapes we used longitudinal data (2001-2014) from a survey of attitudes expressed by Swedish resident’s towards wildlife. We tested for correlations between wolf and wild boar populations and human tolerance towards these species through time, and contrast that with populations of moose, bear and human tolerance. Abundant populations of translocated species may reduce tolerance measured as self-reported fear of the emerging species. We present a model for planning translocations aimed at creating greater tolerance of translocated species.
9:20AM Need for a Paradigm Shift in the Genetic Management of Fragmented Populations
  Michele Dudash
Thousands of small, isolated populations or species are threatened from a lack of gene flow that has resulted in inbreeding depression, lower genetic diversity and hence reduced ability to adapt to changing environments, and ultimately an increased risk of extinction. We offer a new management strategy with clear guidelines that incorporates genetics and evolutionary biology and advocate for this approach rather than inaction. Augmentation of gene flow as a management strategy has been underutilized owing to concerns surrounding outbreeding depression. Our collective body of work demonstrates that the risks of outbreeding depression can be predicted, inbreeding depression is ubiquitous, and taxa (populations or species) with lower genetic diversity will experience even greater challenges with ongoing global climate shifts. We review the essential steps of a science-based genetic management plan for diploid animal and plant populations in the context of current practices, and share examples where this management plan has been successfully deployed to encourage others to adopt this approach.
09:40AM Break
1:10PM A Curse of Few Migrants? Genomic Sweeps, Inbreeding Depression, and Extinction
  Zachary Robinson, Donovan Bell, Andrew Whiteley, Marty Kardos
Restoring gene flow to small, inbred populations has the potential to reverse population declines and prevent extinction. However, genetic swamping (i.e., loss of genetic distinctiveness) is a serious concern regarding the restoration of gene flow. The primary way conservation practitioners avoid genetic swamping is by translocating few individuals. However, there is an emerging concern that moving too few immigrants may also have associated risks. In 1997, a single male wolf immigrated to Isle Royale and had extremely high reproductive success. In approximately three generations, he was related to all remaining wolves on Isle Royale and his ancestry comprised 56 % of the genetic composition of the population. A rapid increase in inbreeding and concurrent decline in the moose population contributed to their functional extirpation in 2018. This outcome on Isle Royale inspired us to examine the influence of immigration rate on the population dynamics of small, inbred populations following gene flow. Using individually-based, population genetic simulations, we explore the possibility that genomic sweeps of few immigrants could increase extinction risk in small, inbred populations.
1:30PM Targeting Translocations with Genomic Data: A Case Study in the Arkansas Darter
  Brendan Reid, Sarah Fitzpatrick
Translocations are increasingly popular as a means of increasing genetic diversity in small populations and restoring extirpated populations. In order to function as an effective conservation tool, translocations should consider population structure, current and historic gene flow, demographic history, local adaptation, and evolutionary potential. Genomic data can provide insights into all of these facets of species ecology. We present a framework for efficiently generating genomic data using a hybrid RADseq/sequence capture method (Rapture) in the Arkansas darter (Etheostoma cragini). Coupled with extensive sampling (n> 2000 individuals), we used this method to infer rangewide metapopulation structure, population-level genetic diversity and inbreeding, and patterns of gene flow and selection. We documented strong genetic differentiation among most major river drainages, as well as population substructure within drainages. Genetic drift and inbreeding were most pronounced in Colorado populations, although several populations in Kansas exhibited elevated inbreeding as well. Genomic data suggest that populations inhabiting the middle Arkansas River constitute the best source for translocations to Colorado and also identify several other populations that could benefit from translocations. The framework used here can be applied to other species at risk to objectively identify the most appropriate sources and recipients for translocations.
1:50PM Parturition Synchrony, Sire Structure, and Calf Survival in a Translocated Ungulate Population
  Ellen Pero, M. Colter Chitwood, Barbara Keller, Aaron Hildreth, Leah Berkman, Chelsea Titus, Joshua Millspaugh
Translocated populations may undergo exceptional changes in physiology, behavior, genetics, and demography following release into their new environment. Understanding how wildlife populations respond to translocation events is crucial for increasing project success, improving subsequent management, and, ultimately, ensuring persistence of translocated populations. We reintroduced a population of elk (Cervus canadensis) to the Missouri Ozarks by translocating 106 individuals from Kentucky over the years 2011-2013. We investigated changes in parturition season timing and synchrony across years following translocation and analyzed consequences of birthdate on calf survival. All translocated individuals were fitted with GPS-radiocollars and tissue-sampled for DNA analysis. Subsequently, we captured Missouri-born calves and recorded birthdates, took tissue samples for paternity analysis, and monitored survival. Results indicated increasing mortality hazards associated with later birthdates; however, we found some evidence for shifts in parturition synchrony and timing across years following translocation. We will further discuss changes in sire structure following translocation and subsequent consequences on calf birthdate and survival. Changes in breeding structure are a little considered aspect of wildlife translocations with potential population genetic and demographic ramifications. Understanding implications of translocation on population processes remains increasingly relevant as number and type of conservation translocation activities increase worldwide.
2:10PM The Importance of Developing a Mechanistic Understanding of Population Persistence to Inform Conservation Translocation
  Catherine Jachowski
The increasingly popular practice of conservation translocation involves releasing individuals with the end goal of demographic recovery of the targeted species. However, translocation is increasingly occurring without a mechanistic understanding of why populations are declining. This is important because if, for example, a population is limited by reproductive success, translocating adults is unlikely to result in a self-sustaining population. I will present a case study involving a fully aquatic, long-lived, aquatic salamander, the hellbender (Cryptobranchus alleganiensis), for which translocation of sub-adults has become an increasingly popular conservation strategy. While post-release survival of translocated hellbenders can be high, emerging studies suggest that many extant populations in need of recovery may be limited by poor reproductive success and/or recruitment to the sub-adult age class rather than adult survivorship. Because hellbenders are long-lived, translocating sub-adults may temporarily increase population abundance but ultimately fails to address underlying mechanism limiting population recovery. This example likely applies to other long-lived species, where observed short term translocation success is not indicative of progress towards long-term goals. To address these challenges, I advocate for interdisciplinary approaches that involve the integration of physiological, behavioral and demographic research and monitoring of populations that are the target of translocation.
2:30PM Experimental Tests of Genetic Rescue in Imperiled Salmonid Populations
  Donovan Bell, Zachary Robinson, Ryan Kovach, Andrew Whiteley
Accumulating evidence suggests that restoring gene flow into small, isolated populations can alleviate inbreeding depression and reverse population declines (i.e., genetic rescue). However, experimental tests of genetic rescue remain rare and some taxa are underrepresented in the genetic rescue literature. Several freshwater salmonid species are highly fragmented throughout much of their range and could likely benefit from restored gene flow, but few studies have examined genetic rescue in salmonids. We discuss taxa specific concerns for salmonids, including resiliency to inbreeding depression and fine-scale local adaptation that may increase the risk of outbreeding depression. We additionally present preliminary results from experimental tests of genetic rescue in natural brook trout and cutthroat trout populations. Despite concerns over outbreeding depression and resiliency to inbreeding depression, early results suggest that gene flow increased individual fitness in the first filial (F1) generation for both species.
2:50PM Refreshment Break
3:20PM Impact of Captive-Bred and Wild Allegheny Woodrat Translocations in Indiana and New Jersey
  Jacqueline Doyle, Gretchen Fowles, Joseph Duchamp, Jeffrey Larkin, Gregory Turner, Brad Westrich, Timothy Smyser
Allegheny woodrats have decreased in abundance and range since the 1930s. Decreases in population numbers can be attributed to reduced availability of food resources, habitat loss and fragmentation, decreased metapopulation connectivity and increased parasitism by the raccoon roundworm (Baylisascaris procyonis). The decline has been particularly dramatic in Connecticut, Indiana, New Jersey, New York, eastern Pennsylvania, and Virginia; with individuals extirpated at hundreds of historic sites. In this talk, we synthesize the results of multiple studies of translocated woodrats to sites in Indiana and New Jersey. These experiments incorporated a number of different strategies, including reinforcement and re-establishment events, introduction of captive-bred or wild individuals, and coupling translocations with additional management efforts (e.g., disease mitigation). Although survival and reproductive success of translocated woodrats varies greatly, human-mediated gene flow consistently facilitates increased genetic diversity in previously depauperate populations and often increases population sizes. In some cases, however, genetic gains were short-lived. On balance, however, if root causes of population declines are not ameliorated, ongoing translocation events may help minimize inbreeding depression in isolated populations.
3:40PM Conserving Trout Populations That Have a History of Translocation Efforts, and Exhibit Genetic Drift and Isolation
  Kasey Pregler, Yoichiro Kanno, Daniel Rankin, Jason A. Coombs, Andrew Whiteley
Vertebrate populations at the periphery of their range can show pronounced genetic drift and isolation, and therefore offer unique challenges for conservation and management. These populations are often candidates for management actions such as translocations that are designed to improve demographic and genetic integrity. This is particularly true of coldwater species like Brook Trout (Salvelinus fontinalis), whose numbers have declined greatly across its historic range. At the southern margin, remnant wild populations persist in isolated headwater streams, and many have a history of receiving translocated individuals through either stocking of hatchery reared fish, relocation of wild fish, or both during restoration attempts. In addition to disentangling the impacts of previous translocation efforts, depleted genetic characteristics of these populations can make choosing source populations challenging. We present a case study from South Carolina on managing peripheral populations with depleted genetic characteristics and a history of translocation efforts. Understanding population persistence for small populations is vital and necessitates a greater comprehension of how translocations can be most effectively used to maintain genetic diversity.
4:00PM The Reintroduction of Columbian Sharp-Tailed Grouse to Nevada and Implications for Restoring Lekking Grouse with Translocation
  Steven Mathews, Peter Coates, Shawn Espinosa, David Delehanty
The conservation of lekking grouse (genera Tympanuchus and Centrocercus) is a priority for wildlife management agencies throughout North America, but translocation of these species often fails to restore populations. From 2013–2017, we reintroduced Columbian sharp-tailed grouse (T. phasianellus columbianus) to northcentral Nevada with goals of re-establishing a viable population and of quantifying post-release performance to better inform translocation methodologies. When only the performance of translocated grouse was considered, a Bayesian integrated population model (IPM) forecasted declining population growth. When locally produced offspring were allowed to exhibit differential demographic rates compared to their translocated parents, the IPM predicted neutral (λ=1.00, 95% CRI=0.44–1.78) growth, which was confirmed by an annual increase in observed lek counts. We found yearling grouse to be ideal for translocation because they exhibited higher breeding season survival (0.63, 0.51–0.73; estimate, 95% CRI) than adults (0.46, 0.36–0.56). Paternity analysis demonstrated that offspring from translocated females were sired predominantly by a few previously translocated males that had survived to become residents at the release site. By focusing on factors that enhance reproduction following translocation, wildlife managers may improve population restoration probabilities in future translocations. Some information is preliminary and provided for timely science.
4:20PM Translocations to Enhance Redundancy of Endangered Humpback Chub in Grand Canyon
  Rebecca Koller, Brian D. Healy, Robert C. Schelly, Emily C. Omana Smith
Native riverine fishes of arid regions are particularly vulnerable to the impacts of invasive species and habitat alterations, as many evolved specialized life history strategies for highly dynamic ecosystems (e.g., frequent flooding). Extensive damming and water diversions led to habitat alterations favoring invasive species, and ultimately, the listing of the Humpback Chub (Gila cypha) under the Endangered Species Act. Currently there are 5 populations remaining in the Colorado River Basin with the largest population persisting in Grand Canyon – a population supported by spawning in one tributary, the Little Colorado River. In an attempt to provide for population redundancy and additional rearing opportunities, we initiated a series of translocations of juvenile Humpback Chub from the Little Colorado to other Colorado River tributaries including Havasu and Shinumo creeks, and following invasive trout removal, to Bright Angel Creek. Through mark-recapture sampling, we estimated vital rates of the translocated cohorts, which we compared to estimates from the source population to monitor success. In Havasu creek, Humpback Chub have been observed reproducing and recruiting to maturity, indicating the potential for the establishment of a self- sustaining population. Our results will improve understanding of population dynamics of endangered fishes and aid in recovery planning.
4:40PM Evaluating Success of a Western Pearlshell Mussel Relocation in the Lake Tahoe Basin
  Erin Miller, Shana Gross
The western pearlshell mussel (Margaritifera falcata) has been documented widely in western North America, but many historic populations have been reduced in size from dense beds to a few isolated individuals. M. falcata was once numerous in the Lake Tahoe basin, but today the only known populations are in the Upper Truckee River and the Truckee River. Reach 5 of the Upper Truckee River Restoration Project dewatered and filled in a 7,400 ft reach that contained ~25,000 M. falcata. We prepared for the relocation effort by completing a pilot translocation of 1,075 mussels to evaluate what factors influence relocation success. We assessed mussel size, habitat characteristics, actions associated with relocation (i.e. marking and measuring), and whether individuals were moved to locations with existing mussel beds. One-year post relocation 72% of the mussels were recaptured, however by three years post relocation (and following a high-water year) only 34% of the mussels were recaptured. Habitat variables associated with substrate type, channel unit type, food availability, and local velocity were a significant predictor of mussel condition. Additionally, mussel condition increased when relocated to reaches where mussels were present, and decreased in reaches where mussels were historically, but not currently, present.

 
Organizers: Andrew Whiteley, Joshua Millspaugh, Zachary Robinson, Donovan Bell, Ellen Pero
 
Supported by: AFS Genetics Section

Symposium
Location: Reno-Sparks CC Date: October 3, 2019 Time: 8:00 am - 5:00 pm