Mesos in the Middle: Strategies for Researching Understudied or Elusive Mid-Sized Mammalian Carnivores

Symposium
ROOM: Room 140 – Aztec
SESSION NUMBER: 23
 
Mid-sized carnivores are prevalent in most ecosystems on the planet, yet they are likely to be underappreciated for the role they play in these environments. The mesopredator release hypothesis suggests that some of these mid-sized carnivores may be on the rise, a result of declining apex carnivore populations. Conversely, several mesocarnivore species are in decline, or lack adequate information to inform conservation status. This symposium is structured to provide an overview of the objectives and methods frequently considered when embarking on research of understudied mesocarnivores. Following an introductory talk on the ecological role of mesocarnivores, presentations will proceed to address three common avenues of wildlife research: monitoring, demographic studies, and collaborative efforts. We will conclude the symposium with two talks that go “beyond research,” during which speakers will address the ways that biologists can synthesize research results to promote informed management actions. This symposium will cover such topics as emerging techniques, like GPS technology for small mammals, and the potential of collaboration between independent researchers and the public for wildlife studies. Further, it will highlight important objectives that should be considered when investigating cryptic and poorly understood carnivores and will provide insights and considerations for addressing some of these difficult objectives. This symposium will focus on material for both researchers and managers, sequentially building on methods to increase our knowledge of the biology, ecology, and potential implications of management (or lack of management) for rare and elusive, mammalian mesocarnivore species.

1:10PM Understudied But Not Forgotten: The Importance of Mesocarnivores to Community Structure and Function
  Gary Roemer
Large mammalian carnivores are often beautiful, sometimes graceful, usually powerful, and frequently invoke fear in humans owing to their potential to cause harm. Revered and loathed, large carnivores have been persecuted to the point where many populations are in jeopardy and some species near extinction. The decline in large carnivores may have allowed the expansion of their smaller relatives, the mesocarnivores, which has now caught our collective attention; studies of mesocarnivores are on the rise. However, mesocarnivores were always far more speciose than large carnivores, with nearly 90% of all terrestrial carnivores weighing less than 20 kg, and although their population and community-level effects are less well known, they have been ubiquitous and ecologically relevant all along. Mesocarnivores may act as apex predators depending on ecological context, they can directly control prey populations and may interact with them to cause population cycles. Mesocarnivores disperse seeds and prey upon seed dispersers influencing not only plant species distributions, but plant landscape genetics as well. Through their scavenging, they clean up carrion and thus may thwart the spread of disease, while they themselves may carry and spread disease to other wildlife species, our commensals, and even us – their myriad ecological roles are being continuously exposed as more species are studied. I suggest that: 1) the ecosystem services they provide have only begun to be elucidated, and 2) studies that focus on the natural history of mesocarnivores, their autecology and synecology, will expose additional ecological roles similar to or perhaps completely different from those of larger carnivores. Given that many mesocarnivores can live near humans, their ecological roles will likely become more pertinent as humans encroach upon and impact natural environs. Up until now mesocarnivores may have been understudied, but to those that know them, they were never forgotten.
1:30PM Remote Camera Sampling to Evaluate Occupancy and Intraguild Predation in Desert Carnivores
  Quinn Robinson; Gary W. Roemer
Remote camera sampling can be a powerful tool for illuminating the habitat relationships and ecological dynamics of species that are cryptic, rare, nocturnal, or otherwise difficult to study using more traditional approaches. Remote camera studies are relatively non-invasive, simple to execute in the field, and can collect large quantities of data with relative ease. Furthermore, remote camera data can be smoothly incorporated into robust, modern analytical approaches such as occupancy modeling and mark-recapture techniques. However, for nuanced, useful inferences to be drawn from remote camera studies, careful thought must be given to experimental design and data analysis before data collection begins. Lacking such an approach, remote camera sampling yields plenty of nice images but little useful data. Our research investigated the patterns of occupancy and intraguild predation between the kit fix (Vulpes macrotis) and coyote (Canis latrans) at White Sands National Monument in southern New Mexico. Using kit fox and coyote image data and abundance data from their shared prey, we used multi-species occupancy modeling to identify complex, previously unknown dynamics in the competitive relationship between these carnivores. Our study illustrates the utility of remote cameras for investigating mesocarnivore systems and elucidating ecological relationships within this guild.
1:50PM How Far Have We Come: Radio Telemetry and GPS Technology for Mid-Sized Forest-Dependent Mammals
  Katie M. Moriarty; Ryan M. Nielson; Aaron N. Facka; Sean M. Matthews; Christopher O. Kochanny
Advances in GPS telemetry provide opportunities to amass unprecedented numbers of accurate location data for many animals. For small and mid-sized mammals (<4kg) such telemetry devices are unavailable or insufficiently designed to meet the demands of wildlife biologists. Further, many small and mid-sized mammals have life history characteristics, including resting in burrows and cavities, or foraging in complex topography and dense canopy, which directly and unpredictably reduce the likelihood of obtaining usable GPS locations. Because inferring individual locations to population level processes (e.g., habitat selection) require data that is representative (e.g., randomization, replication) with locations that are accurate and unbiased (e.g., few missed or inaccurate locations) - GPS telemetry may be a poor tool for many forest-dependent meso-carnivores. Nonetheless, valuable insights can be learned if appropriate study designs are implemented. We review current tools and technology, describe potential techniques for reducing bias as demonstrated from experimental field trials, estimate likelihood of bias from fisher GPS data with modest levels of 3-D fix success (average deployment fix success = 70%, range = 60-76%), and highlight marten and fisher case studies with successful outcomes using GPS telemetry. We emphasize the benefits of testing GPS telemetry products at study locations before deployment on wild animals and the need for designing studies that are appropriate for the species, habitat, and technology. We conclude with considerations and a call for standardization where appropriate. Standards and increased collaboration could increase the likelihood of collecting useful data of appropriate sample sizes (number of animals and number of locations per animal) and data quality, and allow the flexibility needed for local study objectives.
2:10PM Techniques for Studying Reproduction and Associated Habitat Use in Mesocarnivores: Examples from Field Studies of Fisher and Other Members of the Martes Complex
  Rebecca E. Green; Michael J. Joyce; Sean M. Matthews; Kathryn L. Purcell; Mark Higley; Andrzej Zalewski
Information on reproduction is essential to understanding population dynamics and developing conservation plans for wildlife. However, research on reproduction in wild settings can be challenging, especially when studying species with low population densities, elusive behaviors, or tendencies to hide young in cryptic den structures such as tree cavities or snow burrows. Answering basic questions about life history parameters for many species of mesocarnivore involves specialized techniques that have been increasingly refined by researchers over the last half-century. We present a review oftechniques and considerations for researchers initiating studies of mesocarnivore reproduction in wild settings with a focus on members of the Martes complex including fisher (Pekania pennanti) and American marten (Martes americana). Specifically, we discuss details involved in studying reproduction through (1) assessment of teat condition at live captures, (2) assessment of reproductive organs of carcasses, (3) location and monitoring of reproductive dens using telemetry, (4) use of remote cameras at reproductive den structures, and (5) investigation of reproductive den chambers. Additionally, we explore options to apply available techniques to the study of reproduction in other mesocarnivore species, consider ways to minimize impacts to study animals during the sensitive reproductive period, and offer thoughts on initiating research projects with rare or little known mesocarnivore species.
2:30PM Panacea or Pandora’s Box: Building the Foundational Health Knowledge for a Rare Species, the Pacific Fisher
  Mourad W. Gabriel
There are five guiding factors to determine if any particular species is to be considered under the federal Endangered Species Act (ESA), one of which is whether diseases pose any risks to species persistence. Unfortunately, the health and disease threats for many species are poorly understood and the lack of knowledge is commonly interpreted as lack of threat towards the conservation of a species. A contemporary example is the western United States population of fishers, a north American mesocarnivore, which was placed on the candidate list for review under the ESA in 2004. Before this period, health-related literature was sparse and data pertained mainly to parasite accounts, cursory field determinations of mortality and peripheral health parameters at an individual level. Due to these data inadequacies, management agencies could not effectively conclude whether or not disease threats play a conservation role for fishers. As a result, we initiated a collaborative interdisciplinary team of scientists in order to generate baseline health statistics for this species within this distinct population segment being considered for listing under the ESA. Data generated allowed us to determine direct and indirect mortality causes; in addition, serological and molecular applications coupled with ongoing demographic data allowed both temporal and spatial interpretations of exposures to and active infections from selected pathogens. Finally, ongoing conservation efforts (e.g., reintroductions) to restore this population of fishers required our teams to draw upon the health of sympatric mesocarnivores to ascertain what proactive measures were needed prior to reintroductions. Combining all of these health parameters allowed for novel discoveries of infectious and non-infectious disease threats to fishers but also the determination of endemic pathogens for fishers. Lastly, health data and assessments for mesocarnivores or other wildlife should be utilized as a translational science allowing a fuller picture of determining influences on vital rates.
2:50PM Refreshment Break
3:20PM Conservation Genetics of an Uncommon Mesocarnivore, the Eastern Spotted Skunk
  Alexandra A. Shaffer; J. Clint Perkins; Robert C. Dowler; Loren K. Ammerman
Microsatellites are used extensively to assess a variety of population-level parameters including gene flow, structure, dispersal patterns, and heterozygosity. These genetic markers are especially useful when researching rare and understudied species, as they are capable of amplifying homologous sequences in closely related taxa, thus eliminating the need to develop de novo markers on a species-by-species basis. One such species, the plains spotted skunk (Spilogale putorius interrupta), was once an abundant mesocarnivore distributed throughout the great plains of the central and midwestern United States, yet habitat alteration and pesticide usage beginning in the 1940s potentially contributed to the range-wide decline of this now uncommon carnivore. Due to these past declines and a lack of knowledge pertaining to its genetic variability, the plains spotted skunk is currently being considered for listing as endangered at the federal level. To assess the levels of genetic diversity of this subspecies, tissues obtained from field surveys and museum collections (n = 33) were analyzed across 12 cross-species microsatellite loci. Additionally, tissue samples from the Appalachian (S. p. putorius; n = 20) and Florida (S. p. ambarvalis; n = 22) spotted skunks were analyzed to enable genetic comparisons among the 3 eastern spotted skunk subspecies, as well as to test the validity of the subspecies designations. Average heterozygosity did not differ among the subspecies; however, structure analyses indicated the presence of 3 clusters commensurate with morphological subspecies designations. An overwhelming presence of private alleles and a strong degree of genetic differentiation (FST > 0.261) of the plains subspecies from the Appalachian and Florida subspecies highlights a lack of gene flow occurring beyond the range of the plains spotted skunk. Future management strategies for the eastern spotted skunk should therefore account for the genetic dissimilarity among the 3 subspecies and consider each as a unique evolutionarily significant unit.
3:40PM Culturally-Based Wildlife Conservation on Native American Lands: A Challenge of Scale and Governance
  Sean Matthews; Mark Higley; Jodi Hilty
Modern socio-economic pressures for Native American peoples have led to deviations from traditional land use practices to the exploitation and extraction of natural resources on tribal lands. Despite these pressures, many tribal lands still represent some of the largest intact landscapes and significant opportunities for conservation in North America. Sovereignty rights won over the last three decades have included the transfer of natural resource management on many reservations from federal agencies to sovereign tribal governments. On the Hoopa Valley Reservation in northwestern California, the Hoopa Tribal Council now oversees forest management and a timber-based economy, formerly managed by the U.S. Bureau of Indian Affairs (BIA). The Tribe has made significant changes to forest-management on the reservation, including a transition from even-age management through clear cutting practiced by the BIA to uneven-age management through regeneration harvests. The Tribe is also committed to developing a better understanding of the needs of threatened, endangered, and culturally significant wildlife and plant species. Filling information gaps for these species has led the Hoopa Tribe to cultivate collaborative relationships to develop native capacity and management recommendations for the culturally-significant and forest-dependent fisher (Pekania pennanti). The Tribe began monitoring fishers in 1991 and has since become a recognized leader in fisher conservation through research into fisher habitat selection, survival, reproduction, sources of mortality, and carnivore-community dynamics. Research findings on fishers have informed forest management recommendations reflected in the Tribe’s forest management plan. Maintaining a sustainable population of fisher on the reservation and recovering fishers range-wide, however, will require the commitment of neighboring forest managers outside of Hoopa to management practices that will sustain fisher. The Tribe will continue its commitment to bringing field-based science and conservation recommendations to other tribal, private, state, and federal land managers for more effective regional fisher conservation.
4:00PM Crowd-Sourcing, Citizen Scientists, and Collecting Novel Data: The Search for the Eastern Spotted Skunk
  J. Clint Perkins; Alexandra A. Shaffer; Nick W. Sharp; D. Blake Sasse; Robert C. Dowler
The eastern spotted skunk (Spilogale putorius) is a diminutive mesocarnivore distributed in the southeastern and great plains regions of the United States. While historically common, the species has undergone a drastic, range-wide decline, the reason for which is not fully understood. Efforts to learn more about the skunk have been hampered by incomplete knowledge, including both status and distribution, of the species due to a shortage of prior study. Following the 90-day review by the USFWS of the plains subspecies (S. p. interrupta) in 2012, investigators at both states agencies and academic institutions initiated research into the current distribution and status of the skunk. In both Texas and Alabama, verifiable observations were solicited via “wanted posters” and the dissemination of multiple articles that featured both the biology of and the search for the skunk. In Texas, a search for historical museum records yielded 196 records, yet only 11 since 2000. To augment this dataset, we solicited additional observations from academic, biological, and wildlife rehabilitation groups and collected historical trapper accounts from early trapping periodicals. Multiple projects, Eastern Spotted Skunk and Spotted Skunks of Texas, were also created on the citizen scientist platform iNaturalist.org. Finally, follow-up trail camera surveys, led by citizen scientists, were initiated at locations of verified or suspected skunk observations. Using all methods (for both states), we recorded 88 observations with fully verified temporal and spatial data. We also recorded an additional 39 presence only observations at the county level, with at least 11 records occurring in counties without a previous county record. Our results confirm that collaboration among and outside of the scientific community can be an important tool for locating uncommon species and we suggest that researchers and managers make use of these methods when possible.
4:20PM Designing Mesocarnivore Projects to Maximize their Scientific and Conservation Value: Lessons Learned from a Fisher Reintroduction
  Aaron Facka; Roger A. Powell
Scientific inquiry has provided insight into the natural history, behavior and ecology of mesocarnivores. Nevertheless, critical knowledge about causal mechanisms affecting population persistence, individual fitness, and conservation often elude our understanding. New technology, research collaborations, and data sharing networks provide exciting opportunities for research but that are insufficient, of themselves, to maximize research innovation and successful management of mesocarnivores. Wildlife managers and academic researchers often have superficially different goals that may, in fact, be complimentary. Managers need specific, local information to manage mesocarnivore populations and ecosystems whereas academics test hypotheses about phenomena that may address fundamental or theoretic topics. Researchers and managers constantly face limited funding, forcing trade offs between the number and quality of topics that can be reasonably addressed. Such considerations may require using one method to the exclusion of another and, thus, limit the scope of the investigation. Fortunately, mesocarnivores have many similar life-history traits and concordant requirements for scientific knowledge and management. Many management and research projects on mesocarnivores; therefore, can be combined to achieve goals at multiple scales. Defining projects’ objectives a priori is essential for innovative research, identifying requisite resources, and for developing appropriate collaborations. We demonstrate these concepts using the example of a reintroduction of fishers (Pekania pennanti) in northern California. Forest industry partners wished to demonstrate forests commercially-managed for wood products could support fishers, federal and state wildlife managers wished to understand how fishers use landscapes managed for timber; and academic researchers wished to understand causal mechanisms of habitat use, establishment of home ranges, and mate choice. All partners shared the common goal of re establishing fishers within a portion of their former range and designed research centered on this premise. Thus, a combined research and management project on mesocarnivores provided opportunities to meet multiple goals that were important to diverse groups.
4:40PM Integrating Monitoring, Research and Management to Improve Conservation of Mammalian Mesocarnivores
  David Jachowski
Talks during this symposium have individually assessed ecology, monitoring methodology, demography, and public collaboration to inform the ecology and management of mesocarnivores. However, science is often the most powerful tool for conservation when there is integration across methods or disciplines. The black-footed ferret (Mustela nigripes) is one of the most imperiled and thoroughly studied mesocarnivores on the planet, and illustrates how integrating monitoring, research and management can improve conservation. Specifically, since their rediscovery in 1981, conservation of this species has progressed in three key phases: (1) Building a basic natural history understanding, (2) Using that knowledge to guide conservation and management actions, and (3) Monitoring population responses and adapting management strategies. This model is similarly being observed in early phases in several other mesocarnivore species. Perhaps most excitingly, innovative science on not just the mesocarnivore, but the surrounding suite of species begins to inform us of the often important ecological role they play and what future ecological communities will look like. This in turn can have important implications for disease risk, trophic interactions, predator control, invasive species management, and a variety of other management concerns. We also are seeing that when science and public education are linked, mesocarnivores can drive conservation forward as powerfully as larger carnivores. Thus, there is a bright future for using mesocarnivores as tool to both understand ecosystem function and drive conservation.

 
Organizers: Summer Higdon, University of Missouri, Columbia, MO; Robin Eng, Clemson University, Clemson, SC; Stephen Harris, Clemson University, Clemson, SC
 

Symposium
Location: Albuquerque Convention Center Date: September 24, 2017 Time: 1:10 pm - 5:00 pm