• Age-related patterns of neophobia in an endangered island crow: implications for conservation and natural history

      Greggor, Alison L.; Masuda, Bryce M.; Flanagan, Alison M.; Swaisgood, Ronald R. (2020)
      Theory suggests that the balance between unknown dangers and novel opportunities drives the evolution of species-level neophobia. Juveniles show lower neophobia than adults, within mammals and birds, presumably to help minimize the costs of avoiding beneficial novelty, and adults tend to be more neophobic, to reduce risks and focus on known stimuli. How these dynamics function in island species with fewer dangers from predators and toxic prey is not well understood. Yet, predicting neophobia levels at different age classes may be highly valuable in conservation contexts, such as species' translocation programmes, where responses to novelty can influence the effectiveness of prerelease training and animals' survival postrelease. To better understand how neophobia and its age-related patterns are expressed in an island corvid, we surveyed object neophobia in 84% of the world's critically endangered ‘alal?, Corvus hawaiiensis. Individuals repeatedly demonstrated high neophobia, suggesting that neither captivity nor their island evolution has erased this corvid-typical trait. Unexpectedly, juveniles were exceedingly more neophobic than adults, a pattern in stark contrast to common neophobia predictions and known mammalian and avian studies. We discuss the potential conservation ramifications of this age-structured result within the larger context of neophobia theory. Not only may the expression of neophobia be more complicated than previously thought but predicting such responses may also be important for conservation management that requires exposing animals to novelty.
    • Are current research funding structures sufficient to address rapid Arctic change in a meaningful way?

      Ibarguchi, Gabriela; Rajdev, Vinay; Murray, Maribeth S. (Norwegian Polar Institute, 2018)
      Arctic environmental changes already impact regional ecosystems, economies and northerncommunities, and are having increasing influence on many aspects of the global system.Interest in the Arctic has increased in concert with our improved awareness of potentialchanges; however, research funding has not necessarily kept pace with the need to improveour understanding of Arctic system change to inform evidence-based decision making.Analyses of data on research funding trends (2003–14) in Canada, the USA and the EUindicate that less than 3% of the total budget the funding agencies considered is allocatedin any given year to Arctic-related research. Furthermore, alignment is uneven amongestablished scientific research priorities, existing societal needs and projects awarded fund-ing. New support mechanisms and improved alignment among resources, expertise andpriorities, including Indigenous research priorities, are vital to planning and adaptation inthe face of ongoing Arctic change.
    • Capturing pests and releasing ecosystem engineers: translocation of common but diminished species to re-establish ecological roles

      Swaisgood, Ronald R.; Montagne, J.P.; Lenihan, C. M.; Wisinski, Colleen L.; Nordstrom, Lisa A.; Shier, Debra M. (2019)
      Translocation of abundant but declining ecologically important species for re-establishing more sustainable ecosystem function is a neglected but promising form of conservation intervention. Here, we developed a translocation program in which we capture pests and release ecosystem engineers, by relocating California ground squirrels Otospermophilus beecheyi from areas where they are unwanted to conserved lands where they can perform ecosystem services such as burrowing and vegetation alteration. We accomplished this using an experimental approach in which some factors were measured or experimentally manipulated, while others were held constant. We translocated 707 squirrels and examined survival and movement patterns as a function of several translocation tactics and ecological factors. We released squirrels at 9 different plots with varying ecological contexts and at each plot experimentally manipulated post-release habitat using mowing, mowing plus the use of augers to establish starter burrows, and controls that remained unmanipulated. The most influential variables affecting short-term survival, dispersal, and long-term persistence were factors relating to soils and vegetation structure. Translocated squirrels had higher initial survival on plots where dense exotic grasses were experimentally altered, greater dispersal when released at sites with less friable clay soils, and improved long-term persistence at sites characterized by more friable soils associated with metavolcanic than alluvial geological layers. Squirrel persistence was also improved when translocations supplemented previous translocation sites than during initial translocations to sites containing no resident squirrels. Our results demonstrate how California ground squirrels can be successfully translocated as part of a larger objective to favorably alter ecological function in novel grassland ecosystems dominated by non-native vegetation. In broader context, our study highlights the importance of testing release strategies, and examining habitat variables and restoration techniques more closely when selecting release sites to improve translocation outcomes.
    • Experimental habitat restoration for conserved species using ecosystem engineers and vegetation management

      Hennessy, Sarah McCullough; Deutschman, D. H.; Shier, Debra M.; Nordstrom, Lisa A.; Lenihan, C.; Montagne, J.P.; Wisinski, Colleen L.; Swaisgood, Ronald R. (2016)
      We manipulated vegetation and the ecosystem engineer California ground squirrel, Otospermophilus beecheyi, in a replicated, large-scale field experiment for 2 years, and monitored through a third year…. The overarching goal of this experiment was to provide conservation managers with a cost-effective tool for restoring degraded habitats to a hybrid ecosystem state with improved suitability for species of conservation concern, in this case, the western burrowing owl Athene cunicularia hypugaea.
    • Reconsidering habitat associations in the Anthropocene

      Hennessy, Sarah McCullough; Marczak, Susanne A.; Nordstrom, Lisa A.; Swaisgood, Ronald R. (2018)
      The California ground squirrel (Otospermophilus beecheyi) is generally undervalued despite serving as an ecosystem engineer in grassland ecosystems. Evidence of significant engineering effects by squirrels indicates that population reductions have cascading effects on other species, including several conservation-dependent species. While the theory and practices behind habitat association studies are already well established, our application of this approach helped identify priority management options in degraded grasslands expected to change further under shifts in climate. In this study we conducted surveys for California ground squirrels throughout San Diego County grasslands and examined habitat covariates to determine the ecological variables currently associated with occurrence. The primary objectives were to 1) improve our understanding of the habitat variables associated with squirrel presence, and 2) develop a predictive model for squirrel habitat suitability at a local scale. The most predictive models included significant main effects for percent sand (as a component of soil texture) and vegetation cover. A 10% increase in vegetation cover was associated with 1.3 fold lower odds of squirrel presence, whereas a 10% increase in percent sand was associated with 2.0 times higher odds of squirrel presence. Comparison of the predictive accuracy of soil texture data at two scales (fine-scale field vs. landscape scale GIS layers) showed fine-scale field sampling has greater predictive strength. Because soil type is a logistically non-malleable factor for wildlife managers, it is important to categorize management sites by soil type to identify the potential for promoting fossorial species on the landscape. With the prospect of shifting landscape ecotones due to climate change, it is as important to understand the basic habitat requirements of keystone species as for rare species.
    • Ringed seal (Pusa hispida) tooth annuli as an index of reproduction in the Beaufort Sea

      Nguyen, Linda; Pilfold, Nicholas W.; Derocher, Andrew E.; Stirling, Ian; Bohart, Alyssa M.; Richardson, Evan (2017)
      Multi-decadal time-series of biological indices that reflect the state of a population are rare in ecological studies, but invaluable for assessing environmental regulation of population dynamics. We utilized canine teeth extracted from ringed seals (Pusa hispida) killed by polar bears (Ursus maritimus) in the Beaufort Sea, Canada, in 1985–2011, to obtain widths of annual growth layers in the cementum....
    • Spatial and temporal response of wildlife to recreational activities in the San Francisco Bay ecoregion

      Reilly, M. L.; Tobler, Mathias W.; Sonderegger, D. L.; Beier, P. (2017)
      Non-motorized human recreation may displace animals from otherwise suitable habitat; in addition, animals may alter their activity patterns to reduce (or increase) interactions with recreationists. We investigated how hiking, mountain biking, equestrians, and recreationists with domestic dogs affected habitat use and diel activity patterns of ten species of medium and large-sized mammals in the San Francisco Bay ecoregion....
    • Spatiotemporal network structure among “friends of friends” reveals contagious disease process

      Witte, Carmel L.; Hungerford, Laura L.; Rideout, Bruce; Papendick, Rebecca; Fowler, James H. (2020)
      Disease transmission can be identified in a social network from the structural patterns of contact. However, it is difficult to separate contagious processes from those driven by homophily, and multiple pathways of transmission or inexact information on the timing of infection can obscure the detection of true transmission events. Here, we analyze the dynamic social network of a large, and near-complete population of 16,430 zoo birds tracked daily over 22 years to test a novel “friends-of-friends” strategy for detecting contagion in a social network. The results show that cases of avian mycobacteriosis were significantly clustered among pairs of birds that had been in direct contact. However, since these clusters might result due to correlated traits or a shared environment, we also analyzed pairs of birds that had never been in direct contact but were indirectly connected in the network via other birds. The disease was also significantly clustered among these friends of friends and a reverse-time placebo test shows that homophily could not be causing the clustering. These results provide empirical evidence that at least some avian mycobacteriosis infections are transmitted between birds, and provide new methods for detecting contagious processes in large-scale global network structures with indirect contacts, even when transmission pathways, timing of cases, or etiologic agents are unknown.
    • Spring fasting behavior in a marine apex predator provides an index of ecosystem productivity

      Rode, Karyn D.; Wilson, Ryan R.; Douglas, David C.; Muhlenbruch, Vanessa; Atwood, Todd C.; Regehr, Eric V.; Richardson, Evan S.; Pilfold, Nicholas W.; Derocher, Andrew E.; Durner, George M.; et al. (2018)
      The effects of declining Arctic sea ice on local ecosystem productivity are not well understood but have been shown to vary inter-specifically, spatially, and temporally. Because marine mammals occupy upper trophic levels in Arctic food webs, they may be useful indicators for understanding variation in ecosystem productivity. Polar bears (Ursus maritimus) are apex predators that primarily consume benthic and pelagic-feeding ice-associated seals. As such, their productivity integrates sea ice conditions and the ecosystem supporting them. Declining sea ice availability has been linked to negative population effects for polar bears but does not fully explain observed population changes. We examined relationships between spring foraging success of polar bears and sea ice conditions, prey productivity, and general patterns of ecosystem productivity in the Beaufort and Chukchi Seas (CSs). Fasting status (?7 days) was estimated using serum urea and creatinine levels of 1,448 samples collected from 1,177 adult and subadult bears across three subpopulations. Fasting increased in the Beaufort Sea between 1983–1999 and 2000–2016 and was related to an index of ringed seal body condition. This change was concurrent with declines in body condition of polar bears and observed changes in the diet, condition and/or reproduction of four other vertebrate consumers within the food chain. In contrast, fasting declined in CS polar bears between periods and was less common than in the two Beaufort Sea subpopulations consistent with studies demonstrating higher primary productivity and maintenance or improved body condition in polar bears, ringed seals, and bearded seals despite recent sea ice loss in this region. Consistency between regional and temporal variation in spring polar bear fasting and food web productivity suggests that polar bears may be a useful indicator species. Furthermore, our results suggest that spatial and temporal ecological variation is important in affecting upper trophic-level productivity in these marine ecosystems.
    • The i5K Initiative: Advancing arthropod genomics for knowledge, human health, agriculture, and the environment

      Evans, Jay D.; Brown, Susan J.; Hackett, Kevin J.; Robinson, Gene; Richards, Stephen; Lawson, Daniel; Elsik, Christine; Coddington, Jonathan; Edwards, Owain; Emrich, Scott; et al. (2013)
      Insects and their arthropod relatives including mites, spiders, and crustaceans play major roles in the world’s terrestrial, aquatic, and marine ecosystems. Arthropods compete with humans for food and transmit devastating diseases. They also comprise the most diverse and successful branch of metazoan evolution, with millions of extant species. Here, we describe an international effort to guide arthropod genomic efforts, from species prioritization to methodology and informatics. The 5000 arthropod genomes initiative (i5K) community met formally in 2012 to discuss a roadmap for sequencing and analyzing 5000 high-priority arthropods and is continuing this effort via pilot projects, the development of standard operating procedures, and training of students and career scientists. With university, governmental, and industry support, the i5K Consortium aspires to deliver sequences and analytical tools for each of the arthropod branches and each of the species having beneficial and negative effects on humankind.
    • The value of ecosystem services from giant panda reserves

      Wei, Fuwen; Costanza, Robert; Dai, Qiang; Stoeckl, Natalie; Gu, Xiaodong; Farber, Stephen; Nie, Yonggang; Kubiszewski, Ida; Hu, Yibo; Swaisgood, Ronald R.; et al. (2018)
      Ecosystem services (the benefits to humans from ecosystems) are estimated globally at $125 trillion/year [1, 2]. Similar assessments at national and regional scales show how these services support our lives [3]. All valuations recognize the role of biodiversity, which continues to decrease around the world in maintaining these services [4, 5]....