• Behavioral adaptations of a large carnivore to human activity in an extremely arid landscape

      Barocas, Adi; Hefner R.; Ucko M.; Merkle J. A.; Geffen Eli (2018)
      Abstract Driven by the availability of food subsidies and landscape transformation, large carnivore populations are increasingly inhabiting the vicinity of humans. To persist in human proximity, while avoiding conflict and mortality, they must make adjustments in their spatial behavior....
    • 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.
    • Conservation translocations: a review of common difficulties and promising directions

      Berger-Tal, Oded; Blumstein, D. T.; Swaisgood, Ronald R. (2020)
      Translocations are a common conservation and management strategy, but despite their popularity, translocations are a high-cost endeavor with a history of failures. It is therefore imperative to maximize their success by learning from our collective experience....
    • Developmental stability of foraging behavior: evaluating suitability of captive giant pandas for translocation

      Swaisgood, Ronald R.; Martin-Wintle, Meghan S.; Owen, Megan A.; Zhou X.; Zhang H. (2018)
      The behavioral competence of captive-bred individuals - an important source population for translocation programs - may differ from that of wild-born individuals and these differences may influence post-release survival. Some behaviors will be more robust, or developmentally stable, than others in the face of the environmental novelties of captivity. Here, we investigated developmental stability of foraging behavior by quantifying bamboo feeding behavior in captive-bred and wild-born giant pandas, Ailuropoda melanleuca. As an energy-limited species adapted to a low-nutrition diet, any reductions in feeding efficiency may compromise post-release survival. Using video of 22 captive pandas, we measured several components of the panda's elaborate bamboo feeding behavior repertoire. We found that captive-born and wild-born pandas displayed the same repertoire of feeding behaviors, suggesting developmental stability in these motor patterns, but that they employed them differently with different parts of the bamboo. Captive-born pandas devoted less time and effort to handling and chewing leaves while allocating more effort to the consumption of large culms than did wild?born pandas. Captive-born pandas also handled small culm and stripped small culms to prepare them for consumption less often than did wild?born pandas. All of these behavioral differences indicate that wild-born pandas in captivity behave in a manner more similar to wild pandas, and focus their behavioral effort on more nutritious bamboo. Thus, these aspects of captive-born panda feeding behavior may be compromised, and were not developmentally stable in the captive environment. These behavioral differences are cause for concern and should be the subject of future study to determine whether they forecast compromised fitness in translocations. Evaluating developmental stability and behavioral competence should be a key component of captive-release translocation programs, serving to guide pre-release training and selection of individuals to be released.
    • 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.
    • Low MHC variation in the polar bear: Implications in the face of Arctic warming?

      Weber, D.S.; Van Coeverden de Groot, P.J.; Schrenzel, Mark D.; Perez, D.A.; Thomas, S. (2013)
      Animals in the Arctic have low pathogen diversity but with rapid climate warming, this is expected to change. One insidious consequence of climate change is exposure of Arctic species to new pathogens derived from more southern species expanding their range northward. To assess potential vulnerability of polar bears to disease exposure, we examined genetic variation in major histocompatibility complex (MHC) loci (part of immune system) in Canadian polar bears and found low genetic diversity, consistent with long?standing exposure to low pathogen/parasite loads....
    • Moving towards greater success in translocations: recent advances from the herpetofauna

      Germano, Jennifer M.; Ewen, J. G.; Mushinsky, H.; McCoy, E.; Ortiz-Catedral, L. (2014)
      ...While the idea of moving an animal may seem simple at first glance, the reality is that translocations are inherently complex. In order to improve our rates of success, this complexity must be considered....