@article{gillman_mckenney_lafferty_2020, title={Wild black bears harbor simple gut microbial communities with little difference between the jejunum and colon}, volume={10}, ISSN={["2045-2322"]}, url={https://doi.org/10.1038/s41598-020-77282-w}, DOI={10.1038/s41598-020-77282-w}, abstractNote={Abstract The gut microbiome (GMB), comprising the commensal microbial communities located in the gastrointestinal tract, has co-evolved in mammals to perform countless micro-ecosystem services to facilitate physiological functions. Because of the complex inter-relationship between mammals and their gut microbes, the number of studies addressing the role of the GMB on mammalian health is almost exclusively limited to human studies and model organisms. Furthermore, much of our knowledge of wildlife–GMB relationships is based on studies of colonic GMB communities derived from the feces of captive specimens, leaving our understanding of the GMB in wildlife limited. To better understand wildlife–GMB relationships, we engaged hunters as citizen scientists to collect biological samples from legally harvested black bears ( Ursus americanus ) and used 16S rRNA gene amplicon sequencing to characterize wild black bear GMB communities in the colon and jejunum, two functionally distinct regions of the gastrointestinal tract. We determined that the jejunum and colon of black bears do not harbor significantly different GMB communities: both gastrointestinal sites were dominated by Firmicutes and Proteobacteria. However, a number of bacteria were differentially enriched in each site, with the colon harboring twice as many enriched taxa, primarily from closely related lineages.}, number={1}, journal={SCIENTIFIC REPORTS}, author={Gillman, Sierra J. and McKenney, Erin A. and Lafferty, Diana J. R.}, year={2020}, month={Dec} }
 @article{lafferty_zimova_clontz_hacklander_mills_2019, title={Noninvasive measures of physiological stress are confounded by exposure}, volume={9}, ISBN={2045-2322}, DOI={10.1038/s41598-019-55715-5}, abstractNote={Abstract Glucocorticoids and glucocorticoid metabolites are increasingly used to index physiological stress in wildlife. Although feces is often abundant and can be collected noninvasively, exposure to biotic and abiotic elements may influence fecal glucocorticoid metabolite (FGM) concentrations, leading to inaccurate conclusions regarding wildlife physiological stress. Using captive snowshoe hares ( Lepus americanus ) and simulated environmental conditions, we evaluated how different realistic field conditions and temporal sampling constraints might influence FGM concentrations using an 11-oxoetiocholanolone-enzyme immunoassay. We quantified how fecal pellet age (i.e., 0–6 days), variable summer temperatures, and precipitation affected FGM concentrations. Fecal pellet age had a strong effect on FGM concentrations (β Age = 0.395, s.d. = 0.085; β 2 Age = −0.061, s.d. = 0.012), which were lowest at the beginning and end of our exposure period (e.g., mean day6 = 37.7 ng/mg) and typically highest in the middle (mean day3 = 51.8 ng/mg). The effect of fecal pellet age on FGM concentrations varied across treatments with warm-dry and cool-wet conditions resulting in more variable FGM concentrations relative to control samples. Given the confounding effects of exposure and environmental conditions, if fresh fecal pellet collection is not an option, we encourage researchers to develop a temporally consistent sampling protocol to ensure all samples are exposed to similar environmental conditions.}, journal={SCIENTIFIC REPORTS}, author={Lafferty, Diana J. R. and Zimova, Marketa and Clontz, Lindsay and Hacklander, Klaus and Mills, L. Scott}, year={2019} }
 @article{mowat_curtis_lafferty_2017, title={The influence of sulfur and hair growth on stable isotope diet estimates for grizzly bears}, volume={12}, ISSN={["1932-6203"]}, DOI={10.1371/journal.pone.0172194}, abstractNote={Stable isotope ratios of grizzly bear (Ursus arctos) guard hair collected from bears on the lower Stikine River, British Columbia (BC) were analyzed to: 1) test whether measuring δ34S values improved the precision of the salmon (Oncorhynchus spp.) diet fraction estimate relative to δ15N as is conventionally done, 2) investigate whether measuring δ34S values improves the separation of diet contributions of moose (Alces alces), marmot (Marmota caligata), and mountain goat (Oreamnos americanus) and, 3) examine the relationship between collection date and length of hair and stable isotope values. Variation in isotope signatures among hair samples from the same bear and year were not trivial. The addition of δ34S values to mixing models used to estimate diet fractions generated small improvement in the precision of salmon and terrestrial prey diet fractions. Although the δ34S value for salmon is precise and appears general among species and areas, sulfur ratios were strongly correlated with nitrogen ratios and therefore added little new information to the mixing model regarding the consumption of salmon. Mean δ34S values for the three terrestrial herbivores of interest were similar and imprecise, so these data also added little new information to the mixing model. The addition of sulfur data did confirm that at least some bears in this system ate marmots during summer and fall. We show that there are bears with short hair that assimilate >20% salmon in their diet and bears with longer hair that eat no salmon living within a few kilometers of one another in a coastal ecosystem. Grizzly bears are thought to re-grow hair between June and October however our analysis of sectioned hair suggested at least some hairs begin growing in July or August, not June and, that hair of wild bears may grow faster than observed in captive bears. Our hair samples may have been from the year of sampling or the previous year because samples were collected in summer when bears were growing new hair. The salmon diet fraction increased with later hair collection dates, as expected if samples were from the year of sampling because salmon began to arrive in mid-summer. Bears that ate salmon had shorter hair and δ15N and δ34S values declined with hair length, also suggesting some hair samples were grown the year of sampling. To be sure to capture an entire hair growth period, samples must be collected in late fall. Early spring samples are also likely to be from the previous year but the date when hair begins to grow appears to vary. Choosing the longest hair available should increase the chance the hair was grown during the previous year and, maximize the period for which diet is measured.}, number={3}, journal={PLOS ONE}, author={Mowat, Garth and Curtis, P. Jeff and Lafferty, Diana J. R.}, year={2017}, month={Mar} }
 @article{lafferty_hanson-dorr_prisock_dorr_2016, title={Biotic and abiotic impacts of Double-crested cormorant breeding colonies on forested islands in the southeastern United States}, volume={369}, ISSN={["1872-7042"]}, DOI={10.1016/j.foreco.2016.03.026}, abstractNote={Double-crested Cormorant (Phalacrocorax auritus) numbers have increased in North America, and concomitantly cormorants appear to be expanding their nesting range in the southeastern United States. Because colonial nesting waterbirds can impact water quality, soil chemistry and subsequent vegetation succession patterns, our goal was to assess the extent to which cormorant breeding colonies are influencing the biotic and abiotic attributes of forested islands in the southeastern United States. Our objectives were to (1) compare water quality characteristics in near-shore surface waters around forested islands with and without nesting cormorants during the peak-nesting/fledgling period and post-fledgling period, (2) measure soil chemistry parameters for forested islands with and without nesting cormorants, and (3) compare tree health metrics on forested islands with and without nesting cormorants. Our results indicate that cormorant colonies are not significant contributors to general coliforms or Escherichia coli levels in waters surrounding southern breeding colonies. Cormorants also do not appear to have significant direct effects on water chemistry. We did find that cormorant colonies are affecting soil chemistry. Soil from within the nesting colony was more acidic and had greater concentrations of phosphorous than soils on reference islands. In addition, we found evidence that cormorants are negatively affecting tree health within nesting colonies as evidenced by a greater number of trees of lower vigor class within the nesting colonies compared to reference sites. While cormorants do cause abiotic and biotic changes, these are part of the natural ecological processes that occur following waterbird colonization. Management to reduce unwanted impacts that nesting cormorants are having on forested island habitats should be considered within a framework that allows for natural ecological processes, including changes in soil chemistry and subsequent vegetation succession.}, journal={FOREST ECOLOGY AND MANAGEMENT}, author={Lafferty, Diana J. R. and Hanson-Dorr, Katie C. and Prisock, Amanda M. and Dorr, Brian S.}, year={2016}, month={Jun}, pages={10–19} }
 @article{lafferty_loman_white_morzillo_belant_2016, title={Moose (Alces alces) hunters subsidize the scavenger community in Alaska}, volume={39}, ISSN={["1432-2056"]}, DOI={10.1007/s00300-015-1819-4}, number={4}, journal={POLAR BIOLOGY}, author={Lafferty, Diana J. R. and Loman, Zachary G. and White, Kevin S. and Morzillo, Anita T. and Belant, Jerrold L.}, year={2016}, month={Apr}, pages={639–647} }
 @article{lafferty_laudenslager_mowat_heard_belant_2015, title={Sex, Diet, and the Social Environment: Factors Influencing Hair Cortisol Concentration in Free-Ranging Black Bears (Ursus americanus)}, volume={10}, ISSN={["1932-6203"]}, DOI={10.1371/journal.pone.0141489}, abstractNote={Increasingly, measures of glucocorticoid levels (e.g., cortisol), key components of the neuroendocrine stress axis, are being used to measure past hypothalamic-pituitary-adrenal (HPA) activity to index psychological and physiological stress exhibited by wildlife for assessing individual and population-level well-being. However, many intrinsic and extrinsic factors affect HPA activity in animals. Using American black bears (Ursus americanus; n = 116) as an ecological model and hair cortisol concentration (HCC) as an integrative measure of past HPA activity, we evaluated the influence of diet, sex and the social environment on black bear HCC in a free-ranging population that spanned adjoining ecoregions with differing densities of potential conspecific and heterospecific competitors. HCC varied by sex, with female HCC ranging from 0.6 to 10.7 pg/mg (median = 4.5 ± 1.2 mean absolute deviation [MAD]) and male HCC ranging from 0.5 to 35.1 pg/mg (median = 6.2 ± 2.6 MAD). We also observed a three-way interaction among sex, δ14C and ecoregion, which may indicate that some differences in HCC between female and male black bears results from variability in the nutritional needs of larger-bodied males relative to smaller-bodied females, slight differences in food resources use between ecoregions as well as sex-based differences regarding the social environment. Once we understand what drives sex-specific differences in HCC, HCC may aid our understanding of the physiological responses by bears and other wildlife to diverse environmental challenges.}, number={11}, journal={PLOS ONE}, author={Lafferty, Diana J. R. and Laudenslager, Mark L. and Mowat, Garth and Heard, Doug and Belant, Jerrold L.}, year={2015}, month={Nov} }