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Species reintroductions are successful when established populations maintain both demographic stability and genetic diversity. Such a result may be obtained by ensuring both structural habitat connectivity and genetic connectivity among reintroduced and remnant populations. Nevertheless, prezygotic barriers such as assortative mating can prevent the flow of genetic material between populations, even when migration between populations is high. Limited gene flow may be particularly relevant for reintroductions that were sourced either from captive-bred populations or from disparate locations in the wild. American martens (Martes americana) have been reintroduced repeatedly in the Upper Midwestern United States in an effort to establish self-sustaining populations. We quantified levels of genetic diversity within and spatial genetic variance among four marten populations during two time periods separated by 10 years. Spatially informed and naïve discriminant analysis of principal components were used to assign individuals to populations. Results indicate that heterozygosity declined and inbreeding coefficients increased between the two collection periods, while genetic structure among populations also increased. Data are consistent with assortative mating contributing to reapportioning of genetic variation. Population assignment tests show that migration among populations is apparent, but admixture (based on cluster membership probabilities) is low and declined over time. Specifically, martens may be successfully dispersing between populations but a lack of admixture indicates a lack of reproductive contributions to genetic diversity by migrants. Because marten reintroductions in this region are well-documented and well-monitored, lessons can be derived from results to inform future reintroductions. We encourage a careful balance of supplementing genetic diversity via augmentation while avoiding translocation of animals from disparate populations that may result in reproductive isolation of migrants. In combination with the maintenance of a functionally connected landscape, this strategy would maximize the likelihood of a successful reintroduction in terms both of demography and genetics.

Quantifying resource partitioning is central to community and food web ecology and of increasing interest in an era of rapid global change disrupting biotic interactions. Multichannel feeding – consuming resources from both green and brown food webs – can be a stabilizing force in communities. While multichannel feeding has been well-documented in invertebrate and aquatic systems, it has been relatively under-studied in terrestrial vertebrate populations. Applied ecologists are seeking approaches to assess niche partitioning and cryptic trophic pathways, like multichannel feeding, which have been difficult to quantify, especially among vertebrates. Using both bulk (δ13C and δ15N) and compound specific stable isotope ratios (δ15N glutamic acid and phenylalanine), we tested how three common and competing tree squirrel partition resources. Our complementary analyses revealed that squirrels partitioned niche space and, because of differences in multichannel foraging, possessed different trophic identities. While all squirrels consumed food items from green and brown food webs, their dependence on each differed, revealing an important, yet cryptic, mechanism behind apparent stable co-occurrence of these competitors. Our work supports multichannel feeding as a potential mechanism promoting coexistence in this guild of terrestrial vertebrates, and provides a framework to quantify resource partitioning in other ecological communities.

In an attempt to maximize genetic diversity, species reintroductions often target numerous source groups and occur over multiple years. However, the serial introduction of individuals from disparate locations can create unique patterns of genetic structure, with potential implications for demography and population connectivity. To investigate the genetic structure and connectedness of contemporary populations of serially reintroduced American martens ( Martes americana ) in Wisconsin, we sampled the source populations of Colorado, Minnesota, and Ontario, and the two reintroduction sites within the state. In a relatively small area (~ 7000 km 2 ), we detected six distinct genetic clusters, partitioned according to the original source groups. Source groups exhibited differing degrees of success, with Minnesota and Ontario signatures persisting and Colorado disappearing from the landscape. Two of the genetic clusters had unknown sources not attributable to the reintroduced populations, potentially arising from an early reintroduction attempt or the persistence of a cryptic native population of martens. Limited admixture between clusters was detected, yet we found evidence for the occasional dispersal of martens from each site to the other. Our results suggest that reintroductions can create strong and novel patterns of genetic structure − unseen for this species elsewhere or other vertebrates in the region − across small spatial scales.

The purpose of this study was to evaluate whether the home care of noncompliant adolescent orthodontic patients with "poor" oral hygiene could be improved through the use of a deception strategy designed to intentionally induce the Hawthorne effect. This effect is often cited as being responsible for oral health improvements of control groups that receive placebo treatments. It is thought that participating in and fulfilling the requirements of a study alters subjects' behavior, thereby contributing to the improvement. Forty patients with histories of poor oral hygiene were assigned, in a quasi-random fashion, to two groups. Experimental subjects (n = 20) were presented with a situation that simulated participation in an experiment. These included the use of a consent form; distribution of tubes of toothpaste labeled "experimental"; instructions to brush twice a day for two minutes using a timer; and a request to return unused toothpaste. Control subjects (n = 20) had no knowledge of study participation. Tooth surface area covered with plaque was used as a proxy measure of home care behavior. It was measured at baseline, three months, and six months. Mean percentages of tooth surface covered with plaque for the experimental and control groups were 71 (+/- 11.52) and 74 (+/- 11.46) at baseline; 54 (+/- 13.79) and 78 (+/- 12.18) at three months; and 52 (+/- 13.04) and 79 (+/- 10.76) at six months. No statistically significant difference (p > .05) was obtained between groups at baseline. Statistically significant differences (p < .05) were found between groups at three and six months. Significant differences (p < .05) were also found only for the experimental subjects between baseline and each of the two subsequent observation periods. The efficiency and potential effectiveness of this strategy suggest that additional research be conducted to assess oral health improvements and possible applications to the private practice setting.

The purpose of this study was to evaluate whether the home care of noncompliant adolescent orthodontic patients with "poor" oral hygiene could be improved through the use of a deception strategy designed to intentionally induce the Hawthorne effect. This effect is often cited as being responsible for oral health improvements of control groups that receive placebo treatments. It is thought that participating in and fulfilling the requirements of a study alters subjects' behavior, thereby contributing to the improvement. Forty patients with histories of poor oral hygiene were assigned, in a quasi-random fashion, to two groups. Experimental subjects (n = 20) were presented with a situation that simulated participation in an experiment. These included the use of a consent form; distribution of tubes of toothpaste labeled "experimental"; instructions to brush twice a day for two minutes using a timer; and a request to return unused toothpaste. Control subjects (n = 20) had no knowledge of study participation. Tooth surface area covered with plaque was used as a proxy measure of home care behavior. It was measured at baseline, three months, and six months. Mean percentages of tooth surface covered with plaque for the experimental and control groups were 71 (+/- 11.52) and 74 (+/- 11.46) at baseline; 54 (+/- 13.79) and 78 (+/- 12.18) at three months; and 52 (+/- 13.04) and 79 (+/- 10.76) at six months. No statistically significant difference (p.05) was obtained between groups at baseline. Statistically significant differences (p.05) were found between groups at three and six months. Significant differences (p.05) were also found only for the experimental subjects between baseline and each of the two subsequent observation periods. The efficiency and potential effectiveness of this strategy suggest that additional research be conducted to assess oral health improvements and possible applications to the private practice setting.