Long-term patterns in winter habitat selection, breeding and predation in a density-fluctuating, high Arctic lemming population.

Habitat selection is expected to balance benefits and costs that maximizes fitness. Using a rare data set on collared lemming (Dicrostonyx groenlandicus) winter nest location spanning more than two decades, we show that lemmings actively select for Salix snow beds, likely due to its favorable micro-climate, and that lemming habitat selection was density-dependent. Lemmings nevertheless exhibited some flexibility in their habitat selection, which appeared to be influenced by the year-to-year variation in snow conditions. The likelihood of both lemming breeding and nest predation by stoats (Mustela erminea) was not directly linked to habitat despite a delicate interplay between habitat, nest size, breeding, and predation. Hence, the larger lemming nests were found in Salix snow beds, and these were more often used for breeding, but both larger nests and nests used for breeding were also predated more often than other nests. Our study provides a clear example of how density-dependent habitat selection acts to balance fitness in the various habitats utilized by collared lemmings.

Landscapes of fear or competition? Predation did not alter habitat choice by Arctic rodents.

In systems where predation plays a key role in the dynamics of prey populations, such as in Arctic rodents, it is reasonable to assume that differential patterns of habitat use by prey species represent adaptive responses to spatial variation in predation. However, habitat selection by collared (Dicrostonyx groenlandicus) and brown (Lemmus trimucronatus) lemmings depends on intra- and inter-specific densities, and there has been little agreement on the respective influences of food abundance, predators, and competition for habitat on lemming dynamics. Thus, we investigated whether predation affected selection of sedge-meadow versus upland tundra by collared lemmings in the central Canadian Arctic. We first controlled for the effects of competition on lemming habitat selection. We then searched for an additional signal of predation by comparing habitat selection patterns between 12 control plots and one large grid where lemmings were protected from predators by fencing in 1996 and 1997, but not during 5 subsequent years when we monitored habitat use in the grid as well as in the control plots. Dicrostonyx used upland preferentially over meadows and was more numerous in 1996 and 2011 than in other sample years. Lemmus was also more abundant in 1996 than in subsequent years, but its abundance was too low in the exclosure to assess whether exclusion of predators influenced its habitat selection. Contrary to the effects of competition, predation had a negligible impact on the spatial dynamics of Dicrostonyx, at least during summer. These results suggest that any differences in predation risk between the two habitats have little direct influence on the temporal dynamics of Dicrostonyx even if induced through predator-prey cycles.

Spirituality in occupational therapy: do we practice what we teach?

This mixed-method study examined the responses of 97 occupational therapists on the subject of spirituality in occupational therapy practice. The inclusion of spirituality into the Occupational Therapy Practice Framework (2008) implies that clinicians address spirituality as a component of client-centered practice. This research revealed a gap between education, theory, and practice as evidenced in the quantitative and qualitative data. Although occupational therapy is intended to be holistic, therapists require a more complete understanding of what spirituality is and what the role of the occupational therapist is when addressing spirituality in evaluation or treatment. The discussion of this research provides information for future occupational therapy educators and educational programs as they seek to incorporate the construct of spirituality into curricula.

Adaptive responses to habitat change: Theory and tests with field experiments.

Habitat loss and change are often implicated as the primary causes of species extinction. Although any population can be instantly imperiled by catastrophe, most habitat loss occurs gradually, thus enabling affected individuals an adaptive advantage to occupy the best of their dwindling opportunities. I demonstrate how to infer the advantage between two habitats for any density and frequency-dependent strategy of habitat selection. I explore the concept of an Adaptive Dispersal Strategy Landscape to reveal the Evolutionarily Stable Strategy separately for ideal-free and ideal preemptive habitat selectors. Both solutions reveal an initially counterintuitive expectation that individuals living at high density gain insufficient adaptive advantage to disperse from a deteriorating habitat. Adaptive dispersal is constrained at high density because habitats of better quality are fully occupied. I test the theory with measures of movement and foraging in crossover experiments on a seminatural population of meadow voles. The experiment allowed the voles to choose among patches and between enclosures in which I differentially manipulated food and shelter. Although photographs from an infrared camera documented voles venturing from one habitat to the other, none became resident. Voles preferentially foraged in the richer of the two enclosures, even when I reversed treatments, and they foraged more in patches protected by mulched straw. The adaptive advantage of dispersal using a surrogate fitness proxy based on the voles' giving-up densities mirrored that generated by theory. The convergence between theory and experiment yields much-needed insight into our ability to test, predict, and hopefully resolve, the ecological, evolutionary, and conservation consequences of habitat loss.

Do animal personalities promote species coexistence? A test with sympatric boreal rodents.

The coexistence of competing species requires density feedbacks that have a larger effect on their own species' population growth than they do on others in the assembly. The feedbacks are often associated with behavioral tradeoffs that enable species to differentially exploit underlying axes of heterogeneity. Conjoining theories of species coexistence with foraging behavior and density-dependent habitat selection reveals that such tradeoffs impinge on invasion probabilities and equilibrium dynamics emerging from species' differences in habitat use. The resulting habitat separation promotes coexistence by reducing the overall interaction among species. Differential habitat selection depends on the behavioral abilities of organisms to identify and exploit the most profitable habitats and resource patches. One might thus expect that each species will evolve behavioral types distinct from those of other potential competitors. Accordingly, we exposed four coexisting species in four genera of boreal rodents to open-field tests. We used principal components (PC) to summarize their behaviors along three independent axes corresponding with clines of exploratory, vigilant, and apprehensive personalities. We confirmed that the axes represented repeatable behaviors (personalities) and assessed differences among species with a general linear model (GLM). The GLM revealed highly distinct differences among species, and between pairs of species, on each PC. Even so, it is difficult to infer the adaptive advantages of personality to the habitat segregation that reduces otherwise high interactions among species. Rather, personalities are best interpreted as co-adaptive behaviors reflecting the complex of morphological, physiological and behavioral attributes that dictate tradeoffs and enable coexistence.

Can rare positive interactions become common when large carnivores consume livestock?

Livestock populations in protected areas are viewed negatively because of their interaction with native ungulates through direct competition for food resources. However, livestock and native prey can also interact indirectly through their shared predator. Indirect interactions between two prey species occur when one prey modifies either the functional or numerical responses of a shared predator. This interaction is often manifested as negative effects (apparent competition) on one or both prey species through increased predation risk. But indirect interactions can also yield positive effects on a focal prey if the shared predator modifies its functional response toward increased consumption of an abundant and higher-quality alternative prey. Such a phenomenon between two prey species is underappreciated and overlooked in nature. Positive indirect effects can be expected to occur in livestock-dominated wildlife reserves containing large carnivores. We searched for such positive effects in Acacia-Zizhypus forests of India's Gir sanctuary where livestock (Bubalus bubalis and Bos indicus) and a coexisting native prey (chital deer, Axis axis) are consumed by Asiatic lions (Panthera leo persica). Chital vigilance was higher in areas with low livestock density than in areas with high livestock density. This positive indirect effect occurred because lion predation rates on livestock were twice as great where livestock were abundant than where livestock density was low. Positive indirect interactions mediated by shared predators may be more common than generally thought with rather major consequences for ecological understanding and conservation. We encourage further studies to understand outcomes of indirect interactions on long-term predator-prey dynamics in livestock-dominated protected areas.

Psycholegal abilities and restoration of competence to stand trial.

Criminal defendants adjudicated incompetent to stand trial are typically hospitalized for competence restoration in state institutions. Prolonged restoration hospitalizations involve civil rights concerns and increasing financial costs, and there remains interest in determining which individuals are likely to be successfully restored. We retrospectively reviewed hospital records of 455 male defendants admitted to a forensic treatment center for competence restoration in an effort to determine whether psychiatric diagnoses, demographic factors, or psycholegal abilities were predictive of successful or failed restoration. At varying stages of restoration efforts, psychotic disorder, mental retardation, and previous state hospitalization predicted unsuccessful restoration, while substance use and personality disorders were predictive of successful restoration. Psycholegal abilities were predictive of successful restoration and appeared to form a continuum, with basic behavior and outlook, factual legal understanding, and rational attorney assistance factors demonstrating progressively increased importance in successful restoration.

Charge Severity and Aggression during Competence Restoration.

Most competence restoration occurs in secure inpatient settings. As states struggle with strained resources and seek to best utilize restoration services, factors such as charge severity and violence risk remain key considerations in determining the appropriate setting for an individual's competence restoration. This study offers a quantitative analysis of aggressive behavior during inpatient restoration efforts and whether criminal charge severity correlates with inpatient aggression. Results of this study indicate that a substantial minority of defendants engaged in aggressive behavior and required restraint during the initial months of their hospitalizations. Most of those engaged in few episodes of aggression and required few episodes of restraint. Rates of aggression and restraint were higher in individuals with lower severity charges compared with those with higher severity charges. Courts and evaluators may have selected for a more disordered group of defendants with lower severity charges.

Adaptation and habitat selection in the eco-evolutionary process.

The struggle for existence occurs through the vital rates of population growth. This basic fact demonstrates the tight connection between ecology and evolution that defines the emerging field of eco-evolutionary dynamics. An effective synthesis of the interdependencies between ecology and evolution is grounded in six principles. The mechanics of evolution specifies the origin and rules governing traits and evolutionary strategies. Traits and evolutionary strategies achieve their selective value through their functional relationships with fitness. Function depends on the underlying structure of variation and the temporal, spatial and organizational scales of evolution. An understanding of how changes in traits and strategies occur requires conjoining ecological and evolutionary dynamics. Adaptation merges these five pillars to achieve a comprehensive understanding of ecological and evolutionary change. I demonstrate the value of this world-view with reference to the theory and practice of habitat selection. The theory allows us to assess evolutionarily stable strategies and states of habitat selection, and to draw the adaptive landscapes for habitat-selecting species. The landscapes can then be used to forecast future evolution under a variety of climate change and other scenarios.

On the effect of international human migration on nations' abilities to attain CO2 emission-reduction targets.

I merge publicly available data on CO2 emissions, with patterns of human movement, to analyze the anticipated effects of human migration on the abilities of nations to attain 2030 UNFCCC CO2 emission targets. I do so at both global (175 countries) and national (Canada and the USA) scales. The analyses reveal that mean per capita CO2 emissions are nearly three times higher in countries with net immigration than in countries with net emigration. Those differences project a cumulative migration-induced annual increase in global emissions of approximately 1.7 billion tonnes. For Canada and the United States, the projected total emissions attributable to migration from 2021 to 2030 vary between 0.7 and 0.9 billion tonnes. Although staggering, the annual and total emissions represent a small fraction of current global emissions totalling 36 billion tonnes per annum. Even so, the projected decadal immigration of nearly 4 million humans to Canada, and 10 million to the USA, represent significant additional challenges in reducing CO2 emissions. The challenges pale in comparison with poor nations that are minor contributors to climate change. Such nations face the incomprehensible burden of improving the quality of their citizens' lives without increasing global CO2 emissions. National and international strategies aimed at lowering emissions must thus acknowledge, and cooperatively address, consumptive inequities and expected increases in human population size and migration.

Active density-dependent habitat selection in a controlled population of small mammals.

Density-dependent habitat selection has numerous and far-reaching implications to population dynamics and evolutionary processes. Although several studies suggest that organisms choose and occupy high-quality habitats over poorer ones, definitive experiments demonstrating active selection, by the same individuals at the appropriate population scale, are lacking. We conducted a reciprocal food supplementation experiment to assess whether voles would first occupy a habitat receiving extra food, then change their preference to track food supplements moved to another habitat. Meadow voles, as predicted, were more abundant in food-supplemented habitat than in others. Density declined when food supplements ceased because the voles moved to the new habitat receiving extra food. Although males and females appeared to follow different strategies, meadow-vole densities reflected habitat quality because voles actively selected the best habitat available. It is thus clear that behavioral decisions on habitat use can motivate patterns of abundance, frequency, and gene flow that have widespread effects on subsequent evolution.

Considering ecological dynamics in resource selection functions.

1. Describing distribution and abundance is requisite to exploring interactions between organisms and their environment. Recently, the resource selection function (RSF) has emerged to replace many of the statistical procedures used to quantify resource selection by animals. 2. A RSF is defined by characteristics measured on resource units such that its value for a unit is proportional to the probability of that unit being used by an organism. It is solved using a variety of techniques, particularly the binomial generalized linear model. 3. Observing dynamics in a RSF - obtaining substantially different functions at different times or places for the same species - alerts us to the varying ecological processes that underlie resource selection. 4. We believe that there is a need for us to reacquaint ourselves with ecological theory when interpreting RSF models. We outline a suite of factors likely to govern ecologically based variation in a RSF. In particular, we draw attention to competition and density-dependent habitat selection, the role of predation, longitudinal changes in resource availability and functional responses in resource use. 5. How best to incorporate governing factors in a RSF is currently in a state of development; however, we see promise in the inclusion of random as well as fixed effects in resource selection models, and matched case-control logistic regression. 6. Investigating the basis of ecological dynamics in a RSF will allow us to develop more robust models when applied to forecasting the spatial distribution of animals. It may also further our understanding of the relative importance of ecological interactions on the distribution and abundance of species.

Time-averaging voles match density with long-term habitat quality.

An optimal habitat-selecting organism should use a dispersal strategy that enables occupation of the habitat yielding greatest fitness. The strategy is complicated when habitat quality varies through time. Theory predicts that the long-term distribution of individuals will match mean habitat quality while undermatching current habitat quality. I tested the prediction with experiments on controlled populations of meadow voles occupying two pairs of field enclosures. I released equal numbers, and equal sexes, of voles in each enclosure, and varied resource abundance between enclosures by supplemental feeding. I measured the voles' response with giving-up densities (GUDs) in artificial foraging patches, and with live-trapping at the end of the experiment. The data were consistent with only one of four a priori dispersal models. Giving-up densities declined with resource supply because short-term supply had no effect on population density. GUDs were invariant to the time course of the experiment because densities were proportional to each enclosure's long-term mean quality. Similar patterns in sex ratios and patterns of habitat occupation by juvenile voles born during the experiment reinforce the interpretation of time-averaged habitat matching. This study adds to the cumulating evidence that strategies of space use converge toward behavioral and evolutionary optima.

Correction to: Documenting lemming population change in the Arctic: Can we detect trends?

In the original published article, some of the symbols in figure 1A were modified incorrectly during the typesetting and publication process. The correct version of the figure is provided in this correction.

Documenting lemming population change in the Arctic: Can we detect trends?

Lemmings are a key component of tundra food webs and changes in their dynamics can affect the whole ecosystem. We present a comprehensive overview of lemming monitoring and research activities, and assess recent trends in lemming abundance across the circumpolar Arctic. Since 2000, lemmings have been monitored at 49 sites of which 38 are still active. The sites were not evenly distributed with notably Russia and high Arctic Canada underrepresented. Abundance was monitored at all sites, but methods and levels of precision varied greatly. Other important attributes such as health, genetic diversity and potential drivers of population change, were often not monitored. There was no evidence that lemming populations were decreasing in general, although a negative trend was detected for low arctic populations sympatric with voles. To keep the pace of arctic change, we recommend maintaining long-term programmes while harmonizing methods, improving spatial coverage and integrating an ecosystem perspective.

A rare case of isolated right ventricular infarction.

We present a case of right ventricular infarct mimicking, on the electrocardiogram, an anterior myocardial infarction. The Grant method of vector electrocardiography is a seldom used tool but is a very accurate way of evaluating electrocardiograms and is as useful adjunct to pattern recognition.

Indiana v. Davis: revisiting due process rights of permanently incompetent defendants.

With its landmark Jackson v. Indiana (406 U.S. 715 (1972)) decision, the United States Supreme Court ruled that states may not indefinitely confine criminal defendants solely on the basis of incompetence to stand trial. While this decision led to widespread state statutory and procedural changes, the Jackson court left unresolved whether states could indefinitely maintain criminal charges against incompetent defendants. Nearly four decades after the Jackson decision, the Indiana Supreme Court finally revisited this question in Indiana v. Davis (898 N.E.2d. 281 (Ind. 2008)), unanimously ruling that holding criminal charges over the head of a permanently incompetent defendant, when her pretrial confinement extended beyond the maximum period of any sentence the trial court could impose, violated the basic notions of fundamental fairness embodied in the Due Process Clause of the Fourteenth Amendment. In this analysis of Indiana v. Davis, the facts of the case and the court's rationale for its decision are discussed. This unique ruling is considered in light of the questions resolved and still unanswered since Jackson v. Indiana.

Jackson's Indiana: state hospital competence restoration in Indiana.

Restoration to competence (RTC) of mentally disordered defendants has become increasingly important for state hospitals. In Indiana, most RTC admissions are sent to one primarily forensic state hospital, but many are admitted to other state hospitals. A state database of defendants admitted for RTC between 1988 and 2005 was analyzed for trends in annual admissions, length of stay (LOS), and success of restoration by hospital and by diagnostic category. Regression models were developed to identify factors associated with RTC success. Analysis of 1,475 RTC admissions showed increased annual admissions over the study period. While the forensic hospital restored a higher percentage of individuals than the other state hospitals, the percentage of RTC success decreased over time in all hospitals. Admission to the forensic hospital, female gender, and mood disorder diagnosis were associated with increased restoration success. Older age and psychotic disorder or mental retardation diagnoses were associated with decreased likelihood of restoration. Race was not significantly associated with RTC at six months, but white defendants were less likely to be restored within one year.

Pro se competence in the aftermath of Indiana v. Edwards.

The right to represent oneself at trial is well-established, but not absolute. Recently, in Indiana v. Edwards, the United States Supreme Court considered whether states may demand a higher standard of competence for criminal defendants seeking to represent themselves at trial than that necessary for standing trial with attorney representation. Ultimately, the Court ruled that the Constitution allows states to employ a higher competency standard for pro se defendants. In this analysis of the Court's decision, the authors describe the facts of this case, the legal precedents framing the issues facing the Court, and the Court's rationale for its opinion. The ruling is considered in light of available research involving pro se defendants and whether this ruling is consistent with professional guidelines related to forensic psychiatric practice. Implications of the decision for forensic clinicians and limitations of the decision are discussed.