bluuebunny/crossref_metadata_2025 huggingface dataset:
Populations in small, ephemeral habitat patches may drive dynamics in a Daphnia magna metapopulation
Authors: Altermatt Florian , Ebert Dieter
Published: June 2010

Migration is the key process to understand the dynamics and persistence of a metapopulation. Many metapopulation models assume a positive correlation between habitat patch size or stability and the number of emigrants. However, few empirical data exist, and habitat patch size and habitat stability may affect dispersal differently than they affect local persistence. Here, we studied the production of the migration stage (i.e., resting eggs called ephippia) of the cladoceranDaphnia magnain a metapopulation consisting of 530 rock pool habitat patches over 25 years. Earlier, the functioning of this metapopulation was explained with a Levins‐type metapopulation model or with a mainland–island metapopulation model, based on local extinction and colonization data or time series data, respectively. We used pool volume, hydroperiod length, and number of desiccation events to calculate per‐pool production of ephippia (i.e., migration stages). We estimated that populations in small and ephemeral habitat patches produced more than half of the 250 000 to 1 million ephippia that were produced in the metapopulation as a whole per year between 1982 and 2006. Furthermore, these small populations contributed ∼90% of the ephippia exposed during desiccation events, while the contribution of the long‐lived populations in large pools was minimal. We term this an “inverse mainland–island” type metapopulation and propose that populations in small, ephemeral habitat patches may also be the driving force for metapopulation dynamics in other systems.
Experimental test of parasitism hypothesis for population cycles of a forest lepidopteran
Authors: Klemola Netta , Andersson Tommi , Ruohomäki Kai , Klemola Tero
Published: June 2010

Population cycles of herbivores are thought to be driven by trophic interaction mechanisms, either between food plant and herbivore or between the herbivorous prey and its natural enemies. Observational data have indicated that hymenopteran parasitoids cause delayed density‐dependent mortality in cyclic autumnal moth (Epirrita autumnata) populations. We experimentally tested the parasitism hypothesis of moth population cycles by establishing a four‐year parasitoid‐exclusion experiment, with parasitoid‐proof exclosures, parasitoid‐permeable exclosures, and control plots. The exclusion of parasitoids led to high autumnal moth abundances, while the declining abundance in both the parasitoid‐permeable exclosures and the control plots paralleled the naturally declining density in the study area and could be explained by high rates of parasitism. Our results provide firm experimental support for the hypothesis that hymenopteran parasitoids have a causal relationship with the delayed density‐dependent component required in the generation of autumnal moth population cycles.
Scaling community structure: how bacteria, fungi, and ant taxocenes differentiate along a tropical forest floor
Authors: Kaspari Michael , Stevenson Bradley S. , Shik Jonathan , Kerekes Jennifer F.
Published: June 2010

Taxa with smaller individuals tend to have shorter generation times and higher local abundance and diversity. The scaled specialization hypothesis (SSH) posits that taxocenes of smaller individuals should differentiate more rapidly and thoroughly along physiochemical gradients of a given age and extent. In a Panama rainforest, we evaluated how bacteria, fungi, and ants responded to two such gradients: one topographic and the other arising from nine years of NPK fertilization. Terminal restriction fragment length polymorphism (T‐RFLP) delineated bacteria and fungi operational taxonomic units (OTUs); traditional taxonomy delineated the ants. Bacteria had higher local species richness than fungi and ants (averaging 48 vs. 30 vs. 6 OTUs in <0.25 m2). Bacteria OTUs were also more widely distributed (17% of OTUs were found on ≥50% of sample plots compared to 3% for fungi and ants). Consistent with SSH, bacterial composition differed across short‐term (+N and +P) and long‐term (topographic) gradients; fungal taxocenes differed only along the long‐term gradient; and ant taxocenes were homogenous across both. Body size can help predict community responses to a changing environment.
Fossil insect folivory tracks paleotemperature for six million years
Authors: Currano Ellen D. , Labandeira Conrad C. , Wilf Peter
Published: June 2010

Paleoecological studies enhance our understanding of biotic response to climate change because they consider timescales not accessible through laboratory or ecological studies. From 60 to 51 million years ago (Ma), global temperatures gradually warmed to the greatest sustained highs of the last 65 million years. Superimposed on this gradual warming is a transient spike of high temperature and pCO2 (partial pressure of carbon dioxide in the atmosphere; the Paleocene‐Eocene Thermal Maximum 55.8 Ma) and a subsequent short‐term cooling event (∼54 Ma). The highly resolved continental fossil record of the Bighorn Basin, Wyoming, USA, spans this interval and is therefore uniquely suited to examine the long‐term effects of temperature change on the two dominant groups in terrestrial ecosystems, plants and insect herbivores. We sampled insect damage on fossil angiosperm leaves at nine well‐dated localities that range in age from 52.7 to 59 Ma. A total of 9071 leaves belonging to 107 species were examined for the presence or absence of 71 insect‐feeding damage types. Damage richness, frequency, and composition were analyzed on the bulk floras and individual host species. Overall, there was a strong positive correlation between changes in damage richness and changes in estimated temperature, a weak positive relationship for damage frequency and temperature, and no significant correlation for floral diversity. Thus, insect damage richness appears to be more sensitive to past climate change than to plant diversity, although plant diversity in our samples only ranges from 6 to 25 dicot species. The close tracking of the richness of herbivore damage, a presumed proxy for actual insect herbivore richness, to both warming and cooling over a finely divided, extended time interval has profound importance for interpreting the evolution of insects and plant–insect associations in the context of deep time. Our results also indicate that increased insect herbivory is likely to be a net long‐term effect of anthropogenic warming.
Housing is positively associated with invasive exotic plant species richness in New England, USA
Authors: Gavier-Pizarro Gregorio I. , Radeloff Volker C. , Stewart Susan I. , Huebner Cynthia D. , Keuler Nicholas S.
Published: June 2010

Understanding the factors related to invasive exotic species distributions at broad spatial scales has important theoretical and management implications, because biological invasions are detrimental to many ecosystem functions and processes. Housing development facilitates invasions by disturbing land cover, introducing nonnative landscaping plants, and facilitating dispersal of propagules along roads. To evaluate relationships between housing and the distribution of invasive exotic plants, we asked (1) how strongly is housing associated with the spatial distribution of invasive exotic plants compared to other anthropogenic and environmental factors; (2) what type of housing pattern is related to the richness of invasive exotic plants; and (3) do invasive plants represent ecological traits associated with specific housing patterns? Using two types of regression analysis (best subset analysis and hierarchical partitioning analysis), we found that invasive exotic plant richness was equally or more strongly related to housing variables than to other human (e.g., mean income and roads) and environmental (e.g., topography and forest cover) variables at the county level across New England. Richness of invasive exotic plants was positively related to area of wildland–urban interface (WUI), low‐density residential areas, change in number of housing units between 1940 and 2000, mean income, plant productivity (NDVI), and altitudinal range and rainfall; it was negatively related to forest area and connectivity. Plant life history traits were not strongly related to housing patterns. We expect the number of invasive exotic plants to increase as a result of future housing growth and suggest that housing development be considered a primary factor in plans to manage and monitor invasive exotic plant species.
Population size affects vital rates but not population growth rate of a perennial plant
Authors: Kolb Annette , Dahlgren Johan P. , Ehrlén Johan
Published: June 2010

Negative effects of habitat fragmentation on individual performance have been widely documented, but relatively little is known about how simultaneous effects on multiple vital rates translate into effects on population viability in long‐lived species. In this study, we examined relationships between population size, individual growth, survival and reproduction, and population growth rate in the perennial plantPhyteuma spicatum. Population size positively affected the growth of seedlings, the survival of juveniles, the proportion of adults flowering, and potential seed production. Analyses with integral projection models, however, showed no relationship between population size and population growth rate. This was due to the fact that herbivores and pathogens eliminated the relationship between population size and seed production, and that population growth rate was not sensitive to changes in the vital rates that varied with population size. We conclude that effects of population size on vital rates must not translate into effects on population growth rate, and that populations of long‐lived organisms may partly be able to buffer negative effects of small population size on vital rates that have a relatively small influence on population growth rate. Our study illustrates that we need to be cautious when assessing the consequences of habitat fragmentation for population viability based on effects on only one or a few vital rates.
Rapid ecosystem shifts in peatlands: linking plant physiology and succession
Authors: Granath Gustaf , Strengbom Joachim , Rydin Håkan
Published: June 2010

Stratigraphic records from peatlands suggest that the shift from a rich fen (calcareous fen) to an ombrotrophic bog can occur rapidly. This shift constitutes a switch from a species‐rich ecosystem to a species‐poor one with greater carbon storage. In this process, the invasion and expansion of acidifying bog species of Sphagnum (peat mosses) play a key role. To test under what conditions an acidifying bog species could invade a rich fen, we conducted three experiments, contrasting the bog species S. fucsum with the rich‐fen species S. warnstorfii and S. teres. We first tested the effect of calcareous water by growing the three species at different constant height above the water table (HWT; 2, 7, and 14 cm) in a rich‐fen pool and measured maximum photosynthetic rate and production and difference in length growth as an indicator of competition. In none of the species was the photosynthetic capacity negatively affected when placed at low HWT, but S. fuscum was a weaker competitor at low HWT. In our second experiment we transplanted the three species into microhabitats with different and naturally varying HWT in a rich fen. Here, S. fuscum nearly ceased to photosynthesize when transplanted to low HWT (brown moss carpet), while it performed similarly to the two rich‐fen species at the intermediate level (S. warnstorfii hummock level). In contrast to S. fuscum, the rich‐fen sphagna performed equally well in both habitats. The brown moss carpet was seasonally flooded, and in our third experiment we found that S. fuscum, but not S. teres, was severely damaged when submerged in rich‐fen water. Our results suggest two thresholds in HWT affecting the ecosystem switch: one level that reduces the risk of submergence and a higher one that makes bog sphagna competitive against the rich‐fen species.
Experimental evidence for herbivore limitation of the treeline
Authors: Speed James D. M. , Austrheim Gunnar , Hester Alison J. , Mysterud Atle
Published: June 2010

The treeline ecotone divides forest from open alpine or arctic vegetation states. Treelines are generally perceived to be temperature limited. The role of herbivores in limiting the treeline is more controversial, as experimental evidence from relevant large scales is lacking. Here we quantify the impact of different experimentally controlled herbivore densities on the recruitment and survival of birch Betula pubescens tortuosa along an altitudinal gradient in the mountains of southern Norway. After eight years of summer grazing in large‐scale enclosures at densities of 0, 25, and 80 sheep/km2, birch recruited within the whole altitudinal range of ungrazed enclosures, but recruitment was rarer in enclosures with low‐density sheep and was largely limited to within the treeline in enclosures with high‐density sheep. In contrast, the distribution of saplings (birch older than the experiment) did not differ between grazing treatments, suggesting that grazing sheep primarily limit the establishment of new tree recruits rather than decrease the survival of existing individuals. This study provides direct experimental evidence that herbivores can limit the treeline below its potential at the landscape scale and even at low herbivore densities in this climatic zone. Land use changes should thus be considered in addition to climatic changes as potential drivers of ecotone shifts.
Seabird islands take mere decades to recover following rat eradication
Authors: Jones Holly P.
Published: June 2010

Islands house a majority of the world's biodiversity and are thus critical for biodiversity conservation. Seabird nesting colonies provide nutrients that are integral to maintain island biodiversity and ecosystem function. Invasive rats destroy seabird colonies and thus the island ecosystems that depend on seabird‐derived nutrients. After rat eradication, it is unclear how long ecosystem recovery may take, although some speculate on the order of centuries. I looked at ecosystem recovery along a chronosequence of islands that had 12–22 years to recover following rat eradication. I show that soil, plant, and spider marine‐derived nitrogen levels and C:N ratios take mere decades to recover even after centuries‐long rat invasion. Moreover, active seabird restoration could speed recovery even further, giving much hope to quickly conserve many endemic species on islands worldwide.
Modeling species co‐occurrence by multivariate logistic regression generates new hypotheses on fungal interactions
Authors: Ovaskainen Otso , Hottola Jenni , Siitonen Juha
Published: June 2010

Signals of species interactions can be inferred from survey data by asking if some species occur more or less often together than what would be expected by random, or more generally, if any structural aspect of the community deviates from that expected from a set of independent species. However, a positive (or negative) association between two species does not necessarily signify a direct or indirect interaction, as it can result simply from the species having similar (or dissimilar) habitat requirements. We show how these two factors can be separated by multivariate logistic regression, with the regression part accounting for species‐specific habitat requirements, and a correlation matrix for the positive or negative residual associations. We parameterize the model using Bayesian inference with data on 22 species of wood‐decaying fungi acquired in 14 dissimilar forest sites. Our analyses reveal that some of the species commonly found to occur together in the same logs are likely to do so merely by similar habitat requirements, whereas other species combinations are systematically either over‐ or underrepresented also or only after accounting for the habitat requirements. We use our results to derive hypotheses on species interactions that can be tested in future experimental work.
Turning up the heat: Temperature influences the relative importance of top‐down and bottom‐up effects
Authors: Hoekman David
Published: June 2010

Understanding how communities respond to changes in temperature is a major challenge for community ecology. Temperature influences the relative degree to which top‐down and bottom‐up forces structure ecological communities. In greenhouse experiments using the aquatic community found in pitcher plants (Sarracenia purpurea), I tested how temperature affected the relative importance of top‐down (mosquito predation) and bottom‐up (ant carcasses) forces on protozoa and bacteria populations. While bottom‐up effects did not vary consistently with temperature, the top‐down effects of predators on protozoa increased at higher temperatures. These results suggest that temperature could change the relative importance of top‐down and bottom‐up effects in ecological communities. Specifically, higher temperature may increase the strength of top‐down effects by raising predator metabolic rate and concomitant processes (e.g., activity, foraging, digestion, growth) relative to cooler temperatures. These findings apply broadly to an understanding of trophic interactions in a variable environment and are especially relevant in the context of ongoing climate change.
Parenting and Obsessive Compulsive Symptoms: Implications of Authoritarian Parenting
Authors: Timpano Kiara R. , Keough Meghan E. , Mahaffey Brittain , Schmidt Norman B. , Abramowitz Jonathan
Published: June 2010

Cognitive behavioral theories of obsessive-compulsive disorder (OCD) have hypothesized a central role of social learning in the development of OCD. Research indicates that learning via key developmental relationships, such as parent–child interactions, may account for the emergence and maintenance of OC symptoms in adulthood. Baumrind identified three parental authority prototypes or styles, including permissive, authoritative, and authoritarian, that differ on the two dimensions of nurture and behavioral control. Permissive parents allow their children to do as they wish with little discipline, whereas authoritative parents implement reasonable guidelines while still providing a warm and nurturing environment. The third style, authoritarian, represents parenting that is rigid and values strict adherence to rules with lower levels of nurturing. To date, there has been no study examining these parenting styles and OCD symptomatology. The current investigation examined the relationships between parenting styles, obsessive-compulsive (OC) symptoms, and OC-related dysfunctional beliefs (i.e., “obsessive beliefs”) in a nonclinical sample (N = 227). Participants completed measures of these constructs, as well as a measure of general mood and anxiety symptoms. Results indicated that the authoritarian parenting style was significantly associated with both OC symptoms and OC beliefs (e.g., beliefs about the importance of thoughts and personal responsibility), even after controlling for general distress. Analyses also revealed that OC beliefs act as a partial mediator of the relationship between parenting style and OC symptoms. Findings are discussed in light of the implications for future research, particularly that pertaining to risk for OCD and the development of vulnerability factors.
How Are Dysfunctional Beliefs Related to Obsessive-Compulsive Symptoms?
Authors: Taylor Steven , Coles Meredith E. , Abramowitz Jonathan S. , Wu Kevin D. , Olatunji Bunmi O. , Timpano Kiara R. , McKay Dean , Kim Se-Kang , Carmin Cheryl , Tolin David F.
Published: June 2010

Contemporary cognitive models of obsessive-compulsive disorder (OCD) suggest that three types of dysfunctional beliefs contribute to the development and maintenance of obsessivecompulsive (OC) symptoms. These are beliefs characterized by themes of (a) inflated personal responsibility and the overestimation of threat (RT), (b) perfectionism and the intolerance of uncertainty (PC), and (c) overimportance of one’s thoughts and the need to control these thoughts (ICT). To better understand the relationship between symptoms and beliefs, we applied structural equation modeling to belief and symptom data from a large (N = 5,015) nonclinical sample. RT significantly predicted each of the six main types of OC symptoms (checking, hoarding, neutralizing, obsessing, ordering, and washing), beyond the effects attributable to ICT and PC. PC predicted ordering rituals beyond the effects due to ICT and RT. ICT predicted obsessing, neutralizing, and washing compulsions, beyond the effects attributable to RT and PC. The three types of beliefs were strongly correlated with one another, which is consistent with previous theorizing that one type of belief (e.g., RT) influences another (e.g., ICT), which in turn influences OC symptoms (i.e., the indirect effects of beliefs on symptoms). However, there are competing explanations for the strong correlations among beliefs. Research designs are proposed for disentangling the various explanations of the high correlation among beliefs.
Probability and Cost Biases in Social Phobia: Nature, Specificity, and Relationship to Treatment Outcome
Authors: Nelson Elizabeth A. , Lickel James J. , Sy Jennifer T. , Dixon Laura J. , Deacon Brett J.
Published: June 2010

Social phobia is maintained in part by cognitive biases concerning the probability and cost of negative social events. More specifically, individuals with social phobia tend to believe that negative social events are extremely likely to occur, and that if such events were to happen, the consequences would be awful or unbearable. The aim of the present review is to critically evaluate research on the nature and specificity of probability and cost biases in social phobia. Changes in probability and cost estimates during treatment and their relationship to treatment outcome are detailed. The review concludes with a discussion of how current cognitive behavioral interventions target these biases. Directions for future research are proposed.
The Contribution of Experiential Avoidance and Anxiety Sensitivity in the Prediction of Health Anxiety
Authors: Wheaton Michael G. , Berman Noah C. , Abramowitz Jonathan S.
Published: June 2010

Anxiety sensitivity (AS) refers to a fear of arousal-related body sensations based on beliefs that such sensations are dangerous. Experiential (emotional) avoidance (EA) involves an unwillingness to endure upsetting emotions, thoughts, memories, and other private experiences. As both of these constructs are thought to be predictive of health anxiety, the present study examined their relative contribution in the prediction of health anxiety symptoms. A large sample of nontreatment-seeking participants completed measures of AS, EA, and health anxiety. An analogue sample of participants with clinical levels of health anxiety endorsed more AS and EA relative those with less health anxiety. Within the analogue sample, both AS and EA predicted health anxiety symptoms. However, whereas AS (specifically, the physical concerns domain) uniquely predicted health anxiety, EA did not contribute significantly over and above the contributions of AS. Results are also discussed in terms of the conceptualization and treatment of health anxiety.
L’EMDR dans le traitement de la douleur chronique
Authors: Mazzola Alexandra , Calcagno Marìa Lujàn , Goicochea Marìa Teresa , Pueyrredòn Honorio , Leston Jorge , Salvat Fernando
Published: June 2010

La douleur chronique peut réduire considérablement la qualité de vie, engendrant dépression, anxiété et troubles du sommeil ; elle peut déclencher des processus neuroplastiques qui influencent la régulation de la douleur. La présente étude examine le traitement EMDR (Eye Movement Desensitization and Reprocessing) de 38 patients souffrant de douleur chronique, en 12 séances hebdomadaires de 90 minutes. Une batterie de questionnaires auto-administrés, portant sur la qualité de vie, l’intensité de la douleur et le niveau de dépression, a été complétée avant et après le traitement en vue d’une évaluation objective des résultats. L’Entretien clinique structuré du DSM a été administré lors du pré-traitement afin d’identifier les traits de personnalité des participants susceptibles d’influencer la perception de la douleur. Les patients ont manifesté une amélioration statistiquement significative par rapport à leur état initial après 12 semaines de traitement EMDR. Nos résultats suggèrent que l’EMDR constitue un outil efficace pour le traitement psychologique de la douleur chronique, conduisant à une diminution des sensations douloureuses, des affects négatifs en lien avec la douleur, et des niveaux d’anxiété et de dépression. Nous examinons les théories pouvant expliquer les mécanismes par lesquels l’EMDR produit ces effets. Les résultats sont cohérents avec la prémisse sous-jacente de l’EMDR selon laquelle les émotions ont un effet important sur la perception de la douleur.
Precipitation of Ammonium from Concentrated Industrial Wastes as Struvite: A Search for the Optimal Reagents
Authors: Borojovich Eitan J.C. , Münster Meshulam , Rafailov Gennady , Porat Ze'ev
Published: June 2010

Precipitation of struvite (MgNH4PO4) is a known process for purification of wastewater from high concentrations of ammonium. The optimal conditions for precipitation are basic pH (around 9) and sufficient concentrations of magnesium and phosphate ions. In this work, we accomplished efficient precipitation of ammonium from concentrated industrial waste stream by using magnesium oxide (MgO) both as a source of magnesium ions and as a base. Best results were obtained with technical‐grade MgO, which provided 99% removal of ammonium. Moreover, ammonium removal occurred already at pH 7, and the residual ammonium concentration (50 mg/L) remained constant upon addition of more MgO without rising again, as occurs with sodium hydroxide (NaOH). This process may have two other advantages; it also can be relevant for the problem of uncontrolled precipitation of struvite in the supernatant of anaerobic sludge treatment plants, and the precipitate can be used as a fertilizer.
Biodegradation of Direct Blue 15 by Free and Immobilized Trametes versicolor
Authors: Pazarlioglu Nurdan Kasikara , Akkaya Alper , Akdogan Hatice Ardag , Gungor Burcin
Published: June 2010

To investigate biodegradability by Trametes versicolor, five structurally different direct azo‐dyes—Direct Black 38, Direct Blue 15 (DB 15), Direct Orange 26, Direct Green 6, and Direct Yellow 12—were studied. The DB 15 was determined as the best biodegradable dye by this white‐rot fungus. Laccase and manganese peroxidase activities were monitored with the biodegradation process; it was observed that laccase played an important role in the dye degradation, while manganese peroxidase activity could not be detected. Possible degradation products also were examined by gas chromatography‐mass spectrometry, but no metabolite was detected after the degradation and/or decolorization process. To enhance performance of the fungi during the degradation, Trametes versicolor cells were immobilized in alginate beads. Then, DB 15 decolorization by immobilized Trametes versicolor was studied in a small‐scale packed‐bed reactor. The color removal efficiency in repeated batches was found to be 98 and 93% for 50 mg/L DB 15.
Application of Analytic Hierarchy Process‐Grey Target Theory Systematic Model in Comprehensive Evaluation of Water Environmental Quality
Authors: Wu Jun , Tian Xiaogang , Tang Ya , Zhao Yujie , Hu Yandi , Fang Zili
Published: June 2010

Comprehensive evaluation of the water environment for effective water quality management is complicated by a considerable number of factors and uncertainties. It is difficult to combine micro‐evaluation with the macro‐evaluation process. To effectively eliminate the subjective errors of the traditional analytic hierarchy process (AHP), a new modeling approach—the analytic hierarchy process and grey target theory (AHP‐GTT) systematic model—is presented in this study to evaluate water quality in a certain watershed. A case study of applying the AHP‐GTT systematic model to the evaluation and analysis of the water environment was conducted in the Yibin section of the Yangtze River, China. The micro‐evaluation is based on defining the weights of indices of the water quality (IWQ) of each water cross‐section, while the macro‐evaluation is based on calculating the comprehensive indices of water environmental quality and analyzing the tendency of the water environment of each cross‐section. The results indicated that the Baixi and Shuidongmen sections are seriously polluted areas, with the tendencies of becoming worse. Also, the key IWQs of these two cross‐sections are 5‐day biochemical oxygen demand and chemical oxygen demand of permanganate, respectively.
Improved Pretreatment (Coagulation‐Floatation and Ozonation) of Younger Landfill Leachate by Microbubbles
Authors: Liu Shu , Wang Qunhui , Zhai Xuedong , Huang Qifei , Huang Peikun
Published: June 2010

A novel microbubble air/ozone floatation device, TCRI, was developed to enhance the combination of the coagulation and ozonation processes as the pretreatment of landfill leachate. In the coagulation process, microbubble floatation reduced the coagulant dosage. The removal efficiencies of chemical oxygen demand (COD), color, nitrate, and ammonia for the coagulation microbubble floatation were 97, 20, 47, and 163% higher, respectively, than those of the coagulation‐sedimentation process; in the ozonation process, the removal efficiencies of ammonia and COD in microbubble ozonation were increased by 300 and 200%, respectively, compared with a conventional ozonation contactor when the ozonation time was 60 minutes. The results showed that microbubbles could reach a higher ozone‐transfer rate (microbubbles = 0.3018 min−1 > conventional ozone bubbles = 0.2014 min−1). Therefore, the application of the microbubble technology in the coagulation and ozonation combination process may provide an effective and low‐cost approach for wastewater treatment.
Comparative Analysis of Mourning Dove Population Change in North America
Authors: SAUER JOHN R. , LINK WILLIAM A. , KENDALL WILLIAM L. , DOLTON DAVID D.
Published: June 2010

ABSTRACT  Mourning doves (Zenaida macroura) are surveyed in North America with a Call‐Count Survey (CCS) and the North American Breeding Bird Survey (BBS). Analyses in recent years have identified inconsistencies in results between surveys, and a need exists to analyze the surveys using modern methods and examine possible causes of differences in survey results. Call‐Count Survey observers collect separate information on number of doves heard and number of doves seen during counting, whereas BBS observers record one index containing all doves observed. We used hierarchical log‐linear models to estimate trend and annual indices of abundance for 1966–2007 from BBS data, CCS‐heard data, and CCS‐seen data. Trend estimates from analyses provided inconsistent results for several states and for eastern and central dove‐management units. We examined differential effects of change in land use and noise‐related disturbance on the CCS indices. Changes in noise‐related disturbance along CCS routes had a larger influence on the heard index than on the seen index, but association analyses among states of changes in temperature and of amounts of developed land suggest that CCS indices are differentially influenced by changes in these environmental features. Our hierarchical model should be used to estimate population change from dove surveys, because it provides an efficient framework for estimating population trends from dove indices while controlling for environmental features that differentially influence the indices.
Using Citizen Science to Map Human—Coyote Interaction in Suburban New York, USA
Authors: WECKEL MARK E. , MACK DEBORAH , NAGY CHRISTOPHER , CHRISTIE RODERICK , WINCORN ANASTASIA
Published: June 2010

ABSTRACT The expansion of coyotes (Canis latrans) into the northeastern United States is a major challenge to wildlife professionals, especially in suburban and urban areas where reports of human—coyote interaction (HCI) are on the rise. To assist wildlife professionals in identifying potential hot spots of interaction and homeowners in evaluating their risk of a backyard encounter, we used the techniques of citizen science to build a landscape model of HCI for suburban residential properties in Westchester County, New York, USA. We distributed surveys via school children (kindergarten to grade 12) as part of a voluntary class assignment, to maximize the number of homeowners participating in our study and to provide learning experiences for students. Of 6,000 surveys distributed to schools, >1,500 students interviewed their parents on whether a coyote had been seen or heard on their property from 2003 to 2006. Although surveys could not be distributed randomly owing to the participatory process of individual schools, we did receive responses from across Westchester County, representing the spectrum from the most rural to the most urban towns. Homeowners who encountered (i.e., seen or heard) a coyote on their property were on average 50% closer to forest, 36% closer to grassland, and 66% farther from medium‐ to high‐intensity development, complementing existing knowledge on urban coyote habitat use. Our model seemed robust in predicting an independent set of coyote observations (r= 0.88). Based on this model, we generated a map describing the probability of HCI that can be used by both wildlife professionals and homeowners. Regarding the former, state wildlife agencies could more precisely target education campaigns on how to live with coyotes where the possibility of HCI was greatest. Homeowners, in turn, could evaluate their own risk and modify behaviors that would make their property less attractive to coyotes. Furthermore, in creating a descriptive model of HCI from citizen‐generated data, we demonstrated how citizen science can be a useful exploratory tool, generating a wealth of data over a large geographic area in a short period, especially when the inquest is appropriate to stakeholder participation in data collection.
Effectiveness of Raptor Perch Deterrents on an Electrical Transmission Line in Southwestern Wyoming
Authors: SLATER STEVEN J. , SMITH JEFF P.
Published: June 2010

ABSTRACT  In sagebrush—steppe and other open habitats, power lines can provide perches for raptors and other birds in areas where few natural perches previously existed, with potential negative impacts for nearby prey species, such as greater sage‐grouse (Centrocercus urophasianus). Between September 2006 and August 2007, we used driving surveys, behavioral‐observation surveys, and prey‐remains surveys to assess the ability of perch‐deterrent devices to minimize raptor and common raven (Corvus corax) activity on a recently constructed transmission line in southwestern Wyoming. All survey methods demonstrated that activity was significantly lower on the deterrent line compared with a nearby control line; however, deterrent devices did not entirely prevent perching. Considering use of cross‐arms or pole‐tops alone, we sighted 42 raptors and ravens on the deterrent line and 551 on the control line during 192 driving surveys of each line. Golden eagles (Aquila chrysaetos) and ravens were the species most commonly observed successfully overcoming deterrent devices. Smaller rough‐legged hawks (Buteo lagopus) regularly avoided deterrents by perching on conductors (i.e., wires). We documented much off‐line activity near both survey lines and suggest that fewer birds near the deterrent line likely reflected reduced availability of nearby alternate perches. There was a pronounced winter peak in on‐line perch use, with the effect more evident on the control line. Behavior surveys corroborated our driving‐survey results but were otherwise unproductive. During 549 prey‐remains surveys of each line, we found 9 single and 60 grouped prey items near deterrent‐line poles, compared with 277 single and 467 grouped items near control‐line poles. We observed few sage‐grouse in the study area but did witness a likely power line—related, raptor‐caused sage‐grouse mortality. Overall, our results suggest that perch‐deterrent devices can reduce raptor and raven activity on power‐line structures, but to determine their utility on entire power‐line segments, we suggest managers consider 1) what level of reduction in perch activity is worth the cost, and 2) the availability of alternate perches in the surrounding landscape.
Effects of Rain on Palm Springs Ground Squirrel Occupancy in the Sonoran Desert
Authors: BALL LIANNE C. , OSTERMANN‐KELM STACEY D. , MCDONALD MATTHEW W. , DOHERTY PAUL F.
Published: June 2010

ABSTRACT  Long‐term monitoring programs must use informative yet cost‐effective methods. Occupancy estimates that incorporate detection probabilities are used with increasing frequency to describe species status and make management recommendations. Estimating changes in the occupancy of points over time in response to management actions or environmental changes may be especially useful for management of the Palm Springs round‐tailed ground squirrel (Spermophilus tereticaudus chlorus), a subspecies covered under the Coachella Valley Multiple Species Habitat Conservation Plan and Natural Community Conservation Plan. In 2002 and 2003, we estimated occupancy and detection probability of ground squirrels across lands modeled as ground squirrel habitat by the Scientific Advisory Committee for the Habitat Conservation Plan and tested a priori hypotheses about how occupancy varied among vegetation and substrate types. In the 2003 study, we asked whether these associations were affected by winter rains after the 2002 drought year. Occupancy in 2003 was estimated at 0.99 (SE = 0.01) in Western honey mesquite (Prosopis glandulosa) on dunes and hummocks, and occupancy of the remaining modeled habitat was best described by distance to mesquite, with the occupancy probability decreasing with increasing distance from mesquite on dunes or hummocks. The best‐supported model in 2002 described the distribution of ground squirrels as a function of only vegetation and substrate type. However, the best‐supported models in 2003 suggested that distance to mesquite was a component of the occupancy of non‐mesquite vegetation. Mesquite seems to provide high‐quality habitat that can support ground squirrels at high occupancy probabilities that may breed successfully every year. In contrast, other vegetation types provide low‐quality habitat that can only support ground squirrels at low occupancy probabilities that may only breed occasionally. Mesquite could be an essential refugium during drought years, and the 4 best‐supported models in 2003 suggest that restoration of mesquite beginning near currently occupied mesquite patches could be critical for maintaining ground squirrel populations on the preserves.
Home Range and Movement Rates of Female Exurban White‐Tailed Deer
Authors: RHOADS CRAIG L. , BOWMAN JACOB L. , EYLER BRIAN
Published: June 2010

ABSTRACT  White‐tailed deer (Odocoileus virginianus) thrive in fragmented exurban habitats, resulting in increased occurrences of deer‐human conflicts. To develop successful management regimes managers must understand exurban deer ecology, an area deficient in current literature. We investigated exurban white‐tailed deer spatial ecology on Fair Hill Natural Resource Management Area in Cecil County, Maryland, USA. From June 2004 to January 2006, we collected 37,384 telemetry locations and 1,194 visual observations on 66 radiocollared female white‐tailed deer to investigate seasonal home range sizes, home range fidelity, and hourly movement rates. Annual adaptive‐kernel home range size ranged from 8.1 ha to 21.7 ha and 70.9 ha to 144.5 ha among seasons (early, middle, and late‐hunting, posthunting, and fawning) at the 50% and 95% utilization distributions, respectively. Seasonal home range size generally increased from the fawning through posthunting seasons. Seasonal home range overlap differed at 50% and 95% utilization distributions, with the least overlap occurring between the posthunting and fawning seasons (50%: x̄ = 19.4%, 95%: x̄ = 33.3%). Circadian activity varied among seasons with dusk movement rates greatest in all seasons. Our results suggest that this exurban white‐tailed deer population resided on similar ranges throughout the year, making individuals available for harvest during traditional harvest seasons. To maximize deer—hunter contact, efforts should be focused around the dusk activity period to coincide with peak deer activity.
Diet, Prey Selection, and Predation Impact of Black‐Backed Jackals in South Africa
Authors: KLARE UNN , KAMLER JAN F. , STENKEWITZ UTE , MACDONALD DAVID W.
Published: June 2010

ABSTRACT To investigate the role of black‐backed jackals (Canis mesomelas) as predators, we studied diet, prey selection, and predation impact of jackals on 2 game ranches in South Africa that differed in ungulate diversity and biomass. Results showed that large (>15 kg) ungulate species dominated jackal diets throughout the year on both the less diverse (range of ingested biomass across seasons = 39–78%) and more diverse (26–69%) game ranch. Other important food items included medium‐sized mammals (1–3 kg; 1–26%) and fruit (2–69%), whereas small mammals comprised 3–11% of ingested biomass across seasons on both sites. Jackals were not random in consumption of ungulates, and consumption patterns suggested jackals actively hunted certain species rather than consumed them as carrion. During ungulate birthing periods, jackals consumed almost exclusively those ungulate species that were hiders (i.e., fawns were hidden in tall vegetation away from herd) regardless of ungulate densities, suggesting that primarily fawns were preyed upon. Among hiders, there was a negative relationship (P= 0.01) between body size and percent of population consumed by jackals, indicating smaller species were more susceptible than larger species to jackal predation. Consequently, springbok (Antidorcas marsupialis) were always selected over other ungulate species on both sites, and this species was the most impacted by jackal predation. In contrast, ungulate species that were followers (i.e., fawns immediately followed mothers within protection of the herd) were scarcely or not at all consumed by jackals, regardless of body size or density. Medium‐sized mammals were selectively consumed over ungulates, and there was a negative relationship (P< 0.01) between consumption of berries and ungulates, indicating alternative food resources influenced consumption of ungulates on our study sites. Our results will help wildlife managers in Africa identify ungulate species susceptible to jackal predation, and can be used to develop management strategies for reducing jackal predation in areas where it is problematic.
Pedigrees and the Study of the Wild Horse Population of Assateague Island National Seashore
Authors: EGGERT LORI S. , POWELL DAVID M. , BALLOU JONATHAN D. , MALO AURELIO F. , TURNER ALLISON , KUMER JACK , ZIMMERMAN CARL , FLEISCHER ROBERT C. , MALDONADO JESÚS E.
Published: June 2010

ABSTRACT Recently, a number of papers have addressed the use of pedigrees in the study of wild populations, highlighting the value of pedigrees in conservation management. We used pedigrees to study the horses (Equus caballus) of Assateague Island National Seashore, Maryland, USA, one of a small number of free‐ranging animal populations that have been the subject of long‐term studies. This population grew from 28 in 1968 to 175 in 2001, causing negative impacts on the island ecosystem. To minimize these effects, an immunocontraception program was instituted, and horse numbers are slowly decreasing. However, there is concern that this program may negatively affect the genetic health of the herd. We found that although mitochondrial DNA diversity is low, nuclear diversity is comparable to that of established breeds. Using genetic data, we verified and amended maternal pedigrees that had been primarily based on behavioral data and inferred paternity using genetic data along with National Park Service records of the historic ranges of males. The resulting pedigrees enabled us to examine demography, founder contributions, rates of inbreeding and loss of diversity over recent generations, as well as the level of kinship among horses. We then evaluated the strategy of removing individuals (using nonlethal means) with the highest mean kinship values. Although the removal strategy increased the retained diversity of founders and decreased average kinship between individuals, it disproportionately impacted sizes of the youngest age classes. Our results suggest that a combined strategy of controlled breeding and immunocontraception would be more effective than removing individuals with high mean kinships in preserving the long‐term health and viability of the herd.
Can Coyotes Affect Deer Populations in Southeastern North America?
Authors: KILGO JOHN C. , RAY H. SCOTT , RUTH CHARLES , MILLER KARL V.
Published: June 2010

ABSTRACT The coyote (Canis latrans) is a recent addition to the fauna of eastern North America, and in many areas coyote populations have been established for only a decade or two. Although coyotes are known predators of white‐tailed deer (Odocoileus virginianus) in their historic range, effects this new predator may have on eastern deer populations have received little attention. We speculated that in the southeastern United States, coyotes may be affecting deer recruitment, and we present 5 lines of evidence that suggest this possibility. First, the statewide deer population in South Carolina has declined coincident with the establishment and increase in the coyote population. Second, data sets from the Savannah River Site (SRS) in South Carolina indicate a new mortality source affecting the deer population concurrent with the increase in coyotes. Third, an index of deer recruitment at SRS declined during the period of increase in coyotes. Fourth, food habits data from SRS indicate that fawns are an important food item for coyotes during summer. Finally, recent research from Alabama documented significant coyote predation on fawns there. Although this evidence does not establish cause and effect between coyotes and observed declines in deer recruitment, we argue that additional research should proactively address this topic in the region. We identified several important questions on the nature of the deer—coyote relationship in the East.