Independent age estimates resolve the controversy of ancient human footprints at White Sands.

Human footprints at White Sands National Park, New Mexico, USA, reportedly date to between ~23,000 and 21,000 years ago according to radiocarbon dating of seeds from the aquatic plant . These ages remain controversial because of potential old carbon reservoir effects that could compromise their accuracy. We present new calibrated C ages of terrestrial pollen collected from the same stratigraphic horizons as those of the seeds, along with optically stimulated luminescence ages of sediments from within the human footprint-bearing sequence, to evaluate the veracity of the seed ages.

Physico-chemical properties of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) diazonium ion: a theoretical investigation.

We have explored the physico-chemical properties of NNK diazonium ion to gain insight into its shape, bonding, charge distribution, and ro-vibrational features. This information is essential if the chemical reactivity and physical properties of this important intermediate are to be understood. NNK diazonium ion is a well-known alkylating agent.

First record of Nesomesochorinae (Hymenoptera: Ichneumonidae) from America north of Mexico with descriptions of two new species of Nonnus Cresson.

The subfamily Nesomesochorinae is recorded for the first time from America north of Mexico. Two new species of Nonnus (Hymenoptera: Ichneumonidae: Nesomesochorinae) are described, both from Arizona, USA and Mexico. Diagnostic characters and figures are provided to distinguish these two new species from congeners in North and Central America.

The mature larva of Poemenia albipes Cresson (Hymenoptera: Ichneumonidae, Poemeniinae) and a review of the biology of Nearctic Poemenia.

The mature larva of Poemenia albipes is figured and described, providing the first knowledge of the larval morphology of this genus. Poemenia is considered to be an ectoparasitoid on the basis of this information. The implications for the larval morphology of the Poemeniinae are discussed.

Stenarella domator (Poda) [Hymenoptera: Ichneumonidae], a newly introduced species to the Nearctic, and a summary of adventive Nearctic species of Ichneumonidae.

The western Palaearctic ichneumonid Stenarella domator (Poda) is newly recorded for the Nearctic. Photographs and a new key to the genera of Nearctic Osprynchotina (Cryptinae: Cryptini) are provided. Like other species in the Osprynchotina, S.

Examining the effects of chronic, lake-wide elevated temperatures on behavioural expression in largemouth bass, Micropterus salmoides.

Many behaviours have differential fitness consequences across thermal and ecological contexts, indicating that both ecological shifts and warming temperatures induced by climatic change may alter how organisms behave. However, empirical evidence of temperature-driven behavioural selection in natural systems is lacking. We compared behaviours and behavioural syndromes related to activity, exploration, boldness and aggression in populations of largemouth bass (Micropterus salmoides) from ambient lakes to the those from artificially warmed, power plant cooling lakes to investigate changes in behaviours associated with warmer environments.

Growth and physiological responses in largemouth bass populations to environmental warming: Effects of inhabiting chronically heated environments.

Ectotherms are susceptible to increasing environmental temperatures associated with anthropogenic warming. Supra-optimum temperatures lead to declining aerobic capacity and can increase exposure to lethal temperatures, resulting in reduced performance. Although the capacity of phenotypic plasticity to minimize the effects of temperature on physiological processes is well studied, evidence of generational changes (e.

Palaeoenvironmental, epigraphic and archaeological evidence of total warfare among the Classic Maya.

Despite over a century of archaeological research, the nature and broader consequences of Maya warfare remain poorly understood. Classic period (250-950 CE) Maya warfare has largely been viewed as ritualized and limited in scope. Evidence of violent warfare in the Terminal Classic period (800-950 CE) is interpreted as an escalation of military tactics that played a role in the socio-economic collapse of the Classic Maya civilization.

Effects of maternal cortisol treatment on offspring size, responses to stress, and anxiety-related behavior in wild largemouth bass (Micropterus salmoides).

Cortisol, the main glucocorticoid stress hormone in teleost fish, is of interest as a mediator of maternal stress on offspring characteristics because it plays an organizational role during early development. The present study tested the hypothesis that maternal exposure to cortisol treatment prior to spawn affects offspring phenotype using wild largemouth bass (Micropterus salmoides). Baseline and stress-induced cortisol concentrations, body size (i.

Invasive planktivores as mediators of organic matter exchanges within and across ecosystems.

Bighead carp (Hypophthalmichthys nobilis) are an invasive planktivore that can greatly deplete planktonic resources. Due to the inefficient conversion of food into fish tissue, large portions of consumed materials are egested and shunted to benthic habitats. We explored how bighead carp alter pools of organic matter between planktonic and benthic habitats, and across ecosystem boundaries.

Size-Dependent Consequences of Exogenous Cortisol Manipulation on Overwinter Survival and Condition of Largemouth Bass.

Little is known about the size-dependent consequences of stressors on wild animals, which is particularly relevant during winter where size-specific trends in survival are common. Here, exogenous cortisol manipulation was used to investigate the effect of a physiological challenge on overwinter mortality and spring condition of largemouth bass (Micropterus salmoides) across a range of body sizes. Fish were wild-caught in the fall, assigned into either control or cortisol manipulated treatments, and held in replicated experimental ponds.

Does prey community composition affect the way different behavioral types interact with their environment?

We examined how different exploratory behavioral types of largemouth bass responded to differing prey communities by determining effects on growth, survival and diet in experimental ponds. We found evidence that non-explorer largemouth bass target young-of-year bluegill early on in life, but bluegill were not an important diet item by late summer. The presence of young-of-year bluegill as prey does appear to affect the foraging strategy of the two exploring types differently.

Is winter worse for stressed fish? The consequences of exogenous cortisol manipulation on over-winter survival and condition of juvenile largemouth bass.

Over-winter mortality is an important selective force for warm-water fish (e.g., centrarchids) that live in temperate habitats.

Response of largemouth bass (Micropterus salmoides) from different thermal environments to increased water temperature.

Due to concerns of global climate change, additional research is needed to quantify the thermal tolerance of species, and how organisms are able to adapt to changes in thermal regime. We quantified the thermal tolerance and thermal stress response of a temperate sportfish from two different thermal environments. One group of largemouth bass (Micropterus salmoides) inhabited thermally enhanced reservoirs (used for power plant cooling), with water temperatures typically 2-5°C warmer than nearby reservoirs.

Biology, early stages and description of a new species of Adelognathus Holmgren (Hymenoptera: Ichneumonidae: Adelognathinae).

Adelognathus leucotrochi Shaw & Wahl sp. nov. is described from Britain where it is a univoltine slightly gregarious koinobiont ectoparasitoid of late stage larvae of the tenthredinid sawfly Nematus leucotrochus Hartig feeding on Ribes uva-crispa.

Reach-scale land use drives the stress responses of a resident stream fish.

Abstract To date, relatively few studies have tried to determine the practicality of using physiological information to help answer complex ecological questions and assist in conservation actions aimed at improving conditions for fish populations. In this study, the physiological stress responses of fish were evaluated in-stream between agricultural and forested stream reaches to determine whether differences in these responses can be used as tools to evaluate conservation actions. Creek chub Semotilus atromaculatus sampled directly from forested and agricultural stream segments did not show differences in a suite of physiological indicators.

Physiological disturbances and overwinter mortality of largemouth bass from different latitudes.

Thermal conditions associated with winter can influence the distribution of a species. Because winter severity varies along latitudes, populations of temperate fish located along a latitudinal gradient may display variation in both sublethal and lethal responses to cold stressors. Sublethal physiological disturbances were quantified in age 1 largemouth bass (Micropterus salmoides) from populations originating from Alabama and Illinois but raised in a common environment.

Acclimation to a low oxygen environment alters the hematology of largemouth bass (Micropterus salmoides).

One of the most severe impacts of urbanization on aquatic systems is the increasing presence of low oxygen environments caused by anthropogenic sources of pollution. As urbanization increases nationally and globally, it is becoming exceedingly important to understand how hypoxia affects aquatic fauna, especially fish species. In an effort to better understand the impacts of prolonged hypoxia on fishes, largemouth bass were held at 3.

Recreational fishing selectively captures individuals with the highest fitness potential.

Fisheries-induced evolution and its impact on the productivity of exploited fish stocks remains a highly contested research topic in applied fish evolution and fisheries science. Although many quantitative models assume that larger, more fecund fish are preferentially removed by fishing, there is no empirical evidence describing the relationship between vulnerability to capture and individual reproductive fitness in the wild. Using males from two lines of largemouth bass (Micropterus salmoides) selectively bred over three generations for either high (HV) or low (LV) vulnerability to angling as a model system, we show that the trait "vulnerability to angling" positively correlates with aggression, intensity of parental care, and reproductive fitness.

Sex-specific consequences of experimental cortisol elevation in pre-reproductive wild largemouth bass.

Experimental implants were used to investigate the effect of elevated cortisol (the primary stress hormone in teleost fish) on energetic and physiological condition prior to reproduction in male and female largemouth bass (Micropterus salmoides). Fish were wild-caught from lakes in Illinois, and held in experimental ponds for the duration of the study. Between 9 and 13 days after cortisol treatment, and immediately prior to the start of the reproductive period, treated and control animals were sampled.

Influence of behavior and mating success on brood-specific contribution to fish recruitment in ponds.

One source of uncertainty in predicting the response of populations to exploitation is individual differences within a population in both vulnerability to capture and contribution to population renewal. For species with parental care, individuals engaged in nesting behavior are often targeted for exploitation, but predicting outcomes of this nonrandom vulnerability will depend in part on an understanding of how parental traits are related to potential for brood contribution to the population. Variation in brood-specific contribution to recruitment of largemouth bass (Micropterus salmoides), a fish species with extended parental care, was quantified to determine if differences in mating success, parental care behaviors, and timing of reproduction influenced offspring recruitment.

Determining the mechanism by which fish diversity influences production.

Understanding the ability of biodiversity to govern ecosystem function is essential with current pressures on natural communities from species invasions and extirpations. Changes in fish communities can be a major determinant of food web dynamics, and even small shifts in species composition or richness can translate into large effects on ecosystems. In addition, there is a large information gap in extrapolating results of small-scale biodiversity-ecosystem function experiments to natural systems with realistic environmental complexity.

Native fish diversity alters the effects of an invasive species on food webs.

Aquatic communities have been altered by invasive species, with impacts on native biodiversity and ecosystem function. At the same time, native biodiversity may mitigate the effects of an invader. Common carp (Cyprinus carpio) is a ubiquitous, invasive fish species that strongly influences community and ecosystem processes.

Cardiovascular performance of six species of field-acclimatized centrarchid sunfish during the parental care period.

Parental care is an energetically costly period of the life history of many fish species characterized by extended high intensity activity. To date, there have been no studies that have investigated the cardiovascular correlates of extended parental care in fish. Using Doppler flow probes, the cardiovascular performance of six syntopic centrarchid fish species (N=232) that provide sole, male parental care was examined across a range of water temperatures that encompass their reproductive periods (14-26 degrees C).