Publications by authors named "Joshua Ackerman"

How does living in an environment with many or few family relatives shape our psychology? Here, we draw upon ideas from behavioral ecology to explore the psychological effects of ecological relatedness-the prevalence of family relatives in one's environment. We present six studies, both correlational and experimental, that examine this. In general, people and populations that live in ecologies with more family relatives (Studies 1-4b), or who imagine themselves to be living in such ecologies (Studies 2/3a/3b/4b), engage in more extreme pro-group behavior (e.

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In birds, mercury embryotoxicity can occur through the transfer of mercury from the female to her eggs. Maternal transfer of mercury can vary by egg position in the laying sequence, with first-laid eggs often exhibiting greater mercury concentrations than subsequently laid eggs. We studied egg mercury concentration, mercury burden (total amount of mercury in the egg), and egg morphometrics by egg position in the laying sequence for two songbirds: tree swallows (Tachycineta bicolor) and house wrens (Troglodytes aedon).

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An important provision of the Minamata Convention on Mercury is to monitor and evaluate the effectiveness of the adopted measures and its implementation. Here, we describe for the first time currently available biotic mercury (Hg) data on a global scale to improve the understanding of global efforts to reduce the impact of Hg pollution on people and the environment. Data from the peer-reviewed literature were compiled in the Global Biotic Mercury Synthesis (GBMS) database (>550,000 data points).

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Birds are used as bioindicators of environmental mercury (Hg) contamination, and toxicity reference values are needed for injury assessments. We conducted a comprehensive review, summarized data from 168 studies, performed a series of Bayesian hierarchical meta-analyses, and developed new toxicity reference values for the effects of methylmercury (MeHg) on birds using a benchmark dose analysis framework. Lethal and sublethal effects of MeHg on birds were categorized into nine biologically relevant endpoint categories and three age classes.

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Deep ocean foraging northern elephant seals (Mirounga angustirostris) consume fish and squid in remote depths of the North Pacific Ocean. Contaminants bioaccumulated from prey are subsequently transferred by adult females to pups during gestation and lactation, linking pups to mercury contamination in mesopelagic food webs (200-1000 m depths). Maternal transfer of mercury to developing seal pups was related to maternal mercury contamination and was strongly correlated with maternal foraging behavior (biotelemetry and isotopes).

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People sick with infectious illnesses face negative social outcomes, like exclusion, and may take steps to conceal their illnesses from others. In 10 studies of past, current, and projected illness, we examined the prevalence and predictors of infection concealment in adult samples of U.S.

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Article Synopsis
  • Birds need to keep their eggs warm and safe for them to grow properly, which means parents have to spend a lot of time sitting on the eggs.
  • Researchers studied how much time 1,414 duck nests in California were watched by parent ducks and found that they spent more time on the nests as they got closer to hatching.
  • After the parents finished laying all their eggs, they paid more attention to the nests at night, especially if they had more eggs to take care of, which helped keep the eggs at the right temperature.
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Mercury bioaccumulation from deep-ocean prey and the extreme life history strategies of adult female northern elephant seals () provide a unique system to assess the interactive effects of mercury and stress on animal health by quantifying blood biomarkers in relation to mercury (skeletal muscle and blood mercury) and cortisol concentrations. The thyroid hormone thyroxine (tT4) and the antibody immunoglobulin E (IgE) were associated with mercury and cortisol concentrations interactively, where the magnitude and direction of the association of each biomarker with mercury or cortisol changed depending on the concentration of the other factor. For example, when cortisol concentrations were lowest, tT4 was positively related to muscle mercury, whereas tT4 had a negative relationship with muscle mercury in seals that had the highest cortisol concentrations.

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Individual differences exist in perceived vulnerability to disease (PVD). PVD is associated with negative responses (e.g.

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Nest predation is the main cause of nest failure for ducks. Understanding how habitat features influence predator movements may facilitate management of upland and wetland breeding habitats that reduces predator encounter rates with duck nests and increases nest survival rates. For 1618 duck nests, nest survival increased with distance to phragmites (), shrubs, telephone poles, human structures, and canals, but not for four other habitat features.

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Environmental contamination is widespread and can negatively impact wildlife health. Some contaminants, including heavy metals, have immunosuppressive effects, but prior studies have rarely measured contamination and disease simultaneously, which limits our understanding of how contaminants and pathogens interact to influence wildlife health. Here, we measured mercury concentrations, influenza infection, influenza antibodies and body condition in 749 individuals from 11 species of wild ducks overwintering in California.

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Avian influenza viruses can pose serious risks to agricultural production, human health, and wildlife. An understanding of viruses in wild reservoir species across time and space is important to informing surveillance programs, risk models, and potential population impacts for vulnerable species. Although it is recognized that influenza A virus prevalence peaks in reservoir waterfowl in late summer through autumn, temporal and spatial variation across species has not been fully characterized.

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Since the last Arctic Monitoring and Assessment Programme (AMAP) effort to review biological effects of mercury (Hg) on Arctic biota in 2011 and 2018, there has been a considerable number of new Arctic bird studies. This review article provides contemporary Hg exposure and potential health risk for 36 Arctic seabird and shorebird species, representing a larger portion of the Arctic than during previous AMAP assessments now also including parts of the Russian Arctic. To assess risk to birds, we used Hg toxicity benchmarks established for blood and converted to egg, liver, and feather tissues.

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Mercury contamination is a major threat to the global environment, and is still increasing in some regions despite international regulations. The methylated form of mercury is hazardous to biota, yet its sublethal effects are difficult to detect in wildlife. Body condition can vary in response to stressors, but previous studies have shown mixed effects of mercury on body condition in wildlife.

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Article Synopsis
  • Avian influenza viruses (AIVs) are commonly found in waterfowl and can cause significant health issues in poultry and humans, making early detection crucial for preventing outbreaks.
  • Surveillance of wild waterfowl, particularly in high-risk areas, is important, but effective strategies require understanding the factors that influence infection rates.
  • A study in California's Central Valley found a 10.5% prevalence of AIV, with variations based on species, sex, and wetland type, highlighting the need for tailored surveillance efforts based on ecological factors.
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The current study examines predictors of social distancing behavior across populations (students and community members) and across time in the early months of the COVID-19 pandemic, focusing on two factors commonly associated with risk perception and prevention: knowledge and affect. Results showed that, despite similar levels of social distancing, student distancing was predicted only by feelings of threat about COVID-19, whereas community distancing was predicted by both feeling informed and threatened. Examining longitudinal effects, which were limited to students only, students became more informed about COVID-19 over time, and increases in being informed (but not feeling threatened) predicted more distancing.

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Zoonotic diseases are of considerable concern to the human population and viruses such as avian influenza (AIV) threaten food security, wildlife conservation and human health. Wild waterfowl and the natural wetlands they use are known AIV reservoirs, with birds capable of virus transmission to domestic poultry populations. While infection risk models have linked migration routes and AIV outbreaks, there is a limited understanding of wild waterfowl presence on commercial livestock facilities, and movement patterns linked to natural wetlands.

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Identifying migration routes and fall stopover sites of Cinnamon Teal ( septentrionalium) can provide a spatial guide to management and conservation efforts, and address vulnerabilities in wetland networks that support migratory waterbirds. Using high spatiotemporal resolution GPS-GSM transmitters, we analyzed 61 fall migration tracks across western North America during our three-year study (2017-2019). We marked Cinnamon Teal primarily during spring/summer in important breeding and molting regions across seven states (California, Oregon, Washington, Idaho, Utah, Colorado, and Nevada).

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Long-term environmental management to prevent waterfowl population declines is informed by ecology, movement behavior and habitat use patterns. Extrinsic factors, such as human-induced disturbance, can cause behavioral changes which may influence movement and resource needs, driving variation that affects management efficacy. To better understand the relationship between human-based disturbance and animal movement and habitat use, and their potential effects on management, we GPS tracked 15 dabbling ducks in California over ~4-weeks before, during and after the start of a recreational hunting season in October/November 2018.

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Incubating birds must balance the needs of their developing embryos with their own physiological needs, and many birds accomplish this by taking periodic breaks from incubation. Mallard () and gadwall () hens typically take incubation recesses in the early morning and late afternoon, but recesses can also take place at night. We examined nocturnal incubation recess behavior for mallard and gadwall hens nesting in Suisun Marsh, California, USA, using iButton temperature dataloggers and continuous video monitoring at nests.

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Methylmercury concentrations vary widely across geographic space and among habitat types, with marine and aquatic-feeding organisms typically exhibiting higher mercury concentrations than terrestrial-feeding organisms. However, there are few model organisms to directly compare mercury concentrations as a result of foraging in marine, estuarine, or terrestrial food webs. The ecological impacts of differential foraging may be especially important for generalist species that exhibit high plasticity in foraging habitats, locations, or diet.

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Nesting birds must provide a thermal environment sufficient for egg development while also meeting self-maintenance needs. Many birds, particularly those with uniparental incubation, achieve this balance through periodic incubation recesses, during which foraging and other self-maintenance activities can occur. However, incubating birds may experience disturbances such as predator or human activity which interrupt natural incubation patterns by compelling them to leave the nest.

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How do embodied states influence the inferences people make about the meaning that is intended by communicators? We propose that embodied states encourage mental representation of certain meanings while inhibiting others, thereby facilitating or hindering comprehension in social interactions and potentially causing miscommunication. Four experiments demonstrate that bodily postures incompatible with the intended meaning of a sentence attenuated inferences of those meanings, especially when the intended meaning was not articulated directly and required more extensive inference-making effort. Participants were faster at responding to sentences containing verbs inferring a sitting position when they were sitting than when they were standing, and vice versa.

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The coronavirus SARS-CoV-2 (COVID-19) pandemic has created widespread stress. Since many people cope with stress by eating, the current study investigated whether eating behaviors shifted among U.S.

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Bioaccumulation of environmental contaminants in mammalian predators can serve as an indicator of ecosystem health. We examined mercury concentrations of raccoons (Procyon lotor; n = 37 individuals) and striped skunks (Mephitis mephitis; n = 87 individuals) in Suisun Marsh, California, a large brackish marsh that is characterized by contiguous tracts of tidal marsh and seasonally impounded wetlands. Mean (standard error; range) total mercury concentrations in adult hair grown from 2015 to 2018 were 28.

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