The Impact of Land Use and Human Population Density on Benthic Macroinvertebrate Diversity in a Highly Urbanized River

Many studies have documented the detrimental effects of urbanization on aquatic ecosystems. What is less known is how “super urban” centers—areas with unusually high human population densities and immense infrastructures—impact biodiversity. Specifically, freshwater streams and rivers that are situated in highly urbanized metropolitan areas might be more susceptible to anthropogenic disturbance. Here, we evaluated the impacts of land use and human population density on benthic macroinvertebrate diversity along the Bronx River, a freshwater river situated in one of the largest urban centers in the world: the New York metropolitan area. We addressed the following research question: How does (1) high intensity development, (2) distance to the Bronx River Parkway, and (3) human population density impact benthic macroinvertebrate diversity along the Bronx River? To answer this question, we sampled benthic macroinvertebrates from 18 study sites, and calculated five measures of benthic macroinvertebrate diversity: (1) family richness, (2) Ephemeroptera-Plecoptera-Trichoptera (EPT) family richness, (3) Simpson’s diversity index, (4) invasive species abundance, and (5) family dominance. Our study yielded three main results. First, benthic macroinvertebrate diversity was extremely low. Across study sites, family richness ranged from two to seven and EPT family richness ranged from zero to one. Indeed, only four of 18 sites harbored pollution-sensitive mayflies (Ephemeroptera) or caddisflies (Trichoptera), and zero sites supported stoneflies (Plecoptera). Second, two measures of land use, high intensity development (80 to 100% impervious surface cover) and distance to a major highway (Bronx River Parkway) were associated with reduced biodiversity. Specifically, high intensity development was negatively associated with family richness and Simpson’s diversity, and positively associated with invasive species abundance. Study sites located closer to the Bronx River Parkway harbored more invasive species than study sites located further away. One invasive species, the Asian clam (Corbicula fluminea), was the second most dominant taxon on the Bronx River. Finally, we found that high human population density was negatively associated with family richness and positively associated with invasive species abundance. Our results suggest that “super urban” centers are especially vulnerable to anthropogenic pressures and that large urban areas warrant special attention for mitigating the decline of benthic macroinvertebrates

Authentic STEM Research, Practices of Science, and Interest Development in an Informal Science Education Program

Background: Two critical challenges in science education are how to engage students in the practices of science and how to develop and sustain interest. The goal of this study was to examine the extent to which high school youth, the majority of whom are members of racial and ethnic groups historically underrepresented in STEM, learn the skills and practices of science and in turn develop interest in conducting scientific research as part of their career pursuits. To accomplish this goal, we applied Hidi and Renninger’s well-tested theoretical framework for studying interest development in the context of a museum-based, informal science education (ISE) program. We used a mixed methods approach, incorporating both survey and interview data, to address three research questions: (1) As youth engage in authentic science research, do they develop perceived competence in mastering the skills and practices of science? (2) Do participants increase, maintain, or decrease interest in science research as a result of this experience? (3) How does participation in scientific practices manifest in non-program contexts?Results: Our study yielded three main results. First, we found that participants developed competence in mastering several of the skills and practices of science. Strikingly, there was significant improvement in self-reported level of competency for 15 specific research skills. Second, we found that participants maintained their interest in scientific research over time. Our post-survey results revealed that one hundred percent of students were either excited about or expressed deep interest in scientific research. Based on a Phases of Interest Development Rubric developed for this study, most participants exhibited emerging individual interest. Finally, participants exhibited significant increases in the frequency in which they engaged in scientific practices outside of the program.Conclusions: Our findings suggest that participation in authentic research in an ISE context affords youth critical opportunities for gaining mastery of several of the skills and practices of science, which in turn reinforces, and in some cases increases participants’ interest in scientific research beyond the span of the program

Multi-Scale Predictors of Parasite Risk in Wild Male Savanna Baboons (Papio Cynocephalus)

Several factors are thought to shape male parasite risk in polygynous and polygynandrous mammals, including male-male competition, investment in potentially immunosuppressive hormones, and dispersal. Parasitism is also driven by processes occurring at larger scales, including host social groups and populations. To date, studies that test parasite-related costs of male behavior at all three scales—individual hosts, social groups, and the host population—remain rare. To fill this gap, we investigated multi-scale predictors of helminth parasitism in 97 male savanna baboons (Papio cynocephalus) living in the Amboseli ecosystem in Kenya over a 5-year span. Controlling for multi-scale processes, we found that many of the classic indicators of male mating effort—high dominance rank, testosterone, and glucocorticoids—did not predict helminth infection risk. However, we identified two parasite-related costs associated with male behavior: (i) socially connected males exhibited higher Trichuris trichiura egg counts and greater parasite species richness than socially isolated males and (ii) males with stable group residency exhibited higher parasite species richness than males who frequently dispersed to new social groups. At the population level, males harbored more parasites following periods of drought than rainfall. Lastly, parasites exhibited positive covariance suggesting that infection risk increases if a host already harbors one or more parasite taxa. These results indicate that multi-scale processes are important in driving male parasite risk and that some aspects of male behavior are costly. Together, our results provide an unusually holistic perspective on the drivers of parasite risk in the context of male behaviors and life histories

Social Dominance in Male Baboons and Other Vertebrates: Benefits, Costs, and Evolutionary Implications

Group living confers many fitness advantages, but can result in within-group competition for access to resources. When some individuals are better able to monopolize resources than others, this can lead to the formation of dominance hierarchies. Whether high rank confers more benefits or costs than low rank remains an open question. In some studies, low-status individuals exhibit worse health than high-status individuals, while in other studies; high-status individuals exhibit worse health than low-status individuals. These differences are puzzling, and similar ambiguities are evident when researchers have attempted to discern rankrelated differences in parasitism and fitness. To address this puzzle, I conducted meta-analyses of vertebrates and longitudinal observational research of a wild population of male savanna baboons (Papio cynocephalus ) in the well-studied Amboseli population in Kenya. Multivariate meta-analyses revealed that, across vertebrates, high-ranking animals face higher parasite risk than low-ranking animals. The overall pattern – higher parasitism in highstatus individuals – was most evident in male mammals, in linear hierarchies, in mating systems where rank predicts mating effort, and for contact- and environmentally-transmitted parasites. My research revealed that high parasite risk may be an unappreciated cost of high rank while reduced parasite risk might be a benefit of social subordination. Longitudinal analyses of male baboons revealed that contrary to the meta-analyses, male dominance rank was not a predictor of parasitism once I controlled for variation in male age; instead, age was a strong predictor of parasitism. Further, males had higher risk of parasitism during periods of drought, in more competitive environments, and if they had strong social bonds with females. Research on the highest ranking males revealed that among the “best of the best”, males with longer tenures at high rank sire more offspring than males with shorter tenures at high rank; dominant males in less competitive social groups are more successful than dominant males in more competitive groups; and social connectedness to females is associated with reproductive success. Collectively, these finding are important for advancing our understanding of the costs and benefits of social dominance, the evolution of male mating strategies, and the forces that influence male fitness

Data from: Social status, immune response, and parasitism in males: a meta-analysis

In male vertebrates, two conflicting paradigms—the energetic costs of high dominance rank and the chronic stress of low rank—have been proposed to explain patterns of immune function and parasitism. To date, neither paradigm has provided a complete explanation for status-related differences in male health. Here, we applied meta-analyses to test for correlations between male social status, immune responses, and parasitism. We used an ecomimmunological framework, which proposes that males should re-allocate investment in different immune components depending on the costs of dominance or subordination. Spanning 297 analyses, from 77 studies on several vertebrate taxa, we found that most immune responses were similar between subordinate and dominant males, and neither dominant nor subordinate males consistently invested in predictable immune components. However, subordinate males displayed significantly lower delayed-type hypersensitivity and higher levels of some inflammatory cytokines than dominant males, while dominant males exhibited relatively lower immunoglobulin responses than subordinate males. Despite few differences in immunity, dominant males exhibited consistently higher parasitism than subordinate males, including protozoan blood parasites, ectoparasites, and gastrointestinal helminths. We discuss our results in the context of the costs of dominance and subordination, and advocate future work that measures both parasitism and immune responses in wild systems

Data from: Male risk-taking is related to number of mates in a polygynous bird.

Evolutionary theory predicts that when intrasexual competition is intense, risky behaviors can evolve if they enhance reproductive success. Here we tested the idea that polygynous males exhibit predictable variation in risk-taking during intense competition for mates. We conducted an observational study of a village weaverbird (Ploceus cucullatus) breeding colony, and video recorded synchronous fleeing events, a common predator avoidance behavior. Males adjusted their flight from the colony according to the amplitude (loudness) and Wiener entropy (harshness) of conspecific alarm calls during a perceived threat. Males also varied in how often they fled the colony. Specifically, in line with predictions based on the value of a male’s territory, males with more nesting females were less likely to flee, and returned sooner if they did flee, compared to males with fewer nesting females. Males with a nest under construction also returned to their nests sooner than males without constructions in progress, consistent with predictions based on nest sabotage by conspecifics. These results suggest that male weavers perform a cost-benefit analysis in real time in order to decide how to respond to a perceived threat, with self-protection trading off with the security of one’s territory and mates

Behavioural analysis of Village Weavers Ploceus cucullatus in an Ethiopian breeding colony during incubation: 1. Females

We used video recordings to perform a behavioural analysis of a Village Weaver Ploceus cucullatus colony in Awash National Park, Ethiopia. We focused specifically on female behaviour during the pair-formation, egg-laying and early-incubation phases of the nesting cycle. A factor analysis revealed that females’ temporal investments can be partitioned into three broad behavioural categories: (1) behaviours associated with aggression, (2) time away/ inside nest, and (3) behaviours associated with copulation. Time budgets revealed females spent approximately 61% of their time away from the colony and 38% of their time inside their nests. The performance of individual behaviours was largely a function of temporal and social factors, including when the birds were observed and the personality of the territorial male. Females invested more time away from the nest earlier and more time inside the nest later in the observation period. One aspect of a territorial male’s personality, boldness, was a predictor of several female behaviours: a female Village Weaver was significantly more likely to remain on a territory if the resident male had a tendency not to flee during colony-wide disturbances. Lastly, a path analysis revealed that females exhibited consistent sequential patterns of behaviour.Analyse comportementale du Tisserin gendarme Ploceus cucullatus dans une colonie de reproduction éthiopienne pendant l’incubation: 1. FemellesNous avons utilisé des enregistrements vidéos pour effectuer une analyse comportementale d’une colonie du Tisserin gendarme Ploceus cucullatus dans le parc national d’Awash, en Éthiopie. Nous nous sommes concentrés sur le comportement des femelles pendant les phases de formation des couples, de ponte et d’incubation précoce du cycle de nidification. Une analyse factorielle a révélé que les investissements temporels des femelles peuvent être divisés en trois grandes catégories comportementales: (1) comportements associés à l’agression, (2) comportements à l’extérieur / à l’intérieur du nid et (3) comportements associés à la copulation. Les budgetstemps ont révélé que les femelles passaient environ 61% de leur temps loin de la colonie et 38% de leur temps dans leur nid. La performance des comportements individuels était largement fonction des facteurs temporels et sociaux, notamment le moment où les oiseaux étaient observés et de la personnalité du mâle territorial. Les femelles ont investi plus de temps loin du nid plus tôt au cours de la période d’observation et plus de temps à l’intérieur du nid plus tard. L’audace, l’un des aspects de la personnalité d’un mâle territorial, était un facteur prédictif de plusieurs comportements manifestés par les femelles: une femelle tisserin gendarme avait nettement plus de chances de rester sur un territoire si le mâle avait tendance à ne pas fuir lors de perturbations à l’échelle de la colonie. Enfin, une analyse de trajectoire a révélé que les femelles présentaient des modèles de comportement séquentiels cohérents.Keywords: behaviour, Ploceidae, Ploceus, Village Weaver, weaverbird

Social status, immune response, and parasitism

Dataset used for a meta-analysis of the association between male social status and measures of immune response and parasitism across the vertebrate sub-phylum

Behavioural analysis of Village Weavers Ploceus cucullatus in an Ethiopian breeding colony during early incubation: 2. Males

We observed a colony of Village Weavers Ploceus cucullatus in Ethiopia at the height of the breeding season to assess variation and relationships amongst male behaviours. Individuals spent most of their time on behaviours functioning in acquiring and retaining mates, and invested more time in female choice (i.e. nestbuilding and display) compared with male competition (i.e. territory defence and stealing nest material). Males exhibited a tradeoff between competing with other males and attending to or building nests. Stealing nest materials functioned as sabotage rather than for nestbuilding. Tradeoffs were also evident between interacting with females and both constructing nests and leaving the colony to forage. Males left the colony frequently, but only stayed away long when gathering nest materials. As individual males acquired more mates, they visited their nests more often but shifted away from building nests and towards defending them. Individuals differed markedly in their behavioural patterns, but variation was continuous.Analyse comportementale de Tisserin gendarme Ploceus cullucatus au sein d’une colonie de reproduction durant l’incubation précoce : 2. MalesNous avons observé une colonie de Tisserin gendarme Ploceus cucullatus en Ethiopie au plus pic de la saison de reproduction pour évaluer les variations et relations parmi les comportements des mâles. Les individus passaient le plus clair de leur temps à adopter des comportements permettant d’acquérir et de retenir des partenaires et ont investi plus de temps dans le choix d’une femelle (p.ex construction de nid et parade) que dans la compétition avec d’autres males (p.ex défense territoriale and vol de matériau de nidification). Les males présentaient un compromis entre concurrencer d’autres males et assister aux nids ou les construire. Le vol de matériel de nidification s’apparentait plus à du sabotage qu’a de la construction. Des compromis étaient aussi évidents entre interagir avec les femelles et construire les nids plutôt que quitter la colonie en quête de nourriture. Les mâles quittaient la colonie fréquemment, mais ne demeuraient loin pour de longues périodes que pour rassembler des matériaux de nidifications. En tant qu’individus les mâles acquièrent plus de partenaires, ils visitent leurs nids plus souvent mais s’éloignent de la construction de nids pour se consacrer à leur défense. Les comportements différaient considérablement d’un individu à l’autre, mais la variation était continue.Keywords: coloniality, ethogram, mating system, Ploceidae, Ploceus, sexual selection, weaverbird

Data from: Male risk-taking is related to number of mates in a polygynous bird.

Evolutionary theory predicts that when intrasexual competition is intense, risky behaviors can evolve if they enhance reproductive success. Here we tested the idea that polygynous males exhibit predictable variation in risk-taking during intense competition for mates. We conducted an observational study of a village weaverbird (Ploceus cucullatus) breeding colony, and video recorded synchronous fleeing events, a common predator avoidance behavior. Males adjusted their flight from the colony according to the amplitude (loudness) and Wiener entropy (harshness) of conspecific alarm calls during a perceived threat. Males also varied in how often they fled the colony. Specifically, in line with predictions based on the value of a male’s territory, males with more nesting females were less likely to flee, and returned sooner if they did flee, compared to males with fewer nesting females. Males with a nest under construction also returned to their nests sooner than males without constructions in progress, consistent with predictions based on nest sabotage by conspecifics. These results suggest that male weavers perform a cost-benefit analysis in real time in order to decide how to respond to a perceived threat, with self-protection trading off with the security of one’s territory and mates