Testosterone and Group Size in Cliff Swallows: Testing the “Challenge Hypothesis” in a Colonial Bird

The “challenge hypothesis” states that increases in testosterone levels of male animals during the breeding season are directly related to the extent of intrasexual competition for resources or mates that they experience. Although often tested in territorial species, the challenge hypothesis has not been evaluated for colonial animals that live in groups of different sizes and that thus experience different intensities of intrasexual competition. We measured circulating testosterone levels of male and female cliff swallows (Petrochelidon pyrrhonota) in southwestern Nebraska, where these birds nest in colonies of widely different sizes. Males had significantly higher testosterone levels than females, as expected. For males especially, there was a seasonal rise in testosterone levels early in the nesting cycle, corresponding to the period when birds were establishing nest ownership and egg laying, and then a fall as they switched to parental duties. Testosterone levels varied significantly with colony size; for both sexes, birds in larger colonies had higher levels of testosterone than those in smaller colonies when controlling for date. Age and body mass were not related to testosterone levels. Higher levels of testosterone for birds of both sexes in larger colonies probably reflect greater com-petition for matings, often extra pair, in the more social nesting situations. The results support the predictions of the challenge hypothesis

Testosterone and Group Size in Cliff Swallows: Testing the “Challenge Hypothesis” in a Colonial Bird

The “challenge hypothesis” states that increases in testosterone levels of male animals during the breeding season are directly related to the extent of intrasexual competition for resources or mates that they experience. Although often tested in territorial species, the challenge hypothesis has not been evaluated for colonial animals that live in groups of different sizes and that thus experience different intensities of intrasexual competition. We measured circulating testosterone levels of male and female cliff swallows (Petrochelidon pyrrhonota) in southwestern Nebraska, where these birds nest in colonies of widely different sizes. Males had significantly higher testosterone levels than females, as expected. For males especially, there was a seasonal rise in testosterone levels early in the nesting cycle, corresponding to the period when birds were establishing nest ownership and egg laying, and then a fall as they switched to parental duties. Testosterone levels varied significantly with colony size; for both sexes, birds in larger colonies had higher levels of testosterone than those in smaller colonies when controlling for date. Age and body mass were not related to testosterone levels. Higher levels of testosterone for birds of both sexes in larger colonies probably reflect greater com-petition for matings, often extra pair, in the more social nesting situations. The results support the predictions of the challenge hypothesis

Glucocorticoid Hormone Levels Increase with Group Size and Parasite Load in Cliff Swallows

Animals often cope with adverse events by releasing glucocorticoid hormones, which in turn promote increased energy assimilation. In captive animals, crowding also leads to increased glucocorticoid activity, probably because of increased levels of social competition. We investigated how group size and ectoparasite infestations affected endogenous levels of the glucocorticoid hormone, corticosterone, in colonial cliff swallows, Petrochelidon pyrrhonota, in southwestern Nebraska, USA. Parasites were removed from some colonies by fumigating nests. Baseline levels of corticosterone in breeding adults varied significantly with whether parasites were present, colony size (measured by total number of active nests at a site), and nesting stage. Across all analyses, birds from fumigated colonies averaged significantly lower baseline levels of corticosterone. These levels in adults increased with colony size at nonfumigated sites, especially during the period when nestlings were being fed, but no relation or the opposite one was found for birds in fumigated colonies. Baseline corticosterone levels were unrelated to sex, age, body weight, or testosterone levels in adults. Corticosterone concentrations tended to increase during a bad-weather event when food was scarce. Patterns in nestling and recently fledged juveniles were consistent with those in adults. The increased baseline levels of corticosterone in birds of larger colonies appear related to the larger number of parasites there. Higher levels of corticosterone probably facilitate increased allocation of time and energy to foraging and greater energy assimilation during challenging events such as bad weather, parasitism by blood-feeding bugs in large colonies, and the period when young are becoming independent of their parents

Effects of Endogenous Steroid Hormone Levels on Annual Survival in Cliff Swallows

The hormone corticosterone is an important part of animals’ response to environmental stress, modulating short-term adaptive changes in behavior and physiology. The hormone testosterone is also critical, especially for males, in regulating the expression of sexual behavior and parental care. These hormones can have costly consequences, however, and within populations individuals show variation in endogenous levels of both corticosterone and testosterone. We studied how annual survival varied as a function of natural levels of these hormones in colonially breeding Cliff swallows (Petrochelidon pyrrhonota) in southwestern Nebraska, USA, in 2000–2003. We sampled hormone levels of birds caught at colonies and using mark–recapture, monitored their survival through subsequent years in the study area. Maximum-likelihood estimation and model fitting (with program MARK) revealed that birds sampled for corticosterone in colonies of all sizes late in the season had curvilinear survival; individuals with very low and very high levels of corticosterone had lower survival than those with intermediate levels. Annual survival of birds sampled earlier in the season, however, generally declined with increasing corticosterone level. More birds than expected, given the survival functions, had the very low corticosterone levels in nonfumigated colonies later in the year, suggesting perhaps a compensatory benefit unrelated to survival for very low corticosterone levels. In a more limited analysis, testosterone appeared to have little effect on annual survival, although some evidence suggested that females with endogenous testosterone levels below the mean for a given date might have survived better

Effects of Endogenous Steroid Hormone Levels on Annual Survival in Cliff Swallows

The hormone corticosterone is an important part of animals’ response to environmental stress, modulating short-term adaptive changes in behavior and physiology. The hormone testosterone is also critical, especially for males, in regulating the expression of sexual behavior and parental care. These hormones can have costly consequences, however, and within populations individuals show variation in endogenous levels of both corticosterone and testosterone. We studied how annual survival varied as a function of natural levels of these hormones in colonially breeding Cliff swallows (Petrochelidon pyrrhonota) in southwestern Nebraska, USA, in 2000–2003. We sampled hormone levels of birds caught at colonies and using mark–recapture, monitored their survival through subsequent years in the study area. Maximum-likelihood estimation and model fitting (with program MARK) revealed that birds sampled for corticosterone in colonies of all sizes late in the season had curvilinear survival; individuals with very low and very high levels of corticosterone had lower survival than those with intermediate levels. Annual survival of birds sampled earlier in the season, however, generally declined with increasing corticosterone level. More birds than expected, given the survival functions, had the very low corticosterone levels in nonfumigated colonies later in the year, suggesting perhaps a compensatory benefit unrelated to survival for very low corticosterone levels. In a more limited analysis, testosterone appeared to have little effect on annual survival, although some evidence suggested that females with endogenous testosterone levels below the mean for a given date might have survived better

A Bibliometric Analysis of Select Information Science Print and Electronic Journals in the 1990s

This paper examines three e-journals and one paper journal begun in the 1990s within the information science genre. In addition, these journals are compared to what is perhaps the leading information science journal, one that has been published continuously for fifty years. The journals we examine are CyberMetrics, Information Research, the Journal of Internet Cataloging, Libres, and the Journal of the American Society for Information Science. We find that there are a number of important differences among the journals. These include frequency of publication, publication size, number of authors, and the funding status of articles. We also find differences among journals for distributions of authors by gender and corporate authors by region. Some of the regional differences can be explained by journal maturation -- the more mature the journal the greater the dispersion. We also find that women are more likely to publish in the newer journals than in JASIS. The fact that a journal is or is not an e-journal does not appear to affect its presence or behaviour as an information science journal

Novel Fusarium mutualists of two Euwallacea species infesting Acacia crassicarpa in Indonesia

Several species in the Euwallacea fornicatus complex have emerged as important pests of woody plants globally, particularly in habitats where they are invasive aliens. These beetles live in obligate symbioses with fungi in the genus Fusarium. In this study, we identified Euwallacea spp. and their fungal mutualists that have emerged as pests of planted Acacia crassicarpa in Riau, Indonesia. Morphological identification and phylogenetic analyses of the mitochondrial cytochrome oxidase c subunit I (COI) gene confirmed that E. similis and E. perbrevis are the most abundant beetles infesting these trees. Multilocus phylogenetic analyses of their fungal mutualists revealed their nonspecific association with six Fusarium species. These included F. rekanum and five novel Fusarium mutualists within the Fusarium solani species complex (FSSC), four of which reside in the Ambrosia Fusarium Clade (AFC). These new species are described here as F. akasia, F. awan, F. mekan, F. variasi, and F. warna.This study was initiated through the bilateral agreement between the Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, and the APRIL Group, RGE, Indonesia. We acknowledge funding from the RGE-FABI Tree Health Programme and the National Research Foundation (NRF, SFH170527234109), South Africa.https://www.tandfonline.com/loi/umyc20hj2022BiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant Patholog

Euwallacea perbrevis (Coleoptera: Curculionidae: Scolytinae), a confirmed pest on Acacia crassicarpa in Riau, Indonesia, and a new fungal symbiont; Fusarium rekanum sp. nov.

Non-native Acacia plantations in Indonesia were first reported to be infested by a native ambrosia beetle species, identified as Euwallacea fornicatus in 1993. Recently the level of infestation in these plantations by ambrosia beetles has steadily increased. The recent redefinition of the taxonomic parameters of the Euwallacea fornicatus species complex has resulted in the identity of the ambrosia beetle species in these plantations becoming unclear. This is also true for their obligate fungal associates. Therefore, the aim of this study was to identify the ambrosia beetle species, as well as its corresponding fungal associate/s, infesting Acacia crassicarpa plantations in Riau, Indonesia. Morphological identification and phylogenetic analysis of the mitochondrial cytochrome oxidase c subunit I (COI) gene, revealed that the beetles are E. perbrevis, previously a synonym of E. fornicatus and commonly referred to as the Tea Shot Hole Borer A (TSHBa). Multi-locus phylogenetic analyses of the fungal associate of E. perbrevis revealed a Fusarium sp. that is among members of the Ambrosia Fusarium Clade (AFC), but that is genetically distinct from other previously identified Fusarium symbionts of Euwallacea species. This novel fungal species is described here as Fusarium rekanum sp. nov.Supplementary Fig. 1 Phylogenetic analysis of the species in the Ambrosia Fusarium clade (AFC) using sequences obtained from the elongation factor 1- α (TEF1-α). The phylogram was constructed using maximum likelihood with 1000 bootstrap replicates. Isolates in bold were sequenced in this study. The 19 species within the AFC are identified as AF-1 to AF-19 using an ad hoc nomenclature (Kasson et al. 2013; Na et al. 2018). Fusarium neocosmosporiellum (NRRL22468) represents the outgroup. T represents ex-type (PDF 176 kb)Supplementary Fig. 2 Phylogenetic analysis of the species in the Ambrosia Fusarium clade (AFC) using sequences obtained from the DNA-directed RNA polymerase II second largest subunit (RPB2). The phylogram was constructed using maximum likelihood with 1000 bootstrap replicates. Isolates in bold were sequenced in this study. The 19 species within the AFC are identified as AF-1 to AF-19 using an ad hoc nomenclature (Kasson et al. 2013; Na et al. 2018). Fusarium neocosmosporiellum (NRRL22468) represents the outgroup. T represents ex-type (PDF 184 kb)Supplementary Fig. 3 Phylogenetic analysis of the species in the Ambrosia Fusarium clade (AFC) using sequences obtained from the ribosomal internal transcribed spacer (ITS). The phylogram was constructed using maximum likelihood with 1000 bootstrap replicates. Isolates in bold were sequenced in this study. The 19 species within the AFC are identified as AF-1 to AF-19 using an ad hoc nomenclature (Kasson et al. 2013; Na et al. 2018). Fusarium neocosmosporiellum (NRRL22468) represents the outgroup. T represents ex-type (PDF 179 kb)Supplementary Table 1 List of all fungi isolated from the beetle mycangium and brood galleries of ambrosia beetles infesting A. crassicarpa (PDF 98 kb)Members of Tree Protection and Cooperation Programme (TPCP) and the National Research Foundation, South Africa.http://link.springer.com/journal/10482hj2021BiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant Patholog

Patient and public involvement in research: Reflections and experiences of doctoral cancer nurse researchers in Europe

Purpose Early career researchers lack guidance about patient and public involvement (PPI). The overall aim of the study was to explore the knowledge and experiences of using PPI in research among doctoral students who are registered nurses. Methods This qualitative study included findings generated from reflective essays and focus groups involving ten registered cancer nurses who are undertaking doctoral research. The study has two stages of data collection. Participants initially wrote a reflective essay using a set of guiding questions to structure a response which was subsequently analysed. Two focus groups were then conducted to provide further insight into the themes identified in the reflective essays. Reflective thematic analysis was used to identify, name, and define the final themes. Results There were ten participants from seven countries and were at various stages of their doctoral study. Analysis of data from reflective essays (n = 10) and focus groups (n = 2) identified four themes namely, (a) evolving recognition and appreciation of PPI, (b) embracing PPI and impact on doctoral studies, (c) the influence of the research environment, and (d) the need to empower doctoral students to integrate PPI in their research journey. Conclusion Participants reported differing experiences of PPI awareness showing disparity in guidance about PPI for junior researchers across Europe. We recommend provision of early PPI training for doctoral students to support and encourage involvement of patients and the public in their research. Opportunities for sharing PPI experiences to help improve PPI culture in research environments that support doctoral students should be explored