The Adaptive Function of Masturbation in a Promiscuous African Ground Squirrel

Background: Studies of animal mating systems increasingly emphasize female multiple mating and cryptic sexual selection, particularly sperm competition. Males under intense sperm competition may manipulate sperm quantity and quality through masturbation, which could waste sperm and decrease fertility. I examined the factors influencing masturbation by male Cape ground squirrels (Xerus inauris) in light of a number of functional hypotheses. Methodology: Observational data on a marked population of squirrels were collected in east-central Namibia using scan and all-occurrences sampling. Findings: Masturbation was far more frequent on days of female oestrus and mostly occurred after copulation. Masturbation rates were higher in dominant males, which copulate more, than in subordinates and increased with number of mates a female accepts. Conclusions: These results suggest that masturbation in this species was not a response to sperm competition nor a sexual outlet by subordinates that did not copulate. Instead masturbation could function as a form of genital grooming. Female Cape ground squirrels mate with up to 10 males in a 3-hr oestrus, and by masturbating after copulation males could reduce the chance of infection. Sexually transmitted infections (STIs) can profoundly affect fertility, and their consequences for mating strategies need to be examined more fully

Course-Integrated Undergraduate Research Experiences Structured at Different Levels of Inquiry

Enhancing undergraduate students’ preparation and interest in science careers frequently involves engagement in authentic research experiences. Traditional undergraduate research (UR) one-to-one faculty-to-student ratio is challenged by demand and cost, motivating the development of alternative approaches to offering these experiences. Embracing this challenge we integrated UR experiences into three undergraduate biology courses, each taking a different approach to engaging students. The approaches varied the amount of teacher and student responsibility, reflecting different levels of inquiry instruction; one in which students were embedded into the faculty’s on-going research; a second in which faculty provided the hypotheses and methodology and students were responsible for experiment details and implementation; and a third in which students were responsible for all aspects of research on any topic that fit within the scope of the course. We assessed and compared students’ affective and cognitive outcomes related to engagement in scientific research. Overall, all participants felt their experiences were effective for learning and positively influenced interest in and knowledge of science. However, students’ perceived gains differed, with greatest gains detected in students engaged in the most authentic inquiry approach (ANOVA: p \u3c 0.01)

Adherence to ocular hypotensive therapy: Patient health education needs and views on group education

BACKGROUND: In this study the authors sought both to understand the health education needs of patients with glaucoma, with particular regard to adherence to glaucoma treatment, and to examine these patients’ views of group education. METHODS: Using a health promotion approach to health education, 27 qualitative interviews with new and established patients receiving glaucoma treatment were conducted. Health promotion is defined as a way of strengthening people’s capacities to control and optimize their own health. The interviews were transcribed and were then analyzed thematically RESULTS: Nine categories of health education needs were identified from the transcripts: (1) to understand glaucoma; (2) to understand their diagnosis or understand the difficulties in giving a diagnosis; (3) to understand the implications of eye drops, their side effects, and how to renew the eye drops; (4) to feel confident to put in eye drops; (5) to put the condition into perspective - to know how to manage their risk; (6) to be able to ask questions of clinicians; (7) to be able to navigate the health care system; (8) to understand and be able to manage own adherence behavior; and (9) to know where to access other sources of information. The majority of patients had something positive to say about group education, and about half of the patients said they would attend group education if they were offered the opportunity. CONCLUSION: A health promotion approach identified a wide range of patient-centered health education needs regarding adherence to glaucoma treatment. Group education will be attractive to some patients. Clinicians could use the health education needs identified in this study to guide the development of either individual or group-based educational intervention to improve adherence to glaucoma treatment. However, clinicians need to be aware that when developing a group intervention, attention will need to be given to making the education relevant to the circumstances of each patient

Diatom communities differ among Antarctic moss and lichen vegetation types

Continental Antarctica is a polar desert containing sparse pockets of vegetation within ice-free areas. Despite the recognized association between lichens, mosses and epiphytic diatoms, the environmental factors controlling diatom community structure are poorly understood. We investigated the association between diatom communities and host vegetation characteristics by experimentally adding nutrients and/or water to two bryophyte (healthy and moribund) and two lichen (crustose and Usnea) vegetation types in the Windmill Islands. Diatom communities were morphologically characterized, diversity indices calculated and differences between treatments, vegetation type and vegetation characteristics tested. We identified 49 diatom taxa, 8 of which occurred with \u3e 1% relative abundance. Bryophyte and lichen vegetation harboured significantly different diatom communities, both in composition and diversity indices. Specifically, Luticola muticopsis was more prevalent in moribund bryophytes and crustose lichens, and Usnea lichens showed lower species richness than other types. While nutrient and water additions did not significantly alter diatom communities, diversity indices and some species showed relationships with vegetation physiological characteristics, notably %N and δ13C, suggesting the importance of ambient gradients in water and nutrient availability. Collectively, this work suggests that future conditions favouring the dominance of a particular vegetation type may have a homogenizing effect on the terrestrial diatom communities of East Antarctica

Intraspecific variation in male mating strategies in an African ground squirrel (Xerus inauris)

DATA AVAILABILITY STATEMENT : The data that support the findings of this study are available from the corresponding author upon reasonable request. All data are associated with tables and figures: Dryad https://doi.org/10.5061/dryad.jsxksn0cv.Male mating strategies respond to female availability such that variation in resources that affect spatial distribution can also alter cost–benefit tradeoffs within a population. In arid-adapted species, rainfall alters reproduction, behavior, morphology, and population density such that populations differing in resource availability may also differ in successful reproductive strategies. Here, we compare two populations of Cape ground squirrels (Xerus inauris), a sub-Saharan species with year-round breeding and intense mating competition. Unlike most mammals where males resort to aggressive interactions over females, male X. inauris are tolerant of one another, relying instead on other nonaggressive pre-and postcopulatory strategies to determine reproductive success. Our findings suggest that differences in resource availability affect female distribution, which ultimately leads to intraspecific variation in male reproductive tactics and sexual morphology. Sperm competition, assessed by reproductive morphometrics, was more pronounced in our high resource site where females were distributed evenly across the landscape, whereas dominance seemed to be an important determinant of success in our low resource site where females were more aggregated. Both sites had similar mating intensities, and most males did not sire any offspring. However, our low resource site had a higher variance in fertilization success with fewer males siring multiple offspring compared with our high resource site where more individuals were successful. Our results lend support to resource models where variations in female spatial distribution attributed to environmental resources ultimately impact male reproductive behaviors and morphology.National Science Foundation and Natural Sciences and Engineering Research Council of Canada.http://www.ecolevol.orgam2023Zoology and Entomolog

Trade-offs between immunity and testosterone in male African ground squirrels

The immunocompetence handicap hypothesis (ICHH) proposes that testosterone has both beneficial effects on male reproductive potential and negative effects by suppressing the immune system. However, support for the ICHH has been variable and an alternative hypothesis suggests that testosterone may be acting indirectly via cortisol to suppress immunity (the stress-linked ICHH). A third hypothesis is that increased energetic investment in immunity results in the suppression of testosterone. We tested these hypotheses in male Cape ground squirrels (Xerus inauris) through two separate manipulations; first by triggering a strong immune response using a lipopolysaccharide (LPS) injection and secondly by increasing circulating testosterone using silastic testosterone implants. Responding to an immune challenge significantly reduced testosterone, supporting the immunity suppression hypothesis, while increasing circulating testosterone had no effect on immunocompetence, body mass, ectoparasite abundances or cortisol levels, failing to support either the ICHH or stress-linked ICHH. Our results add to the increasing body of literature that challenges the ICHH, and we conclude that the trade-off between testosterone and immunity is mediated through immune activation and not through testosterone in male Cape ground squirrels. Being able to test the ICHH, stress-linked ICHH and immune suppression hypotheses in a free ranging mammal gives us a unique opportunity to examine the mechanisms mediating this trade-off.A Natural Sciences and Engineering Research Council of Canada Discovery grant (#04362), Canadian Foundation of Innovation (#27125), and a University of Manitoba Faculty of Science Field Work Support grant awarded to JMW, a Natural Sciences and Engineering Research Council of Canada Discovery grant (#311909) awarded to WGA, SARChI chair (# 64756) from the Department of Science and Technology and National Research Foundation, RSA awarded to NCB and awards from the University of Manitoba (Barrett- Hamilton Award; Faculty of Science) to KAO.http://jeb.biologists.org2019-08-23am2018Mammal Research InstituteZoology and Entomolog

Moss species on the move in East Antarctic terrestrial communities

Antarctica has experienced major changes in temperature, wind speed and stratospheric ozone levels over the last 50 years. Whilst West Antarctica and the peninsula showed rapid warming and associated ecosystem change, East Antarctica appeared to be little impacted by climate warming, thus biological changes were predicted to be relatively slow. Detecting the biological effects of Antarctic climate change has also been hindered by the paucity of long-term data sets, particularly for organisms that have been exposed to these changes throughout their lives. We monitored vegetation communities in the Windmill Islands, East Antarctica from 2000 to 2014 and found significant changes in moss species composition. In addition, we have shown that radiocarbon signals preserved along shoots of the dominant Antarctic moss flora can be used to determine accurate growth rates over a period of several decades, allowing us to explore the influence of environmental variables on growth. Carbon stable isotopic measurements suggest that the observed effects of climate variation on growth are mediated through changes in water availability and most likely linked to the more positive phase of the Southern Annular Mode and changing westerly wind patterns. For cold remote locations like Antarctica, where climate records are limited and of relatively short duration, this illustrates that mosses can act as microclimate proxies and have the potential to increase our knowledge of coastal Antarctic climate change