Evolution of realized niche breadth diversity driven by community dynamics.

Why many herbivorous insects are host plant specialists, with non-negligible exceptions, is a conundrum of evolutionary biology, especially because the host plants are not necessarily optimal larval diets. Here, I present a novel model of host plant preference evolution of two insect species. Because habitat preference evolution is contingent upon demographic dynamics, I integrate the evolutionary framework with the modern coexistence theory. The results show that the two insect species can evolve into a habitat specialist and generalist, when they experience both negative and positive frequency-dependent community dynamics. This happens because the joint action of positive and negative frequency dependence creates multiple (up to nine) eco-evolutionary equilibria. Furthermore, initial condition dependence due to positive frequency dependence allows specialization to poor habitats. Thus, evolved habitat preferences do not necessarily correlate with the performances. The model provides explanations for counterintuitive empirical patterns and mechanistic interpretations for phenomenological models of niche breadth evolution.

Understanding different dominance patterns in western Amazonian forests.

Dominance of neotropical tree communities by a few species is widely documented, but dominant trees show a variety of distributional patterns still poorly understood. Here, we used 503 forest inventory plots (93,719 individuals ≥2.5 cm diameter, 2609 species) to explore the relationships between local abundance, regional frequency and spatial aggregation of dominant species in four main habitat types in western Amazonia. Although the abundance-occupancy relationship is positive for the full dataset, we found that among dominant Amazonian tree species, there is a strong negative relationship between local abundance and regional frequency and/or spatial aggregation across habitat types. Our findings suggest an ecological trade-off whereby dominant species can be locally abundant (local dominants) or regionally widespread (widespread dominants), but rarely both (oligarchs). Given the importance of dominant species as drivers of diversity and ecosystem functioning, unravelling different dominance patterns is a research priority to direct conservation efforts in Amazonian forests.

Transmission mode and dispersal traits correlate with host specificity in mammalian gut microbes.

Different host species associate with distinct gut microbes in mammals, a pattern sometimes referred to as phylosymbiosis. However, the processes shaping this host specificity are not well understood. One model proposes that barriers to microbial transmission promote specificity by limiting microbial dispersal between hosts. This model predicts that specificity levels measured across microbes is correlated to transmission mode (vertical vs. horizontal) and individual dispersal traits. Here, we leverage two large publicly available gut microbiota data sets (1490 samples from 195 host species) to test this prediction. We found that host specificity varies widely across bacteria (i.e., there are generalist and specialist bacteria) and depends on transmission mode and dispersal ability. Horizontally-like transmitted bacteria equipped with traits that facilitate switches between host (e.g., tolerance to oxygen) were found to be less specific (more generalist) than microbes without those traits, for example, vertically-like inherited bacteria that are intolerant to oxygen. Altogether, our findings are compatible with a model in which limited microbial dispersal abilities foster host specificity.

Colonization ability and uniformity of resources and environmental factors determine biological homogenization of soil protists in human land-use systems.

Humans have substantially transformed the global land surface, resulting in the decline in variation in biotic communities across scales, a phenomenon known as "biological homogenization." However, different biota are affected by biological homogenization to varying degrees, but this variation and the underlying mechanisms remain little studied, particularly in soil systems. To address this topic, we used metabarcoding to investigate the biogeography of soil protists and their prey/hosts (prokaryotes, fungi, and meso- and macrofauna) in three human land-use ecosystem types (farmlands, residential areas, and parks) and natural forest ecosystems across subtropical and temperate regions in China. Our results showed that the degree of community homogenization largely differed between taxa and functional groups of soil protists, and was strongly and positively linked to their colonization ability of human land-use systems. Removal analysis showed that the introduction of widespread, generalist taxa (OTUs, operational taxonomic units) rather than the loss of narrow-ranged, specialist OTUs was the major cause of biological homogenization. This increase in generalist OTUs seemingly alleviated the negative impact of land use on specialist taxa, but carried the risk of losing functional diversity. Finally, homogenization of prey/host biota and environmental conditions were also important drivers of biological homogenization in human land-use systems, with their importance being more pronounced in phagotrophic than parasitic and phototrophic protists. Overall, our study showed that the variation in biological homogenization strongly depends on the colonization ability of taxa in human land-use systems, but is also affected by the homogenization of resources and environmental conditions. Importantly, biological homogenization is not the major cause of the decline in the diversity of soil protists, and conservation and study efforts should target at taxa highly sensitive to local extinction, such as parasites.

Clinical care advice for monitoring of islet autoantibody positive individuals with presymptomatic type 1 diabetes.

BACKGROUND/AIM: Type 1 diabetes is an autoimmune disease that involves the development of autoantibodies against pancreatic islet beta-cell antigens, preceding clinical diagnosis by a period of preclinical disease activity. As screening activity to identify autoantibody-positive individuals increases, a rise in presymptomatic type 1 diabetes individuals seeking medical attention is expected. Current guidance on how to monitor these individuals in a safe but minimally invasive way is limited. This article aims to provide clinical guidance for monitoring individuals with presymptomatic type 1 diabetes to reduce the risk of diabetic ketoacidosis (DKA) at diagnosis. METHODS: Expert consensus was obtained from members of the Fr1da, GPPAD, and INNODIA consortia, three European diabetes research groups. The guidance covers both specialist and primary care follow-up strategies. RESULTS: The guidance outlines recommended monitoring approaches based on age, disease stage and clinical setting. Individuals with presymptomatic type 1 diabetes are best followed up in specialist care. For stage 1, biannual assessments of random plasma glucose and HbA1c are suggested for children, while annual assessments are recommended for adolescents and adults. For stage 2, 3-monthly clinic visits with additional home monitoring are advised. The value of repeat OGTT in stage 1 and the use of continuous glucose monitoring in stage 2 are discussed. Primary care is encouraged to monitor individuals who decline specialist care, following the guidance presented. CONCLUSIONS: As type 1 diabetes screening programs become more prevalent, effective monitoring strategies are essential to mitigate the risk of complications such as DKA. This guidance serves as a valuable resource for clinicians, providing practical recommendations tailored to an individual's age and disease stage, both within specialist and primary care settings.

Generalist versus Specialist Self-Replicators.

Darwinian evolution, including the selection of the fittest species under given environmental conditions, is a major milestone in the development of synthetic living systems. In this regard, generalist or specialist behavior (the ability to replicate in a broader or narrower, more specific food environment) are of importance. Here we demonstrate generalist and specialist behavior in dynamic combinatorial libraries composed of a peptide-based and an oligo(ethylene glycol) based building block. Three different sets of macrocyclic replicators could be distinguished based on their supramolecular organization: two prepared from a single building block as well as one prepared from an equimolar mixture of them. Peptide-containing hexamer replicators were found to be generalists, i. e. they could replicate in a broad range of food niches, whereas the octamer peptide-based replicator and hexameric ethyleneoxide-based replicator were proven to be specialists, i. e. they only replicate in very specific food niches that correspond to their composition. However, sequence specificity cannot be demonstrated for either of the generalist replicators. The generalist versus specialist nature of these replicators was linked to their supramolecular organization. Assembly modes that accommodate structurally different building blocks lead to generalist replicators, while assembly modes that are more restrictive yield specialist replicators.

Evolution of chemosensory genes in Colorado potato beetle, Leptinotarsa decemlineata.

Associating with plant hosts is thought to have elevated the diversification of insect herbivores, which comprise the majority of global species diversity. In particular, there is considerable interest in understanding the genetic changes that allow host-plant shifts to occur in pest insects and in determining what aspects of functional genomic diversity impact host-plant breadth. Insect chemoreceptors play a central role in mediating insect-plant interactions, as they directly influence plant detection and sensory stimuli during feeding. Although chemosensory genes evolve rapidly, it is unclear how they evolve in response to host shifts and host specialization. We investigate whether selection at chemosensory genes is linked to host-plant expansion from the buffalo burr, Solanum rostratum, to potato, Solanum tuberosum, in the super-pest Colorado potato beetle (CPB), Leptinotarsa decemlineata (Coleoptera: Chrysomelidae). First, to refine our knowledge of CPB chemosensory genes, we developed novel gene expression data for the antennae and maxillary-labial palps. We then examine patterns of selection at these loci within CPB, as well as compare whether rates of selection vary with respect to 9 closely related, non-pest Leptinotarsa species that vary in diet breadth. We find that rates of positive selection on olfactory receptors are higher in host-plant generalists, and this signal is particularly strong in CPB. These results provide strong candidates for further research on the genetic basis of variation in insect chemosensory performance and novel targets for pest control of a notorious super-pest.

Evaluating the cost-effectiveness of diabetic foot ulcer management by wound care specialists in Indonesia.

Diabetic foot ulcers affect quality of life and economically burden patients and the Indonesian healthcare system. The comparative cost-effectiveness of wound care specialists in private practices (e.g., wound clinics) and wound care nurses in national hospitals remains unknown. Thus, we used a decision tree to compare the cost and healing rates for patients after 12 weeks of wound care. Uncertainty was addressed using one-way and probabilistic sensitivity analyses. Among 89 participants (42 in the national hospital and 47 in the private practice), no significant differences were observed between the two groups in terms of sex, age, education level, smoking status, duration of diabetes, Wagner wound classification, glycated haemoglobin levels, neuropathy status, ankle-brachial index, baseline characteristics, quality of life, DMIST (depth, maceration, inflammation/infection, size, tissue type of the wound bed, type of wound edge, and tunnelling/undermining) score and wound location (p > 0.05). However, significant differences were observed for days from first visit/assessment until complete healing, mean quality of life (p ≤ 0.001) and wound size (p = 0.047). Wound care specialists in private practices had a significantly lower cost of 2,804,423.3 Indonesian rupiah compared to 6,483,493.4 Indonesian rupiah for wound care nurses in national hospitals. The incremental cost-effectiveness ratio was -165,723.9. Therefore, wound care specialists in private practices are more cost-effective for managing diabetic foot ulcers. Probability sensitivity analysis confirmed that 80%-90% of the scenarios were cost-effective. These findings may inform healthcare resource allocation in Indonesia. Additionally, evidence-based cost-effectiveness measures were strengthened in private practices and national hospitals.

The primary care provider (PCP)-cancer specialist relationship: A systematic review and mixed-methods meta-synthesis.

Although they are critical to models of coordinated care, the relationship and communication between primary care providers (PCPs) and cancer specialists throughout the cancer continuum are poorly understood. By using predefined search terms, the authors conducted a systematic review of the literature in 3 databases to examine the relationship and communication between PCPs and cancer specialists. Among 301 articles identified, 35 met all inclusion criteria and were reviewed in-depth. Findings from qualitative, quantitative, and disaggregated mixed-methods studies were integrated using meta-synthesis. Six themes were identified and incorporated into a preliminary conceptual model of the PCP-cancer specialist relationship: 1) poor and delayed communication between PCPs and cancer specialists, 2) cancer specialists' endorsement of a specialist-based model of care, 3) PCPs' belief that they play an important role in the cancer continuum, 4) PCPs' willingness to participate in the cancer continuum, 5) cancer specialists' and PCPs' uncertainty regarding the PCP's oncology knowledge/experience, and 6) discrepancies between PCPs and cancer specialists regarding roles. These data indicate a pervasive need for improved communication, delineation, and coordination of responsibilities between PCPs and cancer specialists. Future interventions aimed at these deficiencies may improve patient and physician satisfaction and cancer care coordination. CA Cancer J Clin 2017;67:156-169. © 2016 American Cancer Society.

Cannabis use and cannabis use disorders and their treatment in the Europe.

This paper introduces the special issue on cannabis use in Europe. It describes data on the prevalence of cannabis use in Europe and the more limited data on the prevalence of cannabis use disorders, one of the most common forms of drug problem treated in many countries in Europe. It summarises what research has indicated about the adverse effects of acute and chronic cannabis use and discusses potential health system responses that may reduce some of these harms. These include public education about the risks of cannabis use; screening and brief interventions in primary medical settings; and specialist treatment for cannabis use disorders. It briefly indicates the special issues that may need to be addressed in dealing with the high rates of comorbidity between cannabis use disorders, other types of drug use disorders, and common mental disorders.

Patterns of acute hospital and specialist palliative care use among people with non-curative upper gastrointestinal cancer.

PURPOSE: Upper gastrointestinal (GI) cancers contribute to 16.7% of UK cancer deaths. These patients make high use of acute hospital services, but detail about palliative care use is lacking. We aimed to determine the patterns of use of acute hospital and hospital specialist palliative care services in patients with advanced non-curative upper GI cancer. METHODS: We conducted a service evaluation of hospital use and palliative care for all patients with non-curative upper GI cancer seen in one large hospital, using routinely collected data (2019-2022). We report and characterise hospital admissions and palliative care within the study time period, using descriptive statistics, and multivariable Poisson regression to estimate the unadjusted and adjusted incidence rate ratio of hospital admissions. RESULTS: The total with non-curative upper GI cancer was 960. 86.7% had at least one hospital admission, with 1239 admissions in total. Patients had a higher risk of admission to hospital if: aged ≤ 65 (IRR for 66-75 years 0.71, IRR 76-85 years 0.68; IRR > 85 years 0.53; p < 0.05), or lived in an area of lower socioeconomic status (IMD Deciles 1-5) (IRR 0.90; p < 0.05). Over the 4-year period, the rate of re-admission was higher in patients not referred to palliative care (rate 0.52 readmissions/patient versus rate 1.47 readmissions/patient). CONCLUSION: People with advanced non-curative gastrointestinal cancer have frequent hospital admissions, especially if younger or from areas of lower socioeconomic status. There is clear association between specialist palliative care referral and reduced risk of hospitalisation. This evidence supports referral to specialist palliative care.

High-elevation-induced decrease in soil pH weakens ecosystem multifunctionality by influencing soil microbiomes.

Plant environmental stress response has become a global research hotspot, yet there is a lack of clear understanding regarding the mechanisms that maintain microbial diversity and their ecosystem services under environmental stress. In our research, we examined the effects of moderate elevation on the rhizosphere soil characteristics, microbial community composition, and ecosystem multifunctionality (EMF) within agricultural systems. Our findings revealed a notable negative correlation between EMF and elevation, indicating a decline in multifunctionality at higher elevations. Additionally, our analysis across bacterial and protistan communities showed a general decrease in microbial richness with increasing elevation. Using random forest models, pH was identified as the key environmental stressor influencing microbial communities. Furthermore, we found that microbial community diversity is negatively correlated with stability by mediating complexity. Interestingly, while pH was found to affect the complexity within bacterial networks, it did not significantly impact the ecosystem stability along the elevation gradients. Using a Binary-State Speciation and Extinction (BiSSE) model to explore the evolutionary dynamics, we found that Generalists had higher speciation rates and lower extinction rates compared to specialists, resulting in a skewed distribution towards higher net diversification for generalists under increasing environmental stress. Moreover, structural equation modeling (SEM) analysis highlighted a negative correlation between environmental stress and community diversity, but showed a positive correlation between environmental stress and degree of cooperation & competition. These interactions under environmental stress indirectly increased community stability and decreased multifunctionality. Our comprehensive study offers valuable insights into the intricate relationship among environmental factors, microbial communities, and ecosystem functions, especially in the context of varying elevation gradients. These findings contribute significantly to our understanding of how environmental stressors affect microbial diversity and ecosystem services, providing a foundation for future ecological research and management strategies in similar contexts.

Consensus report of the second European Consensus Workshop on Education in Periodontology.

BACKGROUND: The second European Consensus Workshop on Education in Periodontology was commissioned, as a result of the changes in the discipline and the advances in educational methods/technology, to update the 2009 Consensus report of the first European Federation of Periodontology (EFP) Workshop on the same topic that was jointly authored by the Association for Dental Education in Europe. AIM: To identify and propose changes necessary in periodontal education at three levels, namely undergraduate, specialist and continuing professional development (CPD), with respect to learning outcomes, competencies and methods of learning/training and evaluation. METHODS: Four working groups (WGs) considered education in periodontology at the undergraduate, specialist and CPD levels, and education methods. Four commissioned position papers, one per WG, summarized the relevant information. Workshop participants gathered at an in-person consensus meeting to discuss the individual reviews, and this consensus report summarizes the conclusions. RESULTS: The learning outcomes for undergraduate and specialist education in periodontology have been updated, and a proposal for learning outcomes for CPD programmes was made. Learning/teaching/training and evaluation methods were proposed for each level of education, which included face-to-face, virtual and blended learning methods. CONCLUSION: Developments in oral/dental medicine and in contemporary educational technologies have been translated into updated learning outcomes and learning/teaching/ training/evaluation methods relevant to education in periodontology.

Structure, governance and delivery of specialist training programs in periodontology and implant dentistry.

AIM: To update the competences and learning outcomes and their evaluation, educational methods and education quality assurance for the training of contemporary specialists in periodontology, including the impact of the 2018 Classification of Periodontal and Peri-implant Diseases and Conditions (2018 Classification hereafter) and the European Federation of Periodontology (EFP) Clinical Practice Guidelines (CPGs). METHODS: Evidence was gathered through scientific databases and by searching for European policies on higher education. In addition, two surveys were designed and sent to program directors and graduates. RESULTS: Program directors reported that curricula were periodically adapted to incorporate advances in diagnosis, classification, treatment guidelines and clinical techniques, including the 2018 Classification and the EFP CPGs. Graduates evaluated their overall training positively, although satisfaction was limited for training in mucogingival and surgical procedures related to dental implants. Traditional educational methods, such as didactic lectures, are still commonly employed, but they are now often associated with more interactive methods such as case-based seminars and problem-based and simulation-based learning. The evaluation of competences/learning outcomes should employ multiple methods of assessment. CONCLUSION: An update of competences and learning outcomes of specialist training in periodontology is proposed, including knowledge and practical application of the 2018 Classification and CPGs. Harmonizing specialist training in periodontology is a critical issue at the European level.

Health-related quality of life in psychiatric outpatients: a cross-sectional study of associations with symptoms, diagnoses, and employment status.

BACKGROUND: This cross-sectional study aimed to explore health-related quality of life (HRQoL) in a large heterogeneous patient sample seeking outpatient treatment at a specialist mental health clinic. METHOD: A sample of 1947 patients with common mental disorders, including depressive-, anxiety-, personality-, hyperkinetic- and trauma-related disorders, completed the EuroQoL 5-Dimension 5-Level (EQ-5D-5L) to assess HRQoL. We investigated clinical and sociodemographic factors associated with the EQ-5D index and the EQ Visual Analogue Scale (VAS) using regression analyses. RESULTS: The sample reported lower HRQoL compared with the general population and primary mental health care patients. Sick leave, disability pension, work assessment allowance, and more symptoms of anxiety and depression were associated with lower EQ-5D index and EQ VAS scores. Furthermore, being male, use of pain medication and having disorders related to trauma were associated with reduced EQ-5D index scores, while hyperkinetic disorders were associated with higher EQ-5D index scores. CONCLUSION: HRQoL of psychiatric outpatients is clearly impaired. This study indicated a significant association between employment status, symptom severity, and HRQoL in treatment-seeking outpatients. The findings highlight the importance of assessing HRQoL as part of routine clinical assessment.

A plea for urgent action: Addressing the critical shortage of cardiothoracic surgical workforce in the COSECSA region.

BACKGROUND: The College of Surgeons of East, Central, and Southern Africa (COSECSA) comprises 14 countries, many of which currently grapple with an increasing burden of cardiothoracic surgical (CTS) diseases. Health and economic implications of unaddressed CTS conditions are profound and require a robust regional response. This study aimed to define the status of CTS specialist training in the region (including the density of specialists, facilities, and active training posts), examine implications, and proffer recommendations. METHODS: A desk review of COSECSA secretariat documents and program accreditation records triangulated with information from surgical societies was performed in May 2022 and September 2023 as part of education quality improvement. A modified nominal group process involving contextual experts was used to develop a relevant action framework. RESULTS: Only 6 of 14 (43%) of COSECSA countries offered active training programs with annual intake of only 18 trainees. Significant training gaps existed in Burundi, Botswana, Malawi, Rwanda, South Sudan, Zambia, and Zimbabwe. Country specialist density ranged from 1 per 400,000 (Namibia) to 1 per 8,000,000 (Ethiopia). Overall, the region had 0.2 CTS specialists per million population as compared with 7.15 surgeons per million in High-Income Countries. Surgical education experts proposed an action framework to address the training crisis including increasing investments in CTS education, establishing regional centers of excellence, retention incentives and opportunities for women, and leveraging international partnerships. CONCLUSION: Proactive investments in infrastructure, human resources, training, and collaborative efforts by national governments, regional intergovernmental organizations, and international partners are critical to expanding regional CTS training.

More than the sum of its parts-A constructivist grounded-theory study on specialist palliative care during crises like the COVID pandemic.

BACKGROUND: The COVID pandemic is an example of a crisis challenging healthcare systems worldwide. The impact of the pandemic on providing high-quality palliative care calls for a deeper understanding of specialist services during crises. This is essential in preparation for further crises. AIM: To develop a conceptual understanding of the impact of the pandemic on specialist palliative care as an example for arising future crises. DESIGN: Qualitative interview study across Germany, following a constructivist grounded theory methodology. SETTING/PARTICIPANTS: Eleven semi-structured interviews with experts with overarching knowledge of structures and processes in specialist palliative care between 05-07/2020 and between 02-06/2021, 23 semi-structured interviews with healthcare professionals working in a specialist palliative care setting. RESULTS: The complex system of palliative care provision during crises has properties that cannot be understood as separated parts of the care process. The pandemic led to unique structural and processual challenges characterized by interconnectedness, uncertainty, dynamic, underlying dilemmas, and unclear long-term goal. In response to the pandemic, teams experienced different phases, which enhanced adaption, innovation, and progress within complex care situations. Creative strategy approaches and dynamic responsiveness facilitated innovative development and could lead to long-lasting improvement within services. Availability of information, transparent communication, comprehensible instructions, participation in decision-making, and search for solutions contributed to teams' proactive development throughout the pandemic. CONCLUSION: Addressing the complex problems in specialist palliative care caused by crises requires system thinking and a learning mindset. This can facilitate teams to overcome the crisis and move forward rather than bounce back to normal.

'Selection into training will always be an inexact process': A survey of Directors of Physician Education on selection into Basic Physician Training in Australia and New Zealand.

BACKGROUND: Despite being one of the largest medical specialty training programmes in Australasia, there is no standardised method for selection into Basic Physician Training (BPT), and limited data exist regarding current practices. AIMS: To address existing knowledge gaps, we aimed to create a 'snapshot' of current BPT selection practices and explore the perspectives of Directors of Physician Education (DPEs) regarding trainee selection. METHODS: An electronic survey of DPEs from adult and paediatric medicine BPT sites in Australia and New Zealand was undertaken in January-February 2022. A combination of free text, multiple-choice and yes/no answers were analysed using descriptive statistics and qualitative content analysis. RESULTS: A total of 70 responses were received, achieving a response rate of 35% (70/198). Selection practices were found to be heterogenous across BPT sites. Respondents had varying opinions regarding the utility of selection tools and desirable candidate attributes. A heavy reliance upon interviews and the reported use of subjective assessments raise concerns for selection process bias. CONCLUSION: BPT sites should critically evaluate their selection methods, and more research in this field is needed to establish best practice.

Telemedicine in specialist outpatient care during COVID-19: a qualitative study.

BACKGROUND: COVID-19 accelerated healthcare changes, introducing various telehealth services. Work is needed to determine the suitability of telemedicine in the post-pandemic era. AIMS: To explore perceptions and experiences of telemedicine among patients and providers (clinicians and health administrators) who were involved in telemedicine appointments in hospital outpatient clinics in 2020-2022. DESIGN, SETTING AND PARTICIPANTS: Qualitative study: semi-structured interviews were conducted with 37 participants (16 patients and 21 providers) in various hospital specialist outpatient clinics in a New South Wales local health district. RESULTS: Patients were generally satisfied with telemedicine consultations, especially during COVID restrictions, because of the convenience of accessing care from home and minimising the risk of COVID exposure. However, patients considered that the inability to receive a physical examination was a significant disadvantage of telemedicine. Providers had ambivalent perceptions and expressed concerns about mis- and under-diagnoses because of the inability to conduct physical examinations. They considered telemedicine suitable for review appointments but noted an associated increased workload and stressed the need for sustainable funding models (Medicare items). Both patients and providers recognised the need for education/training and better integration of telemedicine platforms into existing infrastructure to facilitate an optimal hybrid model of care. CONCLUSION: Despite expressing some concerns over its limitations, patients valued telemedicine for its convenience and for meeting their needs during the pandemic. While acknowledging that patients experienced some benefits from telemedicine, clinicians expressed concerns about potential missed diagnoses, uncertain clinical outcomes and lack of administrative and technological infrastructure. The ultimate test of telemedicine will be its impact on clinical outcomes versus longstanding models of in-person care.

Dietary flexibility of the greater bamboo lemur (Prolemur simus), a specialized feeder, in eastern Madagascar.

The degree of dietary flexibility in primates is species specific; some incorporate a wider array of resources than others. Extreme interannual weather variability in Madagascar results in seasonal resource scarcity which has been linked to specialized behaviors in lemurs. Prolemur simus, for example, has been considered an obligate specialist on large culm bamboo with >60% of its diet composed of woody bamboos requiring morphological and physiological adaptations to process. Recent studies reported an ever-expanding list of dietary items, suggesting that this species may not be an obligate specialist. However, long-term quantitative feeding data are unavailable across this species' range. To explore the dietary flexibility of P. simus, we collected data at two northern sites, Ambalafary and Sahavola, and one southern site, Vatovavy, from September 2010 to January 2016 and May 2017 to September 2018, respectively. In total, we recorded 4022 h of behavioral data using instantaneous sampling of adult males and females from one group in Ambalafary, and two groups each in Sahavola and Vatovavy. We recorded 45 plant species eaten by P. simus over 7 years. We also observed significant differences in seasonal dietary composition between study sites. In Ambalafary, bamboo was the most frequently observed resource consumed (92.2%); however, non-bamboo resources comprised nearly one-third of the diet of P. simus in Sahavola and over 60% in Vatovavy. Consumption of all bamboo resources increased during the dry season at Ambalafary and during the wet season at Vatovavy, but never exceeded non-bamboo feeding at the latter. Culm pith feeding was only observed at Ambalafary, where it was more common during the dry season. We identify P. simus as a bamboo facultative specialist capable of adjusting its feeding behavior to its environment, indicating greater dietary flexibility than previously documented, which may enable the species to survive in increasingly degraded habitats.