Prey monitor surrounding dangers independently or cooperatively (synchronized and coordinated vigilance), with independent and synchronized scanning being prevalent. Coordinated vigilance, including unique sentinel behaviour, is rare in nature, since it is time-consuming and benefit-limited. Evidence does not indicate animals adopting alternative vigilance strategies during antipredation scanning. Considering the cooperative nature of both synchronization and coordination, we assessed whether group members could keep alert synchronously or coordinatedly under different circumstances, determining whether cooperative vigilance is context dependent. Under the framework of conservation behavior, we studied how human behaviour and species-specific variables impacted individual and collective vigilance of globally threatened Black-necked Cranes (Grus nigricollis) and explored behaviour-based wildlife management. We tested both predation risk (juveniles in group) and human disturbance (level and distance) effects on individual and collective antipredation vigilance of black-necked crane families. Adults spent significantly more time (proportion and duration) on scanning than juveniles, and parents with juveniles behaved more vigilant. Observer distance affected individual vigilance of adults while juveniles were influenced by none of these variables. With the number of juveniles and disturbance increased, crane couples decreased synchronization of vigilance and they shifted to coordination, which has so far never been reported yet. Similarly, with observer approaching, adults shift vigilance from synchronization to coordination. The collective vigilance shift from synchronization to coordination as a function of observer distance could help us determining a safe distance of c. 400m for the most vulnerable family groups with two juveniles, so as no obvious interference with the threatened birds by human proximity. We argue that vigilance behaviour could be a reliable indicator in future nature-based tourist management and decision-making, which can be derived from conservation solutions in nature.
The analysis of stable isotope composition is an important tool in research on plant physiological ecology. However, large-scale patterns of leaf stable isotopes for aquatic macrophytes have received considerably less attention. In this study, we examined the spatial pattern of the leaf δ13C and δ15N of macrophytes collected across the arid zone of northwestern China and tried to illustrate how they were affected by different environmental factors. Our results showed that the mean values of leaf δ13C and δ15N in the macrophytes sampled from the arid zone were -24.49‰ and 6.82‰, respectively, which were drastically higher than the values of terrestrial plants. In addition, leaf δ13C varied significantly among different life forms, possibly reflecting the complex photosynthetic fixation and adaptations of macrophytes. In addition to, our studies indicated that the foliar δ13C values of all the aquatic macrophytes were only negatively associated with precipitation, but the foliar δ15N values were mainly associated with temperature, precipitation and potential evapotranspiration. Therefore, we speculated that the determinant of the leaf δ13C of macrophytes in the arid zone of northwestern China is water factors and the leaf δ15N values is the complex combination of water and energy factors.
Huanglongbing (HLB) is the most devastating citrus disease worldwide. The causal organism of the disease is spread by an insect vector, Diaphorina citri, commonly known as Asian citrus psyllid (ACP). Current management of HLB relies either on physical removal of the infected plants or on chemical control of ACP. Both methods are not overly effective and costly. In addition, public concerns regarding insecticide residues in fruit have greatly increased in recent years. It has been hypothesized that plant volatiles could act as repellents to ACP, thus reduce the incidence of HLB. To test this hypothesis, the repellency of fresh tissues of 41 aromatic plant species to ACP was investigated. The repellency of individual species was determined using a Y-tube olfactometer. Our results showed that volatiles of five plant species were highly effective in repelling ACP with repellency as much as 76%. Among these, the tree species, Camptotheca acuminate, and the two shrubs, Lantana camara and Mimosa bimucronata, could potentially be planted as a landscape barrier. The two herbs, Capsicum annuum and Gynura bicolor, could potentially be used as interrow plantings in orchards. This is the first time that the repellency of fresh tissues from a diverse range of plant species to ACP has been determined. Although further field evaluation of various interplanting regimes and landscape barriers are needed to assess their effectiveness, our results showed that these aromatic species, being highly repellent to ACT, offer great potential as more cost-effective and environmentally sustainable alternatives to the current methods of managing HLB.
Interspecific hybrid frequencies can vary considerably across contact zones of a single pair of progenitor species. The reasons for this are not well understood, but could help explain processes such as species diversification or the range expansion of invasive hybrids. The widespread cattails Typha latifolia and T. angustifolia seldom hybridize in some parts of their range, but in other areas produce the dominant hybrid T. × glauca. We used a combination of field and greenhouse experiments to investigate why T. × glauca has invaded wetlands in the Laurentian Great Lakes region of southern Ontario, Canada, but is much less common in the coastal wetlands of Nova Scotia in eastern Canada. One potentially important environmental difference between these two regions is salinity. We therefore tested three hypotheses: 1) T. latifolia and T. angustifolia in Nova Scotia are genetically incompatible; 2) the germination or growth of T. × glauca is reduced by salinity; and 3) T. latifolia, a main competitor of T. × glauca, is locally adapted to saline conditions in Nova Scotia. Our experiments showed that Nova Scotia T. latifolia and T. angustifolia are genetically compatible, and that saline conditions do not impede growth of hybrid plants. However, we also found that under conditions of high salinity, germination rates of hybrid seeds were substantially lower than those of Nova Scotia T. latifolia. In addition, germination rates of Nova Scotia T. latifolia were higher than those of Ontario T. latifolia, suggesting local adaptation to salinity in coastal wetlands. This study adds to the growing body of literature which identifies the important roles that local habitat and adaptation can play in the distributions and characteristics of hybrid zones.
The utility of elevational gradients as tools to test either ecological hypotheses and delineate elevation-associated environmental factors that explain the species diversity patterns is critical for moss species conservation. We examined the elevational patterns of species richness and evaluated the effects of spatial and environmental factors on moss species predicted a priori by alternative hypotheses, including mid-domain effect (MDE), habitat complexity, energy, and environment proposed to explain the variation of diversity. Last, we assessed the contribution of elevation toward explaining the heterogeneity among sampling sites. We observed the hump-shaped distribution pattern of species richness along elevational gradient. The MDE and the habitat complexity hypothesis were supported with MDE being the primary driver for richness patterns, whereas little support was found for the energy, and the environment. Moss species richness pattern in the mountain is driven by ecological and evolutionary effects, whereas evolutionary factors predominately shape the large heterogeneity through dispersal, extinction and speciation processes.
Climate change is expected to systematically alter the distribution and poEurycea pulation dynamics of species around the world. The effects are expected to be particularly strong at high latitudes and elevations, and for ectothermic species with small ranges and limited movement potential, such as salamanders in the southern Appalachian Mountains. In this study, we sought to establish baseline abundance estimates for plethodontid salamanders (family: Plethodontidae) over an elevational gradient in Great Smoky Mountains National Park. In addition to generating these baseline data for multiple species, we describe methods for surveying salamanders that allow for meaningful comparisons over time by separating observation and ecological processes generating the data. We found that Plethodon jordani had a mid-elevation peak (1500 m) in abundance and Desmognathus wrighti increased in abundance with elevation up to the highest areas of the park (2025 m), whereas Eurycea wilderae increased in abundance up to 1600 m and then plateaued with increasing uncertainty. In addition to elevation, litter depth, herbaceous ground cover, and proximity to stream were important predictors of abundance (dependent upon species), whereas daily temperature, precipitation, ground cover, and humidity influenced detection rates. Our data provide some of the first minimally biased information for future studies to assess changes in the abundance and distribution of salamanders in this region. Understanding abundance patterns along with detailed baseline distributions will be critical for comparisons with future surveys to understand the population and community-level effects of climate change on montane salamanders.
1. Studies on the effects of human-driven forest disturbance usually focus on either biodiversity or carbon dynamics but much less is known about ecosystem processes that integrate trophic levels. Herbivory is one fundamental ecological process for ecosystem functioning that remains underexplored and is poorly quantified in human-modified tropical rainforests. 2. Here, we present the results of the largest study to date on the impacts of human disturbances on herbivory. We quantified the incidence and severity of herbivory caused by chewers, miners and gall-formers in 199,869 canopy leaf blades from 1,102 trees distributed across 20 forest plots located along a gradient of human disturbance in the Amazon. 3. We found that chewers dominated herbivory incidence, yet were not a good predictor of the other forms of herbivory either at the stem or plot level. Herbivory severity was correlated with disturbance intensity, being greater at more disturbed sites. 4. Synthesis. Although our large-scale study of canopy herbivory in Amazonian forests suggests that human disturbance increases the severity of leaf herbivory, effects were weak. Additionally, we found no effect of human disturbance in incidence of leaf herbivory. These results combined indicate that herbivory is a relatively resilient process to human impacts.
This spring, instructors moved their courses online in an emergency fashion as campuses were closed due to the pandemic. As colleges prepare for the next academic year, there is a need to provide flexible instruction that is more intentional for quality online learning. We taught two undergraduate courses online for the first time this spring and surveyed our students’ reactions to the course experiences. From our experiences and student feedback we identified design elements and activities that were beneficial in promoting student engagement, sense of connectivity, and learning. We describe four qualities for a successful transition to online learning: 1) big questions and core concepts; 2) peer groups including reflective writing; 3) outreach to broader scientific community; and 4) instructor’s social presence in the class. Our experience gives us confidence that courses can be redesigned for online without compromising rigor or essential learning goals.
The investigation of ecological processes that maintain species coexistence is important in harsh environments, as they act as strong drivers of species selection. Congeneric species are a good model to investigate the relative importance of such processes, as closely related species tend to have similar niches. We aim to find evidence for the action and relative importance of different ecological processes hypothesized to maintain species coexistence in a tropical forest subject to seasonal flooding, using the spatial structure of populations of three congeneric species. We collected data on a 1-ha plot of a Brazilian white-sand flooded tropical forest, where individuals of three Myrcia species were tagged, mapped, and measured for diameter at soil height. We also sampled seven environmental variables in the plot. We employed several spatial point pattern models to simultaneously investigate habitat filtering, interspecific competition, stochasticity, and dispersal limitation. Habitat filtering was the most important process driving the local distribution of the species, as they showed associations, albeit of different strength, to environmental variables related to flooding. We did not detect spatial patterns consistent with interspecific competition, i.e. spatial segregation and smaller size of nearby congeners. The three species do not seem to show evidence of stochasticity even though congeners were spatially independent, since they responded to differences in the environment. Last, dispersal limitation only led to spatial associations of different size classes for one of the species. Using data from congeneric species in a harsh environment as a model, we demonstrated that habitat filtering to areas subject to flooding is the most important ecological process driving the local distribution of the species studied in a white-sand forest. Even though many studies on topo-edaphic variation in tropical forests have shown that habitat filtering is an important ecological process, other processes that drive community structuring may have gone undetected.
Experience and training in field work is a critical component of undergraduate education in ecology, and many university courses incorporate field-based or experiential components into the curriculum in order to provide students hands-on experience. Due to the onset of the COVID-19 pandemic and the sudden shift to remote instruction in the spring of 2020, many instructors of such courses found themselves struggling to identify strategies for developing rigorous field activities that could be completed online, solo, and from a student’s backyard. This case study illustrates the process by which one field-based course, a UC California Naturalist certification course offered at the University of California, Davis, transitioned to fully remote instruction. The transition relied on established, publicly available, online participatory science platforms (e.g., iNaturalist) to which the students contributed data and observations remotely. Student feedback on the course and voluntary continued engagement with the participatory science platforms indicates that the student perspective of the experience was on par with previous traditional offerings of the course. This case study also includes topics and participatory science resources for consideration by other faculty facing a similar transition from group field activities to remote, individual field-based experiences.
COVID-19 created a host of challenges for science education; in our case, the pandemic halted our in-person elementary school outreach project on bird biology. This project was designed as a year-long program to teach fifth grade students in Ithaca, New York, USA about bird ecology and biodiversity, using outdoor demonstrations and in-person games and activities to engage students in nature. As a central part of this effort, we set up nest boxes on school property and had planned to monitor them with students during bird breeding in the spring. Here, we describe our experiences transitioning this program online: we live streamed nest boxes to students’ virtual classrooms and used them as starting points for virtual lessons on bird breeding and nestling development. We suggest that instituting similar programs at local schools can promote equitable learning opportunities for students across geographical locations and with various living situations. In an era of social distancing and isolation, we propose that nest box live streaming and virtual lessons can support local communities by providing access to the outdoors and unconventional science learning opportunities for all students.
Team-Based Learning (TBL) is a pedagogical tool that has great potential to develop student engagement, accountability, and equity in the online classroom. TBL is rooted in evidence-based educational theories and practices that underlie many active learning approaches such as self-testing, team discussion, and application of knowledge. The use of these approaches is associated with better student performance, retention, and sense of belonging in the classroom, aspects that are often reported to be especially lacking in online courses. Here, we describe how we implemented TBL in a face-to-face and an online introductory level evolution and biodiversity course. Our experiences using TBL approaches in the online course have been rewarding, students are engaged and accountable for their learning, and performed well in the course. Our goal is to provide an example of how we designed a life science course using TBL approaches and transitioned the course to an online environment. With the current switch to remote instruction and online learning, we recommend the use of TBL as a course design approach that can improve the students online learning experience.
Education in ecology and evolution often utilizes field instruction to teach key learning outcomes. Remote teaching of learning outcomes that have been traditionally taught in the field, necessitated by the COVID-19 pandemic, presents unique challenges for students, instructors, and institutions. A survey of 117 faculty conducted during spring 2020 revealed substantial reduction of learning outcomes typically taught in the field, and frequent substitutions of less active and more instructor-centered remote activities for field activities. The survey revealed generally negative instructor views on many remote teaching substitutions, yet also showed several approaches that instructors regarded as more effective, despite potential challenges with equitably teaching them. I suggest several models of remote substitutions for traditional field teaching of identification, field techniques, data collection, and study design in the context of the results of this survey.
The coronavirus disease of 2019 (COVID-19) pandemic has impacted educational systems worldwide, in particular primary and secondary schooling. To enable students of the local secondary school in Brisbane, Queensland, to continue with their practical agricultural science learning and facilitate online learning, a small-scale citizen science project was designed and rapidly implemented as a collaboration between the school and a multidisciplinary university research group focused on pollen allergy. Here we reflect on the process of developing and implementing this project from the perspective of the school and the university. A learning package including modules on pollen identification, tracking grass species, measuring field greenness, using a citizen science data entry platform, forensic palynology, as well as video guides, risk assessment and feedback forms were generated. Junior agriculture science students participated in the learning via online lessons and independent data collection in their own local neighborhood and/or school grounds situated within urban environments. The project provided useful data on local distribution and flowering of grass species. The experience allowed two-way knowledge exchange between the secondary and tertiary education sectors. The unique context of restrictions imposed by the social isolation policies as well as Public Health and Department of Education directives, allowed the team to respond by adapting teaching and research activity to develop and trial learning modules and citizen science tools. The project provided a focus to motivate and connect teachers, academic staff, and school students during a difficult circumstance. Extension of this citizen project for the purposes of research and secondary school learning, has the potential to offer ongoing benefits for grassland ecology data acquisition and student exposure to real-world science.
The increasingly wide application of chloroplast(cp) genome super-barcode in taxonomy and the recent breakthrough in cp genetic engineering make the development of new cp gene resources urgent and significant. Corydalis is recognized as the most genotypes complicated and taxonomically challenging plant taxa in Papaveraceae. However, no complete cp genome for this genus has been reported to date. In this study, we sequenced four complete cp genomes of two endangered lithophytes Corydalis saxicola and C. tomentellav in Corydalis, conducted a comparative genomics study on them, and a highly variable cp genome structure was found. The cp genomes have a large genome size of 189,029 to 190,247 bp, possessing a quadripartite structure and with two highly expanded inverted repeat (IR) regions (length: 41,955 to 42,350 bp). Comparison between the cp genomes of C. tomentella, C. saxicola and Papaveraceae species, five NADH dehydrogenase-like genes (ndhF, ndhD, ndhL, ndhG, ndhE) with psaC, rpl32, ccsA and trnL-UAG normally located in the SSC region have migrated to IRs, resulting in IR expansion and gene duplication. An up to 9 kb inversion involving five genes (rpl23, ycf2, ycf15, trnI-CAU and trnL-CAA) was found within IR regions. The accD gene was found to be absent and the ycf1 gene has shifted from the IR/SSC border to the SSC region as a single copy. Phylogenetic analysis based on the sequences of common CDS showed that the genus Corydalis is quite distantly related to the other genera of Papaveraceae, it provided a new clue for recent advocacy to establish a separate Fumariaceae family. Our results revealed one special cp genome structure in Papaveraceae, provided a useful resources for classification of the genus Corydalis, and will be valuable for understanding Papaveraceae evolutionary relationships.
The current COVID-19 pandemic has forced the global higher education community to rapidly adapt to partially- or fully-online course offerings. For field- or lab-based courses in ecological curricula, this presents unique challenges. Fortunately, a diverse set of active learning techniques exist, and these techniques translate well to online settings. However, limited guidance and resources exist for developing, implementing, and evaluating active learning assignments that fulfil specific objectives of ecology-focused courses. To address these informational gaps, we (1) identify broad learning objectives across a variety of ecology-focused courses, (2) provide examples, based on our collective online teaching experience, of active learning activities that are relevant to the identified ecological learning goals, and (3) provide guidelines for successful implementation of active learning assignments in online courses. Using The Wildlife Society’s list of online higher education ecology-focused courses as a guide, we obtained syllabi from 45 ecology-focused courses, comprising a total of 321 course-specific learning objectives. We classified all course-specific learning objectives into at least one of five categories: (1) Identification, (2) Application of Concepts/Hypotheses/Theories, (3) Management of Natural Resources, (4) Development of Professional Skills, or (5) Evaluation of Concepts/Practices. We then provided two examples of active learning activities for each of the five categories, along with guidance on their implementation in online settings. We suggest that, when based on sound pedagogy, active learning techniques can enhance the online student’s experience by activating ecological knowledge; moreover, active learning techniques should also be incorporated into in-person offerings once the current COVID-19 crisis has abated.
Barriers to fieldwork exist for many reasons such as physical ability, financial cost, and time availability. Unfortunately, these barriers disproportionately affect minority communities and create a disparity in access to fieldwork experience in the natural science community. Travel restrictions and the global lockdown has extended this barrier to fieldwork across the community and led to increased anxiety about gaps in productivity, especially for graduate students and early-career researchers. In this paper, we discuss Agent-Based Modeling as an open-source, accessible, and inclusive resource to substitute for lost fieldwork during COVID-19 and future scenarios of travel restrictions such as climate change. We detail the process of model development with a plethora of examples from the literature on how Agent-Based Models can be applied broadly across life-science research. We aim to amplify awareness and adoption of this technique to broaden the diversity and size of the Agent-Based Modeling community in ecology and evolutionary research. We also describe the benefits of Agent-Based models as a teaching and training resource for students across education levels. Finally, we discuss the current challenges facing Agent-Based Modeling and discuss how the field of quantitative ecology can work in tandem with traditional field ecology to improve both methods.
DNA barcoding based on mitochondrial (mt) nucleotide sequences is an enigma. Neutral models of mt evolution predict DNA barcoding cannot work for recently diverged taxa, and yet, mt DNA barcoding accurately delimits species for many bilaterian animals. Meanwhile, mt DNA barcoding often fails for plants and fungi. I propose that because mt gene products must cofunction with nuclear gene products, the evolution of mt genomes is best understood with full consideration of the two environments that impose selective pressure on mt genes: the external environment and the internal genomic environment. Moreover, it is critical to fully consider the potential for adaptive evolution of not just protein products of mt genes but also of mt transfer RNAs and mt ribosomal RNAs. The tight linkage of genes on mt genomes that do not engage in recombination could facilitate selective sweeps whenever there is positive selection on any element in the mt genome, leading to the purging of mt genetic diversity within a population and to the rapid fixation of novel mt DNA sequences. Accordingly, the most important factor determining whether or not mt DNA sequences diagnose species boundaries may be the extent to which the mt chromosomes engage in recombination.