Phylogenetic structure of vertebrate communities across the A ustralian arid zone

Aim To understand the relative importance of ecological and historical factors in structuring terrestrial vertebrate assemblages across the A ustralian arid zone, and to contrast patterns of community phylogenetic structure at a continental scale. Location Australia. Methods We present evidence from six lineages of terrestrial vertebrates (five lizard clades and one clade of marsupial mice) that have diversified in arid and semi‐arid A ustralia across 37 biogeographical regions. Measures of within‐lineage community phylogenetic structure and species turnover were computed to examine how patterns differ across the continent and between taxonomic groups. These results were examined in relation to climatic and historical factors, which are thought to play a role in community phylogenetic structure. Analyses using a novel sliding‐window approach confirm the generality of processes structuring the assemblages of the A ustralian arid zone at different spatial scales. Results Phylogenetic structure differed greatly across taxonomic groups. Although these lineages have radiated within the same biome – the A ustralian arid zone – they exhibit markedly different community structure at the regional and local levels. Neither current climatic factors nor historical habitat stability resulted in a uniform response across communities. Rather, historical and biogeographical aspects of community composition (i.e. local lineage persistence and diversification histories) appeared to be more important in explaining the variation in phylogenetic structure. While arid‐zone assemblages show an overall tendency towards phylogenetic clustering, this pattern was less pronounced at finer spatial scales. Main conclusions By focusing within different taxonomic groups and between those groups within regions, we show that although the vertebrate lineages we examined exhibited high diversity and low turnover across the arid zone, the underlying phylogenetic structure differs between regions and taxonomic groups, suggesting that taxon‐specific histories are more important than habitat stability in determining patterns of phylogenetic community relatedness.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98265/1/jbi12077.pd

How Many Squirrels Are in the Shrubs? A Lesson Plan for Comparing Methods for Population Estimation

Estimating the population sizes of animals is a key skill for any student interested in ecology, conservation, or management. However, counting animals in natural habitats is difficult, and the many techniques that exist each rely on assumptions that can bias results. Most wildlife courses teach one or two of these methods, but rarely are students given an opportunity to compare approaches and explore how underlying assumptions affect the accuracy of estimates. Here, we describe a hands-on activity in which students estimate the size of a single population of animals using multiple methods: strip censuses, scat counts, and camera traps. They then compare the estimates and evaluate how the assumptions of each model (e.g., random use of habitats and animal behavior) bias the results. Finally, students submit their data to a national database that aggregates observations across multiple institutions as part of Squirrel-Net (http://squirrel-net.org). They can then analyze the national dataset, permitting exploration of these questions across a broader variety of habitats and species than would be possible at any single institution. Extensions of this activity guide students to enumerate the advantages and disadvantages of each method in different contexts and to select the most appropriate method for a given scenario. This activity and the database focus on estimating population sizes of squirrels, which are diurnal, charismatic, easily identified, and present in a wide range of habitats (including many campuses), but the same methods could be broadly used for other terrestrial species, including birds, amphibians, reptiles, or invertebrates

Squirrels in Space: Using Radio Telemetry to Explore the Space Use and Movement of Sciurid Rodents

Biotelemetry is used by researchers to track the interactions of animals with each other and the environment. While advancing technology has led to the development of numerous biotelemetry tools, radio telemetry remains the most common method for tracking small animals. Moreover, telemetry tracking of animal movement is an important skill for entry-level positions in wildlife biology. Thus, hands-on experience using radio telemetry provides students with an advantage as they pursue careers in wildlife biology, as well as an opportunity to build science process skills. We present a lesson in which students use radio telemetry to track animals; collect, analyze and interpret spatial data; and consider its applications to local wildlife management and conservation. Students submit their data to a national database collecting observations from multiple institutions as part of Squirrel-Net (http://squirrel-net.org). The aggregated data allows students to generate and test hypotheses across a broader variety of species and habitats than would be possible at any single institution. The lesson is designed for adaptation to diverse educational contexts, from a single two-hour laboratory period (basic skills acquisition) to a semester-long student-driven research project (open inquiry Course-based Undergraduate Research Experience, or CURE). Although this activity and the national database focus on spatial data for squirrels, which are diurnal, charismatic, easily identified, and present on most college campuses, the same methods and materials can be modified for any animal capable of carrying a radio transmitter and being safely tracked by students

Squirreling from Afar: Adapting Squirrel-Net Modules for Remote Teaching and Learning

The shift from face-to-face instruction to remote teaching and learning has proven to be a challenging endeavor for many reasons, including lack of time, resources, and inspiration. Lab courses, the “hands-on” portion of many curricula, may be especially difficult to adapt to online learning given the common use of specialized equipment, materials, and techniques that require close supervision. Without the time and resources to creatively modify existing activities or create new ones, remote lab courses run the risk of becoming less effective, equitable, and/or engaging. Squirrel-Net has created four field-based activities for biology labs that are easy to implement, highly flexible for different course aims, and readily adaptable to a remote learning environment. In this essay, we briefly summarize the modules and propose several ways that each can be adjusted to accommodate online teaching and learning. By providing authentic learning opportunities through distance delivery we hope to promote widespread student engagement and creative solutions for instructors

Sorry to Eat and Run: A Lesson Plan for Testing Trade-off in Squirrel Behavior Using Giving Up Densities (GUDs)

All animals need to find and compete for food, shelter, and mates in order to survive and reproduce. They also need to avoid being eaten by predators. Optimal foraging theory provides a framework to examine the trade-offs individuals make while foraging for food, taking into account an animal’s body condition, predation pressure, quality of food resources, and food patch availability in the habitat. Here we describe an activity that uses Giving Up Densities (GUDs), which could be used as part of a course-based undergraduate research experience (CURE) or as a stand-alone activity. GUDs provide an experimental approach to quantify the costs and benefits of foraging in a particular patch and is simple to measure in that it is literally the density of food remaining in a patch. However, its interpretation allows students to compare foraging decisions under different environmental conditions, between species, or with different food sources. This activity was designed to study the foraging behavior of squirrels, which are active during the day, forage on seeds, and are found on and around many college campuses, but it can be adapted to nocturnal animals, birds, or other vertebrates. This module is hands-on. Students weigh seeds, sift sand, walk out into the field with bags of sand and trays, and analyze data. The module can be designed at various levels of inquiry to suit the needs of a particular class. Further, students can work individually, in pairs, or in teams. Finally, students and instructors are encouraged to upload their data to a national dataset, which is available to instructors for use in the classroom to broaden the possible hypotheses and analyses students can explore

An Introduction to the Squirrel-Net Teaching Modules

Although course-based undergraduate research experiences (CUREs) are gaining popularity in biology, most are designed for benchwork-based laboratory courses while few focus on field-based skills. Many barriers to implementing field CUREs exist, including the difficulty in designing authentic research that can be accomplished in a limited lab timeframe, permitting and liability issues, and problems gathering sufficient data to meaningfully analyze. Squirrel-Net (http://squirrel-net.org) is a consortium of mammalogists from eight different institutions who have worked to overcome these limitations through four field-based CUREs focused on sciurid rodents (e.g., squirrels, chipmunks, marmots, prairie dogs). Each module is linked to a national dataset, allowing for broader and more complex hypotheses and analyses than would be possible from a single institution. Modules have been field tested at different institutions and are easily implemented and highly flexible for different courses, levels of inquiry, habitats, and focal species. Beyond the basic lesson plan, each module also provides suggestions for adaptation at different levels of inquiry and scaffolding across a course or an entire curriculum. Moreover, our website provides templates to help lower barriers to CURE implementation (e.g., selecting a field site and writing institutional animal care protocols). Here, we introduce Squirrel-Net and give an overview of the four CURE modules. Additionally, we demonstrate how the modules can be used singly or together to provide authentic research experiences to a diversity of undergraduates

Squirreling Around for Science: Observing Sciurid Rodents to Investigate Animal Behavior

Hands-on research experiences are important opportunities for students to learn about the nature of inquiry and gain confidence in solving problems. Here, we present an inquiry-based lesson plan that investigates the foraging behavior of sciurid rodents (squirrels) in local habitats. Squirrels are an ideal study system for student research projects because many species are diurnal, easy to watch, and inhabit a range of habitats including college campuses. In this activity, instructors identify appropriate field sites and focal species, while students generate questions and brainstorm predictions in small groups regarding factors that might influence behavioral trade-offs in sciurids. Students conduct observational surveys of local squirrels in pairs using a standardized protocol and upload their data to a national database as part of the multi-institutional Squirrel-Net (http://squirrel-net.org). Instructors access the nationwide dataset through the Squirrel-Net website and provide students with data for independent analysis. Students across the country observe and record a range of squirrel species, including behaviors and habitat characteristics. The national dataset can be used to answer student questions about why squirrels behave in the way they do and for students to learn about authentic analyses regarding behavior trade-offs. Additionally, the lesson is designed to be modified across a range of inquiry levels, from a single two-hour laboratory activity to a unit- or semester-long student-driven course-based research experience. Our activity highlights the value of using observational data to conduct research, makes use of the Squirrel-Net infrastructure for collaboration, and provides students equitable access to field-based projects with small mammals

Intraspecific Polymorphism, Interspecific Divergence, and the Origins of Function-Altering Mutations in Deer Mouse Hemoglobin

Major challenges for illuminating the genetic basis of phenotypic evolution are to identify causative mutations, to quantify their functional effects, to trace their origins as new or preexisting variants, and to assess the manner in which segregating variation is transduced into species differences. Here, we report an experimental analysis of genetic variation in hemoglobin (Hb) function within and among species of Peromyscus mice that are native to different elevations. A multilocus survey of sequence variation in the duplicated HBA and HBB genes in Peromyscus maniculatus revealed that function-altering amino acid variants are widely shared among geographically disparate populations from different elevations, and numerous amino acid polymorphisms are also shared with closely related species. Variation in Hb-O2 affinity within and among populations of P. maniculatus is attributable to numerous amino acid mutations that have individually small effects. One especially surprising feature of the Hb polymorphism in P. maniculatus is that an appreciable fraction of functional standing variation in the two transcriptionally active HBA paralogs is attributable to recurrent gene conversion from a tandemly linked HBA pseudogene. Moreover, transpecific polymorphism in the duplicated HBA genes is not solely attributable to incomplete lineage sorting or introgressive hybridization; instead, it is mainly attributable to recurrent interparalog gene conversion that has occurred independently in different species. Partly as a result of concerted evolution between tandemly duplicated globin genes, the same amino acid changes that contribute to variation in Hb function within P. maniculatus also contribute to divergence in Hb function among different species of Peromyscus. In the case of function-altering Hb mutations in Peromyscus, there is no qualitative or quantitative distinction between segregating variants within species and fixed differences between species

Skeletal indicators of ecological specialization in pika (Mammalia, Ochotonidae)

Pika species generally fall into two ecotypes, meadow‐dwelling (burrowing) or talus‐dwelling, a classification that distinguishes a suite of different ecological, behavioral, and life history traits. Despite these differences, little morphological variation has previously been documented to distinguish among ecotypes. The aim of this study was to test whether postcranial features related to burrowing are present in meadow‐dwelling species and whether talus‐dwelling species exhibit postcranial modifications related to frequent leaping between rocks. To test this, the scapula, humerus, ulna, radius, innominate, femur, tibia, and calcaneus of 15 species were studied and measured. Twenty‐three measurements were taken on 199 skeletons, and 19 indices were constructed from these measurements. Indices were compared between the two ecotypes using Student's t ‐test. Comparisons among ecotypes, species, and subgenera were made using one‐way ANOVA with the Tukey honest significant difference post hoc test. Multivariate results were generated using principal components analyses. Thirteen forelimb and hind limb indices proved significant in distinguishing the meadow‐dwelling, talus‐dwelling, and intermediate forms. A number of these indices are associated with burrowing or leaping in other mammals, providing some support for the hypothesis that postcranial modifications in pika are related to locomotor differences. This evidence of morphological responses to ecological specialization will be useful for reconstructing the paleobiology of extinct taxa, assessing the behavioral variability of extant species, and improving our understanding of the evolutionary history of pikas. J. Morphol., 2013. © 2013 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/97461/1/20127_ftp.pd