Orb-weaving spiders spin the wheel-shaped webs often seen on dewy mornings in meadows and hedges, or on the walls and the eaves of buildings. This manual provides descriptions, illustrations, and taxonomic keys for the identification of the 94 species of these spiders represented in Canada and neighbouring regions.

Spiders are among the most diverse groups of terrestrial invertebrates, yet they are among the least studied and understood. This first comprehensive guide to all 68 spider families in North America beautifully illustrates 469 of the most commonly encountered species. Group keys enable identification by web type and other observable details, and species descriptions include identification tips, typical habitat, geographic distribution, and behavioral notes. A concise illustrated introduction to spider biology and anatomy explains spider relationships. This book is a critical resource for curious naturalists who want to understand this ubiquitous and ecologically critical component of our biosphere.

"NRC Monograph Publishing Program"--T.p. verso.

Cities pose formidable obstacles to nonhuman life. Vast expanses of asphalt and concrete are inhospitable to plants and animals; traffic noise and artificial light disturb natural rhythms; sewage and pollutants imperil existence. Yet cities teem with life: In rowhouse neighborhoods, tiny flowers bloom from cracks in the sidewalk. White clover covers lawns, its seeds dispersed by shoes and birds. Moths flutter and spiders weave their webs near electric lights. Sparrows and squirrels feast on the scraps people leave behind. Pairs of red-tailed hawks nest on window ledges. How do wild plants and animals in urban areas find mates? How do they navigate the patchwork of habitats to reproduce while avoiding inbreeding? In what ways do built environments enable or inhibit mating? This book explores the natural history of sex in urban bacteria, fungi, plants, and nonhuman animals. Kenneth D. Frank illuminates the reproductive behavior of scores of species. He examines topics such as breeding systems, sex determination, sex change, sexual conflict, sexual trauma, sexually transmitted disease, sexual mimicry, sexual cannibalism, aphrodisiacs, and lost sex. Frank offers a guide to urban reproductive diversity across a range of conditions, showing how understanding of sex and mating furthers the appreciation of biodiversity. He presents reproductive diversity as elegant but vulnerable, underscoring the consequences of human activity. Featuring compelling photographs of a multitude of life forms in their city habitats, this book provides a new lens on urban natural history.

Why do males and females frequently differ so markedly in body size and morphology?lSex, Size, and Gender Roles is the first book to investigate the genetic, developmental, and physiological basis of sexual size dimorphism found within and among the major taxonomic groups of animals. Carefully edited by a team of world-renowned specialists in the field to ensure a coherence of style and approach between chapters, it presents a compendium of studies into the evolution, adaptive significance, and developmental basis of gender differences in body size and morphology. Adaptive hypotheses allude to gender-specific reproductive roles and associated differences in trophic ecologies, life history strategies, and sexual selection. This "adaptationist" approach is balanced by more mechanistic studies of the genetic, developmental and physiological basis of sexual size dimorphism to provide a comprehensive and authoritative overview of the subject. Throughout the volume the emphasis is on sexual dimorphism in overall size; however, the scope of enquiry encompasses gender differences in body shape, the size and structure of secondary sexual characteristics, patterns of growth (ontogeny), and patterns of gene regulation. This advanced, research level text is suitable for graduate level students and researchers in the fields of evolutionary biology, behavioural ecology, physiology, developmental biology, and genetics. It will also be of relevance and use to non-biologists from fields such as anthropology and gender studies.

This issue is dedicated to Dr. Christo Deltshev, the doyen of Bulgarian araneology. It contains seventeen arachnological publications, including a concise biography of Dr. Deltshev, a list of his scientific publications and his described taxa. The volume comprises taxonomic contributions in the spider families Hypochilidae, Sicariidae, Dysderidae, Hersiliidae, Theridiidae, Linyphiidae, Lycosidae, Dictynidae, Gnaphosidae, Sparassidae, Philodromidae and Salticidae and fossil taxa in the harvestmen suborders Dyspnoi and Eupnoi, written by a total of 36 authors. Four new genera and 37 new spider and harvestmen species have been described in this volume, and dozens of new taxonomic alterations (new combinations, new synonyms, new statuses, etc.) are proposed too. Geographically, the papers deal with material originating from Europe, Africa, Asia, North and South America. There is also an overview of the use of barcoding to identify spiders in species-rich genera.