Spider love: Little guys get lots more

December 08, 2008

Big males outperform smaller ones in head-to-head mating contests but diminutive males make ten times better lovers because they're quicker to mature and faster on their feet, a new study of redback spiders reveals.

Published in the current online issue of Journal of Evolutionary Biology, the study shows the importance of maturation in defining mating and paternity success. In field enclosures, researchers simulated two competitive contexts favouring the development of differently sized male redbacks (Latrodectus hasselti). The larger males were more successful at mating with and impregnating females when they competed directly with smaller males. However, when faster maturing smaller males were given a one-day head start, reflecting their earlier maturation in nature, they had a ten-times higher paternity rate than larger males.

Courtship between redbacks lasts an average of 50 minutes when males are competing and 4.5 hours for single, non-competing males. Copulation lasts from 6 to 31 minutes, and males are usually injured or killed during the process.

"The results reveal that big males don't get it all their own way," says lead author, UNSW postdoctoral fellow, Dr Michael Kasumovic, who co-authored the paper with Maydianne Andrade of the University of Toronto. "Nature favours larger and smaller males under different circumstances. Larger males experienced a longer maturation process so they are unable to search for and mate with females and produce offspring at the same rate as smaller redback spiders.

"Large size and weaponry are strong predictors of a male's competitive strengths because those traits help them dominate smaller males when they compete for food and mating rights. However, evidence from studies of midges, dung flies and seed beetles reveals that smaller males develop sooner than larger males and often mate before larger competing males arrive on the scene. Size isn't the only ruler by which we can measure a male's quality. Many other factors, including maturation time, are critical in that definition."

University of New South Wales

---

---

	Time For Kids: Spiders! by Editors of TIME For Kids (Author) From deserts to forests to inside your living room, spiders are everywhere! You can spot the sticky webs that they weave to catch their dinners. Spiders can be many different colors and move in surprising ways. Some roll across the sand. Others walk on water! In SPIDERS!, TIME For Kids® unravels the mysteries of these amazing eight-legged creatures.
	Are You a Spider? (Backyard Books) by Tudor Humphries (Author) Did you know that when a spider's web is damaged, a spider will often eat the remaining silk before making a new one? Young children will make many amazing discoveries about spiders in this captivating account.
	Nic Bishop Spiders (Sibert Honor Book) by Nic Bishop (Author) Nic Bishop's signature up-close, stop-action photographs show spiders larger than life. For the first to third grade set, spiders are fascinating and suitably gruesome, especially when looked at in EXTREME close-up. Amazing images show the beauty and otherworldliness of spiders. Simple, engaging text conveys basic information about spiders as well as cool and quirky facts. One stop-action montage shows a spider leaping twenty times its body length!
	Spiders by Seymour Simon (Author) Exceptional nonfiction for children from two of the most trusted names in science education: Seymour Simon and the Smithsonian Institution.
	Spiders and Their Kin (Golden Guide) by Herbert W. Levi (Author), Lorna R. Levi (Author), Nicholas Strekalovsky (Illustrator) Enjoy and Learn! Expert Knowledge! Easy-to-Read! This introduction to the diverse yet little known world of spiders is packed with concise, accurate information. With full-color pictures and readable text, this guide identifies representative species and describes: Their characteristics and habits Growth, courtship and enemies Where they are found Includes information on poisonous species and how to collect, preserve, and raise spiders.
	Spiders of North America: An Identification Manual by Paula Cushing (Author), Darrell Ubick (Author) This beautifully illustrated guide to the spiders of North America, north of Mexico, provides more than 1,400 illustrations and keys to the genera in 68 spider families. The book includes more than 550 genera. The manual contains 72 chapters and a wealth of information including an introduction to spider morphology, natural history, collecting techniques and preservation methods; an overview of the current status and most recent developments in spider evolutionary history; a key to the 68 families of spiders found in North America, north of Mexico; keys to the genera in each of these 68 families; an etymological dictionary explaining the derivation of the names of spider genera and families; and a well illustrated glossary.
	Spiders (Science and Nature for Young Readers) Did you know that spider silk is stronger than steel of the same thickness? Or that the venom from a Black Widow is more powerful a Rattle Snake’s? Learn all about the mysterious world of SPIDERS in the Science and Nature Series for Young Readers.
	National Geographic Readers: Spiders by Laura Marsh (Author) You don’t have to look far to see a spider’s web—in the corner of the window, on a fence, or in a bush—spiders make their homes everywhere. And there are so many kinds of spiders! Some red, some blue, yellow, and more…all fascinating. Amazing photography and easy-to-understand text makes Spiders a hit in this National Geographic Kids series.
	National Wildlife Federation Field Guide to Insects and Spiders & Related Species of North America by Arthur V. Evans (Author), Craig Tufts (Foreword) National Wildlife Federation’s new all-photographic field guide to North American insects, spiders, and related species, is the most up-to-date of its kind, and lets both amateur and expert naturalists identify more than 940 species quickly and accurately. More than 2,000 close-up color photographs by leading nature photographers reveal the field marks that distinguish each creature, and the clear and concise text that accompanies each image describes the range, habitat, life cycle, and behavior. Budding entomologists will be inspired to explore further with the detailed information on starting a collection, planting an arthropod garden, keeping insects and spiders in captivity, and learning the techniques of macro photography. The unique waterproof cover makes it ideal for use...
	The Life of the Spider by Jean-Henri Fabre (Author) The Life of the Spider is presented here in a high quality paperback edition. This popular classic work by Jean-Henri Fabre is in the English language, and may not include graphics or images from the original edition. If you enjoy the works of Jean-Henri Fabre then we highly recommend this publication for your book collection.