 |
|
Spider love: Little guys get lots more
December 08, 2008Big 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
"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
Spiders Current Events and Spiders News RSSShedding light on the cosmic skeleton
"Matter is not distributed uniformly in the Universe," says Masayuki Tanaka from ESO, who led the new study. "In our cosmic vicinity, stars form in galaxies and galaxies usually form groups and clusters of galaxies. The most widely accepted cosmological theories predict that matter also clumps on a larger scale in the so-called 'cosmic web', in which galaxies, embedded in filaments stretching between voids, create a gigantic wispy structure."
Spider web glue spins society toward new biobased adhesives
With would-be goblins and ghosts set to drape those huge fake spider webs over doorways and trees for Halloween, scientists in Wyoming are reporting on a long-standing mystery about real spider webs: It is the secret of spider web glue.
Scientists discover largest orb-weaving spider
Researchers from the United States and Slovenia have discovered a new, giant Nephila species (golden orb weaver spider) from Africa and Madagascar and have published their findings in the Oct. 21 issue of the journal PLoS ONE.
First 'mainly vegetarian' spider described
The 40,000 or so spiders that have been described are generally known as strict predators, trapping their prey in elaborate webs or hunting them down directly.
Herbivory discovered in a spider
There are approximately 40,000 species of spiders in the world, all of which have been thought to be strict predators that feed on insects or other animals. Now, scientists have found that a small Central American jumping spider has a uniquely different diet: the species Bagheera kiplingi feeds predominantly on plant food.
Researchers go underground to reveal 850 new species
Australian researchers have discovered a huge number of new species of invertebrate animals living in underground water, caves and "micro-caverns" amid the harsh conditions of the Australian outback.
U of T scientists identify gene that has enabled water striders to glide across water
Water striders, the familiar semi-aquatic bugs gliding across the lake at the cottage, have a novel body form that allows them to walk on water.
Researchers to study rebirth of an island after volcanic eruption
When Alaska's Kasatochi Volcano erupted on Aug. 7, 2008, it virtually sterilized Kasatochi Island, covering the small Aleutian island with a layer of ash and other volcanic material several meters thick.
Scary ancient spiders revealed in 3-D models, thanks to new imaging technique
Early relatives of spiders that lived around 300 million years ago are revealed in new three-dimensional models, in research published today in the journal Biology Letters.
Reduced diet thwarts aging, disease in monkeys
The bottom-line message from a decades-long study of monkeys on a restricted diet is simple: Consuming fewer calories leads to a longer, healthier life.
More Spiders Current Events and Spiders News Articles
 |
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. |
![MINI SPIDER FINGER PUPPET [Toy]](http://ecx.images-amazon.com/images/I/41ymTxwk7ZL._SL160_.jpg) |
MINI SPIDER FINGER PUPPET [Toy] by Folkmanis Finger Puppet |
|
Ed Hardy Spider Skull Men's White With Black Band Boxer Brief (L) by Ed Hardy Ed Hardy Spider Skull Men's White With Black Band Boxer Brief | |
 |
Nic Bishop Spiders (Sibert Honor Book) by Nic Bishop (Author) 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! |
 |
Uncle Milton Remote Control Tarantula by Uncle Milton It's RC Tarantula! Watch it crawl with real spider-like movement. Its furry texture makes it seem like the real thing! Use the unique spider egg remote control to send RC Tarantula scurrying across any smooth, flat surface. Go ahead, scare your friends and family! Ages 6 and up with Adult assistance recommended. |
 |
Spiders Starring: Lana Parrilla, Josh Green, Oliver Macready, Nick Swarts, Mark Phelan Directed By: Gary Jones |
 |
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. |
 |
Black Onyx Widow Sterling Silver Spider Pendant Charm by Silver Insanity Black Onyx Inlay7/8" tall and 5/8" wide3x4mm bail OpeningWeight is 2.5 gramsStamped .925 No chain is included with the pendant Add a Sterling Silver Chain to your pendant for $5.49 (Save 50%)- available at Checkout in Gift Options |
 |
Large Hairy Poseable Black Spider ~ Halloween Spider Decorations & Props by SeasonsTrading |
 |
LEGO Star Wars Hail-Fire Droid & Spider Droids by LEGO The Separatist army is on the attack! Roll into battle with the giant-wheeled Hail-fire droid with eight flick-firing missiles. The heavily-armed and armored spider droid is close behind, backed up by a squad of battle droids. Includes folding Hail-fire droid, spider droid, super battle droid, battle droid commander and two battle droids. 249 pieces. |
| © 2009 BrightSurf.com |