Science Current Events | Science News | Brightsurf.com
 
Email a Friend Send to a friend
Printer Friendly Print Females do best if they wait a while
Slashdot It! Slashdot Females do best if they wait a while
Submit to Reddit Submit Females do best if they wait a while to Reddit
Reading: Females do best if they wait a whileTwitter This Reading: Females do best if they wait a whileTwitter Females do best if they wait a while
Add to Facebook Add Females do best if they wait a while to Facebook

Females do best if they wait a while

April 09, 2007

Doubt has now been cast on one of the biggest assumptions in behavioral ecology, by researchers from the University of Bristol, UK, and published today in Current Biology

Starting to breed late in life is a bad idea if you want to maximise the number of offspring that you produce-or so the theory goes.




But doubt has now been cast on this hypothesis-one of the biggest assumptions in behavioural ecology-by researchers from the universities of Bristol and Cape Town and published today in Current Biology.

Green woodhoopoes are a cooperative bird species that live in year-round, residential groups of 2-12 individuals in which only one pair breeds per season. The remaining individuals help to raise the offspring of the dominant pair, while waiting to breed themselves. Consequently, although both males and females reach reproductive maturity at one year of age, individuals may not start breeding for several years.

Using data gathered over 24 years, Dr Andy Radford and colleagues demonstrate that the females that started breeding later in life actually had more offspring than those that started earlier. Males, on the other hand, met the traditional expectation that a delayed start to breeding results in fewer offspring.

The researchers hypothesise that this surprising and apparently paradoxical situation is because females that attempt to start breeding early in life have a very high mortality rate. In contrast, females who start breeding later tend to live longer, have longer breeding careers, and thus produce more fledglings.

Dr Radford, from Bristol University's School of Biological Sciences, who is funded by the BBSRC, said: "It has been generally assumed that males and females suffer similarly from a delayed start to breeding, and many studies have investigated how non-breeding birds might mitigate this assumed cost. However, as in many facets of life, the sexes differ dramatically: although male woodhoopoes do indeed suffer if they don't start breeding as soon as possible, females do best to wait a while."

The authors postulate that the reason why young females have such a high mortality rate when attempting to breed is that they are not in as good condition as older females. Because breeding female woodhoopoes lay all the eggs and conduct all the incubation, they pay a potentially high cost.

This is exacerbated because in incubating the eggs overnight, the breeding female sleeps alone, while the rest of the group roost communally; she therefore suffers a potential thermoregulatory cost in addition to the costs associated with laying and incubation. If young females are in poorer condition than older females, they will be more likely to die as a consequence of these costs.

University of Bristol





Science News and Science Current Events Tag Cloud
This tag cloud is a visual representation of term frequencies of random science news topics with common terms grouped together and emphasized by their display size.
Fruit Flies   Fossil Fuel   Large Hadron Collider   Peripheral Artery Disease   Medulloblastoma   Obese   Contraception   Dengue Fever   Influenza   Fossil   Tonsillectomy   Down syndrome   Long-term Memory   Gastric Bypass Surgery   Behavioral Problems   Ants   Leptin   Sleeping Sickness   Malpractice   Public Health   Polycystic kidney disease   Lung Function   Ear Infection   Biodiesel   Cannabinoids  
Related Breeding Current Events and Breeding News Articles Breeding Current Events and Breeding News RSS Breeding Current Events and Breeding News RSS
Iowa State University researcher looks at the future of agriculture
Dramatic price fluctuations, increasing demand, the food vs. fuel debate, and other events of the past year may have food producers wondering which way is up.

Stress puts double whammy on reproductive system, fertility
University of California, Berkeley, researchers have found what they think is a critical and, until now, missing piece of the puzzle about how stress causes sexual dysfunction and infertility.

1 moose, 2 moose: Scientist seeks correction in number of species
It is a misinterpretation of the application of the bedrock of scientific naming with regard to the number of moose species that Kris Hundertmark, a University of Alaska Fairbanks wildlife geneticist at the Institute of Arctic Biology, seeks to correct.

Biologist discovers pink-winged moth in Chiracahua Mountains
University of Arizona biologist Bruce Walsh has identified a new species of moth in southern Arizona. Normally, this is not a big deal.

Hatchery fish may hurt efforts to sustain wild salmon runs
Steelhead trout that are originally bred in hatcheries are so genetically impaired that, even if they survive and reproduce in the wild, their offspring will also be significantly less successful at reproducing.

Bone bed tells of life along California's ancient coastline
In the famed Sharktooth Hill Bone Bed near Bakersfield, Calif., shark teeth as big as a hand and weighing a pound each, intermixed with copious bones from extinct seals and whales, seem to tell of a 15-million-year-old killing ground.

Horse whisperers, lion tamers not needed: Scientists find genetic regions that soothe savage beasts
In what could be a breakthrough in animal breeding, a team of scientists from Germany, Russia and Sweden have discovered a set of genetic regions responsible for animal tameness.

Engineered pig stem cells bridge the mouse-human gap
The discovery that adult skin cells can be 'reprogrammed' to behave like stem cells has been a major scientific boon, providing a way to tap the potential of embryonic stem cells without the associated ethical quandaries.

Insomniac flies resemble sleep-deprived humans
Researchers at Washington University School of Medicine in St. Louis have created a line of fruit flies that may someday help shed light on the mechanisms that cause insomnia in humans.

Shatter-resistant brassicas
An international team of scientists has cracked the problem of pod shatter in brassica crops such as oilseed rape.
More Breeding Current Events and Breeding News Articles
Breeding: A Partial History of the Eighteenth Century

Breeding: A Partial History of the Eighteenth Century
by Professor Jenny Davidson (Author)

The Enlightenment commitment to reason naturally gave rise to a belief in the perfectibility of man. Influenced by John Locke and Jean-Jacques Rousseau, many eighteenth-century writers argued that the proper education and upbringing& mdash;breeding& mdash;could make any man a member of the cultural elite.

Yet even in this egalitarian environment, the concept of breeding remained tied to theories of blood lineage, caste distinction, and biological difference. Turning to the works of Locke, Rousseau, Swift, Defoe, and other giants of the British Enlightenment, Jenny Davidson revives the debates that raged over the husbandry of human nature and highlights their critical impact on the development of eugenics, the emergence of fears about biological determinism, and the history of...

The Complete Book of Dog Breeding

The Complete Book of Dog Breeding
by Dan Rice D.V.M. (Author)

A veterinarian with many years of canine practice experience offers guidance to novice and professional dog breeders, emphasizing the responsibilities of reputable breeders to their dogs and to the buyers of the puppies they produce. Topics covered include: the choosing, health, quality, and conditioning of brood stock; practical DNA use, and Canine Health Information Center (CHIC) surveys and data storage to scientifically improve the selection of healthy brood stock and puppies; potential breeding problems; artificial insemination; pregnancy and its duration; embryonic and fetal activity; pregnancy nutrition; physical changes during pregnancy; stages of labor; normal and Cesarean-section births, and how to assist in both; nutrition of dams and puppies and how to recognize and prevent...

Spiders II: Breeding Ground

Spiders II: Breeding Ground
Starring: Stephanie Niznik, Greg Cromer, Daniel Quinn, Richard Moll, Harel Noff
Directed By: Sam Firstenberg

When jason and alexandria are rescued from their sinking boat by dr. Grbac and his floating medical lab jason insists there is more to the charming doctor than meets the eye. Suspicious jason starts snooping around the cargo boat and finds dead bodies in a freezer vault. Studio: Lions Gate Home Ent. Release Date: 05/23/2006 Starring: Stephanie Niznik Richard Moll Run time: 96 minutes Rating: R

Successful Dog Breeding: The Complete Handbook of Canine Midwifery

Successful Dog Breeding: The Complete Handbook of Canine Midwifery
by Howell Book House

Here, at last, is a revised and expanded edition of this award-winning breeders' reference. Successful Dog Breeding is a book for the first-time breeder and longtime fancier alike, no matter what the breed. Down-to-earth practical information is given to cover virtually every contingency associated with breeding and whelping. Presented in a humorous format, even the most serious information is made easier to understand.

Chris Walkowicz and Bonnie Wilcox, D.V.M., are both veteran dog fanciers who bring a wealth of personal and professional experience to every chapter. Covering topics from planning the breeding (should I or shouldn't I?) to problems encountered in breeding, delivery and neonatal care, the authors offer viable solutions to innumerable problems, whether old or new....

Breeding Dogs for Dummies

Breeding Dogs for Dummies
by Richard G. Beauchamp (Author)

Packed with tips on breeding champion-quality puppies

Start a breeding program that will ensure your dogs’ health and enhance their lineage

Breeding puppies involves many responsibilities, but it can also be one of the most enjoyable and rewarding experiences you ever have. This friendly guide provides all the information you need to create a positive breeding environment for your dogs so that they produce happy, healthy offspring. Attention pet owners! Get free Dummies Daily™ e-mail newsletters Sign up for tips on a variety of pets Keep your pet healthy and content – the Dummies Way™

Breeding Trap 3 in 1

Breeding Trap 3 in 1
by ROLF C HAGEN

An excellent way to watch your livebearers have their young, while still keeping them in your tank. The V-Insert allows the young fish to fall through once the mother gives birth and allows them to grow and mature without being eaten or pestered by the other fish in the tank. The floating trap can also be used for wounded fish to allow them time to heal from superficial wounds.

In the Key of Calloused Fingers

In the Key of Calloused Fingers
by Devil in the Woods



Successful Dog Breeding: The Complete Handbook of Canine Midwifery (Howell reference books)

Successful Dog Breeding: The Complete Handbook of Canine Midwifery (Howell reference books)
by Chris Walkowicz (Author), Bonnie Wilcox (Author)

Here, at last, is a revised and expanded edition of this award-winning breeders' reference. Successful Dog Breeding is a book for the first-time breeder and longtime fancier alike, no matter what the breed. Down-to-earth practical information is given to cover virtually every contingency associated with breeding and whelping. Presented in a humorous format, even the most serious information is made easier to understand.

Chris Walkowicz and Bonnie Wilcox, D.V.M., are both veteran dog fanciers who bring a wealth of personal and professional experience to every chapter. Covering topics from planning the breeding (should I or shouldn't I?) to problems encountered in breeding, delivery and neonatal care, the authors offer viable solutions to innumerable problems, whether old or new....

  Breeding News for Sport Horses
by Breeding International Limited

Breeding News for Sport Horses is an independent publication dedicated exclusively to the sport horse breeding industry. The magazine's focus is the FEI disciplines around the world--primarily showjumping, dressage, and eventing.

Breeding the Spawn

Breeding the Spawn
by Suffocation



© 2009 BrightSurf.com