Navigation Links
Early bird doesn't always get worm, UNC researcher finds
Date:3/12/2008

CHAPEL HILL Competing against older brothers and sisters can be tough work, as any youngest child will tell you.

But new research from a biologist at the University of North Carolina at Chapel Hill shows that when it comes to some birds, you should reserve any underdog sympathies for the first born or rather, first laid siblings as well.

The finding, published in the March 12 issue of PLoS ONE, runs somewhat counter to common wisdom, which holds that baby birds that are laid before their brood mates have a better chance of surviving long enough to leave the nest.

But after studying a population of Lincolns sparrows in a remote stretch of Colorados San Juan Mountains, Keith Sockman, an assistant biology professor in UNCs College of Arts and Sciences, has discovered that first-laid eggs are, in fact, the least likely to hatch at all.

I believe this is the first study to follow siblings from laying through fledging and demonstrate that the effect of laying order on hatching is very different from its effect post-hatching, said Sockman.

It is a well-documented fact that being born just a day or so later often sets the stage for a situation whereby youngest hatchlings die. Thats because theyre too small to compete against their feistier brood-mates for the limited resources provided by their parents. Such competitive disparities caused by hatching or birth order can be found in other animals from beetles to marsupials to humans which sometimes produce their young in series, then rear the resulting offspring simultaneously.

But Sockman says up until now, such observations have usually failed to take account of what happens to eggs before they hatch.

Female Lincolns sparrows lay one egg per day, usually producing three to five eggs in total. While carefully observing and tracking the tiny birds for three breeding seasons, Sockman and his team of researchers noticed that typically, mothers do not settle down and start incubating the eggs right away, since they still have other concerns during the laying cycle, such as foraging for food.

Sockman believes this contributes to the lower probability that first-laid eggs will hatch at all but also helps to ensure that overall, a greater number of reasonably healthy, strong and feisty chicks hatch and go on to develop into young birds.

At these elevations, conditions can be fairly harsh even during the summer when Lincoln's sparrows breed, said Sockman. Its often freezing at night, which is hard on an un-incubated egg, while daytime temperatures are warm enough to foster the growth of harmful microbes. As a result, since the mother sparrow isnt keeping them at the most optimal incubating temperature from day one, first-laid eggs can be exposed to environmental conditions that lower the chance those embryos will ever see the world outside their shell.

If the female did start incubating all her eggs as soon as she laid them, it would increase the probability theyd all hatch. But it would also give a huge head start to those first-laid eggs and the chicks that emerge from them, putting their younger siblings at even more of a competitive disadvantage once they begin battling for food and their mothers attention, said Sockman. It may also reduce the number of eggs she is capable of laying.

The mothers careful balancing of this trade-off enables her to end up with three or four relatively equally robust offspring, instead of one or two strong hatchlings and several runts of the litter, said Sockman.

Sockman now intends to examine what, if any repercussions laying order has once young birds reach adulthood. The severely competitive environment in the nest may have consequences on the individual's ability to compete for resources and mates the following year when it is reproductively mature, said Sockman.


'/>"/>

Contact: Patric Lane
patric_lane@unc.edu
919-962-8596
University of North Carolina at Chapel Hill
Source:Eurekalert

Related medicine news :

1. Pot bellies linked to early signs of cardiovascular disease
2. Eye-staining technique offers early detection for dry eye syndrome
3. Early Weight Loss in Women Linked to Dementia
4. Isolation of a new gene family essential for early development
5. U of M study: Early treatment can reverse heart damage
6. Gerresheimer to be Included in the SDAX Early Decision on Inclusion in the MDAX on September 5, 2007
7. Rock N Roll: Sex, Drugs and an Early Exit
8. Pop stars more than twice as likely to die an early death
9. Exercise and yoga improves quality of life in women with early-stage breast cancer
10. Research says doctors gender may hinder early diagnosis of heart disease in women
11. Antidepressant shows early promise in treating agitation and psychotic symptoms of dementia
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/24/2016)... PASADENA, CA (PRWEB) , ... June 24, 2016 , ... Marcy was in a crisis. ... he would lash out at his family verbally and physically. , “When something upset him, ... table, he would use it. He would throw rocks at my other children and say ...
(Date:6/24/2016)... CA (PRWEB) , ... June 24, 2016 , ... ... is now offering micro-osteoperforation for accelerated orthodontic treatment. Dr. Cheng has extensive experience ... Damon brackets , AcceleDent, and accelerated osteogenic orthodontics. , Micro-osteoperforation is ...
(Date:6/24/2016)... ... June 24, 2016 , ... People across the U.S. ... magazine’s Code Talker Award, an essay contest in which patients and their families pay ... be presented at the 2016 National Society of Genetic Counselors (NSGC) Annual Education Conference ...
(Date:6/24/2016)... Vegas, Nevada (PRWEB) , ... June 24, 2016 ... ... Las Vegas client, The Grove Investment Group (TGIG), has initiated cultivation and processing ... Grove, in Las Vegas and Pahrump, Nevada. , Puradigm is the manufacturer of ...
(Date:6/24/2016)... (PRWEB) , ... June 24, 2016 , ... Venture ... Golf Classic Tournament held on June 20th at the Woodmont Country Club at ... Luke’s Wings, an organization dedicated to helping service members that have been wounded in ...
Breaking Medicine News(10 mins):
(Date:6/23/2016)... 23, 2016 Bracket , a leading clinical ... generation clinical outcomes platform, Bracket eCOA (SM) 6.0, at ... 26 – 30, 2016 in Philadelphia , ... Outcome Assessment product of its kind to fully integrate with ... Bracket eCOA 6.0 is a flexible platform for electronic clinical ...
(Date:6/23/2016)... RIDGE, Ill. and INDIANAPOLIS ... of students receiving a Lilly Diabetes Tomorrow,s Leaders Scholarship ... The 2016 scholarship winners, announced today online at ... to let type 1 diabetes stand in the way ... Diabetes has supported the Foundation,s scholarship program since 2012, ...
(Date:6/23/2016)... Revolutionary technology includes multi-speaker listening to conquer ... in advanced audiology and hearing aid technology, has today ... world,s first internet connected hearing aid that opens up ...      (Photo: http://photos.prnewswire.com/prnh/20160622/382240 ) , ... , TwinLink™ - the first dual communication ...
Breaking Medicine Technology: