Navigation Links
Hormones dictate when youngsters fly the nest, says new research
Date:7/4/2012

Seabirds feed their young less as they reach an age to fly the nest, but it's hormones that actually control when the chicks leave home, according to new research from the University of Leeds.

The study published online in Behavioural Ecology today (05 July) aimed to pinpoint the main trigger which causes chicks to leave the nest and embark on an independent life, a process known as fledging.

While studying a colony of Manx Shearwaters (Puffinus puffinus), on the island of Skomer, researchers from the University's Faculty of Biological Sciences noticed that parent birds seemed to become increasingly insensitive to their chicks' demands for food as they grew close to fledging. At the same time the chicks showed a marked increase in levels of the hormone corticosterone. However, the team needed to know whether this increase was independent of, or caused by, the reduction in feeding.

They decided to trick the parent birds, by swapping chicks of different ages between nests which the birds make in burrows in the ground to see how this affected both parental care and the time chicks took to fledge.

"Manx Shearwaters don't recognise their own offspring, but will simply go back to the same nest after they've gathered food. They have one chick, which makes the interactions between parent and offspring easier to study," explains lead researcher, Dr Keith Hamer. "We swapped chicks which were between 10 days and two weeks apart in age, to see what impact it would have. We wanted to find out whether parents and chicks were responding to each other's behaviour, or whether each was acting independently."

The team discovered that adults reduced their food provisioning after about 60 days of raising a chick, regardless of the chick's stage of development. Although females more than males will adjust their feeding levels to how much their chicks beg for food, after around 60 days both parents start to ignore their pleas. This held true whether parents were feeding their own chicks, or foster-chicks of different ages.

The surge in corticosterone took place over the final few weeks before chicks fledged at about 70 days of age. This held true even when chicks had been fostered by parents at a different stage of the feeding cycle, so was clearly independent of the parent's behaviour and any reduction in food.

"Our findings show that young Manx Shearwaters leave home of their own accord when their corticosterone levels have reached a peak rather than as a result of changes in parental behaviour," says Dr Hamer. "Both parents and chicks need large energy reserves for their arduous migration across the Atlantic to South and Central America, and parents seem to reduce how much they feed their young simply to protect themselves."

"Unlike some other bird species, which let their offspring dictate the level of care, seabirds appear to weigh up the cost of a chick fledging underweight against the greater cost of losing the chance to breed again," he adds. "Manx Shearwaters have a breeding life of around forty years, so parents pay a high cost if they end the season too weak to complete their own migration."


'/>"/>

Contact: Dr. Keith Hamer
k.c.hamer@leeds.ac.uk
44-113-343-2983
University of Leeds
Source:Eurekalert  

Related biology news :

1. BRG1 mutations confer resistance to hormones in lung cancer
2. Study by UC Santa Barbara researchers suggests that bacteria communicate by touch
3. Research reveals first evidence of hunting by prehistoric Ohioans
4. Diabetes Research Institute develops oxygen-generating biomaterial
5. APS issues new policy requiring identification of sex or gender in reporting scientific research
6. UC Santa Barbara researchers discover genetic link between visual pathways of hydras and humans
7. Study jointly led by UCSB researcher supports theory of extraterrestrial impact
8. U of Alberta researcher steps closer to understand autoimmune diseases
9. Research on flavanols and procyanidins provides new insights into how these phytonutrients may positively impact human health
10. A project to research biological and chemical aspects of microalgae to fuel approach
11. Scripps Research discoveries lead to newly approved drug for infant respiratory distress syndrome
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Hormones dictate when youngsters fly the nest, says new research
(Date:3/14/2016)... NXTD ) ("NXT-ID" or the "Company"), a company ... of a new series of commercials on Time Warner Cable ... .  The commercials will air on Bloomberg TV, Fox Business ... show. --> NXTD ) ("NXT-ID" or the "Company"), ... the airing of a new series of commercials on Time ...
(Date:3/10/2016)... --> --> ... and Access Management Market by Component (Provisioning, Directory Services, ... Organization Size, by Deployment, by Vertical, and by Region ... market is estimated to grow from USD 7.20 Billion ... a Compound Annual Growth Rate (CAGR) of 12.2% during ...
(Date:3/9/2016)... , March 9, 2016  Crossmatch ® ... and enrollment solutions, today announced the addition of ... Altus multi-factor authentication platform. New contextual ... managers to step-up security where it,s needed most ... Washington, DC . --> ...
Breaking Biology News(10 mins):
(Date:4/27/2016)... ... April 27, 2016 , ... Global Stem Cells Group and ... Symposium as other research and development initiatives for potential stem cell protocol management for ... Stem Cells Group executives began meeting to establish a working agenda and foster initiatives ...
(Date:4/27/2016)... April 27, 2016 ReportsnReports.com ... with specific focus on US, EU, ... , to the healthcare business intelligence collection of ... Complete report on the Flow Cytometry market ... supported with 282 tables and figures is now ...
(Date:4/26/2016)... ... 26, 2016 , ... BaseHealth , the comprehensive predictive ... as Chief Business Officer. Arianpour, a genomics pioneer and visionary commercial leader with ... recently Chief Commercial Officer of Pathway Genomics. He has held senior executive roles ...
(Date:4/26/2016)... Baden-Württemberg (PRWEB) , ... April 26, 2016 , ... ... of laser lithography systems, announces the latest technology innovation for its Volume Pattern ... fulfill tomorrow’s demand for production of advanced photomasks as well as a solution ...
Breaking Biology Technology: