Navigation Links
Seagulls: Are males the weaker sex?
Date:5/7/2008

Male seagulls may be more vulnerable to their environment during embryonic development than females, according to Maria Bogdanova and Ruedi Nager from the University of Glasgow in the UK. Until now, the sex differences in developmental rate and susceptibility to unfavorable conditions during the embryonic stage in birds have received little attention. The paper (1) has just been published in Springers journal, Behavioral Ecology and Sociobiology.

In many birds, siblings hatch at different times, resulting in age hierarchies within broods, with younger chicks often suffering reduced competitive ability and poorer survival compared to older siblings. During the last phase of incubation, birds auditory system is developed and embryos communicate with each other by auditory stimuli. These vocalizations may act as a cue for later-developing embryos about forthcoming competition, and there is evidence that they can respond to these cues by accelerating their hatching time, to reduce their age disadvantage. However, it is unclear whether this flexibility in developmental rates is sex-specific.

Bogdanova and Nager experimentally manipulated the social environment of herring gull embryos and tested whether sibling contact during the embryonic stage affects the developmental rate of males and females differently, and whether this has consequences for their post-hatching performance. The last-laid eggs female gulls commonly lay three eggs - were incubated either alone with no information about the presence of older siblings (experimental group), or in contact with other eggs which provided information about the presence of more advanced embryos (control group, replicating natural conditions). Post-hatching, the chicks were reared either with nest mates or alone.

The researchers found a sex-specific effect of social environment on hatching duration and fledging* condition. When incubated in isolation, males hatched faster than females but both sexes fledged in similar, relatively good, condition. In contrast, when incubated with normal between-embryo contact, males were unable to hatch as fast and fledged in significantly poorer condition than females, regardless of whether they were reared singly or in a brood.

The authors conclude that their findings confirm that there are differences in the way male and female herring gull chicks respond to the challenges of hatching at different times. It would appear that females have the upper hand.


'/>"/>

Contact: Joan Robinson
joan.robinson@springer.com
49-622-148-78130
Springer
Source:Eurekalert

Related biology news :

1. Variety is the spice of life: too many males, too little time...
2. Gene in male fish lures females into sex
3. Simple reason helps males evolve more quickly
4. Vaginal reconstruction not needed for most inter-sex females, Hopkins study shows
5. Why do males and females frequently differ in body size and structure?
6. Influenza vaccine causes weaker immune response for children of rural Gabon than in semi-urban areas
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/9/2017)... March 9, 2017 4Dx has publicly released ... Imaging Workshop at the University of Pennsylvania. Founder and ... deliver the latest data to world leaders in lung ... together leaders at the forefront of the industry to ... "The quality of the imaging is ...
(Date:3/7/2017)... March 7, 2017 Brandwatch , the leading social ... The Prince,s Trust to uncover insights to support its reporting, ... The UK,s leading youth charity will be using Brandwatch ... and get a better understanding of the topics and issues that ... ...
(Date:3/6/2017)... 6, 2017 Mintigo , the ... announced Predictive Sales Coach TM , its new ... intelligence into Salesforce. This unique AI application will ... organizations with deep knowledge of their customers and ... engagement. Predictive Sales Coach extends Mintigo,s existing customer ...
Breaking Biology News(10 mins):
(Date:4/26/2017)... ... April 26, 2017 , ... As the call ... healthcare industry stakeholders, the discussion surrounding the topic will continue at WEDI 2017- ... in Los Angeles, Calif. Hosted by the Workgroup for Electronic Data Interchange (WEDI), ...
(Date:4/25/2017)... April 25, 2017 Providence ... licensed its novel immune-modulating technology to an undisclosed global ... allergy. Tregitopes, pronounced TĀ·rejĀ·itopes, are a ... by EpiVax CEO Annie De Groot ... immunoglobulin G, an autoimmune disease therapy, Tregitopes are ...
(Date:4/24/2017)... , April 24, 2017  Dante Labs announced today ... only EUR 850 (ca. $900). While American individuals have been ... first time Europeans can access WGS below EUR 1,000. ... crucial to leveraging genetic information to make informed decisions about ... ...
(Date:4/21/2017)... ... ... The AMA is happy to announce that $48,000 in scholarships will be ... are created through funds donated by model aviation organizations and individuals, AMA members, and ... Scholarship Committee, which is made up of model aviation pilots and enthusiasts. The committee ...
Breaking Biology Technology: