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:11/28/2016)... "The biometric system market ... The biometric system market is in the growth stage ... future. The biometric system market is expected to be ... CAGR of 16.79% between 2016 and 2022. Government initiative ... in smartphones, rising use of biometric technology in financial ...
(Date:11/21/2016)...   Neurotechnology , a provider of high-precision ... that the MegaMatcher On Card fingerprint matching algorithm ... NIST Minutiae Interoperability Exchange (MINEX) III ... of the evaluation protocol. The ... fingerprint templates used to establish compliance of template ...
(Date:11/16/2016)... Calif. , Nov. 16, 2016 ... user experience and security for consumer electronics, and ... the financial and retail industry, today announced a ... and convenient way to authenticate users of mobile ... Sensory,s TrulySecure™ software which requires no ...
Breaking Biology News(10 mins):
(Date:12/2/2016)... Research and Markets has announced the addition of ... to their offering. ... , , An ... is anticipated. Nanotechnology will be applied at all stages of ... applications in clinical trials. Many of the assays based on ...
(Date:12/2/2016)... ... December 01, 2016 , ... The Conference Forum has announced that the ... will take place on February 1-3, 2017 at the Roosevelt Hotel in New York ... program provides a unique 360-degree approach, which addresses the most up-to-date information regarding business ...
(Date:12/2/2016)... 2016   SurePure, Inc. (OTCQB: SURP) a ... Company has concluded an agreement with Tamarack Biotics under ... period to acquire units of the Company,s patented photopurification ... million.  Concurrently with the option, SurePure ... Tamarack will seek regulatory approvals in the ...
(Date:11/30/2016)... November 30, 2016 The global ... players hold a dominant share in the overall market. ... International, Inc., and Merck KGaA, held a lion,s share ... Market Research observes that these companies are expected to ... products that are do not require rabbit pyrogen testing ...
Breaking Biology Technology: