Getting help with baby care could keep families healthier and extend their lives, according to a new study into bird behaviour.
Research into weaver birds in South Africa, carried out at the University of Exeter and published in Proceedings of the Royal Society B, found that a heavy breeding workload led to increased free radical damage to cells, which can be associated with ageing and ill health. However, where birds were in larger groups and the workload was shared, no increase in cell damage was found.
The team studied cooperative white-browed sparrow weaver birds in the Kalahari Desert during their breeding season and compared groups of birds that were not breeding with others that were raising chicks.
In the three weeks after hatching, adult birds work feverishly to bring chicks food and as a result they grow to 40 times their original size. Meanwhile, non-breeding birds live a life of relative leisure, with no hungry mouths to feed.
"We investigated oxidative stress, which occurs when free-radicals cause damage to cells. Antioxidants usually prevent this damage, but during hard work, free-radicals can overwhelm antioxidant protection," said lead researcher Dominic Cram, who is now based at the University of Cambridge.
"We found that the birds that were feeding nestlings often had weaker antioxidant defences and suffered from oxidative stress. However, in large groups where many birds assist with nestling care, the birds showed stronger antioxidants and lower free radical damage. So in larger groups many hands appear to have made light work."
Dr Andrew Young from the Centre for Ecology and Conservation at the University of Exeter's Penryn Campus in Cornwall, who leads this research programme, said that: "We have long known that helpers lighten the workloads of breeders in many cooperative species, such as ourselves, but the impact of this on health and ageing are largely unknown. Our findings provide exciting evidence of the potential for cooperation to reduce free radical damage, and so examining its later-life effects on patterns of ageing is now our primary focus of research."
Oxidative stress is not something that only occurs in weaver birds, it has been implicated in over a hundred human diseases, including cancer and Alzheimer's disease.
The researchers say their results provide rare experimental evidence that reproduction can negatively impact both oxidative status and body mass in the wild. Furthermore, the findings suggest that these costs can be mitigated in cooperative societies by the presence of additional helpers.
"One can imagine similar processes at play in humans - if a couple had a baby and were getting help from one or two generous family members, then it would make life easier for the parents, a difference that might ultimately be reflected in their health and lifespan" added Dr Cram. "Of course, this would need further research, but the weaver birds of the Kalahari Desert have given us an insight into the way workloads and teamwork can affect health and ageing."
This study received funding from the Biotechnology and Biological Sciences Research Council (BBSRC), the Royal Society and the Natural Environment Research Council (NERC).
The oxidative costs of reproduction are group-size dependent in a wild cooperative breeder by Dominic Cram, Jonathan Blount and Andrew Young is published in Proceedings of the Royal Society B.
Images of the white-browed sparrow weaver bird: https:/
Image credits: Dominic Cram
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About the University of Exeter
The University of Exeter is a Russell Group university and in the top one percent of institutions globally. It combines world-class research with very high levels of student satisfaction. Exeter has over 19,000 students and is one of the global top 100 universities according to the Times Higher Education World University Rankings 2015-16, positioned 93rd. Exeter is also ranked 7th in The Times and The Sunday Times Good University Guide 2016, 9th in the Guardian University Guide 2016 and 10th in The Complete University Guide 2016. In the 2014 Research Excellence Framework (REF), the University ranked 16th nationally, with 98% of its research rated as being of international quality. Exeter was named The Times and The Sunday Times Sports University of the Year 2015-16, in recognition of excellence in performance, education and research. Exeter was The Sunday Times University of the Year 2012-13.
The University has four campuses. The Streatham and St Luke's campuses are in Exeter and there are two campuses in Cornwall, Penryn and Truro. The 2014-2015 academic year marks the 10-year anniversary of the two Cornwall campuses. In a pioneering arrangement in the UK, the Penryn Campus is jointly owned and managed with Falmouth University. At the campus, University of Exeter students can study programmes in the following areas: Animal Behaviour, Conservation Biology and Ecology, English, Environmental Science, Evolutionary Biology, Geography, Geology, History, Human Sciences, Marine Biology, Mining and Minerals Engineering, Politics and International Relations, Renewable Energy and Zoology.
The University has invested strategically to deliver more than £350 million worth of new facilities across its campuses in the past few years; including landmark new student services centres - the Forum in Exeter and The Exchange at Penryn - together with world-class new facilities for Biosciences, the Business School and the Environment and Sustainability Institute. There are plans for further investment between now and 2016.
About the University of Exeter's Centre for Ecology and Conservation (CEC)
Staff at the Centre for Ecology and Conservation, based on the Penryn Campus, undertake cutting-edge research that focusses on whole organism biology. The CEC has three interlinked research groups: Behaviour, Ecology and Conservation, and Evolution which constitute 40 academics and over 100 early career researchers. It engages widely with businesses, charities and government agencies and organisations in Cornwall, the Isles of Scilly and beyond to translate its research into societal impact. Staff at the CEC deliver educational programs to some 500 undergraduate and 100 postgraduate students.
A new £5.5 million Science and Engineering Research Support Facility (SERSF) is currently under construction at the Penryn Campus. The facility will bring pioneering business, science and engineering together and will provide space for the growing CEC alongside the University of Exeter Business School, which is expanding into Cornwall, and the University's Marine Renewables team.
The University of Exeter and Falmouth University are founding partners in the Combined Universities in Cornwall (CUC), a unique collaboration between six universities and colleges to promote regional economic regeneration through Higher Education, funded mainly by the European Union (Objective One and Convergence), the South West Regional Development Agency and the Higher Education Funding Council for England, with support from Cornwall Council.