Navigation Links
Uncertainty drives the evolution of 'cooperative breeding' in birds

Rather than striking out to start a family of their own, members of some bird species will stick around longer to help a relative raise their young. Now, researchers report evidence that in African starlings such altruistic tendencies are most common among species that live in savannas, where the rainfall in any given year is virtually impossible to predict. The findings appear online August 16 in the journal Current Biology, a publication of Cell Press.

When the unpredictability of your environment is high, you dont know in advance what conditions you will be facing when the next breeding season rolls around, said Dustin Rubenstein of the University of California, Berkeley and the Cornell Laboratory of Ornithology. Faced with this uncertainty, it pays, evolutionarily speaking, to live and breed in social groups that will help you weather the bad times and make the most of the good times. Living in cooperative family groups may be like a form of insurance against the unpredictable nature of the environment that allows individuals to maximize their reproductive success over the course of their lifetimes.

Over the past few decades, mounting evidence has shown that many species of cooperatively breeding birds live in semi-arid tropical and sub-tropical environments, particularly in sub-Saharan Africa and Australia. Although that pattern suggested that the environment might explain the behavior, few studies showed a strong relationship between the incidence of cooperative breeding among species and any particular environmental feature, the researchers noted.

In the new study, the researchers examined the pattern of breeding behavior exhibited by 45 species of African starlings in relation to the environments in which they liveincluding savannas, deserts and tropical forestswhile controlling for the evolutionary relationships among them. They also examined the rainfall patterns typical of each of those environments in 47 African countries as far back as 147 years ago.

They found evidence that different starling species have independently evolved the cooperative breeding system upon moving to savannas, where they showed that the amount of year-to-year variation in rainfall is greatest. Rubensteins group suggested that cooperative breeding is probably advantageous in environments that vary over time because it allows for reproduction in harsh years, as well as sustained breeding during benign years.

Such a strategy might become more widespread in an increasingly uncertain future, the researchers suggested.

Some researchers have argued that climate change will lead to greater temporal environmental variability, Rubenstein said. That is, we might expect more extreme weather like severe droughts and devastating floods, and ultimately more variable environments than we see now. If this increase in variability occurs, many species of animalsincluding humanswill have to adapt to the increasing unpredictability of their environments. By studying how animals have already adapted to temporally variable and unpredictable environments, we can gain insights into how social behavior may change in the wake of climate change.

Contact: Nancy Wampler
Cell Press

Related biology news :

1. Unchecked DNA replication drives earliest steps toward cancer
2. Climate change drives widespread amphibian extinctions
3. Habitat microstructure drives salamander metamorphosis
4. Mindless autopilot drives people to underestimate food decisions
5. Buildup of damaged DNA in cells drives aging
6. A genetic gang of 4 drives spread of breast cancer
7. Molecular biology fills gaps in knowledge of bat evolution
8. Same mutation aided evolution in many fish species, Stanford study finds
9. Researchers trace evolution to relatively simple genetic changes
10. Family trees of ancient bacteria reveal evolutionary moves
11. Great White shark evolution debate involves WSU Lake Campus geology professor
Post Your Comments:
(Date:10/27/2015)... 27, 2015 In the present market scenario, ... for various industry verticals such as banking, healthcare, defense, ... growing demand for secure & simplified access control and ... as hacking of bank accounts, misuse of users, , ... as PC,s, laptops, and smartphones are expected to provide ...
(Date:10/26/2015)... LAS VEGAS , Oct. 26, 2015 ... an innovator in modern authentication and a founding member ... launch of its latest version of the Nok Nok™ ... to use standards-based authentication that supports existing and emerging ... Suite is ideal for organizations deploying customer-facing applications that ...
(Date:10/22/2015)... Inc. (NASDAQ: AWRE ), a leading supplier of biometrics software ... September 30, 2015.  --> --> ... a decrease of 33% compared to $6.0 million in the same ... was $2.2 million, or $0.10 per diluted share, which compared to ... a year ago.  --> --> ...
Breaking Biology News(10 mins):
(Date:11/24/2015)... 2015 /CNW/ - iCo Therapeutics ("iCo" or "the Company") ... for the quarter ended September 30, 2015. Amounts, ... and presented under International Financial Reporting Standards ("IFRS"). ... said Andrew Rae , President & CEO ... not only value enriching for this clinical program, ...
(Date:11/24/2015)... CITY , Nov. 24, 2015 /PRNewswire/ - Aeterna ... request of IIROC on behalf of the Toronto Stock ... news release there are no corporate developments that would ... --> --> About ... . --> Aeterna Zentaris is ...
(Date:11/24/2015)... ... ... This fall, global software solutions leader SAP and AdVenture Capital brought together ... their BIG ideas to improve health and wellness in their schools. , Now, the ... title of SAP's Teen Innovator, an all-expenses paid trip to Super Bowl 50, and ...
(Date:11/24/2015)... New York , November 24, 2015 ... to a recent market research report released by Transparency ... projected to expand at a CAGR of 17.5% during ... "Non-invasive Prenatal Testing Market - Global Industry Analysis, Size, ... estimates the global non-invasive prenatal testing market to reach ...
Breaking Biology Technology: