Sibling rivalry is not something restricted to humans. A new study has revealed that food begging habits of chicks have sibling rivalry as a major causative factor.
When that accentuates, chicks show dishonesty along with other pressure points like insecurity that stems from feared competition from half siblings or instability coming from the death of parents or parents changing partners.
The study," Sibling conflict and dishonest signaling in birds", conducted by Oxford University's team of scientists was published in the journal PNAS.
The research paper notes that events like death or divorce of parents could inject an element of conflict in the group and provoke dishonesty among chicks as manifested in the habit of seeking extra food even if they do not need it. It may be an ostensible way to deny the needed food to the sibling.
The expressions of food begging also varied among birds and the signs include making sounds, blowing wings or keeping the mouth wide open to the extreme.
As an exhaustive analysis of 60 species of birds, the study remains significant. Oxford researchers observed that chicks sought more food if they felt the parents are going to breed more chicks. The authors duly point out that as an endorsement of the evolutionary theory of natural selection.
"We hypothesized that you could explain the relative levels of honesty among chicks across species based on how much conflict exists. A chick that has the nest to itself is always going to get the worm, but if you add other chicks then there is going to be conflict over food resources", noted co-author Shana Caro, a doctoral candidate in Oxford's Department of Zoology.
Caro said the focal point of the study was to assess whether dishonesty was going up when a number of siblings were sharing the same nest.
What Did They Study?
In the study, the researchers applied factors such as the condition of the birds, sibling relations and the number of siblings in advancing their observations.
Pursuing a novel path, the study brought to the fore the pull factor from half siblings in triggering chicks' dishonesty over matters of food.
Caro noted the study came across the fact that chicks behaved less honestly when they faced competition from current siblings. Similarly, they had pressure points that took them to the path of dishonesty such as parents seeking to breed again or worries about parental divorce or death, making future chicks may not be their full siblings.
In other words, any form of conflict triggered dishonesty among chicks. The study then refers to natural selection that evolved over millions of years and caused species higher levels of conflict to have chicks that begged for food even if they did not want it.
Coming to the specifics, the study says the most honest birds included the albatross and dishonesty reigned the most among blackbirds or great tits.
To conclude, the findings finely explain the fine variations in dishonest begging behaviors of different bird species. The paper notes that such weird begging ceases when the home is stable and chicks are convinced that they have full siblings.
Photo: Kent McFarland | Flickr